Reply by Uwe Hercksen January 14, 20132013-01-14

Jeff Liebermann schrieb:

> 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.
>Guilty as charged. I didn't notice the chart: ><http://lh6.ggpht.com/_VexMxYnip6A/S5uMrmV4d7I/AAAAAAAABDo/_khx29Nk_2I/s800/album_pic.jpg> > ><http://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery> > All voltages are at 20 &#4294967295;C (68 &#4294967295;F), and must be > adjusted -0.0235V/&#4294967295;C for temperature changes. > >Here's another chart that shows increasing voltage with temperature: ><http://www.meeknet.co.uk/e38/E38_Battery_SOC_Table.jpg> > >while these go the other way: ><http://chinashengneng.en.alibaba.com/product/517939386-209676959/UPS_AGM_Sealed_Lead_Acid_Battery_12V_250AH_High_rate_capacity_Accumulator_.html>
><http://www.windsun.com/pictures/Charge_voltage.gif>
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
><http://www.chbattery.com/uppic/2009414102430492.jpg> > >Looks like Fred Bloggs is correct and the charts are wrong.
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?
>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
Guilty as charged. I didn't notice the chart: <http://lh6.ggpht.com/_VexMxYnip6A/S5uMrmV4d7I/AAAAAAAABDo/_khx29Nk_2I/s800/album_pic.jpg> <http://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery> All voltages are at 20 &#4294967295;C (68 &#4294967295;F), and must be adjusted -0.0235V/&#4294967295;C for temperature changes. Here's another chart that shows increasing voltage with temperature: <http://www.meeknet.co.uk/e38/E38_Battery_SOC_Table.jpg> while these go the other way: <http://chinashengneng.en.alibaba.com/product/517939386-209676959/UPS_AGM_Sealed_Lead_Acid_Battery_12V_250AH_High_rate_capacity_Accumulator_.html> <http://www.windsun.com/pictures/Charge_voltage.gif> <http://www.chbattery.com/uppic/2009414102430492.jpg> Looks like Fred Bloggs is correct and the charts are wrong. -- 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 26, 20122012-12-26
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
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:
> On Tue, 25 Dec 2012 01:46:34 -0800 (PST), andrew_kennedy7@yahoo.com > > wrote: > > > > >Power Wheels Charger for Gray 12v Battery 00801-1778 > > > > This might help: > > <http://www.modifiedpowerwheels.com/forum/topic.asp?TOPIC_ID=15855> > > About 14 hrs and no more, assuming a totally discharged battery. > > > > Looks like the Power Wheels fans are going for replacement chargers. I > > can see why as the stock charger appears to be a constant current > > charge with no automatic shutoff. Leave it on for extended periods, > > and you have a dead battery. > > <http://www.modifiedpowerwheels.com/forum/topic.asp?TOPIC_ID=695> > > <http://www.modifiedpowerwheels.com/forum/topic.asp?TOPIC_ID=4156> > > > > There's also some advice on batteries and chargers on the FAQ: > > <http://www.modifiedpowerwheels.com/forum/forum.asp?FORUM_ID=12> > > Looks like a good place to start reading. > > -- > > 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
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