Battery / Three Bank Charger Question???

[keeferfish]

I think one bank of my charger banks has quit charging. The starting battery and one of the trolling batteries charge fine but the other one don’t. The bad bank shows negative 1.46 volts but when I reverse polarity it shows positive 1.46 when the good banks both show over 12 volts. I assume the one bank is shot so my question is ------ can I just run a jumper from one of the good banks and let it charge both trolling motor batteries?

[Barnacle Bill]

Did you check the fuse on that lead?

[keeferfish]

each lead has a good fuse. Each wire (all 6) that goes to a terminal has a fuse and they all look good.

[wannabe fisherman]

each lead has a good fuse. Each wire (all 6) that goes to a terminal has a fuse and they all look good.

Fuses can LOOK good but not be put a continuity tester on each end of the fuses and check them manually. just a thought

[Hanr3]

Swap the suspected bad charger to a good battery, and put the charger from the good battery to where the bad charger was hooked up. In other words, are you sure its the charger and not the battery?

[keeferfish]

Fuses are fine, switched banks and both batteries are new, test fine and hold a charge. What I can’t figure out is why the one bank is showing a negative charge but when you reverse the positive and negative backward on the volt meter it shows a positive charge. It only shows about +/- 1.46 volts on the bad bank and the good side shows 10????

[Scrapper]

Moved this to electronics forum. Some pretty sharp cookies over here on electronics. Thought canepole and his crew could help you out!!

[Cane Pole]

How are you "reading" the charger output? At the battery terminals or the charger leads with the battery disconnected? What make charger? Some chargers will output a continuous voltage and some will not output unless it recognizes a connection to the battery.

[CatFan]

How are you "reading" the charger output? At the battery terminals or the charger leads with the battery disconnected? What make charger? Some chargers will output a continuous voltage and some will not output unless it recognizes a connection to the battery.

I think safety rules for onboard stuff require the output be clamped to 2V or less when not connected to a battery. 1.46V sounds awfully close to 2 diodes to ground, so it sounds like the charger is in safe mode thinking it is disconnected.

[Cane Pole]

I think safety rules for onboard stuff require the output be clamped to 2V or less when not connected to a battery. 1.46V sounds awfully close to 2 diodes to ground, so it sounds like the charger is in safe mode thinking it is disconnected.

I understand. My old quest puts out 12v continuous, but it is 20 years old.