How long Gelcell?

[chris63]

I have a few different amp/size gelcell batterys that are getting weak.Do any of you guys know how long say,a seven amp gel will keep a 50watt bulb lit?How many amps will it draw in 1 hour?Just trying to figure out if the oldies are worth even dragging along?50watts by 12 volts =4.2amps so does that mean in less than 2 hours the 7.2amp gel will be dead? c63

[LMITOUT]

Probably won't even last that long if you say the battery is weak already, but that would be about right.

[Whoaru99]

Even with a fresh 7.2A battery, it probably wouldn't last much more than about 1 hour or so at 4 amp load.

That 7.2A rating is how many total amps can be delivered over a 20-hour period. If you draw the power quickly like a 4A load will do, the battery will not deliver as many total amps-hours.

[chris63]

Thanx for the reply,so are my calculations correct,50wattdivided by voltage(12)will give me 4.2amps.So a 7.2amp cell will give me less than 2 hours.I've heard that with a 500 milleamp charge(1/2 amp)a 7.2 amp cell will take aprox. 14 hours to charge.(Is this right?)thanx again....c63

[Whoaru99]

Roughly, assuming it's completely discharged.

[MuskieJunkie]

How many years do you guys typically get out of a Gel Cell before you replace them?

[Whoaru99]

I've had my Vex for several years and was still using the original battery until last year. It didn't fail, per se, but had an unfortunate accident that resulted in it being lost, literally.

So, I can't say for sure, but five years does not sound too unreasonable to me - assuming good battery care/charging practices.

[JP Z]

First off, I would like to point out. That 90% of the batteries sold for Vexs, Aqua-Vu's and Marcums are SLA or Sealed Lead Acid. Very few are actually Gel-Cell. But with proper maintenance SLA's can last 10 years or more. But now with their relative inexpensiveness you can get a new one every 3-4 years and be set.

[chris63]

I will add another term or two here then.AGM stands for absorbed glass mat.(Mat that absorbes acid).Both AGM and Gelcell batteries are interchangeable and either can be used to replace the other.AGM are much more common for sealed lead acid batteries.Nearly all SLA batteries under 100Ah are AGM.c63