equalizing voltages

Nov 26, 2008
1,970
Endeavour 42 Cruisin
My 900 amp/hr house bank has been staying around 1.275 SG pretty well, until recently. We've been sitting on a mooring and using a lot of juice lately. SG dropped to 1.17 even with voltages in the hi 12's.
Time to equalize with my zantrax truecharge 40+. Over a 7 hour period, SG rose to 1.25 on most cells with a few at 1.26 and a few at 1.24.
The mystery to me is that voltage on the victron never exceeded 14.15. The truecharge equalization charge is allegedly 16 volts. I number dropped to about 20.
As soon as I exited eq, voltage dropped to 13.8 and I dropped to 10 amps.

Why did I never get above 14.15 volts on eq over 7 hours?

Thnx
 
Nov 26, 2008
1,970
Endeavour 42 Cruisin
Interesting that overnight, SG drifted up to about 1.265. Still not up to the old 1.275.
Considering another EQ cycle.
 
Nov 26, 2008
1,970
Endeavour 42 Cruisin
I've kept draw to a minimum by using the engine drive for refrigeration. Solar and alternator have kept the voltage up in the hi 12s to hi 13s.
Specific gravity is holding at 1.265, below our previous norm of 1.275.

Should I run equalization again after the 7 hours I did 2 days ago?
 
Feb 6, 1998
11,709
Canadian Sailcraft 36T Casco Bay, ME
Need to know what the terminal voltage at the batteries got to as measured with a DVM...

A 40A charger on a 900Ah bank is going to take numerous charge cycles to fully charge as it may time out on absorption and go to float before the bank is really full..

Also many chargers will not enter equalization mode until a full absorption cycle has been completed.
 
Nov 26, 2008
1,970
Endeavour 42 Cruisin
Need to know what the terminal voltage at the batteries got to as measured with a DVM...
At what point? At the end of equalization it was 14.15 on the victron but I didnt read dirwct with meter.
Tomorrow I can take a direct reading at the terminals with a corresponding sg. But you know, this won't be a resting voltage reading.
 
Feb 6, 1998
11,709
Canadian Sailcraft 36T Casco Bay, ME
At what point? At the end of equalization it was 14.15 on the victron but I didnt read dirwct with meter.
Tomorrow I can take a direct reading at the terminals with a corresponding sg. But you know, this won't be a resting voltage reading.
I am looking for a voltage reading, at the batteries, with a DVM, during equalization. Also what is the current the charger is delivering during EQ..
 
Nov 26, 2008
1,970
Endeavour 42 Cruisin
Haven't had the opportunity to fully charge and run another eq yet.
But here are some numbers that may or may not be helpful. We got pretty full today so I checked the numbers...
This is not in an eq cycle, just running a 40 amp Truecharge charger off the honda

Voltage at the batteries 13.38 (13.41 on the victron)
Specific gravity. 1255
I number reading on the victron, only 10 to 12 amps
 
Feb 6, 1998
11,709
Canadian Sailcraft 36T Casco Bay, ME
Haven't had the opportunity to fully charge and run another eq yet.
But here are some numbers that may or may not be helpful. We got pretty full today so I checked the numbers...
This is not in an eq cycle, just running a 40 amp Truecharge charger off the honda

Voltage at the batteries 13.38 (13.41 on the victron)
Specific gravity. 1255
I number reading on the victron, only 10 to 12 amps
Was the charger in float or absorption?
 
Nov 26, 2008
1,970
Endeavour 42 Cruisin
Not what you asked for but...

With the new 100w solar panels now running, the wind gen stopped with wind blowing 25 k. Victron says 14.1 v and specific gravity is back up to around 1270 and the I number is only around 10 amps in full noonday sun, which is less than half of capability. Since sg is looking back to normal, do I still need to consider another eq cycle?