Battery bank advice

[tokoloshe]

I have two five year old Elecsol carbon 100ah batteries that have had light use and
a new unit of the same type. I also have a spare 75ah deep cycle battery.

Is it practical /wise to use the three Elecsol units as the domestic bank and use the
75ah unit as the engine battery? I don't want to waste the advantage of the new
Elecsol.

 

[AndyJ76]

Deep cycle batteries are ill-suited to starting an engine, although some of the AGM types can do double duty.

Is the 75Ah battery labelled with a CCA value (cold cranking amps)?

 

[tokoloshe]

Deep cycle batteries are ill-suited to starting an engine, although some of the AGM types can do double duty.

Is the 75Ah battery labelled with a CCA value (cold cranking amps)?

It is a Humax 75ah leisure battery to start a vp2002.

I'm probably more concerned about knackering the new Elecsol battery.

 

[vyv_cox]

I have not done exactly what you are asking but something similar. I had a bank of two 110 Ah leisure types as domestic, they were about three years old, and another identical one about four years old that was for starting but had been used very little. I combined the three into a domestic bank, making it far more useful. The combined version lasted several more years. The old adage about older batteries 'dragging a new one down' doesn't seem to apply unless the old ones have cells that are on their last legs.

Leisure batteries are perfectly OK for starting small yacht engines. Different if you are using them to start a truck on an icy morning perhaps. I have been using only leisure batteries for the past 20 years, for starting and domestic, no problems at all. I have had eight years from some, less now as they receive considerably more discharges.

 

[Rigger Mortice]

A leisure battery will be be fine. It's stretching things a bit to call Leisure batteries "deep cycle".

 

[VicS]

It is a Humax 75ah leisure battery to start a vp2002.

I'm probably more concerned about knackering the new Elecsol battery.

I take it you mean "NUMAX"

Generally as said above a leisure battery will be Ok for starting a small engine such as the VP 2002

However its suitability will depend upon which battery you have

The Numax XV23MF is described as suitable for "deep cycling" and starting

The Numax LV22MF is decribed as a semi-traction, deep cycling battery ... presumably a little less suitable for starting than the XV23MF

Although you are unlikely to harm your new Elecsol battery you may not see the full benefit of it if linked with to couple of others which are past their prime.

 

[tokoloshe]

Numax NX23MF.....the very chap!

The plan is now to set up a three battery domestic bank and use the Numax as an
engine starting unit.

Many thanks y'all.