Mixing batteries

[Chalky]

Is it ok to mix battery types in a domestic bank? We've already had a thread about different AH ratings, but what about wet cell leisure batteries and AGMs? My concern is due to the different charge /discharge rates and also self discharge characteristics.

Edited January 23, 2011 by Chalky

[blackrose]

Is it ok to mix battery types in a domestic bank? We've already had a thread about different AH ratings, but what about wet cell leisure batteries and AGMs? My concern is due to the different charge /discharge rates and also self discharge characteristics.

 

You can't mix wet lead/acid & AGM batteries in the same bank because you wouldn't be able to set the charger for the correct voltage depending on the battery type. Unless of course you don't mind using the lower voltage setting on the charger, but that would mean you're not really charging the lead/acids properly and not getting the best from them.

 

Edit: I'm assuming that like most other sealed batteries AGMs charge at 14.4v max from most chargers rather than 14.8v like wet lead/acids?

Edited January 23, 2011 by blackrose

[Chalky]

My alternators charge at 14.4, there is no other charger

[blackrose]

My alternators charge at 14.4, there is no other charger

 

Then you might be ok - but wait for some other advice, I don't know about AGM batteries.

[Gibbo]

No you can't mix them. The terminal voltages are different so if you put AGMs with wet cells one will discharge into the other. They end up being at completely different states of charge.

[matty40s]

No you can't mix them. The terminal voltages are different so if you put AGMs with wet cells one will discharge into the other. They end up being at completely different states of charge.

 

 

bugger, that means I will have to take my one remaining good wet cell batt off my bank now..........

I thought I had finished in the batery bank area for a while since installing vince's 6 sealed gel batteries - mind you , it has made a massive difference to this winter.

[nb Innisfree]

No you can't mix them. The terminal voltages are different so if you put AGMs with wet cells one will discharge into the other. They end up being at completely different states of charge.

 

Unless you have two separate banks... no no, quick, my coat...

[Chalky]

No you can't mix them. The terminal voltages are different so if you put AGMs with wet cells one will discharge into the other. They end up being at completely different states of charge.

Thought that might be the case - more used to LiFe & LiPo.

[blackrose]

bugger, that means I will have to take my one remaining good wet cell batt off my bank now..........

I thought I had finished in the batery bank area for a while since installing vince's 6 sealed gel batteries - mind you , it has made a massive difference to this winter.

 

Why don't you use the wet lead/acid as a start battery by adding it to your existing start battery to give you a big start battery bank - assuming it's a wet lead acid too? At least that would keep it topped up. Is there any disadvantage to having a big start battery bank?

[RLWP]

Why don't you use the wet lead/acid as a start battery by adding it to your existing start battery to give you a big start battery bank - assuming it's a wet lead acid too? At least that would keep it topped up. Is there any disadvantage to having a big start battery bank?

 

It takes up unnecessary space?

 

Richard