Equalization cycle

[SeaBreeze]

My 2003 Charles charger doesn't have an equalization cycle. I'm thinking of purchasing a regulated and adjustable DC power supply to accomplish the task. My last boat had a charger with equalization cycle so I understand how it works and what to do in terms of setting the power supply outputs, monitoring the battery throughout the day and safety precautions. Does anyone have thoughts or suggestions?
Rick Parish
Sea Breeze
#78

[wolfe10]

I just use a cheap Sears 6 amp (automatic, NOT) charger.

Start with the batteries fully charged by your main charger.

Connect this one-- max charge rate is 6 amps, but it will quickly drop to less than half that. BUT, the important thing as far as equalization goes, voltage will continue to rise. I record voltage every half hour-- when it is no longer rising it is finished. Can take from 1 hour to 5 hours depending on size of battery bank and amount of sulfation.

Another way to monitor is with a battery hydrometer. When all cells read the same/high SG, you are done.

Brett

[SeaBreeze]

Thanks Bret. I was planning to monitor sg every hour until close to 1.265 then more frequently until each cell hits that number. Monitoring voltage would not be as messy. If I can ask some questions -
1. what ah rating are the batteries you are equalizing
2. what is the voltage reading when you see no more voltage rise
3. are you measuring that voltage with charger on or disconnected each time you take a voltage reading

[MorningStar]

Great info as I still use the lead acid batteries. What does "NOT" stand for in reference to a simple automatic charger?
s/v Morning Star #35
Kemah, TX

[SeaBreeze]

Charles help desk says they do have an equalization function that is activated by turning off power to the charger, then turning power back on. According to the help desk this forces the charger to supply 14.1 - 14.5 vdc for about 4 hours then go to float mode. If more time is needed to bring sg up to 1.265 repeat the procedure by turning the charger off, then back on. (I haven't verified this using my charger)
Rick

[wolfe10]

OK, NOT means that their "automatic battery charger is NOT automatic-- but will continue to let voltage rise to over 16 VDC.

As far as size of battery banks I have equalized this way, spans the range from a pair of golf cart batteries (220 ah @ 12 VDC) to 3 8D's (660 ah @ 12 VDC). Again once fully charged, the amps really is not that important, as long is it will drive voltage up to where the batteries equalize.

Voltage when you see no more rise really depends on battery bank size, whether you start fully charged and probably the most important, how sulfated the batteries are. I have seen it as low as 15.2 and as high as mid 16's.

Measure voltage with charger still on. It could be done the other way, but just more work (with no better information resulting). Again, with wet cell batteries, SG is most accurate, but you will find that SG and "no more increase in voltage) really happen about the same time. We are not talking about a precise "science". With my 6 amp charger, charge rate is down to around 2 amps (into a pair of golf cart batteries). So no "if I don't turn it off at exactly the right time bad things will happen".

Oh, and to protect sensitive electrical systems, best to disconnect the batteries from the house when doing this. Some PC boards do not play nice with 15+ VDC.

And, if you need to add water to the batteries, best to do it before fully charging. So fill (do NOT overfill), fully charge and then start equalization. That way all the "fluid" will be stirred up. In fact, just did this with the batteries in our motorhome (6 golf cart batteries= 660 ah at 12 VDC).