> I thought I understood ah ratings this battery says (5ah/20h) that's a
little
> confusing.
>
> Jim

ie: the batt wil provide 5ampere hours if discharged over an interval of 20
hours. This would imply a current of 250ma.

Bob Ammerman
RAm Systems


>
> -----Original Message-----
> From: Byron A Jeff <byron@CC.GATECH.EDU>
> To: PICLIST@MITVMA.MIT.EDU <PICLIST@MITVMA.MIT.EDU>
> Date: Saturday, July 20, 2002 8:38 PM
> Subject: Re: [EE]:speaking of gellcell's ?
>
>
> >On Sat, Jul 20, 2002 at 06:57:05AM -0700, Jim wrote:
> >> Hi
> >
> >> Pardon my ignorance
> >
> >No need. You have very cogent questions.
> >
> >> I'm working on a home project using a 12v gellcell.
> >
> >One piece of information that's missing here is how are you using the
> >battery. What type of charging you need depends on how it's being cycled.
> >
> >> It has charging info printed on it but I'm kinda new to charging these.
> >> It say's cycle use 14.5 ` 14.9v (25deg c) initial current less than 2
> amps
> >> stand by use 13.6 ` 13.8v (25deg c)
> >
> >Typical...
> >
> >>
> >> I have been looking at charging info on the web
> >> I would like to use an lm317 for the charging and have already
> breadboarded
> >> a cicuit that will switch between the 2 voltages
> >> How important is the temp compensation?
> >
> >It's important if there's a wide variation of temperature from 25C.
> >
> >> Can I charge it at around 1 amp without any ill effect?
> >
> >Not at 14.6V. This voltage will guarantee an overcharge if left
> indefinitely.
> >
> >>if the charger is working properly should I be able to measure aprox
14.6v
> >>when I first connect it to the battery or does it have to climb to this
> >> voltage as it charges?
> >
> >The latter. The battery will drag the voltage down to its level as it
takes
> >on charge, slowly rising to the target voltage.
> >
> >Battery charging is serious and complicated business. Essentially
charging
> >under any conditions other than ideal will eventually result in battery
> >failure:
> >
> >* No charge will result in a dead battery.
> >* Undercharging will cause sulfation resulting in lowered capacities and
> >  premature failure.
> >* Overcharging will result in gassing causing premature battery failure.
> >
> >I would advise not charging your battery from 14.5V source unless you
have
> >a an automatic cutoff mechanism (or two) in place. I finally decided that
> >float charging was the safest dumb charging course of action.
> >
> >A good reliable gell cell charger is high on my list of things to build.
I
> >really want a 3 stage charger with autodetion of stages (bulk,
absorption,
> and
> >float) and decent indicators. What I really haven't figured out is how to
> get
> >really high current for fast charging. My 33Ahr 12V gel cell will accept
up
> >to 10A current. But finding a 10A transformer is a tough proposition.
> >
> >Hope this gives you some help,
> >
> >BAJ
> >
> >--
> >http://www.piclist.com hint: To leave the PICList
> >mailto:piclist-unsubscribe-request@mitvma.mit.edu
> >
> >
> >
>
> --
> http://www.piclist.com hint: PICList Posts must start with ONE topic:
> [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads
>
>

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads