A few months ago we started having some battery issues. Specifically, we no longer had anywhere near the capacity we should have. Our battery bank is rated at 465Ah, but we were only getting about 50. We’ve been working with Firefly directly as well as through their distributors and I’m happy to say that we have installed 4 brand new batteries. Oh, and as Brent informed me of the delivery he had just had a call from the other boat he ordered and installed batteries for at the same time as ours. Guess what? His 8 batteries are doing the exact same thing ours were.
I started testing these batteries immediately. Once installed I charged the batteries to capacity, then shut off the charger. This was Tuesday evening. Wednesday morning, everything looked great so I took another step and turned off all AC-In. This made the boat completely self reliant on the batteries. Both Shannon and I ran our computers for work all day, and we didn’t try and conserve anything. By the evening when the sun went down things were still holding strong. so the test continued.
Its Thursday now and were reading 28%. The batteries are still holding strong at 11.8v. That’s lower than I would take them in normal circumstances, but were trying to test capacity here, and I’m following instructions from Firefly to do a complete “restore charge” right away. This means running them down to dead at 10.5v. We work another full work day with everything running. Nearing the end of the day, were still holding steady at 11.3v. I don’t want the batteries to go dead in the middle of the night when I cant charge them immediately, so I take the step to shut off the solar charger as well. Now were pulling 40-45Amps and and down under 10%. It takes until 10PM before they finally quit.
Final capacity reading of 501Ah. That’s nearly 8% more than rated! Now comes the long term testing. The old batteries only seemed to fail after about 8-9 months. They are expected to last 10 years.
Thanks to Firefly and Brent for getting things done!
Any information from the manufacture as to what was wrong with that batch of batteries?
No word, but they want these back to test them. I hope I hear from them, but I doubt I will. They read me the original test results of my batteries when I talked to them, but nothing out of spec there.
Sorry to hear about your battery issues. We’ve had ours going on 3 years now and have not had any problems of the sort.
I noticed in one photo (you can only see part of your bank) that you had an extremely short jumper from one battery to another, but then a much longer cable going to another 2 batteries maybe?
Granted I have no idea what your wiring schematic looks like, but that was a red flag for me. I can’t say that it would cause ALL of the issues that you’re seeing. But if you’ve got your bank wired in series, i.e. 4 batteries in a 12v bank, that wiring set up is definitely not helping.
It’s really important to balance your bank and to ensure that each battery in the bank has the same resistance between them. Otherwise you’ll be drawing down one battery more than another, and over time, it will cause all sorts of issues. This is a fantastic resource on this topic: http://www.smartgauge.co.uk/batt_con.html
If I’ve mistaken your wiring setup, and you know all this please carry on and good luck. Cheers
Hi Kirk, we were paying a lot of attention to cable lengths and runs when we put it all together. In a perfect world we could have had everything matching, but due to the space restrictions and where we can run the cables,and place the batteries we had to have some differences. We did over guage the cables so that the length losses and differences would be minimised. Also the picture may be of an incomplete installation.
Though, in the end Firefly came through with replacements, and they’ve performed perfectly so far. Also, it turns out the other 8 batteries that were ordered and installed on another boat at the same time as mine are showing the same issues.