So you have a small open frame genset with 12 V electric start.

Said genset has a 12 V battery charging abilty.

Would you expect it to charge its own battery when running?


--
Cheers
Dave.

On Wednesday, 7 October 2015 22:28:05 UTC+1, Dave Liquorice wrote:

So you have a small open frame genset with 12 V electric start.

Thank you, much appreciated.

Said genset has a 12 V battery charging abilty.

Would you expect it to charge its own battery when running?

If I designed it, yes. If I paid a shockingly low price for it I'd expect any sneaky scheme the mfr could pull to save 5p.


NT

"Dave Liquorice" wrote in message
ll.co.uk...
So you have a small open frame genset with 12 V electric start.

Said genset has a 12 V battery charging abilty.

Would you expect it to charge its own battery when running?


No, and yes.
No, I don't have such a set. Used to have a Honda of this flavour.
Yes, it should charge its own battery. I don't know of any electric start
engine that does not have inbuilt battery charging apparatus.

On Wed, 7 Oct 2015 14:44:30 -0700 (PDT), wrote:

Said genset has a 12 V battery charging abilty.

Would you expect it to charge its own battery when running?

If I designed it, yes.

So that's four of us (SWMBO'd also expected it to charge it's own
battery).

If I paid a shockingly low price for it I'd expect any sneaky scheme the
mfr could pull to save 5p.

Well it's no-name Chinese single cylinder diesel so I guess they have
saved their 5p.

The battery charging terminals hit about 30 V open circuit dropping
to 15 V @ 7 to 8A across the (old, removed and partially dead)
battery. Measure the volts of the gensets (new, installed) battery
and they are about 12.9 just after starting the set slowly rising to
13.5 ish. Makes no difference if the set is running or not. Obviously
not being charged.

Pretty sure I've seen a wiring diagram for it somewhere but can't
find it now. B-(

--
Cheers
Dave.

On Friday, 9 October 2015 00:58:07 UTC+1, Dave Liquorice wrote:
On Wed, 7 Oct 2015 14:44:30 -0700 (PDT), nt wrote:

Said genset has a 12 V battery charging abilty.

Would you expect it to charge its own battery when running?

If I designed it, yes.

So that's four of us (SWMBO'd also expected it to charge it's own
battery).

If I paid a shockingly low price for it I'd expect any sneaky scheme the
mfr could pull to save 5p.

Well it's no-name Chinese single cylinder diesel so I guess they have
saved their 5p.

The battery charging terminals hit about 30 V open circuit dropping
to 15 V @ 7 to 8A across the (old, removed and partially dead)
battery. Measure the volts of the gensets (new, installed) battery
and they are about 12.9 just after starting the set slowly rising to
13.5 ish. Makes no difference if the set is running or not. Obviously
not being charged.

Pretty sure I've seen a wiring diagram for it somewhere but can't
find it now. B-(

Sounds like it's not under guarantee, in which case presumably you could add an external battery charger.


NT

wrote:
On Friday, 9 October 2015 00:58:07 UTC+1, Dave Liquorice wrote:
On Wed, 7 Oct 2015 14:44:30 -0700 (PDT), nt wrote:

Said genset has a 12 V battery charging abilty.

Would you expect it to charge its own battery when running?

If I designed it, yes.

So that's four of us (SWMBO'd also expected it to charge it's own
battery).

If I paid a shockingly low price for it I'd expect any sneaky scheme the
mfr could pull to save 5p.

Well it's no-name Chinese single cylinder diesel so I guess they have
saved their 5p.

The battery charging terminals hit about 30 V open circuit dropping
to 15 V @ 7 to 8A across the (old, removed and partially dead)
battery. Measure the volts of the gensets (new, installed) battery
and they are about 12.9 just after starting the set slowly rising to
13.5 ish. Makes no difference if the set is running or not. Obviously
not being charged.

Pretty sure I've seen a wiring diagram for it somewhere but can't
find it now. B-(

Sounds like it's not under guarantee, in which case presumably you could add an external battery charger.


NT

If it rising to 13.5 then it is getting a charge however small from
somewhere.

A standard 12v battery is not going to self recover to any more than
12.6 or so with no external influence.

By applying a variable load to the battery once the genset is running
you should be able assess the charging current. when the battery sits at
12.6, the current in the load will be about the same as the charging
current.

In article o.uk,
Dave Liquorice wrote:
So you have a small open frame genset with 12 V electric start.

Said genset has a 12 V battery charging abilty.

Would you expect it to charge its own battery when running?


I've never known anything like that which doesn't. Would be pretty
pointless given how little it would cost to do.

--
*I wished the buck stopped here, as I could use a few*

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

In article o.uk, Dave
Liquorice scribeth thus
So you have a small open frame genset with 12 V electric start.

Said genset has a 12 V battery charging abilty.

Would you expect it to charge its own battery when running?



Yes, ours does...


But its float charged as well just in case !..
--
Tony Sayer

On Fri, 9 Oct 2015 15:06:01 +0100, Bob Minchin wrote:

The battery charging terminals hit about 30 V open circuit
dropping
to 15 V @ 7 to 8A across the (old, removed and partially dead)
battery. Measure the volts of the gensets (new, installed)
battery
and they are about 12.9 just after starting the set slowly rising
to
13.5 ish. Makes no difference if the set is running or not.
Obviously
not being charged.

If it rising to 13.5 then it is getting a charge however small from
somewhere.

A standard 12v battery is not going to self recover to any more than
12.6 or so with no external influence.

Hum, further investigation required, I'll admit the exact numbers
might be misremembered but I pretty certain of the 12.9 and
13.something.

Wouldn't the measured terminal voltage drop straight away when the
charging voltage is removed? It didn't change between genset running
and genset not running... This and seeing under 13 V with the set
running is what really makes me think the battery isn't being
charged.

--
Cheers
Dave.

Dave Liquorice wrote:
On Fri, 9 Oct 2015 15:06:01 +0100, Bob Minchin wrote:

The battery charging terminals hit about 30 V open circuit
dropping
to 15 V @ 7 to 8A across the (old, removed and partially dead)
battery. Measure the volts of the gensets (new, installed)
battery
and they are about 12.9 just after starting the set slowly rising
to
13.5 ish. Makes no difference if the set is running or not.
Obviously
not being charged.

If it rising to 13.5 then it is getting a charge however small from
somewhere.

A standard 12v battery is not going to self recover to any more than
12.6 or so with no external influence.

Hum, further investigation required, I'll admit the exact numbers
might be misremembered but I pretty certain of the 12.9 and
13.something.

Wouldn't the measured terminal voltage drop straight away when the
charging voltage is removed? It didn't change between genset running
and genset not running... This and seeing under 13 V with the set
running is what really makes me think the battery isn't being
charged.

My school boy memory is of a standard lead acid being 2.2v per cell just
off charge and quickly dropping to 2v ish giving its all until getting
seriously discharged and volts falling off rapidly.

Bob

In article o.uk,
"Dave Liquorice" writes:

Hum, further investigation required, I'll admit the exact numbers
might be misremembered but I pretty certain of the 12.9 and
13.something.

Wouldn't the measured terminal voltage drop straight away when the
charging voltage is removed?

No, it decays slowly, but I suspect it would decay very quickly
with a small load.

It didn't change between genset running
and genset not running... This and seeing under 13 V with the set
running is what really makes me think the battery isn't being
charged.

It could be either that it was low to start with.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

On 10/10/2015 23:55, Bob Minchin wrote:
Dave Liquorice wrote:
On Fri, 9 Oct 2015 15:06:01 +0100, Bob Minchin wrote:

The battery charging terminals hit about 30 V open circuit
dropping
to 15 V @ 7 to 8A across the (old, removed and partially dead)
battery. Measure the volts of the gensets (new, installed)
battery
and they are about 12.9 just after starting the set slowly rising
to
13.5 ish. Makes no difference if the set is running or not.
Obviously
not being charged.

If it rising to 13.5 then it is getting a charge however small from
somewhere.

A standard 12v battery is not going to self recover to any more than
12.6 or so with no external influence.

Hum, further investigation required, I'll admit the exact numbers
might be misremembered but I pretty certain of the 12.9 and
13.something.

Wouldn't the measured terminal voltage drop straight away when the
charging voltage is removed? It didn't change between genset running
and genset not running... This and seeing under 13 V with the set
running is what really makes me think the battery isn't being
charged.

My school boy memory is of a standard lead acid being 2.2v per cell just
off charge and quickly dropping to 2v ish giving its all until getting
seriously discharged and volts falling off rapidly.

That was my general understanding as well, but in practice the terminal
voltage is dependent on charge state.


https://pssurvival.com/PS/Batteries/...ltage_1993.pdf

This PDF gives a good indication. Sadly the figure on page 2 doesn't
give the battery temperature, where volts go down with increasing
temperature. It also depends on how accurate the battery AH is stated.

It is actually possible, at a small trickle current, that 13.5 volts
represents near fully charged.

In article o.uk,
Dave Liquorice wrote:
Wouldn't the measured terminal voltage drop straight away when the
charging voltage is removed? It didn't change between genset running
and genset not running... This and seeing under 13 V with the set
running is what really makes me think the battery isn't being
charged.

No - a lead acid measured with a high impedance voltmeter will give an
oddly high reading immediately after charge. There is a term for this I've
forgotten. Check it under load.

--
*No word in the English language rhymes with month, orange, silver,purple

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