I'm irredeemably clueless about electrical things (amps/watts/volts 'n'
all that) -- sorry.


Sooooo: I have a John Lewis portable digital radio (£30.00). The sound
is *great*, and it has a nice simple unpretentious style about it
(looks-wise and functionality-wise).

However I can't get it to work portably: my batteries won't power it.
On checking the manual again, I find it requires 4x 1.5V AAs. (On
checking the batteries) I find I've been using rechargeable 1.2V
(2500mAh) NiMH AAs (which I suppose are quite old by now).

Sooooo: I've decided I need to buy some new batteries. Before I go
looking for rechargeables that will give me 1.5V, are there any *types*
that I should be looking out for? NiMH was all the rage when I last
bought rechargeables, but I suspect there are all sorts of new types
about these days.

Any advice gratefully received,

Thanks
John

On Sun, 16 Mar 2014 20:47:28 +0000, Another John
wrote:

I'm irredeemably clueless about electrical things (amps/watts/volts 'n'
all that) -- sorry.


Sooooo: I have a John Lewis portable digital radio (£30.00). The sound
is *great*, and it has a nice simple unpretentious style about it
(looks-wise and functionality-wise).

However I can't get it to work portably: my batteries won't power it.
On checking the manual again, I find it requires 4x 1.5V AAs. (On
checking the batteries) I find I've been using rechargeable 1.2V
(2500mAh) NiMH AAs (which I suppose are quite old by now).

Sooooo: I've decided I need to buy some new batteries. Before I go
looking for rechargeables that will give me 1.5V, are there any *types*
that I should be looking out for? NiMH was all the rage when I last
bought rechargeables, but I suspect there are all sorts of new types
about these days.

Any advice gratefully received,

Thanks
John

6V or 4.8 shouldn't make a lot of difference.

Splash out on four AA's and if the wireless works with four, take one
out and replace it with a link. If it still works, bin your nicads. If
it doesn't then you have no choice but to use the correct Voltage
batt's



In the olden days, one or two of those supersonic heterodyne devices
wouldn't work if the batteries were slightly down, I seem to recollect
that the manufacturers got the biasing wrong on the mixer- oscillator
and dropping the value of the base feed resistor would allow them to
function to the point of dry cell dribbling.

'Wouldnt even know if the digital devices oscillated any more :-(


AB


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Another John wrote:

However I can't get it to work portably: my batteries won't power it. On
checking the manual again, I find it requires 4x 1.5V AAs. (On checking
the batteries) I find I've been using rechargeable 1.2V (2500mAh) NiMH AAs
(which I suppose are quite old by now).

Worse, even when new they'd only provide 4.8V, not 6. For some sorts of
devices that doesn't matter, but for others it does.

You really might need an external box of five 1.2V batteries; whether that's
practical may depend on whether there's a DC in power socket on the radio,
or whether you're willing to create a connection into the existing battery
compartment. And, of course, whether you can make a suitable 5-cell box
etc.

Before I go looking for rechargeables that will give me 1.5V

There used to be a kind, known as RAM cells:
http://en.wikipedia.org/wiki/Recharg...kaline_battery
but they don't seem to be made any longer, and even if they were still
available another problem would be if the radio (eg when running off mains)
tries to charge batteries in it if it assumes they are NiCd or NiMH cells,
as the charger needed for RAM cells is different from that for NiCd & NiMH.

--
Jeremy C B Nicoll - my opinions are my own.

Email sent to my from-address will be deleted. Instead, please reply
to replacing "aaa" by "284".

Archibald wrote:

6V or 4.8 shouldn't make a lot of difference.

It will if there's 5V logic in the digital part...


Splash out on four AA's and if the wireless works with four, take one out
and replace it with a link.

What? You're saying if it works with 4x1.2V then let's try just 3.6 V?

Could you better explain what you mean?

--
Jeremy C B Nicoll - my opinions are my own.

Email sent to my from-address will be deleted. Instead, please reply
to replacing "aaa" by "284".

On 16/03/2014 21:17, Jeremy Nicoll - news posts wrote:
Archibald wrote:

6V or 4.8 shouldn't make a lot of difference.

It will if there's 5V logic in the digital part...


Splash out on four AA's and if the wireless works with four, take one out
and replace it with a link.

What? You're saying if it works with 4x1.2V then let's try just 3.6 V?

Could you better explain what you mean?

Try four AAs. That's 6V.

Take one out and replace with a link. That's 4.5.

Better?

Andy

On Sun, 16 Mar 2014 21:17:32 +0000, Jeremy Nicoll - news posts
wrote:

Archibald wrote:

6V or 4.8 shouldn't make a lot of difference.

It will if there's 5V logic in the digital part...


Splash out on four AA's and if the wireless works with four, take one out
and replace it with a link.

What? You're saying if it works with 4x1.2V then let's try just 3.6 V?

Could you better explain what you mean?

I would have thought it reasonably obvious.

Re- read & think.


Your humble tranny even these days would be expected to work in a
variety of temperatures using batteries that are not at their best.

An off the shelf AA can match a nicads Voltage after less than half
it's capacity has been used.

Now I cannot see too many manufacturers producing goods that consume
batteries so greedily.

TTL logic [I assume thats what you mean], functioned at less than 5V.
Some of the more exotic equivalents went to 3V and lower. Somehow I
would doubt that you'd find a few 7400's tucked away in the case
though.

Now to s p e l l t h i n g s o u t

Four aa's from Asda or Lidl will cost peanuts

Use all four in the wireless [6V]

The wireless works [ go to step b]

The wireless doesn't work [ Fix it then try the old nicads]

step [b]

Remove one cell & link [4.5V]

The wireless works [buy fresh nicads]

The wireless doesn't work, use dry batteries, buy a long mains
extention or build a battery box.

There we are- Comprehend now?

AB

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In message , Archibald
writes
On Sun, 16 Mar 2014 21:17:32 +0000, Jeremy Nicoll - news posts
wrote:

Archibald wrote:

6V or 4.8 shouldn't make a lot of difference.

It will if there's 5V logic in the digital part...


Splash out on four AA's and if the wireless works with four, take one out
and replace it with a link.

What? You're saying if it works with 4x1.2V then let's try just 3.6 V?

Could you better explain what you mean?

I would have thought it reasonably obvious.

Re- read & think.


Your humble tranny even these days would be expected to work in a
variety of temperatures using batteries that are not at their best.

An off the shelf AA can match a nicads Voltage after less than half
it's capacity has been used.

Now I cannot see too many manufacturers producing goods that consume
batteries so greedily.

I can They're called digital radio manufacturers
snip
AB

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--
bert

On Sun, 16 Mar 2014 21:54:47 -0000, Vir Campestris wrote:

On 16/03/2014 21:17, Jeremy Nicoll - news posts wrote:
Archibald wrote:

6V or 4.8 shouldn't make a lot of difference.

It will if there's 5V logic in the digital part...


Splash out on four AA's and if the wireless works with four, take one out
and replace it with a link.

What? You're saying if it works with 4x1.2V then let's try just 3.6 V?

Could you better explain what you mean?

Try four AAs. That's 6V.

Take one out and replace with a link. That's 4.5.

Better?

When he wrote AAs, he should have written AA non-rechargeables, or Duracells.

--
Some people are alive only because it's illegal to kill them.

On Sun, 16 Mar 2014 21:14:12 -0000, Jeremy Nicoll - news posts wrote:

Another John wrote:

However I can't get it to work portably: my batteries won't power it. On
checking the manual again, I find it requires 4x 1.5V AAs. (On checking
the batteries) I find I've been using rechargeable 1.2V (2500mAh) NiMH AAs
(which I suppose are quite old by now).

Worse, even when new they'd only provide 4.8V, not 6. For some sorts of
devices that doesn't matter, but for others it does.

You really might need an external box of five 1.2V batteries; whether that's
practical may depend on whether there's a DC in power socket on the radio,
or whether you're willing to create a connection into the existing battery
compartment. And, of course, whether you can make a suitable 5-cell box
etc.

The only piece of **** I've ever had that won't take rechargeables is a room stat for my central heating. One one of them I bothered to fit an extra AA holder inside it as there was plenty of room for one, and it ran happily off 3 rechargeables. The other I couldn't be bothered and just shoved Duracells in it. Quite why people are still making devices that use outdated battery technology only, I don't know. Domestic rechargeables were common in the 80s for ****'s sake. If I spent 30 quid on a radio and it refused to take NiMH, I'd take it back to the shop.

Before I go looking for rechargeables that will give me 1.5V

There used to be a kind, known as RAM cells:
http://en.wikipedia.org/wiki/Recharg...kaline_battery
but they don't seem to be made any longer, and even if they were still
available another problem would be if the radio (eg when running off mains)
tries to charge batteries in it if it assumes they are NiCd or NiMH cells,
as the charger needed for RAM cells is different from that for NiCd & NiMH.

I once had a charger that charged ANY battery, it would charge Duracells 10 times, but it didn't put that much capacity in them.

--
Uncle Larry was smoking in a restaurant the other day when a guy came up to him and said, "That smoke's bothering me."
Larry said, "Well, it's killing me. If I don't care about what it's doing to me, why would I give a **** what it's doing to you?"

Archibald wrote:

Now I cannot see too many manufacturers producing goods that consume
batteries so greedily.

You havent tried a DAB radio using batteries have you?
Mine uses 4 C cells, they last around 8 hours.
The first time they died, I thought it must be poor quality batteries,
so I put Duracells in. They lasted a day at work too.

I now use an FM radio, with 4 AA's, which usually last 2 weeks+
--
Alan
To reply by mail, change '+' to 'plus'

In article id,
Jeremy Nicoll - news posts
wrote:
6V or 4.8 shouldn't make a lot of difference.

It will if there's 5V logic in the digital part...

It would be a very poor design if it ceased working when the voltage from
6v alkalines dropped below 5v.

--
*I didn't say it was your fault, I said I was blaming you.

Dave Plowman London SW
To e-mail, change noise into sound.

In article ,
A.Lee wrote:
Archibald wrote:

Now I cannot see too many manufacturers producing goods that consume
batteries so greedily.

You havent tried a DAB radio using batteries have you?
Mine uses 4 C cells, they last around 8 hours.
The first time they died, I thought it must be poor quality batteries,
so I put Duracells in. They lasted a day at work too.

I now use an FM radio, with 4 AA's, which usually last 2 weeks+

I have an elderly AM portable where the 9v battery lasts many months of
heavy use. The speaker size is 7x4" and gives plenty level.

--
*It's o.k. to laugh during sexŒ.Œ.just don't point!

Dave Plowman London SW
To e-mail, change noise into sound.

On Sunday, March 16, 2014 8:47:28 PM UTC, Another John wrote:
I'm irredeemably clueless about electrical things (amps/watts/volts 'n'
all that) -- sorry.
Sooooo: I have a John Lewis portable digital radio (£30.00). The sound
is *great*, and it has a nice simple unpretentious style about it
(looks-wise and functionality-wise).
However I can't get it to work portably: my batteries won't power it.
On checking the manual again, I find it requires 4x 1.5V AAs. (On
checking the batteries) I find I've been using rechargeable 1.2V
(2500mAh) NiMH AAs (which I suppose are quite old by now).
Sooooo: I've decided I need to buy some new batteries. Before I go
looking for rechargeables that will give me 1.5V, are there any *types*
that I should be looking out for? NiMH was all the rage when I last
bought rechargeables, but I suspect there are all sorts of new types
about these days.
Any advice gratefully received,
Thanks
John

Charge your nicd/nimhs, measure voltage of each one with a £2 multimeter. You may have a bad cell.

If theyre all good but the radio wont run on them, Maplin sell NiZn rechargeables that should do teh job.


NT

wrote:

... Maplin sell NiZn rechargeables that should do teh job.

That's interesting! I've never heard of these before.

The 5th review here is a little worrying though:
http://www.maplin.co.uk/p/nickel-zin...s-4-pack-n37ka

More info on the technology:
http://en.wikipedia.org/wiki/Nickel%...93zinc_battery


--
Jeremy C B Nicoll - my opinions are my own.

Email sent to my from-address will be deleted. Instead, please reply
to replacing "aaa" by "284".

Jeremy Nicoll - news posts wrote:

wrote:

... Maplin sell NiZn rechargeables that should do teh job.

That's interesting! ...

And following that up, googling more generally for: NiZn performance,
NiZn review, NiZn fail ... etc suggests that it's easy to kill these
cells. There doesn't seem to be a vast pool of experience using them.

I've also read several accounts of people having problems (eg with torches)
where the extra voltage has caused bulbs to burn out.

Someone (was it the Maplin site?) suggested that they have a slightly larger
diameter than other AA cells, so might not fit in a tight battery
compartment.

--
Jeremy C B Nicoll - my opinions are my own.

Email sent to my from-address will be deleted. Instead, please reply
to replacing "aaa" by "284".

wrote:

Charge your nicd/nimhs, measure voltage of each one with a £2 multimeter. You may have a bad cell.

A 3V torch battery connected for a minute imposes a load and thus gives
a more realistic indication.

Bill

On 16/03/2014 23:04, A.Lee wrote:
Archibald wrote:

Now I cannot see too many manufacturers producing goods that consume
batteries so greedily.

You havent tried a DAB radio using batteries have you?
Mine uses 4 C cells, they last around 8 hours.
The first time they died, I thought it must be poor quality batteries,
so I put Duracells in. They lasted a day at work too.


I have a Pure Radio with one of their rechargeable batteries (£15).
Lasts a claimed 18 hours, which seems about right.

I now use an FM radio, with 4 AA's, which usually last 2 weeks+


The bathroom FM radio used maybe 30 minutes daily, with 3 rechargeable
AAs, seems to go on forever - maybe 6 months

--
Cheers, Rob

Actually 1.5v batteries are usually of the dry cell type. Most rechargeable
are a bit under this, but many pieces of modern equipment is fine on them.
If you have recharged them a lot then yes, they will eventually die. Many in
radio chargers seem to be very crude as well, so can knacker batteries
faster than kind external chargers. External ones tend to charge the cells
as separate cells, whereas radios do them in series, so if one of more is a
bit dodgy it just tends to get hot instead of charging, or worse presents a
resistance so the others never charge completely.

The newer versions of those you already have from Maplin and other places I
find very good, but now try to remove them from radios when they go down and
put them in a proper charger and this means if you are using it portably,
you need two sets.
Unfortunately, it is a known issue withed DAB that the dab chips are power
hungry. they are not as bad as the first generation were, but still not
good, hence people using rechargeable in the first place.
Of course one could modify the radio to use other types of battery, but
given your admission of not being electronically minded, this might be
dangerous, literally, as Lithium Iron batteries can burst into flames if
shorted out.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Another John" wrote in message
]...
I'm irredeemably clueless about electrical things (amps/watts/volts 'n'
all that) -- sorry.


Sooooo: I have a John Lewis portable digital radio (£30.00). The sound
is *great*, and it has a nice simple unpretentious style about it
(looks-wise and functionality-wise).

However I can't get it to work portably: my batteries won't power it.
On checking the manual again, I find it requires 4x 1.5V AAs. (On
checking the batteries) I find I've been using rechargeable 1.2V
(2500mAh) NiMH AAs (which I suppose are quite old by now).

Sooooo: I've decided I need to buy some new batteries. Before I go
looking for rechargeables that will give me 1.5V, are there any *types*
that I should be looking out for? NiMH was all the rage when I last
bought rechargeables, but I suspect there are all sorts of new types
about these days.

Any advice gratefully received,

Thanks
John

Bill Wright wrote in
:

wrote:

Charge your nicd/nimhs, measure voltage of each one with a £2
multimeter. You may have a bad cell.

A 3V torch battery connected for a minute imposes a load and thus
gives a more realistic indication.

Bill


The ready to use Rechargeables are best IMHO as they don't self discharge.
I once tried NiCads in a Vivitar Flashgun and they wouldn't work due to
their lower voltage. I had to use ordinary non-rechargeables.
I thik the radio is a poor choice and you should consider sending it back
as not being suitable for battery use - but first check it with a new set
of batteries so that you can provide some hard data.

In the meantime check this out (still 1.2v)
http://www.eneloop.info/home.html

Personally - I would never consider rechargeables in low current devices
such as TV Remotes, Wireless Thermostats, etc. Their "self discharge" rate
makes it pointless.

Actually the worse things for not likening 1.25 v cells were portable tape
recorders. they could wow, or sound like the speaker had a rattle due to
crossover. Luckily, that seems to be a thing of the past and the only effect
using rechargables now is slightly lower max volume as one might expect.
Best not to mess with it, just replace like with like but see my long reply
first.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Archibald" wrote in message
...
On Sun, 16 Mar 2014 20:47:28 +0000, Another John
wrote:

I'm irredeemably clueless about electrical things (amps/watts/volts 'n'
all that) -- sorry.


Sooooo: I have a John Lewis portable digital radio (£30.00). The sound
is *great*, and it has a nice simple unpretentious style about it
(looks-wise and functionality-wise).

However I can't get it to work portably: my batteries won't power it.
On checking the manual again, I find it requires 4x 1.5V AAs. (On
checking the batteries) I find I've been using rechargeable 1.2V
(2500mAh) NiMH AAs (which I suppose are quite old by now).

Sooooo: I've decided I need to buy some new batteries. Before I go
looking for rechargeables that will give me 1.5V, are there any *types*
that I should be looking out for? NiMH was all the rage when I last
bought rechargeables, but I suspect there are all sorts of new types
about these days.

Any advice gratefully received,

Thanks
John

6V or 4.8 shouldn't make a lot of difference.

Splash out on four AA's and if the wireless works with four, take one
out and replace it with a link. If it still works, bin your nicads. If
it doesn't then you have no choice but to use the correct Voltage
batt's



In the olden days, one or two of those supersonic heterodyne devices
wouldn't work if the batteries were slightly down, I seem to recollect
that the manufacturers got the biasing wrong on the mixer- oscillator
and dropping the value of the base feed resistor would allow them to
function to the point of dry cell dribbling.

'Wouldnt even know if the digital devices oscillated any more :-(


AB


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On 16/03/2014 23:25, Dave Plowman (News) wrote:

In article id,
Jeremy Nicoll - news posts
wrote:
6V or 4.8 shouldn't make a lot of difference.

It will if there's 5V logic in the digital part...

It would be a very poor design if it ceased working when the voltage from
6v alkalines dropped below 5v.


That unfortunately describes most digital radios to a tee!

The OPs best chance is to find a Maplin carrier for 5 batteries
(probably have to do it as a 2 and a 3) and then feed the radio with the
output of that as a nominal external 6v supply. Generally it is easier
to run them on mains since they all use too far much current.

They look OK and sound OK if you have enough signal otherwise they eat
batteries and break up into burbling subterraneans off Stingray which is
OK if you like that sort of thing but otherwise fairly annoying.

I have given up entirely on DAB and now stream radio over ethernet.

--
Regards,
Martin Brown

On 16/03/2014 23:04, A.Lee wrote:
Archibald wrote:

Now I cannot see too many manufacturers producing goods that consume
batteries so greedily.

You havent tried a DAB radio using batteries have you?
Mine uses 4 C cells, they last around 8 hours.

That sounds unusually bad, but my experience is broadly similar DAB is a
waste of space consuming batteries very rapidly and with borderline
signal is not actually worth listening to. I have built several
different DAB aerials to improve things and can now get enough signal
provided it doesn't rain with leaves on the trees but I have given up on
DAB and now stream radio over ethernet which suffers a longer delay from
realtime but doesn't keel over anything like so easily.

Most of the DAB radios I have are pretty useless and crash out to dead
air if they encounter any signal corruption they don't like even with a
very good aerial. This affects the earliest (expensive) one I got and
the most recent ones too (if anything the most recent are worse).

Unless you are partial to listening to the silence of the pregnant
pauses on R3 or John Cages's 4'33" DAB radio has nothing to offer

The first time they died, I thought it must be poor quality batteries,
so I put Duracells in. They lasted a day at work too.

If you can power it from mains. Cheap wall wart will do it.

I now use an FM radio, with 4 AA's, which usually last 2 weeks+

And will probably work OK with NiMH cells too. As wartime emergency
radios DAB will be completely useless since most people will run out of
batteries within 48 hours unless they have huge personal stocks.

--
Regards,
Martin Brown

On 16/03/2014 20:47, Another John wrote:
I'm irredeemably clueless about electrical things (amps/watts/volts 'n'
all that) -- sorry.


Sooooo: I have a John Lewis portable digital radio (£30.00). The sound
is *great*, and it has a nice simple unpretentious style about it
(looks-wise and functionality-wise).

Your best bet is to look for a mains powered wall wart to power it.

The thing will eat batteries like there is no tomorrow and will only
ever be happy with primary cells or if you are feeling brave an external
battery box containing 5x 1.25 NiMH/NiCads.

If you must use internal batteries feed it the cheapest nastiest
Poundshop zinc chloride batteries you can find - they will never have
time to leak since you will be replacing them every three days or so.

However I can't get it to work portably: my batteries won't power it.
On checking the manual again, I find it requires 4x 1.5V AAs. (On
checking the batteries) I find I've been using rechargeable 1.2V
(2500mAh) NiMH AAs (which I suppose are quite old by now).

This is par for the course the chipsets barely work to begin with and
draw just enough current to be troublesome but not enough to benefit
from the very low internal resistance of the rechargeable cells. The
result is that with a very fresh newly charged set of NiMH you might if
you are lucky get an hour or so out of it before it fails "low battery".

Sooooo: I've decided I need to buy some new batteries. Before I go
looking for rechargeables that will give me 1.5V, are there any *types*
that I should be looking out for? NiMH was all the rage when I last
bought rechargeables, but I suspect there are all sorts of new types
about these days.

Any advice gratefully received,

It is unlikely to work satisfactorily on rechargable batteries that an
end user who isn't happy with electronics can handle.

I might be tempted to try my luck with 2x rechargable AA Lithium cells
(nominal 3.6v) and a silicon diode in series with each. This is not for
the fainthearted - mistakes could result in them catching fire!

Boeing, Sony and Toshiba have all had serious fires from this technology
and it is very unforgiving.

--
Regards,
Martin Brown

On 17/03/14 08:42, Brian Gaff wrote:
Actually 1.5v batteries are usually of the dry cell type. Most rechargeable
are a bit under this, but many pieces of modern equipment is fine on them.
If you have recharged them a lot then yes, they will eventually die. Many in
radio chargers seem to be very crude as well, so can knacker batteries
faster than kind external chargers. External ones tend to charge the cells
as separate cells, whereas radios do them in series, so if one of more is a
bit dodgy it just tends to get hot instead of charging, or worse presents a
resistance so the others never charge completely.

The newer versions of those you already have from Maplin and other places I
find very good, but now try to remove them from radios when they go down and
put them in a proper charger and this means if you are using it portably,
you need two sets.
Unfortunately, it is a known issue withed DAB that the dab chips are power
hungry. they are not as bad as the first generation were, but still not
good, hence people using rechargeable in the first place.
Of course one could modify the radio to use other types of battery, but
given your admission of not being electronically minded, this might be
dangerous, literally, as Lithium Iron batteries can burst into flames if
shorted out.
Brian

The correct replacement for four x 1.5 is 5 x 1.2v Nicad etc.
Li - Ion.

If this is a serious thing you want to do, then get a model plane/car
charger and some sub Cs and make up a proper rig to fit into the radio.

I would advise to use Nicads rather than NiMh or Li Ion, simple because
they don't mind going flat and staying flat.


a 6v 3330mAh receiver pack for model aircraft is around 20 quid though
mostly they are NiMh these days.

http://www.jperkinsdistribution.co.u...20and%20others


--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

Now I cannot see too many manufacturers producing goods that consume
batteries so greedily.


DAB radio is renowned for high battery power consumption, its one of its
known faults apart from **** poor audio quality...

--
Tony Sayer

In article ,
tony sayer wrote:
Now I cannot see too many manufacturers producing goods that consume
batteries so greedily.


DAB radio is renowned for high battery power consumption, its one of its
known faults apart from **** poor audio quality...


I wonder if high battery consumption has anything to do with poor
implementation. I have a modern Pure portable which has good battery
consumption. When teletext was new a decoder (as built by GEC) used masses
of TTL chips with a correspondingly high power consumption, then Mullard
did it all in one chip!

--
From KT24

Using a RISC OS computer running v5.18

On Mon, 17 Mar 2014 11:11:47 +0000 (GMT), charles
wrote:

In article ,
tony sayer wrote:
Now I cannot see too many manufacturers producing goods that consume
batteries so greedily.


DAB radio is renowned for high battery power consumption, its one of its
known faults apart from **** poor audio quality...


I wonder if high battery consumption has anything to do with poor
implementation. I have a modern Pure portable which has good battery
consumption. When teletext was new a decoder (as built by GEC) used masses
of TTL chips with a correspondingly high power consumption, then Mullard
did it all in one chip!

I have a personal DAB radio that works off a single AA cell. An 800mAH
rechargable battery gives me about 5hrs listening in DAB mode; 15-20
hours in MP3 mode. It's the ATMT MP170 which is a pretty-well outmoded
design now but there are still one or two about on Amazon.

Nick

On 17/03/2014 10:54, tony sayer wrote:
Now I cannot see too many manufacturers producing goods that consume
batteries so greedily.


DAB radio is renowned for high battery power consumption, its one of its
known faults apart from **** poor audio quality...

The **** poor audio quality is only because they standardised on the
wrong (too early) MP2 codec as opposed to MP4/AAC in DAB+ and too low a
bitrate. There is no reason why DAB couldn't be almost studio quality
Radio3 manages extremely good quality over the internet at 320kbps AAC.

--
Regards,
Martin Brown

In article ,
Martin Brown wrote:
The **** poor audio quality is only because they standardised on the
wrong (too early) MP2 codec as opposed to MP4/AAC in DAB+ and too low a
bitrate. There is no reason why DAB couldn't be almost studio quality
Radio3 manages extremely good quality over the internet at 320kbps AAC.

I've had DAB here in the form of a tuner since very early on - due to the
them poor FM reception in this part of S London. And the quality was just
fine before the bitrate was reduced. To be fair take up was very poor
among those who in theory cared about audio quality (Hi-Fi types) who
probably weren't much interested in radio by then. And of course the
reduced bitrate allowed more channels per mux.

I no longer use DAB at home - FreeView receivers are cheaper. ;-) But I do
have it in one car where the better reception than FM in London is
appreciated.

I don't use any portable radios at home.

--
*A fool and his money can throw one hell of a party.

Dave Plowman London SW
To e-mail, change noise into sound.

On 17/03/14 11:11, charles wrote:
In article ,
tony sayer wrote:
Now I cannot see too many manufacturers producing goods that consume
batteries so greedily.


DAB radio is renowned for high battery power consumption, its one of its
known faults apart from **** poor audio quality...


I wonder if high battery consumption has anything to do with poor
implementation. I have a modern Pure portable which has good battery
consumption. When teletext was new a decoder (as built by GEC) used masses
of TTL chips with a correspondingly high power consumption, then Mullard
did it all in one chip!


Exactly. yu are running with DAB a whole computer and RAM assembly at
bloody high speed to do all the decoding.


Its where an ARM chip and integrated DAC plus a few others is the way
to go, but not all chipsets are created equal.

Had exactly the same issues on model RC gear when the old SW based 'FM'
receivers - drawing 5mA or so were replaced by hungry 'digital' stuff at
2.4Ghz,drawing 20-40mA and suddenly people were running out of battery
much earlier than they thought. Worse, they had an annoying habit of
going totally ape**** if - say - retracting the undercarriage put such a
strain on the battery that the voltage dropped below 5V..




--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

On 17/03/14 12:53, Martin Brown wrote:
The **** poor audio quality is only because they standardised on the
wrong (too early) MP2 codec as opposed to MP4/AAC in DAB+ and too low a
bitrate. There is no reason why DAB couldn't be almost studio quality
Radio3 manages extremely good quality over the internet at 320kbps AAC.

+1
--
Ineptocracy

(in-ep-toc-ra-cy) €“ a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

On Sun, 16 Mar 2014 20:47:28 +0000, Another John
wrote:

I'm irredeemably clueless about electrical things (amps/watts/volts 'n'
all that) -- sorry.


Sooooo: I have a John Lewis portable digital radio (£30.00). The sound
is *great*, and it has a nice simple unpretentious style about it
(looks-wise and functionality-wise).

However I can't get it to work portably: my batteries won't power it.
On checking the manual again, I find it requires 4x 1.5V AAs. (On
checking the batteries) I find I've been using rechargeable 1.2V
(2500mAh) NiMH AAs (which I suppose are quite old by now).

Sooooo: I've decided I need to buy some new batteries. Before I go
looking for rechargeables that will give me 1.5V, are there any *types*

The only rechargeable "1,5V" cells that I know of are the rather
dubious Nickel Zinc (NiZn) ("1.65v nominal") rechargeables which were
developed into a commercial product a few years ago but they still had
issues, not the least being their excessively high fully charged
voltage of 1.85v per cell.

Some kit could handle this, but other kit could be damaged by a
straight swapout from a 1.5v per cell battery pack (4 x 1.85v = 7.4v,
somewhat higher than the 6.6v typically seen in a fresh 4 cell battery
pack)

that I should be looking out for? NiMH was all the rage when I last
bought rechargeables, but I suspect there are all sorts of new types
about these days.

NiMH is "Still all the rage" today in as far as they replace NiCad
cells designed as drop-in substitutes for carbon zinc or alkaline
primary cells. However, the latest "All the Rage" feature is the
development of Low Self Discharge (LSD) versions (at a modest
reduction of AH capacity) which vastly improves their usability.

If you're looking to buy replacement NiMH AA cells today, I strongly
advise against getting 'ordinary' NiMH cells (typically 3AH
capacities) and choose the LSD type even if the AH capacity is reduced
to between 2 and 2.5 AH. In practice, the lower rate of self discharge
will give you a much longer service life in something like a compact
digital camera or conventional portable radio.

Any advice gratefully received,

I hope that sentiment includes 'and all' since there's a lot more to
come. :-)

Quite frankly, that battery performance sounds "bloody awful' if it
can't be powered from a set of fully charged NiMH cells (hint: check
the voltage of those NiMH cells of yours. They should each read around
the 1.4v mark shortly after being fully recharged and settle down to
around 1.35v a day or so after).

It has been the practice for the last 5 decades or so with kit
designed for portable battery powered operation (particulary when
primary carbon zinc cells or their modern alkaline equivilents are the
power source) to design for an end of life voltage of 1 volt per cell.

Quite clearly, unless you have a duff cell or two in your battery of
NiMH cells, this practice has not been followed since the end point
voltage per cell appears to be higher than the 1.2 volt end point for
NiMH and NiCad which both exhibit a pretty flat discharge voltage
curve from a high point of 1.4v down to 1.2v after which the voltage,
on a constant current load, plummets rather rapidly below the 1v mark.

Since the designers chose a 4 cell battery pack, the radio would
reasonably be expected to continue working down to 4 volts (possibly
as high as 4.4v) which _will_ allow the use of NiMH in place of
primary 1.5v carbon zinc or alakaline cells (battery holder contact
resistance issues aside).

The problem appears to be due to bad design and therefore you'd be
within your rights to return it as "Unfit for Purpose" (but make sure
that your NiMH pack is producing a voltage of 4.8v or better before
storming off to the shop).

The designer has two choices when it comes to battery power
solutions. The first is to design the circuit to work off a more
economic battery cell count (1, 2 or 4) where possible, or else
specify the number of cells required to meet this 1v per cell rule by
using a non standard cell count such as 3 or, in this case, 5 cells.

Modern switching regulator technology can be used to power kit that
needs a voltage higher than the battery can maintain e.g. a single or
two cell LED torch or maintain a 3.3v logic supply off a two cell 3
volt battery or 5 volts off a four cell battery. Plainly none of these
options have been applied in this case.

Considering the much higher current drain and voltage sensitivity of
a DAB portable radio compared to its conventional analogue counterpart
(the classic 'Tranny Radio'), you'd expect a hell of a lot more
thought would be put into this aspect of a portable DAB radio's
performance.

From all the comments on the very short battery life of portable DAB
radios that I've been observing over the past 5 or 6 years, it would
seem that the 'battery option' has simply been 'bolted on' as an
afterthought in almost all cases.

Alternatively, you could simply purchase your AA zinc carbon 'Super
Heavy Duty' cells 16 at a time from your local Pound Shop, in my
case, "Poundworld"(tm).

I purchsed a set only yesterday on account I needed _one_ ordinary
carbon zinc _unjacketted_ cell for my venerable analogue multimeter.
The steel jacketing used on the more commonly available zinc carbon
and alkaline cells desentisizes the meter movement by reducing the
reluctance of the leakage magnetic flux of the meter's magnet; a
problem common to almost all makes of such meters back in the day.
This is a classic case of "Only a cheap zinc carbon cell will do the
job.".

You might be forgiven for thinking that the only mistake a designer
can make to curse battery powered kit with unnaturally short battery
life is to under-specify the cell count.

Well, it would be only right and proper to forgive such thinking
since I've only ever experienced the opposite case of too high a cell
count resulting in a halving of battery life.

You might be surprised to know that it was a Sinclair product which
exhibited this "Schoolboy Howler" example of sloppy design. The item
in question being his 'famous' Executive Electronic Handheld
Calculator which used a set of _FOUR_ aspirin sized silver oxide cells
when only _THREE_ were actually required.

Quite simply, the lack of any voltage regulation and the simple LED
display driver circuit used meant the surplus to requirements extra
1.5v caused it to draw two or more times the current that was actually
needed to provide an amply lit display (the calculator would
cheerfully keep functioning even when the battery voltage dropped so
low that you could only see the display in a darkened room).

My solution, once I'd realised why the battery life was so excerable
was simple. I just made up a dummy cell to reduce the active cell
count to three. Double the battery life at 75% of the cost which made
it nearly 3 times more economic to run (those silver oxide cells
weren't particularly cheap).

Clive might have been an 'innovator' but he had a very bad habit (as
many can testify with many of his 'other innovations') of being a bit
'slapdash' in the matter of design and component choice. This one
particular example sticks in my mind simply because of the sheer scale
of its monumental stupidity.
--
Regards, J B Good

On Mon, 17 Mar 2014 09:21:43 +0000, Martin Brown
wrote:

On 16/03/2014 20:47, Another John wrote:
I'm irredeemably clueless about electrical things (amps/watts/volts 'n'
all that) -- sorry.


Sooooo: I have a John Lewis portable digital radio (£30.00). The sound
is *great*, and it has a nice simple unpretentious style about it
(looks-wise and functionality-wise).

Your best bet is to look for a mains powered wall wart to power it.

I rather got the impression that the radio was supplied with its own
wallwart.

The thing will eat batteries like there is no tomorrow and will only
ever be happy with primary cells or if you are feeling brave an external
battery box containing 5x 1.25 NiMH/NiCads.

If you must use internal batteries feed it the cheapest nastiest
Poundshop zinc chloride batteries you can find - they will never have
time to leak since you will be replacing them every three days or so.

+1 for that advice :-) Poundland only had the steel jacketed heavy
duty zinc carbon AA cell pack (8 or 12 per pack) and I had to shop in
Poundworld before I found the type I needed (a pack of 16).

The only risk is that you might forget to remove them if the radio
isn't being used portably for any extended period. Unfortunately
usually an unplanned for event for which the need to empty the battery
compartment might not become apparent until it's too late. :-(


However I can't get it to work portably: my batteries won't power it.
On checking the manual again, I find it requires 4x 1.5V AAs. (On
checking the batteries) I find I've been using rechargeable 1.2V
(2500mAh) NiMH AAs (which I suppose are quite old by now).

This is par for the course the chipsets barely work to begin with and
draw just enough current to be troublesome but not enough to benefit
from the very low internal resistance of the rechargeable cells. The
result is that with a very fresh newly charged set of NiMH you might if
you are lucky get an hour or so out of it before it fails "low battery".

If the radio had been designed properly in the matter of using the
One volt per cell end point rule, you should still get full uitlity
out of a set of rechargeables.


Sooooo: I've decided I need to buy some new batteries. Before I go
looking for rechargeables that will give me 1.5V, are there any *types*
that I should be looking out for? NiMH was all the rage when I last
bought rechargeables, but I suspect there are all sorts of new types
about these days.

Any advice gratefully received,

It is unlikely to work satisfactorily on rechargable batteries that an
end user who isn't happy with electronics can handle.

I might be tempted to try my luck with 2x rechargable AA Lithium cells
(nominal 3.6v) and a silicon diode in series with each. This is not for
the fainthearted - mistakes could result in them catching fire!

A very good point which suggests that such a solution would be best
implemented as an external battery pack. Once you're considering the
use of an external battery pack, you might as well consider using a
set of four D cells (cheap heavy duty carbon zinc, 2 for a quid in
most pound shops which will give just over 7 times the AH capacity of
AA carbon zinc cells).

On the face of it, buying 8 times the AH's worth in AA cell form for
the same 2 quid spend would seem to be better value but it's likely
that the much lower cell resistance of the D cell size will more than
compensate for this anyway so it's very likely that, in terms of run
time, you'll be no worse off and you'll have the benefit of only
having to change the battery pack once per 2 quid spend versus 8 times
per 2 quid spend on two 16 pack sets of AAs.

The external battery pack, regardless of whether it's to implement a
2 cell rechargeable lithium battery pack or just to allow the use of a
pack of four cheap D cell sized 'heavy duty' carbon zinc batteries
does rather neatly solve the issue of increased risk of damaging the
radio itself due to fire or corrosion.

Unless you absolutely must have 'self contained portability', an
external pack has a lot going for it.


Boeing, Sony and Toshiba have all had serious fires from this technology
and it is very unforgiving.

Not just those companies, Dell was one of the first laptop makers
forced to recall their product by the millions for exactly this
problem. There are plenty of Youtube videos demonstrating the ferocity
of lithium battery fires if you care to search.
--
Regards, J B Good

On Sunday, 16 March 2014 20:47:28 UTC, Another John wrote:

However I can't get it to work portably: my batteries won't power it.
On checking the manual again, I find it requires 4x 1.5V AAs. (On
checking the batteries) I find I've been using rechargeable 1.2V
(2500mAh) NiMH AAs (which I suppose are quite old by now).

Sooooo: I've decided I need to buy some new batteries.


I have very good experience using the Nickel Zinc batteries from Maplin
in a digital camera (high drain), but have not tried them in a digital
radio.

The digital radio in use here is a Pure model which uses 6 C sized
cells. It uses NiMH rechargeables from Lidl, and are charged by the Lidl
charger, it seems to be rather good.

BUT, as others have said, don't expect much running time from a DAB radio
on batteries compared to an FM radio.

In article , Martin Brown |||newspam|||
@nezumi.demon.co.uk scribeth thus
On 17/03/2014 10:54, tony sayer wrote:
Now I cannot see too many manufacturers producing goods that consume
batteries so greedily.


DAB radio is renowned for high battery power consumption, its one of its
known faults apart from **** poor audio quality...

The **** poor audio quality is only because they standardised on the
wrong (too early) MP2 codec as opposed to MP4/AAC in DAB+ and too low a
bitrate. There is no reason why DAB couldn't be almost studio quality
Radio3 manages extremely good quality over the internet at 320kbps AAC.


Now tell us something we haven't known for a long time;-!!...
--
Tony Sayer

In article ,
says...

The digital radio in use here is a Pure model which uses 6 C sized
cells. It uses NiMH rechargeables from Lidl, and are charged by the Lidl
charger, it seems to be rather good.


Also, watch out for C cells which are really AA cells wrapped in a fat
overcoat.

Even a few D cells are AAs in disguise.


--
Sam

On 17/03/2014 20:19, tony sayer wrote:
In article , Martin Brown |||newspam|||
@nezumi.demon.co.uk scribeth thus
On 17/03/2014 10:54, tony sayer wrote:
Now I cannot see too many manufacturers producing goods that consume
batteries so greedily.


DAB radio is renowned for high battery power consumption, its one of its
known faults apart from **** poor audio quality...

The **** poor audio quality is only because they standardised on the
wrong (too early) MP2 codec as opposed to MP4/AAC in DAB+ and too low a
bitrate. There is no reason why DAB couldn't be almost studio quality
Radio3 manages extremely good quality over the internet at 320kbps AAC.


Now tell us something we haven't known for a long time;-!!...

The Beeb keep on interviewing slimy suits telling us that DAB is all
fine and interviewing half deaf old biddies to say how wonderful it is!

--
Regards,
Martin Brown

RJH wrote:

I have a Pure Radio with one of their rechargeable batteries (£15).
Lasts a claimed 18 hours, which seems about right.

I bought one of the NiMH ChargePaks for mine, it cooked itself in little
over a year, the battery had expanded and pushed its way out of the
compartment, so I replaced it with a Li-ion ChargePak that lasted a few
years (it was more or less only ever used as a builtin UPS for the
radio/alarm rather than as a battery radio) but is now also dead.

On 18/03/2014 07:28, Andy Burns wrote:
RJH wrote:

I have a Pure Radio with one of their rechargeable batteries (£15).
Lasts a claimed 18 hours, which seems about right.

I bought one of the NiMH ChargePaks for mine, it cooked itself in little
over a year, the battery had expanded and pushed its way out of the
compartment, so I replaced it with a Li-ion ChargePak that lasted a few
years (it was more or less only ever used as a builtin UPS for the
radio/alarm rather than as a battery radio) but is now also dead.



Blimey. We have a couple of Pure radios/chargepaks in the family - the
large white weatherproof ones. The one I bought my sister is still going
strong after 3 years, about 50/50 battery mains. The other, the battery
died about 3 years back after 8 years. It's still inside. Must take a look.

The one I bought is a Li-ion, so we'll see.

--
Cheers, Rob

On 17/03/2014 12:53, Martin Brown wrote:
On 17/03/2014 10:54, tony sayer wrote:
Now I cannot see too many manufacturers producing goods that consume
batteries so greedily.


DAB radio is renowned for high battery power consumption, its one of its
known faults apart from **** poor audio quality...

The **** poor audio quality is only because they standardised on the
wrong (too early) MP2 codec as opposed to MP4/AAC in DAB+ and too low a
bitrate. There is no reason why DAB couldn't be almost studio quality
Radio3 manages extremely good quality over the internet at 320kbps AAC.


Agreed, and an opportunity missed.

As it is, I've got a few portable dab radios, and they're excellent for
my use - R4 and 6, and the occasional weird station - in the
kitchen/study/diying.

--
Cheers, Rob