Helppppppp Papajohn or anyone please

Ok not major problem but......

My batteries charge on solar or hook up to 14.3 amp.
When off hook up they slowly run down at what i would think at a normal rate.
Till they get to 12.8 then they suddenly crash to 11.1!!!!
I presume i need new batteries?

 

Yes!

 

yep

 

Thought so, just checking!

 

sounds like you have more than one battery, my bet is one has failed, you probably only need to identify and replace that one

I know this because I bought 2 for mine, then found I only needed one

I was amazed that one failed battery can so badly affect the total voltage

 

Yep I have two 100amp batts.

 

How do you find out if it's just one that's failing and which one?

 

turn off the charger, disconnect batteries from each other then check the voltage with a meter

or you could use your controller for an indication of voltage if you don't have a meter, just connect one at a time

 

As they are both the same age I will replace them both so as not to end up in the same situation further down the road.
But thank you!

 

mine are gel batteries and over £200 each, one would have done nicely at the time

but at least they are both guaranteed now

 

That is the best plan..

ideally, batteries or cells in banks should be

* same make
* same capacity
* same age

The pedantic will even try to buy with consecutive serial numbers so they are as near identical as possible..