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Post by sabmd42 on Mar 18, 2019 1:59:11 GMT
I am getting the boat ready to go in the water for the season. I have been keeping my batteries in my garage and trickle charging them every month. They are lead acid batteries, 3 house batteries at 105 amp hours each. They are 2 years old. On a whim, I checked the voltage on them after I had charged them a few days ago. I haven't done this before. I usually just charge them, add distilled water if needed, and put them back in the boat. They measured 12.8, 12.9 and 10.6. I charged the one that measured 10.6 again, and it charged to 12.08, then immediately started dropping voltage, back down to 10.6. The meter on the charger indicated that it was fully charged. My questions are: What would have happened to the electrical system on the boat if I hadn't checked the voltage and found a bad battery? Do you normally check the voltage on each battery periodically? Is there some other way I would have known that a battery was bad?
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Post by Trevor on Mar 18, 2019 7:05:13 GMT
Hello sabmd42,
You have an interesting problem. Batteries that are 2 years old are pretty young so it looks like you have one that has failed so you either replace all of the batteries and start again or replace one and accept that the battery bank has batteries at various stages of their life.
The failed battery would manifest as a reduced house battery capacity when you go sailing. You would have flatter house batteries faster and you would have to recharge your batteries at earlier intervals than if all three batteries were in good condition.
I'm not sure how others monitor their system but I have never measured the individual battery voltages. I do have some expectation of our house battery capacity and would know if these batteries lost capacity compared to previous seasons. I have had exceptional service life from our house battery bank so when I notice they are no longer maintaining charge I will simply replace the battery bank.
Regards,
Trevor
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Post by Fabrice-Erta on Mar 18, 2019 10:59:32 GMT
Hello sabmd42 Could you detail how you are charging the battery ? I assume that in the garage you are using a battery charger and swap them one after one. The charger should not be involved ( at this stage) as it is used for all the bank. It happens that battery fails so short. May be they are not from the same built in date even if bought together. You can check with usbattery.com/wp-content/uploads/2014/12/2015_US-Battery-Date-Codes-2.pdfDo not worry of the impact of such a battery failure on the electrical systems, this is similar as if your car went off gazoline. The system balance the load on the others, having them more solicited. May be you can also consider that it is still under warranty. Some are 5 years in France Fabrice |
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Post by zaphod on Mar 19, 2019 6:43:50 GMT
I dont think you need to replace the whole battery bank, just the defective battery. It is likely just a bad cell, in which case it wouldn't contribute anything to the bank. Worst case, (less likely) scenario is if it has an internal short causing it to discharge, which could also discharge the rest of the bank.
You should definitely find out if it is under warranty, it should not have failed after just 2 years.
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Post by sabmd42 on Mar 20, 2019 2:26:31 GMT
The battery is not under warranty. It was only a 1 year warranty. I replaced it with a new one and will combine it with the 2 other 2 year old batteries. We'll see how it goes. The battery guy suggested that I get a load tester and test them each year before putting them in service.
Steve
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Post by Trevor on Mar 20, 2019 23:59:53 GMT
Hahaha...It sounds like he sells load testers!
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Post by zaphod on Mar 21, 2019 1:15:30 GMT
Hahaha...It sounds like he sells load testers! Yeah no kidding! Your voltage test method is just fine. It will tell you if a battery has a bad cell. Down the road if you find they just dont seem to be lasting as long as they used to, you can get them load tested at any garage or battery shop. No need to buy your own load tester! |
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