Is it possible to maintain a battery indefinitely using a maintainer of some type? I bought a replacement battery for one that was getting weak, now the weak one won't die!

 

I'd just replace the battery now and not worry about when the older battery is going to die and leave you stranded somewhere remote. Protect the investment in the new battery by putting it into service as they are like avacodos, they don't get better sitting on the counter top.

Paul

 

Agreed. I would just replace it. It sounds like it's time. It's good preventive maintenance.

 

Charge the new one fully and install it. Go ahead and replace the old weak one, it may seem like it won't die but it will take a dump on you when you least expect it.


Since batteries are now sold ready to go, they don't really store well and their usable life starts as soon as they leave the manufacturing line. In the "ole days" when you bought a battery and had to put the acid/ water in the battery they could be stored for quite a while. But with most batteries now being sealed and technologies like absorbed glass mat it is not really possible for the consumer to store a battery and wait until needed to fill the battery up with acid.

And according to my local battery store the best way to extend battery life is to use it regularly and or at least monthly give the battery a full charge even if installed in a vehicle. I've been on that program for about two years now, so a little too early to tell if it extends battery life but I do feel that the batteries I've been doing it to have been holding up well and even after my truck and bike sit for a month while I'm gone for work they start right up with no signs of weakening.

 

Odd man Out...I do Not do Any Battery Maintenance...None!
I buy Inexpensive Batteries (agm), and they go 3 years...after that, they go into a non Critical environment...sometimes get another year..
Matters Not to me...I have My Program...Not like Most other folks...But, Works for Me.

 

To answer the question directly, yes a lead acid battery can be maintained almost indefinitely on a float charge if the electrolyte level is maintained. Large battery banks used for emergency back up in telecommunications have been doing it for decades so it is possible, but in your case it doesn't make much practical sense to do so and if it's a maintenance free sealed battery you won't be able to maintain the electrolyte level anyway. Just install the new one then charge up the old one once in a while and keep it in the shop to use as a 12 volt source for testing.