> A new lead acid battery has a Coulombic Efficiency of about 75%. That
> means for every amp you feed the battery, only 75% of it stays in the
> battery.
> 12v * 9.5 Amp-Hr / 0.75 = 152 watt-hrs
> will be needed to recharge the battery. If your charger actually
> delivers 1 amp, it will take:
> 152 watt-hrs / (12v * 1 amp) = 13 hrs
Hello,
it is not necessary to multiply with 12 V and then to divide with 12 V
again.
9.5 Ah/(1 A * 0,75) = 12,66 h will do.
Bye
Reply by John Fields●January 5, 20132013-01-05
On Tue, 25 Dec 2012 06:59:40 -0800 (PST), orion.osiris@virgin.net
wrote:
>On Tuesday, 25 December 2012 11:50:30 UTC+1, Phil Allison wrote:
>> <andrew_kennedy7@yahoo.com
>>
>>
>>
>> > Power Wheels Charger for Gray 12v Battery 00801-1778
>>
>> >
>>
>>
>>
>>
>>
>> ** Always post links.
>>
>>
>>
>> DO NOT expect others to do the running around for you.
>>
>>
>>
>> And BTW - this is the WRONG NG for such a question.
>>
>>
>>
>>
>>
>>
>>
>> .... Phil
>
>Autistic?
----
Fuck you, pissant.
Phil's right and you're not only wrong, you're out of the running.
--
JF
Reply by ●December 27, 20122012-12-27
On Wed, 26 Dec 2012 20:04:02 -0800, Jeff Liebermann <jeffl@cruzio.com>
wrote:
>On Wed, 26 Dec 2012 22:25:06 -0500, ehsjr <ehsjr@nospamverizon.net>
>wrote:
>
>>On 12/25/2012 5:54 PM, Jeff Liebermann wrote:
>>> On Tue, 25 Dec 2012 11:18:46 -0800 (PST),
>>> bloggs.fredbloggs.fred@gmail.com wrote:
>>>
>>>> There's something wrong with the chart for state of charge someone posted. Lead-acid has a negative cell voltage tempco...
>>>
>>> I checked every message in this thread. There's no chart and no
>>> mention of lead acid battery temperature coefficient. Maybe a
>>> different newsgroup or thread?
>
>>Didn't you post this?
>>"This might help:
>><http://www.modifiedpowerwheels.com/forum/topic.asp?TOPIC_ID=15855>
>>About 14 hrs and no more, assuming a totally discharged battery."
>>The chart is there.
>>Ed
>
The first chart shows open circuit voltage change with electrolyte
temperature... It goes up slightly with rising temperature and
capacity goes down with rising temperature.
The WindSun graph shows the voltage you are supposed to charge to vs.
temperature (Absorb voltage). They're different things.
You usually hold the battery voltage at the Absorb voltage
(temperature compensated relative to 25 degrees C), for a certain
amount of time OR even better, until the charge current drops to
what they call the ending amps or finishing amps which is somewhere
around 1% to 3% or so of its Amp-Hour capacity rating. That time and
current will vary some with battery age and capacity.
For a vented/flooded lead acid deep cycle battery, you can just let it
sit longer than necessary at the Absorb voltage but just have to watch
the electrolyte level and add water (distilled) if it gets too low.
For sealed LA batteries, the temperature compensated voltage range
has to be limited to whatever they say in the battery specs otherwise
they'll plump when you cook 'em.
boB
K7IQ
Reply by Jeff Liebermann●December 27, 20122012-12-27
On Wed, 26 Dec 2012 22:25:06 -0500, ehsjr <ehsjr@nospamverizon.net>
wrote:
>On 12/25/2012 5:54 PM, Jeff Liebermann wrote:
>> On Tue, 25 Dec 2012 11:18:46 -0800 (PST),
>> bloggs.fredbloggs.fred@gmail.com wrote:
>>
>>> There's something wrong with the chart for state of charge someone posted. Lead-acid has a negative cell voltage tempco...
>>
>> I checked every message in this thread. There's no chart and no
>> mention of lead acid battery temperature coefficient. Maybe a
>> different newsgroup or thread?
> On Tue, 25 Dec 2012 11:18:46 -0800 (PST),
> bloggs.fredbloggs.fred@gmail.com wrote:
>
>> There's something wrong with the chart for state of charge someone posted. Lead-acid has a negative cell voltage tempco...
>
> I checked every message in this thread. There's no chart and no
> mention of lead acid battery temperature coefficient. Maybe a
> different newsgroup or thread?
>
Reply by Jeff Liebermann●December 25, 20122012-12-25
On Tue, 25 Dec 2012 11:18:46 -0800 (PST),
bloggs.fredbloggs.fred@gmail.com wrote:
>There's something wrong with the chart for state of charge someone posted. Lead-acid has a negative cell voltage tempco...
I checked every message in this thread. There's no chart and no
mention of lead acid battery temperature coefficient. Maybe a
different newsgroup or thread?
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Reply by ehsjr●December 25, 20122012-12-25
On 12/24/2012 4:02 PM, andrew_kennedy7@yahoo.com wrote:
> I have a 12 Volt battery, 9.5 Ah that uses a 12 volt charger 1.0 amp.
>
> Assuming the battery is completely discharged, is there a way to determine how long to charge ?
>
> Thanks,
> Andy
>
Yes, with a rule of thumb type approximation:
The amount of charge you put back into the battery needs
to be about 1.2 times as much as you took out of it.
So if you know how much charge your charger puts into
the battery per unit time, divide that into 1.2 times the
amount of charge taken out to get an idea of the total
time needed.
All of that goes out the window with a modern variable rate
charger and/or if you don't know how much charge was taken
out or the rate of charge supplied by the charger or if
the battery has been damaged etc etc.
Ed
Reply by ●December 25, 20122012-12-25
On Monday, December 24, 2012 4:02:57 PM UTC-5, andrew_...@yahoo.com wrote:
> I have a 12 Volt battery, 9.5 Ah that uses a 12 volt charger 1.0 amp.
>=20
>=20
>=20
> Assuming the battery is completely discharged, is there a way to determin=
e how long to charge ?
>=20
>=20
>=20
> Thanks,
>=20
> Andy
That's a standard 0.1C trickle charger. C is battery capacity 9.5AH, chargi=
ng current in amps is 1/10 C, so ideally charge time is C/(0.1C)=3D10 hrs. =
Problem is battery does not store all the charge passed through it, so you=
need to add about 25%, that gets you about 12 hours. It is one of the best=
ways to charge because nothing is real critical as far as damaging battery=
with overcharge or reducing battery life.
Reply by ●December 25, 20122012-12-25
On Tuesday, December 25, 2012 1:06:32 PM UTC-5, Jeff Liebermann wrote:
There's something wrong with the chart for state of charge someone posted. Lead-acid has a negative cell voltage tempco...
Reply by Jeff Liebermann●December 25, 20122012-12-25
On Tue, 25 Dec 2012 21:50:30 +1100, "Phil Allison" <phil_a@tpg.com.au>
wrote:
><andrew_kennedy7@yahoo.com
>> Power Wheels Charger for Gray 12v Battery 00801-1778
>** Always post links.
> DO NOT expect others to do the running around for you.
Yeah, that would be nice. However, I have a different formula for
asking questions:
1. What problem are you trying to solve? A one sentence description
is sufficient. Details can come later.
2. What do you have to work with? Hardware, software, versions,
makers, models, photos, etc. Numbers please, not prose. Also test
equipment available, level of expertiese, and such.
3. What have you done so far and what happened?
There are plenty of other things that would be helpful, but these are
the basics.
> And BTW - this is the WRONG NG for such a question.
Yeah, but I like off topic questions. It suggests that the OP is
either clueless, lazy, or both. That makes it easier for them to
accept my guesswork and pontifications.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558