Re: [Amel Yacht Owners] Wet Cell Batteries

Dan Carlson

"End of life" of lead acid batts is a good question.  I would think that it is some relation to the banks ability meet your daily energy needs.  Perhaps getting thru the night and still being at a 50% state of charge in the am would be one value? Or some other value based on personal comfort (i.e.are you close to marinas and services or are you heading fare off shore...).    I think that with your solar capacity and generator, you can push your batteries close to that before replacing.  You can estimate state of charge in the morning before the sun gets up by the bank voltage. You can corroborate this periodically with SG measurements.

I monitor my batteries pretty much daily now by checking the bank voltage at 6:30am (before getting solar input), and noting the current load and my overnight consumption  (amp/hrs on the meter).  

I think another good question is battery bank capacity.  Our SM's were sizes up with 12 batteries when the extra freezer was added, and that was before solar. With significant solar charging throughout the day, do we really need 630 amp/hrs when you are using less than 10% overnight?  So based on this you can afford to remove a pair or two of bad batteries before you would need to replace the rest of your bank.

Sorry for the delayed response. We are off sailing.

Best regards, Dan and Lori Carlson on sv BeBe, SM#387. 

On Fri, Feb 2, 2018 at 1:39 PM, sailor63109@... [amelyachtowners]


Thanks for the informative reply.  

I had tried to upload a spreadsheet with our SG readings in it, but Yahoo was acting up.  I tried again in this reply, but it won't upload the attachment.  The average SG was 1.226 with a low cell of 1.215 and a high cell of 1.445.  

I think I'm probably going to have to remove the pair that has the low SG reading battery in it from the wiring.  I won't pull the batteries out of the box since they make for a nice tight fit.

The batteries were new in August of 2016, so they're less than two years old.  The next time I replace the batteries, I'm going to replace the charger as well.  Having a charger that will equalize the batteries, and has adjustable charging voltages, only makes sense.  The cost of the battery charger is about equal to new batteries so it's an investment, but we plan to keep the boat a few more years.

I'm still wondering when you replace the entire suite of batteries?  The lower limit of the "fair" range on my SG tester is 1.210 so I guess that's the trigger for replacement?

Replacing the charger with a charger/inverter, the inverter will be a boon for AC for the microwave and outlets (i.e. popcorn and computer charging anytime you want to!).  I don't expect my third Xantrex Prosine 1800 watt inverter to last any longer than the first two did (replaced sequentially under a two year warranty).

Thanks again,

Wanderer, SM#477

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