leisure battery set up.

[mattp41]

hi all can anyone help? i have a LC 95 uk one with the two batteries in parallel set up..i want to fit a leisure battery whats the best way to go? thanks matt.

 

[Bob]

Sorry I'm not much help, but I've often wondered if the second battery could be turned into a leisure battery. The truck doesn't need two batteries, Irish spec trucks got only one, and it's started first turn in everything down to -15℃. I've thought about putting in a second in the empty space, but purely as a leisure battery. It's the split charge stuff that seems to be fiddly

 

[Chris]

I did this in Lil Blue. You certainly can split them. What you have to decide though is what sort of battery you want and then which charge system you need to keep that battery happy. It's nowhere near as complex as the 80 series which uses a 12v running and 24v starter.

You also need to determine what sort of capacity you want. What do you want to run from the LB and for how long? It really might not be necessary to split them in the first place. In parallel, you basically have one huge battery. Light loads wouldn't be an issue but if you start to deep discharge them, then you do need to do the split and put a specialised battery in the aux position.

 

[goodoldboy]

The

I did this in Lil Blue. You certainly can split them. What you have to decide though is what sort of battery you want and then which charge system you need to keep that battery happy. It's nowhere near as complex as the 80 series which uses a 12v running and 24v starter.

You also need to determine what sort of capacity you want. What do you want to run from the LB and for how long? It really might not be necessary to split them in the first place. In parallel, you basically have one huge battery. Light loads wouldn't be an issue but if you start to deep discharge them, then you do need to do the split and put a specialised battery in the aux position.

only thing I would add to the above that regular , heavy use will dramatically shorten the life of even a deep discharge battery.

 

[Chris]

If you stay within the parameters of what discharge actually means, does this really still mean that it will shorten the life?

OK what I mean is that deep discharge batteries are misunderstood. Running them past something like 11.8v is damaging. People think DD means running them flat. it doesn't. Running a 12 volt battery to 50 5 means 12.2 volts. If you keep the discharge floor to say 60% then it's surely operating within its design?

Here's a table on discharge percentage. It's one of the reasons that the Optima is so good because it pushes out a higher, flatter voltage for longer rather than the wet type that drop in a more linear fashion. However, they make up for that with higher capacity

 

[goodoldboy]

If you stay within the parameters of what discharge actually means, does this really still mean that it will shorten the life?

OK what I mean is that deep discharge batteries are misunderstood. Running them past something like 11.8v is damaging. People think DD means running them flat. it doesn't. Running a 12 volt battery to 50 5 means 12.2 volts. If you keep the discharge floor to say 60% then it's surely operating within its design?

Here's a table on discharge percentage. It's one of the reasons that the Optima is so good because it pushes out a higher, flatter voltage for longer rather than the wet type that drop in a more linear fashion. However, they make up for that with higher capacity

View attachment 104085

1+ to the above .a battery regularly discharged to 20 % of its capacity will last half as long as of its discharged to 50% .only using 10% will increase its life by a factor if 5 over the 50% DOD(depth of discharge) obviously you dont want a huge battery adding weight & taking up space so accurate calculation of load is important plus what headroom - time without charging - you expect.this applies most if you are running a fridge & expect to be parked up for some time.this of course leads to thinking about a solar panel.....my main battery bank on my home set up us sized so that average use is 20% of capacity.