By: Mike Cecchini
Optimate Battery Charger
It goes through about 5-6 different cycles to monitor how the battery acts on and off the charging. I will say that it can be "fooled" by a really low battery and it will say that the battery is "no good" (red light). I then break out a manual (non-automatic) charger and give it a 2-5 amp charge for about an hour. Then the opitmate will say: "Ok...........I can do this". 12-15 hrs later the battery is fully charged.
You guys got to get a "feel" for a battery when it's charging. It's not as cut and dry as you might think. You need to monitor the "amps" the battery is taking and how it's taking the amps. A low battery can take an itinital charge and come up to aboaut 70% done and then just sit ther for 20-30 hrs and cook it's self to death. So when I charge a low battery (without a ampmeter on the charger) I hook one up and see what it is doing. The big clue is when the amps don't go down (as normal). Then I let the battery sit for 3-10 hrs and just "settle". Then I come back with the auto charger and ampmeter and hit it again.
All of this is done remembering that a battery likes a 10% charge rate. If it's a 18 amp/hour batter (our ducks) then I charge it at>1.8 amps. 700 amp/hr batteries (my van) get charged with 70 amps..........and so on. All of this, again, is charging. Maintenance charges are MUCH lower. 1-2 amps is fine for small batteries (remembering the 10% rule) and is even used for the biggest of batteries. I do a maintenance charges of everything I have........once a month......overnight.
I realize that I have a garage senario that lets me pull my stuff up to the door and put thd charger on it ....and I go to bed. Next morn my stuff is jumpin' right. Full 13.8 volts. Batteries love it and last a long time (8-10 yrs.) So..............after say ing all that. Get a small (.25-10 amp) automatic charger that has a ampmeter on the front of it. Use it and pay attention to what it's doing. That way you'll get a feel for what it's doing and you can make judgements. Radio shack has great small digital voltmeters for $10-20 that will geive you years of service.
A battery below 12.80 volts needs to be maintence charged. Below 12.5 volts it needs a real charge. A battery full charge and ready to rock is in the 13.5-14.0 volts. That's what works for me.