Forums

Charge gel cell with car charger?

Started by Mike Cook February 24, 2013
On Tue, 26 Feb 2013 06:58:16 -0800, dave <ricketzz@earthlink.net> wrote:

> A lot of mobile equipment will >not work properly on 12 Vdc.
Stop lying. The devices designed for 13.6 v typically will operate within a supply source voltage window. 12 volts is far too close to 13.6 for any device I can think of having a problem. I think you are making shit up.
On 02/26/2013 07:39 AM, SoothSayer wrote:
> On Tue, 26 Feb 2013 06:58:16 -0800, dave <ricketzz@earthlink.net> wrote: > >> A lot of mobile equipment will >> not work properly on 12 Vdc. > > > Stop lying. > > The devices designed for 13.6 v typically will operate within a supply > source voltage window. > > 12 volts is far too close to 13.6 for any device I can think of having > a problem. I think you are making shit up. >
http://forums.qrz.com/showthread.php?246634-ATX-Power-Supply-for-Ham-Radio
dave wrote:
> > On 02/26/2013 06:52 AM, SoothSayer wrote: > > On Tue, 26 Feb 2013 06:42:48 -0800, dave <ricketzz@earthlink.net> wrote: > > > >> they always include a safety pressure relief valve. > >> > >> As > > > > > > For NORMAL battery utilization. NOT a vent for charging pressure > > relief.. The device and or person doing the charging has to keep the > > process below any overt gassing level. > > > > OK. My only other point was that 12 Vdc nominal is never 12 Vdc, except > when the battery is severely discharged. A lot of mobile equipment will > not work properly on 12 Vdc. > > "A car battery is considered charged at 12.4 volts or higher. It is > considered discharged when it's at 12.39 volts or less." > > -http://www.autobatteries.com/basics/voltage1.asp > > You are allowed to nag precise, and I am too.
12.4 volts? The cells are 2.1 volts each when fully charged & sitting idle.

"John Fields" <jfields@austininstruments.com> wrote in message 
news:2dvni890e0mu6d56odaunfsqgu8ssjt7qm@4ax.com...
> On Mon, 25 Feb 2013 22:36:52 -0000, "Ian Field" > <gangprobing.alien@ntlworld.com> wrote: > >> >> >>"Jan Panteltje" <pNaonStpealmtje@yahoo.com> wrote in message >>news:kgcpgh$ipp$1@news.albasani.net... >>> On a sunny day (Sun, 24 Feb 2013 00:06:18 -0800) it happened Mike Cook >>> <mcham@NOTyahoo.com> wrote in >>> <0001HW.CD4F09FA05B8251DB04179BF@news.eternal-september.org>: >>> >>>>A friend has a battery powered Ryobi lawn trimmer ("weed whacker") which >>>>doesn't work. The 12vdc wall wart puts out only ~ 12.4v. >>>> >>>>I charged the lead-acid gel cell using a car charger. The charge rate >>>>(selectable) was 0.5A. Afterward the trimmer seemed to work as new. >>>> >>>>Can the car charger be used to charge this battery? He can install a >>>>timer >>>>to >>>>limit charge time if that's something required. >>>> >>>>Thanks. >>> >>> Old trick was to put a car headlight or some other low voltage bulb >>> (break >>> light) >>> in series as current limiter. >>> Maybe modern car has only LEDs, dunno, :-) >> >> >>Its a trick I often use if I have to, but increasingly I turn to the more >>modern electronic/microcontroller type chargers that automatically switch >>to >>trickle charge. > > --- > That's a good thing, since it puts you squarely into the rank of a > "consumer", where you clearly belong, instead of into the ranks of > designers, where you've clearly demonstrated you don't belong. > > I could be wrong of course,
Indeed.
On Sunday, February 24, 2013 5:49:26 AM UTC-5, mrob...@att.net wrote:
> Followups set to sci.electronics.repair . >=20 >=20 >=20 > In sci.electronics.components Mike Cook <mcham@notyahoo.com> wrote: >=20 > > Can the car charger be used to charge this battery? >=20 >=20 >=20 > Probably. Do you know what the amp-hour capacity is of the battery that >=20 > is in there now? A little Googling *1 suggests that the original 12 V >=20 > battery might have been six Gates/Hawker/Enersys "Cyclon" 2 V cells in >=20 > series; the replacement that one site sells looks suspiciously like the >=20 > common or garden 12 V 7 amp-hour "gel cell", plus a couple of brackets >=20 > to make it fit. If the battery capacity is around 6 or 7 amp-hours, >=20 > then the 0.5 A charger will work OK, as long as you don't mind it taking >=20 > 12 or more hours for a full charge. >=20 >=20 >=20 > One manufacturer of these batteries *2 says this is how you charge the >=20 > 12 V, 7 Ah size: >=20 >=20 >=20 > "Limit initial current to 2.1A. Charge until battery voltage (under >=20 > charge) reaches 14.4 to 14.7 volts at 68=B0F (20=B0C). Hold at 14.4 to 1=
4.7
>=20 > volts until current drops to under 70mA. Battery is fully charged under >=20 > these conditions, and charger should be disconnected or switched to >=20 > "float" voltage." >=20 >=20 >=20 > So... the 0.5 A car battery charger should be OK. The charger you have >=20 > may not do the automatic float and shutoff - more below. >=20 >=20 >=20 > The voltage output by the car charger will be slightly different than >=20 > what a sealed battery needs; this is probably not too important in this >=20 > application, but may reduce battery life a little. If you want, you can >=20 > get an "official" charger for sealed batteries for $35 or so; *3 has >=20 > 0.8 A output and will work a little faster. Or, get one of the >=20 > automatic car battery maintainers like a Deltran Battery Tender or >=20 > Schumacher Battery Companion; these usually have 1.0 to 1.5 A outputs >=20 > and will automagically switch to a low-current charge once the battery >=20 > is full. These are easy to find at local stores. >=20 >=20 >=20 > > He can install a timer to limit charge time if that's something >=20 > > required. >=20 >=20 >=20 > If the charger doesn't have any kind of automatic shutoff, then this >=20 > might not be a bad idea. The million dollar question is "how long is >=20 > enough". The answer depends on how discharged the battery is. The >=20 > simple answer (for a 7 amp-hour battery) is 7 amp-hours / 0.5 amps =3D >=20 > 14 hours. But: the charge won't be 0.5 A for the whole time. It may >=20 > start off that way but it will go down as the battery charges up, so >=20 > a full charge will take longer. >=20 >=20 >=20 > At a guess, I would get one of those 12 hour spring wound timer switches >=20 > (often used with attic fans) from the hardware store, and put it in an >=20 > outlet box along with an outlet and a cord. Maybe set it for 2 or 3 >=20 > hours the first time, then when it shuts off, measure the battery >=20 > voltage to find out how full it is. If not full enough, repeat. After >=20 > a few runs you will know what to set the timer to initially. >=20 >=20 >=20 > *1 http://www.ereplacementparts.com/ryobi-150r-41ae150f034-volt-battery-t=
rimmer-parts-c-7931_15633_18531.html
>=20 >=20 >=20 > *2 http://www.power-sonic.com/images/powersonic/sla_batteries/ps_psg_seri=
es/12volt/PS-1270_11_Feb_21.pdf
>=20 >=20 >=20 > *3 http://www.mouser.com/ProductDetail/Power-Sonic/PSC-12800A-C/?qs=3DXAT=
L/JQ9g1zerdAMdrMzKQ=3D=3D
>=20 >=20 >=20 > Standard disclaimers apply; I don't get money or other consideration >=20 > from any companies mentioned. >=20 >=20 >=20 > Matt Roberds
You have him so wrapped up in safeguards it will take 24 hours to re-charge= that battery at 0.5A. The OP is the same ignorant eternal-september troll = living in a junkyard who knows enough to be dangerous. All his posts are ab= out junk he's fished out of a dumpster.
On Mon, 25 Feb 2013 18:27:34 -0800, dave <ricketzz@earthlink.net>
wrote:

>On 02/25/2013 05:07 PM, krw@attt.bizz wrote: >> On Mon, 25 Feb 2013 15:54:23 -0800, dave <ricketzz@earthlink.net> >> wrote: >> >>> On 02/25/2013 10:54 AM, Michael A. Terrell wrote: >>>> >>>> dave wrote: >>>>> >>>>> On 02/24/2013 05:37 AM, SoothSayer wrote: >>>>>> On Sun, 24 Feb 2013 05:17:53 -0800, dave <ricketzz@earthlink.net> wrote: >>>>>> >>>>>>> On 02/24/2013 05:14 AM, Phil Allison wrote: >>>>>>>> "dave" >>>>>>>>> >>>>>>>>> You answered your own question. As long as the battery doesn't heat up on >>>>>>>>> a big charge you're probably OK. >>>>>>>> >>>>>>>> >>>>>>>> ** SLA or "gel cells" are prone to gassing when overcharged. >>>>>>>> >>>>>>>> The pressure builds up inside until something gives - then you have bits >>>>>>>> of battery and acid all over the place. >>>>>>>> >>>>>>>> Voltage & current limited charging is the only safe and sensible way. >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> ... Phil >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> They have vents. >>>>>> >>>>>> Which are NOT meant for overcharge relief. >>>>>> >>>>> >>>>> I didn't say they were. I was speaking to the "bits of battery and acid" >>>>> prediction above. >>>> >>>> >>>> I've seen the results of several car batteries exploding. Maybe your >>>> head should be under the hood when one blows. >>>> >>> >>> Why is everyone so rude around here? >> >> Why are you here? >> > >I am here for entertainment, mainly.
Ah Ha!
>most of the substantive stuff is >over my head, but the lead-acid battery is on the FCC exams you take for >an advanced license,
Oohhh! I'm impressed. You took a *real* FCC license exam. Did you pass?
>plus I used to maintain a fleet of trucks at a >construction company, where I also serviced 2-way radios and 5 mW >surveyor lasers.
So you know it all. Great!
krw@attt.bizz wrote:
> > On Mon, 25 Feb 2013 18:27:34 -0800, dave <ricketzz@earthlink.net> > wrote: > > >On 02/25/2013 05:07 PM, krw@attt.bizz wrote: > >> On Mon, 25 Feb 2013 15:54:23 -0800, dave <ricketzz@earthlink.net> > >> wrote: > >> > >>> On 02/25/2013 10:54 AM, Michael A. Terrell wrote: > >>>> > >>>> dave wrote: > >>>>> > >>>>> On 02/24/2013 05:37 AM, SoothSayer wrote: > >>>>>> On Sun, 24 Feb 2013 05:17:53 -0800, dave <ricketzz@earthlink.net> wrote: > >>>>>> > >>>>>>> On 02/24/2013 05:14 AM, Phil Allison wrote: > >>>>>>>> "dave" > >>>>>>>>> > >>>>>>>>> You answered your own question. As long as the battery doesn't heat up on > >>>>>>>>> a big charge you're probably OK. > >>>>>>>> > >>>>>>>> > >>>>>>>> ** SLA or "gel cells" are prone to gassing when overcharged. > >>>>>>>> > >>>>>>>> The pressure builds up inside until something gives - then you have bits > >>>>>>>> of battery and acid all over the place. > >>>>>>>> > >>>>>>>> Voltage & current limited charging is the only safe and sensible way. > >>>>>>>> > >>>>>>>> > >>>>>>>> > >>>>>>>> ... Phil > >>>>>>>> > >>>>>>>> > >>>>>>> > >>>>>>> They have vents. > >>>>>> > >>>>>> Which are NOT meant for overcharge relief. > >>>>>> > >>>>> > >>>>> I didn't say they were. I was speaking to the "bits of battery and acid" > >>>>> prediction above. > >>>> > >>>> > >>>> I've seen the results of several car batteries exploding. Maybe your > >>>> head should be under the hood when one blows. > >>>> > >>> > >>> Why is everyone so rude around here? > >> > >> Why are you here? > >> > > > >I am here for entertainment, mainly. > > Ah Ha! > > >most of the substantive stuff is > >over my head, but the lead-acid battery is on the FCC exams you take for > >an advanced license,
The ham + CHEESE test! ;-)
> Oohhh! I'm impressed. You took a *real* FCC license exam. Did you > pass? > > >plus I used to maintain a fleet of trucks at a > >construction company, where I also serviced 2-way radios and 5 mW > >surveyor lasers. > > So you know it all. Great!
On Tue, 26 Feb 2013 16:46:14 -0000, "Ian Field"
<gangprobing.alien@ntlworld.com> wrote:

> > >"John Fields" <jfields@austininstruments.com> wrote in message >news:2dvni890e0mu6d56odaunfsqgu8ssjt7qm@4ax.com... >> On Mon, 25 Feb 2013 22:36:52 -0000, "Ian Field" >> <gangprobing.alien@ntlworld.com> wrote: >> >>> >>> >>>"Jan Panteltje" <pNaonStpealmtje@yahoo.com> wrote in message >>>news:kgcpgh$ipp$1@news.albasani.net... >>>> On a sunny day (Sun, 24 Feb 2013 00:06:18 -0800) it happened Mike Cook >>>> <mcham@NOTyahoo.com> wrote in >>>> <0001HW.CD4F09FA05B8251DB04179BF@news.eternal-september.org>: >>>> >>>>>A friend has a battery powered Ryobi lawn trimmer ("weed whacker") which >>>>>doesn't work. The 12vdc wall wart puts out only ~ 12.4v. >>>>> >>>>>I charged the lead-acid gel cell using a car charger. The charge rate >>>>>(selectable) was 0.5A. Afterward the trimmer seemed to work as new. >>>>> >>>>>Can the car charger be used to charge this battery? He can install a >>>>>timer >>>>>to >>>>>limit charge time if that's something required. >>>>> >>>>>Thanks. >>>> >>>> Old trick was to put a car headlight or some other low voltage bulb >>>> (break >>>> light) >>>> in series as current limiter. >>>> Maybe modern car has only LEDs, dunno, :-) >>> >>> >>>Its a trick I often use if I have to, but increasingly I turn to the more >>>modern electronic/microcontroller type chargers that automatically switch >>>to >>>trickle charge. >> >> --- >> That's a good thing, since it puts you squarely into the rank of a >> "consumer", where you clearly belong, instead of into the ranks of >> designers, where you've clearly demonstrated you don't belong. >> >> I could be wrong of course, > >Indeed.
--- But, more than likely not, since I requested that you elaborate with an explanation of your "tricks" and you reply with snippage and dodging. -- JF

"John Fields" <jfields@austininstruments.com> wrote in message 
news:gh9qi8t3alcietnh2r674clj7ne976j2af@4ax.com...
> On Tue, 26 Feb 2013 16:46:14 -0000, "Ian Field" > <gangprobing.alien@ntlworld.com> wrote: > >> >> >>"John Fields" <jfields@austininstruments.com> wrote in message >>news:2dvni890e0mu6d56odaunfsqgu8ssjt7qm@4ax.com... >>> On Mon, 25 Feb 2013 22:36:52 -0000, "Ian Field" >>> <gangprobing.alien@ntlworld.com> wrote: >>> >>>> >>>> >>>>"Jan Panteltje" <pNaonStpealmtje@yahoo.com> wrote in message >>>>news:kgcpgh$ipp$1@news.albasani.net... >>>>> On a sunny day (Sun, 24 Feb 2013 00:06:18 -0800) it happened Mike Cook >>>>> <mcham@NOTyahoo.com> wrote in >>>>> <0001HW.CD4F09FA05B8251DB04179BF@news.eternal-september.org>: >>>>> >>>>>>A friend has a battery powered Ryobi lawn trimmer ("weed whacker") >>>>>>which >>>>>>doesn't work. The 12vdc wall wart puts out only ~ 12.4v. >>>>>> >>>>>>I charged the lead-acid gel cell using a car charger. The charge rate >>>>>>(selectable) was 0.5A. Afterward the trimmer seemed to work as new. >>>>>> >>>>>>Can the car charger be used to charge this battery? He can install a >>>>>>timer >>>>>>to >>>>>>limit charge time if that's something required. >>>>>> >>>>>>Thanks. >>>>> >>>>> Old trick was to put a car headlight or some other low voltage bulb >>>>> (break >>>>> light) >>>>> in series as current limiter. >>>>> Maybe modern car has only LEDs, dunno, :-) >>>> >>>> >>>>Its a trick I often use if I have to, but increasingly I turn to the >>>>more >>>>modern electronic/microcontroller type chargers that automatically >>>>switch >>>>to >>>>trickle charge. >>> >>> --- >>> That's a good thing, since it puts you squarely into the rank of a >>> "consumer", where you clearly belong, instead of into the ranks of >>> designers, where you've clearly demonstrated you don't belong. >>> >>> I could be wrong of course, >> >>Indeed. > > --- > But, more than likely not, since I requested that you elaborate with > an explanation of your "tricks"
No you didn't (the senility really is robbing your faculties!) The trick was already described by someone else - I merely replied I do that too (and no - I can't be bothered drawing pictures because you're too thick to understand). You're not only wrong, but stumbling about in a state of advanced dementia.
SoothSayer wrote:
> On Tue, 26 Feb 2013 06:58:16 -0800, dave <ricketzz@earthlink.net> wrote: > > >>A lot of mobile equipment will >>not work properly on 12 Vdc. > > > > Stop lying. > > The devices designed for 13.6 v typically will operate within a supply > source voltage window. > > 12 volts is far too close to 13.6 for any device I can think of having > a problem. I think you are making shit up.
I hate to burst your bubble but he's correct, a lot of mobile equipment do not work correctly at 12V. They need to be up to 13+ volts. Jamie