Battery Draw

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kartracer

Guru
Joined
Aug 5, 2014
Messages
529
Location
USA
Vessel Name
M/V LUNASEA
Vessel Make
45ft Bluewater Coastal
I have a electrical draw on one house battery or a bad battery, battery will be dead in about 4 days without charger on. Is there a way to check an see if there is a draw with an ohm meter before pulling everything out. :banghead:
 
Is the battery in a bank with other batteries?
 
Possibly there is a bilge pump connected directly to the battery and it is pumping.
 
Switch your panel to the other bank and then just disconnect it and check it in four days.
 
I'd kill to get 4 days from our house bank. I take it there is no ammeter on you panel to gauge house loads? Should be relatively easy to measure with a clamp meter. To test the batteries you'll need to bring them to full charge and then isolate them for 24 hours before you can test them. You might as well prepare for that and record daily voltage decay in the meantime. You might try and borrow a conductance analyzer from a battery shop if they are 8ds to avoid moving them.


Via iPhone.
 
Sometimes hidden DC loads: CO detectors, shower sumps (AC condensate), amplified UHF/VHF/TV antennas, etc.

-Chris
 
Charge it up , disconnect it and use a temp compensating Hydrometer to see if it has a dead cell.
 
Yes, easy. Get a cheap multimeter (less than $10 @ Harbor Freight and other places. Shut everything off. Put the meter on the 10A scale. With your battery switch off put the meter leads between one of the battery inputs and the output terminal of the switch. Read out the current draw of your parasitic load on the meter.
Now, assuming all your switches are off, start disconnecting items w/o switches (Example: wiper park circuit which should be fused but has no switch)
 
Charge it up , disconnect it and use a temp compensating Hydrometer to see if it has a dead cell.

Do this first before you spend time tracking down loads. If batteries are sealed, you will need a battery tester instead of a hydrometer. If it tests good, leave it disconnected overnight and test it again. If still OK, start tracking down loads.
 
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