Vex/Gel-cel Batteries

[Phred52]

After reading the post by nluchau (12/28). I took a sidebar line of thinking, regarding the recharging of these batteries. WHY do they come with a 500mA charger? It's a 7, 8 or 9 amp battery, why can't they be recharged with a 2 amp automatic battery charger (aka, trickle charger)?? Are these batteries not capable of taking on a charge that quick? Sure would shorten charging time! I know I wouldn't wanna put it on a "non" automatic charger, don't need it fried, but why wouldn't it work??? I've also heard, a LONG time ago, that you should replace the battery charge about as quickly as you used it. Maybe there's something to that. Come-on battery guys, What do you think????

[Eric Wettschreck]

I use a trickle charger on mine. I have, however noticed that the battery only lasts a couple of years. This very well could be due to the fact I'm using a trickle charger. I figure for only about 10 bucks at Fleet Farm a couple years life is not worth squaking about.

[swalleyi]

10 bucks at fleet farm? give 5 of them. I'll have 3 charged batterys with me every day. I don't no i got a gel battery with my marcum and it never kept a charge very long. Bad battry or thats the way they are,i don't no. i always use the 1 amp charger.

[Whoaru99]

No battery expert here, but I have done a bunch of reading on batteries.

My .02 is that higher rate chargers with gel-cels damages them because the gel electrolyte cannot release the gas generated during charging as quickly as a liquid electrolyte in a standard battery. Therefore, they require a much lower charge rate - hence the 500ma chargers.

Also, gel-cels normally have a slightly lower charge voltage requirement(preference?). Most "normal" chargers apply too much voltage that can also damage the battery. Overcharging creates "holes" in the gel electrolyte that don't heal and causes reduced capacity.

I'd say 1 amp on this size battery is about the max you'd want to go and it's probably on the high side too. Some reading I've done says that gels should be charged at rougly 5%-10% of their amp-hour rating.

[nluchau]

Vexilar told me that you need to charge the battery for 2-3 hours for every 1 hour of use. At Gander Mtn. this morning I saw they have a charger that plugged into a cigarette lighter. Dont know how fast it would charge the battery though.

[Giant_Jackpot]

Phred,

Whoareu99 is correct. I used to work for a place that made battery chargers for these types of batteries and I can say his info is good. See below for some general care info on these types of batteries. Boilerguy mentions that his battery is only lasting a couple of years. My guess is that he is leaving the trickle charger on too long and cooking the batteries. You should be able to get 4 years easy if you take care of them. But at $10 bucks each not a huge deal……

First of all, the batteries are sealed lead acid and just like the battery in your car, they like to be charged. Charge the battery after each use and you can get them to last 4 or more years. The worst thing you can do to a lead acid battery is run it down and not charge it as soon as possible. Also charge the battery every month or so during the off season.

With that said, the cheap chargers that come with these batteries will cook the battery and shorten its life if you leave charger on the battery for extended periods. If you really want to take care of the battery, connect a voltmeter to the battery during charging. When the battery reaches about 14.8 volts disconnect the charger. Otherwise don’t leave the charger connected for more than 24 hours (unless the charger is a smart charger).

The smart chargers are a good idea if they are doing the right thing. They should charge the battery to about 14.8 volts and then drop into a maintenance or float mode at about 13.2 volts. These are available at Gander and Cabela’s.

As far as the LED battery indicators go, don’t believe everything you see. The components used in an inexpensive device like this can have tolerance swings of up to 20%. On a properly charged battery, one indicator may read fully charged while another might say ¾. Just something to keep in mind.

[harvey lee]

When I charge my vex battery, I only use the charger that came with it and after 5 years the battery that came with my vex is still doing great. I charge it right away when I get home and then a couple times in the off season and who knows how long this battery will last. To big of a charger will take the life right out of your battery and then off to the store for another one.

[Guest]

I am using a 1.25 amp charger(automatic) for my 7 ah battery. I havent had any problems with it, or any batteries fried yet.

It states on the charger not to use that charger on any battery larger than 20Ah due to heat building up.. are they talking about in the battery or the charger?

I also have a 37.5 Ah battery (Gel Cel) that I use for extended trips for lights and other gadgets. Its coincidence we have electronics here that use these batteries and have a built in charger for these batteries that will max out at about 8 amps, but runs the average of about 4 during normal charge(not a completely dead battery).

Anyway, when I put this battery on a 10 amp automatic charger(with guage) it always seem to draw about 4.5 amps at the height of the charge, and slows down as the battery gets close to full charge.

Taking this into consideration, 1.25 amps does not *seem* like an excessive charge rate for a 7 amp battery.. unless the smaller battery doesnt have the tolerance of the larger battery.

I guess I will find out in the long run. Neither battery ever generates any heat while charging.

For anyone curious where to get the 1.25 automatic(Gel Cell) battery chargers... the have them at Ax-Man surplus in St Louis park for $12.50(new).

[Whoaru99]

In all honesty, I have the 1.25A charger from Ax Man too. It seems to work just fine as you say, but I'm using a 12Ah battery mostly, but I have charged 7Ah with it. So far, things seem OK, but time will tell by how long they last...

Just because I know the "rules" doesn't mean I necessarily follow them to the letter.

Probably the reason the 1.25A charger does OK is because it is a dedicated gel-cell charger with the right voltage/charge profile.

[Whoaru99]

Quote:

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It states on the charger not to use that charger on any battery larger than 20Ah due to heat building up.. are they talking about in the battery or the charger?

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About the charger, I think.

[Phred52]

Thanks guys, This site is a veritable font of information! I have been using the 500mA charger that came with my battery, I was just curious WHY a charger with a greater amp output couldn't be used thus shortening recharge time. I'm glad I asked before I tried it (and FRIED it!) Thanks again. Phred52