24V high Amp draw when attempting to charge Bj45 (1 Viewer)

greenbeast

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While I was out of town the wife reported that the Bj45 wouldn't start and sounded if batteries were the cause. Today I got chance to look at it and definitely had low voltage when key turned on. Glow plug light barely came on and no enough juice to crank starter.

Threw the Charger on it (large box type with 24V option) done it before and everything worked well. Immediately when turning on timer the Amperage flew past 60 amps and nothing noted on the Voltmeter.

What in the heck can cause something to pull this many amps? Gonna pull fuses shortly and see what goes on. IT does have electric PS but 20 amp inline fuse is fine.

Talked to mdkaboom and he says batteries possibly replaced in 2012-2013 but would bad cell even cause this?

Can a starter that's going bad cause this?
 
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Try disconnecting your batteries from everything, then connect the charger to one at a time. A fully dishcarged battery could easily pull 60 amps at the start of the charge (depending on your charger), so I would recommend setting your charger to the smallest setting (trickle charge) to prevent battery exploding.

On the cause - a bad ground is most likely - but even a very small discharge (light a light) - will, over time, kill the most robust battery.
 

greenbeast

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Sep 21, 2009
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Try disconnecting your batteries from everything, then connect the charger to one at a time. A fully dishcarged battery could easily pull 60 amps at the start of the charge (depending on your charger), so I would recommend setting your charger to the smallest setting (trickle charge) to prevent battery exploding.

On the cause - a bad ground is most likely - but even a very small discharge (light a light) - will, over time, kill the most robust battery.

Thanks for help!!
I replaced both batteries with those damn expensive Optima's and once the temp warmed up enough I was able to start Blue.
Appreciate the help. Lesson learned for sure!
Cheers
 
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Columbia, SC
Try disconnecting your batteries from everything, then connect the charger to one at a time. A fully dishcarged battery could easily pull 60 amps at the start of the charge (depending on your charger), so I would recommend setting your charger to the smallest setting (trickle charge) to prevent battery exploding.

On the cause - a bad ground is most likely - but even a very small discharge (light a light) - will, over time, kill the most robust battery.

I've had a similar issue that eventually lead to the system not charging at all.

Early on, the batteries would grow week over a two month period. I'd have to swap them with spares and charge the originals. Amp Gauge would read positive. The frequency of this picked up eventually getting to every two weeks. During all of this, my Amp gauge read that it was charging with and without headlights being on. Eventually, it would read dead even when the lights were on. It took some time to notice, since I don't drive my BJ40 B much at night.

Then one day, I noticed it would read dead-center with the lights off. Pull the headlight switch, it dipped way down into the - side of the gauge. Naturally, that killed the batteries quick. I tested the voltage output at the battery terminals, and it was barely 24v using a voltmeter. Knowing it should be higher, I pulled the alternator and had a local shop "rebuild it." I'm not confident in their job, however, the output did go up by .3. That's it.

I've chased the wires, run continuity, and tried all I know to do. Truth be told, I'm not much with electrical systems. Like the OP, a fresh charge brings it back to life. Amp shows good, then it drops fast. Could it be that I need new batteries after the rebuild? OR should my alternator be reading 27-29v no matter what the batteries themselves are reading? Could the ground be the major issue as in this case posted here?
 

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