Rewiring a small 48 VDC pack

[HBB]

Hello,
I have a small 4 element Trojan 12 V @ 105 A-h bank.
It is wired with 100 mm2 copper wire soldered to good terminals.
It has been in service for 15 months with no problem.
Since a couple of months we notice frequently HVD (high voltage Disconnect) contition fired up by the MorningStar PWM regulator.
Seems to be that a contact opens in one battery.

I have also noticed that one positive battery terminal, instead of being dry and light gray color, is dark and seems humid.
There are also small signs of corrosion in that terminal.
I cannot imagine how acid could be present well up of the max level it has inside the battery.

There is not sign of corrosion on other terminals (the ones that are light grey color and dry)

Electric behavior of batteries is normal.

When this happens, I stop completely the system, clean up all the 8 terminals and restart the system.

What can I do ?

Do you need pics of the terminals ?

Thanks for your help,
Horacio

[inetdog]

Hello,
I have a small 4 element Trojan 12 V @ 105 A-h bank.
It is wired with 100 mm2 copper wire soldered to good terminals.
It has been in service for 15 months with no problem.
Since a couple of months we notice frequently HVD (high voltage Disconnect) contition fired up by the MorningStar PWM regulator.
Seems to be that a contact opens in one battery.

I have also noticed that one positive battery terminal, instead of being dry and light gray color, is dark and seems humid.
There are also small signs of corrosion in that terminal.
I cannot imagine how acid could be present well up of the max level it has inside the battery.

There is not sign of corrosion on other terminals (the ones that are light grey color and dry)

Electric behavior of batteries is normal.

When this happens, I stop completely the system, clean up all the 8 terminals and restart the system.

What can I do ?

Do you need pics of the terminals ?

Thanks for your help,
Horacio

If the moisture is not coming from spray from one of the filler caps when the battery is charging, it might be the result of a leak in the plastic battery case around the post. That could be drawing electrolyte up from the lower liquid level inside the battery.
Check the fluid level in all of the cells to see if the one nearest the wet terminal is using water faster.

[HBB]

If the moisture is not coming from spray from one of the filler caps when the battery is charging, it might be the result of a leak in the plastic battery case around the post. That could be drawing electrolyte up from the lower liquid level inside the battery.
Check the fluid level in all of the cells to see if the one nearest the wet terminal is using water faster.

I check often electrolyte levels in all 24 cells and find it normal.
The filler caps are rectangular plastics that covers three cells each.
There is no way (I Think) to spray out electrolyte.

Very strange.

I will clean up again all the top of the 4 batteries.
Only two of them have this behavior.

Any ideas to perform an efficient cleaning ?

Thanks again,
Horacio

[inetdog]

Any ideas to perform an efficient cleaning ?

Thanks again,
Horacio

Clear water for the most part, nylon or other non-metallic brush.
Use baking soda if there seems to be some crud retaining acid.
Don't get the baking soda solution into the cells.
Wear waterproof gloves. Acid resistant (nitrile) is nice but not critical.