battery charging question

[stripernut]

ok right after you quit laughing at this stupid question.....
put a new deep cycle battery in this morning, been on the "on-board charger" all day and the charge light is still on. in the event the charger has gone bad i would like to unplug the "on-board" charger from the wall outlet ----hook up the portable charger for awhile and see what happens.

the question??? if the on board charger is not hooked to an electrical outlet can i hook the portable charger (alligator clips) to the battery wihtout taking the negative and postive leads of the on board charger off the battery ----without shorting something out in the battery or the on board charger.

thanks in advance

[Tyme2fish]

Well now, that is a puzzler. Never thought about it before. It's not that big of a chore to take off the on-board charger leads, so I'd take them off just to be safe.

[sweetwater]

It won't hurt it to leave the charger connected with another charger running on the battery terminals. Chargers have diodes that allow electricity to flow in only one direction. Without them the battery itself would kill the charger. Just make sure both chargers are not turned on at the same time. I've always hoped my classes in electronics engineering would come in handy for something.

[stripernut]

yep thats what im thinkin, the only problem is the positive lead is a #$%to get to, but as i typed this it just came to me....all i have to do is remove the negative lead ! DERRR um DUH

[stripernut]

sweetwater....great info! this really helps.
thanks a bunch

[Tyme2fish]

It shouldn't bother but the safe way to do it is to remove just one of the charger leads -- doesn't matter which.

[jrunger]

Hi,

I had a thought as I read your post and replies ----- is there any chance you connections are corroded and/or dirty? I've found over time that they get corroded and have impact on both charging and battery power to what ever being powered. Just a thought and possibly what is causing on-board charger to not charge the batteries. Might also be a good idea to check the water levels (distilled water if adding any). Good luck.

Jeff

[Duayne]

While it normally wouldn't be an issue to leave the on board plugged in, you might want to get it out of the way if you think it's bad. I recently saw an old dual pro charger than went bad and just having it plugged in would kill a battery in no time.

[HURRICANEBOB]

Something to thinks about.

Charger might not be bad. You know how it normally operates, but some after doing the relatively short term bulk charge, enter into a longer term trickle or maintenance charge cycle. I had a Batt Cat dual bank that did this. Sometimes, a down trolling motor on the charger had the light go out in 2-3 hours, other times, it stayed on for a day, then finally went off. In both cases the batteries were in about the same condition.

Some chargers are pretty sensitive, and just a partilly bad connects, with a little corrosion, can "trick the charger". Seems like the better the charger, more advanced they are, the more sensitive they can be.

Like women, smart but sensitive.

[stoner]

Is there any way of telling if a charger is bad? To the point of over charging and ruining the battery?

I plug mine in from time to time thru the off season to keep them topped off, but noticed the other day that after 24 hours of charge there were a few charge lights left still on.

Im sure my batteries are due to be replaced but dont want to fry a new set. Espeacilly cause im considering optima batteries this time around.

Any input is appreciated.

Stoner

[Duayne]

Is there any way of telling if a charger is bad? To the point of over charging and ruining the battery?

I plug mine in from time to time thru the off season to keep them topped off, but noticed the other day that after 24 hours of charge there were a few charge lights left still on.

Im sure my batteries are due to be replaced but dont want to fry a new set. Espeacilly cause im considering optima batteries this time around.

Any input is appreciated.

Stoner

I had one that caused the batteries to need water about every month and a half or so. I waited until I knew it had been fully charged for more than six hours and felt the batteries. They were still as warm as when doing a full charge so I disconnected and replaced it. Now that's my check when I can. My batteries are cool if the chargers have indicated a full charge for more than a few hours. I'm not around my boat for good stretches, so I try to get my batteries charged before I leave, then turn off the chargers. I'd be different of I could check it every week or so.

[stoner]

Thanks Duayne,

Ill keep an eye on battery temp the next time I charge.