BCDC 1240 LV overcharging battery maybe ???

[mole man Lurker Find all posts View Profile Close mole man]

hi all, i recently had installed a BCDC 1240lv dual battery system with a century marine pro 620 battery. it has been a disaster !!!!! since the installation it has boiled the battery 3 times sending acid over evrything !!! i rang redarc and they said to change the wiring configuration for the gel battery and it would lower the charge. they also said if its under the bonnet then it might be getting to hot from the engine and to insulate it.
So today i changed the wiring and put the battery back in and went for a drive for about a km, got home popped the bonnet and acid everywhere again!!!!!! i have tested the battery and its fine... the auto elec doesnt really know what is causing it (and pretty sure he doesnt care ) i need some answers but no one seems to know a solution.... if anyone knows anything about this your help would be awesome.. cheers mole

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

What voltage are you getting on the battery terminals when the aux is charging?

[mole man Lurker Find all posts View Profile Close mole man]

when it was wired for the lead acid battery it was between 14.5 to 14.8v
when i changed it to the gel wiring today it was 14.4v

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

A marine pro should be ok at 14.4V, I would let the battery rest for a couple of days and
then check the terminal voltage before starting the car, maybe the battery has a faulty
cell?

If not then monitor the voltage during charging and make sure it doesn't exceed 14.5V

The battery hasn't been overfilled by any chance?

[mole man Lurker Find all posts View Profile Close mole man]

i had the battery load tested and it came back in good condition. i have taken the battery out cause i dont want any more acid going over everything. can you get the marine deep cycles in a sealed case ??? the battery was brand new and we checked the levels and they were fine..

[QUICKY Senior Member Find all posts View Profile Close QUICKY]

I had a similar problem when I first installed my 1220 with a wet cell deep cycle battery. It kept boiling the battery and it turns out the battery was designed to charge at a lower rate then the 1220 put out. On a close look at the battery label we found a max charge rate voltage for the battery.Once we changed it to a gel battery rated to take the charge we had no more problems

[mole man Lurker Find all posts View Profile Close mole man]

thanks quicky i will read the battery and see what it says ..

the battery says maximum charge of 14.5v

[drivesafe Senior Member Find all posts View Profile Close drivesafe]

Hi mole man and the 14.5v limit is to stop excess gassing but the battery should not be "boiling" if it’s charge at 14.8v.

Have you got any loads connected to the auxiliary battery?

[mjrandom Out of control poster! Find all posts View Profile Close mjrandom]

I think Quicky has it. The DC DC charger can throw 40A at your auxiliary and I would think that is too much. Check the maximum charge that battery can accept. Voltage is ok.

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

Somethings wrong, marine pro's don't normally gas at 14.4V, mine has been charged via
a VSR with booster diode at 14.4V for 6 years with no problems, 14.4V is normal for a
standard alternator and that's what the battery is designed to be charged at and an alternator can supply a lot more than 40A if the battery wants it.

Only things that will cause excessive gassing are excessive voltage or very high under
bonnet temperatures.

I would put the battery on a charger at 14.4V and see what happens, you should only
see the occasional gas bubble in the electrolyte, if it freely gasses there is something wrong
with the battery.

I would also discharge the battery somewhat then take it for a drive and monitor the battery
voltage to make sure the charger is working correctly.

Just a thougth there's no chance the battery terminals are being shorted somehow though
I would have thought you would notice the results if this was occurring.

Leigh

[mole man Lurker Find all posts View Profile Close mole man]

hi drive safe, there are no loads connected to the battery.

[mole man Lurker Find all posts View Profile Close mole man]

hi mjrandom, i cant find anywhere the maximum charge for the battery where can i find this info ??

[mole man Lurker Find all posts View Profile Close mole man]

hi leigh, i have discharged the battery a couple of times and taken it for a drive for only a short distance and only about 10 minutes and popped the bonnet and there was acid everywhere. the first time while driving it was charging at 14.5v to 14.9v. i then changed the wiring and tried it again and was charging at 14.4v and the same thing happened..

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

moleman,

The marine pro is designed to be charged off an alternator, excessive current won't be the
issue, if the charger is only putting out 14.4V.

Leigh

[mole man Lurker Find all posts View Profile Close mole man]

so leigh do you think its the battery or the bcdc causing the problem ???