Quick Battery Question

Hey y'all,


I have a quick couple of questions about my batteries.

About three years ago now, I completely overhauled the battery system on Skinny Dippin' and used eight of your standard-issue Johnson Controls 6V - 220AH golf cart batteries. Since then, because of a myriad of reasons, we really haven't used the bank (and the boat for that matter) for its intended purpose and she has stayed plugged into shore power 95% on the time. When I did the overhaul, I used a Sterling 60A smart charger that does have float capabilities. After three years, what can I expect the condition of the batteries to be? Would it make sense to consider replacing them? Moreover, would a 24hr resting voltage test give me an idea of their life expectancy? If not, is there a test I could use?

Thanks.

If the charger was on most of the time and the batteries stayed pretty much fully charged, you can expect them to be almost like new. Good quality golf cart batteries are remarkably resilient. Lead Acid batteries die from either sulphation due to lack of being fully charged or from many drawdowns. There is no easy way to get a true idea of their capabilities except for running them in an extended draw down while monitoring the voltage and actual power removed.


Ken

If they are lead acid, first thing I would do is check the level of water in them as if you never checked in 3 years chances are they miss some.

L

Lou_tribal said:

If they are lead acid, first thing I would do is check the level of water in them...

Click to expand...

This ^^^^^


If the water level is good then the batteries are probably good. If the plates are exposed then the batteries may be toast.


A simple voltage check will not really tell you much about whether or not they have lost some (most?) of their capacity. For that you need to do a load test, and the easiest way to do that is with something like this...
https://tinyurl.com/y6dyj84e


Good luck!

Lou_tribal said:

If they are lead acid, first thing I would do is check the level of water in them as if you never checked in 3 years chances are they miss some.

L

Click to expand...

I said they were not used. I NEVER said they were ignored. I check the water regularly.

Check the specific gravity with a hydrometer. If they all read about the same, near 1270 they are probably good to go.

Thanks everybody.

And if you want good test, unplug and use them, check how long they can power you based on your load, easy way to see if they still can take the load.

L

Lou_tribal said:

And if you want good test, unplug and use them, check how long they can power you based on your load, easy way to see if they still can take the load.

L

Click to expand...

I used to do that a while back, but with 900ah, i have to take a few days off work to conduct a proper test. Inverter is still on the install list