On Fri, 06 Apr 2018 15:17:34 +0100, "Dave Plowman (News)"
wrote:

In article ,
The Other Mike wrote:
On Fri, 06 Apr 2018 13:58:27 +0100, "Dave Plowman (News)"
wrote:

In article ,
Chris Green wrote:
Not really. A lead-acid battery should be charged to something like
14.5 volts to get it fully charged (and it's important to get them
fully charged sometimes). Then, when it's fully charged, the charger
should drop back to 13.5 volts or so to maintain the battery in
'float'. Most 'intelligent' lead-acid battery chargers will do
something like this, the 14.5 volts guarantees full charge but if
maintained long term will make the battery gas. Really clever
chargers will occasionally wake up out of float mode and do a sort of
battery conditioning sequence.

Very odd. SLA batteries have been charged at constant voltage for many
many years. What has changed?

Nothing except it allows the cells to be restored to full capacity quicker and
without damage. It's the kind of thing APC haven't been doing for over 25
years.

Page 22 "Two Stage Constant Voltage Charging"

https://news.yuasa.co.uk/wp-content/...5/NPManual.pdf

First page or so of that says it refers to spill proof wet electrolyte
batteries. Which are not gel type SLA. The type I'm referring to.

Didn't wade through the rest as I'm aware different versions of wet
batteries need different charging methods for best results.

I'd hazard a guess that the vast majority of what people regard as sealed cells
are actually Yuasa's or clones of Yuasa designs. Drop one on its corner and no
liquid actually spills out, actually there is no leakage of anything at all

Compare to a dryfit 'gel' cell from Sonnenschein and you'll see there is little
difference in the charging regime.

https://docs-emea.rs-online.com/webd...6b81270ea4.pdf

Yuasa (from the reference previously given page 23)
1st stage is 2.4-2.45v per cell
2nd stage is 2.27 v per cell

Sonnenschein
1st stage is 2.4-2.45v per cell
2nd stage is 2.3v per cell

30mV per cell difference when on float or 180mV per 12v nominal battery

--

On 07/04/2018 00:55, Steve Walker wrote:
On 06/04/2018 11:30, Brian Reay wrote:
On 06/04/18 11:10, Theo wrote:
Chris Green wrote:
I think you'd be surprised how expensive that would be, transformers
in particular are quite pricey.Â* A PC switch mode PSU would probably
be cheaper for that sort of rating (though would likely have lots of
5v and 3.3v output as well).

12V 32A, silent, six quid:
http://www.ebay.co.uk/itm/Sony-PlayS...C/152246465886


and it's possible to tweak the voltage upwards:
https://www.experimental-engineering...y-voltage-mod/

slightly easier on a different version:
https://www.experimental-engineering...y-voltage-mod/


Theo


Why does a Playstation need 32A?Â* Could it be perhaps 3.2A?

Looking at the moulding, it looks like the rating on the PSU is 23.5A at
12V, plus 0.6A at 5V. That is 285W

Some PC video cards are a fair chunk of that, plus 90 to 125W for the
processor, so it's not really surprising for a games console to need
that much.

SteveW

Obviously a Playstation isn't the gizmo I thought it was (never played
with one).


Thankfully, our offspring never expressed any interest in computer games.





--

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Benefit or Personal Independence Payment when they don't need it? They
are depriving those in real need!

https://www.gov.uk/report-benefit-fraud

In article ,
The Other Mike wrote:
First page or so of that says it refers to spill proof wet electrolyte
batteries. Which are not gel type SLA. The type I'm referring to.

Didn't wade through the rest as I'm aware different versions of wet
batteries need different charging methods for best results.

I'd hazard a guess that the vast majority of what people regard as sealed cells
are actually Yuasa's or clones of Yuasa designs. Drop one on its corner and no
liquid actually spills out, actually there is no leakage of anything at all

Compare to a dryfit 'gel' cell from Sonnenschein and you'll see there is little
difference in the charging regime.

https://docs-emea.rs-online.com/webd...6b81270ea4.pdf

Yuasa (from the reference previously given page 23)
1st stage is 2.4-2.45v per cell
2nd stage is 2.27 v per cell

Sonnenschein
1st stage is 2.4-2.45v per cell
2nd stage is 2.3v per cell

30mV per cell difference when on float or 180mV per 12v nominal battery

2.3v per cell on float just happens to be 13.8v So using 13.8v at all
times just means it won't re-charge quite so quickly. Also using 13.8v
only means you can use a lower power supply than one which can deliver the
maximum current into a low battery.

--
*What happens if you get scared half to death twice? *

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

On 05/04/2018 23:47, Dave Plowman (News) wrote:
The mains to 12v power supplied failed in a mate's motorhome, so although
he got it replaced I offered to look at it to see if it could be repaired
as a spare.

It is branded PowerPart, and is a 20 amp 13.8v device which charges the
leisure battery as well as running any 12v things when on mains. Cost
about 100 quid.

It was well and truly fried. Only heatsink for the power Mosfets was the
thin ally case - and a small cooling fan. Not that much for a device
likely mounted inside a cupboard of some sort.

Rectifier was short circuit and a transformer burnt with half the
laminations lying loose inside the case, so gave up.

This is one I purchased recently, though not from this seller:

https://www.ebay.co.uk/itm/12V-20A-C...t/122314362986

In article ,
Fredxx wrote:
On 05/04/2018 23:47, Dave Plowman (News) wrote:
The mains to 12v power supplied failed in a mate's motorhome, so although
he got it replaced I offered to look at it to see if it could be repaired
as a spare.

It is branded PowerPart, and is a 20 amp 13.8v device which charges the
leisure battery as well as running any 12v things when on mains. Cost
about 100 quid.

It was well and truly fried. Only heatsink for the power Mosfets was the
thin ally case - and a small cooling fan. Not that much for a device
likely mounted inside a cupboard of some sort.

Rectifier was short circuit and a transformer burnt with half the
laminations lying loose inside the case, so gave up.

This is one I purchased recently, though not from this seller:

https://www.ebay.co.uk/itm/12V-20A-C...t/122314362986

It certainly looks better than the one I have here. Which looks decidedly
home made, case wise. ;-)

But wonder if that unit could be used as a stand alone power supply for
12v stuff in the van, with no battery present? The current one can.

--
*Do infants enjoy infancy as much as adults enjoy adultery?

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

On 07/04/2018 11:26, Dave Plowman (News) wrote:
In article ,
Fredxx wrote:
On 05/04/2018 23:47, Dave Plowman (News) wrote:
The mains to 12v power supplied failed in a mate's motorhome, so although
he got it replaced I offered to look at it to see if it could be repaired
as a spare.

It is branded PowerPart, and is a 20 amp 13.8v device which charges the
leisure battery as well as running any 12v things when on mains. Cost
about 100 quid.

It was well and truly fried. Only heatsink for the power Mosfets was the
thin ally case - and a small cooling fan. Not that much for a device
likely mounted inside a cupboard of some sort.

Rectifier was short circuit and a transformer burnt with half the
laminations lying loose inside the case, so gave up.

This is one I purchased recently, though not from this seller:

https://www.ebay.co.uk/itm/12V-20A-C...t/122314362986

It certainly looks better than the one I have here. Which looks decidedly
home made, case wise. ;-)

But wonder if that unit could be used as a stand alone power supply for
12v stuff in the van, with no battery present? The current one can.

I haven't tried that. I always have batteries in situ. It's the only way
I can provide the additional power for a microwave through a 3kW inverter.

In article ,
Fredxx wrote:
But wonder if that unit could be used as a stand alone power supply for
12v stuff in the van, with no battery present? The current one can.

I haven't tried that. I always have batteries in situ. It's the only way
I can provide the additional power for a microwave through a 3kW
inverter.

It does say reverse polarity protected, so may not even fire up if the
battery is totally flat.

--
*Verbs HAS to agree with their subjects *

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

In article , "Dave Plowman (News)"
writes
The mains to 12v power supplied failed in a mate's motorhome, so although
he got it replaced I offered to look at it to see if it could be repaired
as a spare.

It is branded PowerPart, and is a 20 amp 13.8v device which charges the
leisure battery as well as running any 12v things when on mains. Cost
about 100 quid.

It was well and truly fried. Only heatsink for the power Mosfets was the
thin ally case - and a small cooling fan. Not that much for a device
likely mounted inside a cupboard of some sort.

Rectifier was short circuit and a transformer burnt with half the
laminations lying loose inside the case, so gave up.

Get a Zig. And I don't think any of my leisure vehicles including, 2
campervans, one motorhome and 5 caravans having a cooling fan.
--
bert

"Brian Reay" wrote in message
news
On 07/04/2018 00:55, Steve Walker wrote:
On 06/04/2018 11:30, Brian Reay wrote:
On 06/04/18 11:10, Theo wrote:
Chris Green wrote:
I think you'd be surprised how expensive that would be, transformers
in particular are quite pricey. A PC switch mode PSU would probably
be cheaper for that sort of rating (though would likely have lots of
5v and 3.3v output as well).

12V 32A, silent, six quid:
http://www.ebay.co.uk/itm/Sony-PlayS...C/152246465886

and it's possible to tweak the voltage upwards:
https://www.experimental-engineering...y-voltage-mod/
slightly easier on a different version:
https://www.experimental-engineering...y-voltage-mod/

Theo


Why does a Playstation need 32A? Could it be perhaps 3.2A?

Looking at the moulding, it looks like the rating on the PSU is 23.5A at
12V, plus 0.6A at 5V. That is 285W

Some PC video cards are a fair chunk of that, plus 90 to 125W for the
processor, so it's not really surprising for a games console to need that
much.

SteveW

Obviously a Playstation isn't the gizmo I thought it was (never played
with one).


Thankfully, our offspring never expressed any interest in computer games.




or ham radio ...