Question about my battery tender and optima

[EScanlon]

Although the FAQ, Manual and other tech instructions for this particular charger read that it will CHARGE your battery... I agree with Bart. I just don't think a small transformer plugged into your wall, similar to a radio power supply will have the strength to fully charge a car's battery.

Use a proper charger and top off your battery, THEN use the trickle charger.

2¢

E

[Travel'n Man]

I can understand a trickle or a tender change in winter but come on guys - its the middle of summer..........

[Unkle]

''Float mode'' sees no voltage go through to make it warm to the touch !

You should disconnect the positive lead wire when maintaining your battery

with this type of charger . Generally these small charger/maintainers are

meant for low amp, motorcycle batteries , not optimas . Maybe get a better,

larger spec unit . Spend the money , don't expect a 30.00 unit to do anything

miraculous for you !

[Mikes Z car]

Been following this thread, just remembered that in solar battery systems there is a periodical equalization charge done so that the battery is briefly overcharged as sometimes one cell in the series doesn't charge as fast as the other ones. The charger I left on my Z all winter is a ProXone model 610004 dual rate which doesn't boil out the battery like the cheapie one I had. I guess the proXone works like the battery tender.

Edited July 24, 2010 by Mikes Z car

[sblake01]

.....don't expect a 30.00 unit to do anything

miraculous for you !

Good point. He's talking about the 'Junior' (.75A) and that may be the problem. I have the 'Plus' (1.25A) and have never been throught that with an Optima or any other batteries I've used it on.

[Zedyone_kenobi]

''Float mode'' sees no voltage go through to make it warm to the touch !

You should disconnect the positive lead wire when maintaining your battery

with this type of charger . Generally these small charger/maintainers are

meant for low amp, motorcycle batteries , not optimas . Maybe get a better,

larger spec unit . Spend the money , don't expect a 30.00 unit to do anything

miraculous for you !

That is a good enough point. I may have to invest in something more meaty.

[mlc240z]

I picked up the Battery Tender Plus at Amazon for $46/free shipping.

[MikeW]

I have a 6 Amp charger if needed. However, I'm convinced I killed my previous battery by letting it go dead multiple times. I'd want to drive the car for the first time in months, find the battery dead, use the charger long enough to be able to crank it up, go for a long drive to charge the battery, and then repeat the whole process a few months later. It got to the point where the battery just wouldn't charge (although it was several years old at that point). Since I needed a new battery I went with the Optima after seeing good reviews of it on this site and got the tender to keep it charged. We're only talking about dealing with the small drain of the clock or any other small natural leaks. A milliamp tender is more than sufficient for that. It's not like I leave the headlights on by mistake and then want to use the tender to recharge it completely.

[Captain_Zeros]

I've got the "Junior" model myself and it's never done me wrong. It won't charge all the way up from a completely flat battery, it's not designed for that kind of amperage (It'll blink the red light at you for 'error'), however I found a little trick to jerry rig it into trying. If you throw a pair of jumper cables from a good battery to the dead one like you are gonna jump start it, then clip the battery tender to the dead battery, the microcontroller in the charger will see mean voltage between the two and start charging, then you can pull off the jumper cables and let it keep charging the dead battery. I wouldn't really suggest this on an extremely dead battery, but I did it anyways to no problems. I'd assume it's not that common of a problem to need to charge a battery when you have a good battery laying around and a pair of jumper cables... but... well.... my car doesn't run yet, not like I can start it up and let it charge off the alternator.

[sblake01]

I have a battery charger if I need charge a battery. The battery tender is simply to maintain an inactive battery. Even if you get the Junior to charge how long would it take at 3/4 of an amp?

[Carl Beck]

How old is your Optima? The actually have some good tech tip videos (specifically #3) that may help you recover yours.

I think MikeW gave you the best advice - go watch the video's. They are pretty good.. and they seem to answer your questions.

Is you Battery Tender AGM enabled?

FWIW,

Carl B.

[Captain_Zeros]

I've charged a flat battery (under 7 volts) using my trick to fully charged green light in under 24 hours with my Battery Tender Junior.