Reusing older Lifeline batteries

[cardude01]

I recently replaced my 4 Lifeline 125ah AGM batteries in the house bank with new ones. They were 7 years old and had been pretty severely discharged when my boat got caught in Dorian in the Bahamas 2.5 years ago. My 12v bow thruster is hooked up to this house bank and on our last trip the thruster would barely work.
Got the new batteries in and everything working well now.

I brought the old batteries back home thinking maybe I could use them for something, like on my electric boat for lights or maybe for a house bank for a solar project or something. When I tested them three of them were at 12.9 volts (after sitting uncharged for two weeks) and one was at 11.7 volts. I’m attempting to charge that discharged battery to see if will hold a charge, but I suspect it has a problem.

Lifeline has a method to bring back a sulfated battery, and I was wondering if anyone had tried that before with any success. Or should I try something else? I’m currently charging that discharged battery at 10 amps for 7 hours as recommended by Lifeline to see what happens. Maybe it will hold a charge?

 

[AKDoug]

I got a good six years out of mine, the process is called "equalizing" and many battery chargers have this function built into them. I have a friend who bought a new boat with old batteries and thought he could use my old ones, it didn't improve anything after equalizing.

I had never performed this function, just charged them regularly from the alternator with a smart charging system (Balmar). I could tell something was off with the batteries when my forced air heater showed "low voltage" after charging and would fault.

Good luck with that equalizing thing, maybe if it were performed more regularly it would have helped.

 

[Barking Sands]

That reconditioning method can work in a limited capacity...sometimes. On aircraft we do a full capacity test every 24 months. If the battery does not pass on the first round but is close we will do this reconditioning procedure and then redo the full cap check. You can gain back 10 to 25 % depending on the battery condition. But if the battery fails the cap check miserably we don't bother. If the battery is under warranty they will require a recondition procedure before the warranty is honored. For your battery I would bet it's too far gone. However what do you have to lose. It would be nice if you could do a capacity test of each battery before...then do the reconditioning procedure followed by a cap test after.

 

[cardude01]

That reconditioning method can work in a limited capacity...sometimes. On aircraft we do a full capacity test every 24 months. If the battery does not pass on the first round but is close we will do this reconditioning procedure and then redo the full cap check. You can gain back 10 to 25 % depending on the battery condition. But if the battery fails the cap check miserably we don't bother. If the battery is under warranty they will require a recondition procedure before the warranty is honored. For your battery I would bet it's too far gone. However what do you have to lose. It would be nice if you could do a capacity test of each battery before...then do the reconditioning procedure followed by a cap test after.

How do you do that capacity test?

 

[Barking Sands]

Funny. Your manual reference looked so familiar I was struck by the fact I knew exactly what they were referring too. The logo also looked familiar. The lifeline batteries are made by Concorde company. Same logo using a different word. Almost certainly very similar batteries. Concorde batteries have been the gold standard in aviation for 15-20 years or more. The manual you refer to is nearly identical to the concorde manual.

My only worry is if you are doing this procedure correctly. Its supposed to be a constant current. That means the voltage will vary (increase) with time as the batter is charged with a constant current. If you are using a manual power supply you will have to watch the amperage every so often...maybe every half hour and adjust the voltage in order to keep amperage constant. The voltage is likely to get pretty high. An automatic machine would be set up to maintain current and it will adjust voltage to maintain current.

If you are able to recover the battery to some degree. Then try the previous procedure 5.5

To do a cap check you need some equipment. There are all in one units that you simply set the parameters into and it runs the test. But you can cobble together a few items that you can do a basic test. It is described in your references. You can check youtube and ill bet someone has a low cost rig in a video.

 

[cardude01]

Yeah Lifelines made by Concord.

I have not tried to do the equalizing thing yet. I don’t have a charger big enough to do that. I think the manual says I need 25 amps minimum, and like you say it probably needs to be variable so I can keep turning it up. Need something like this maybe
https://mastechpowersupply.com/volt...10a-over-voltage-over-current-protection.html

I had the one suspect battery on my little 10 amp old school non-automatic charger for 8 hours yesterday and it only brought it up to 12.7 volts. So I wonder if it’s toast.