Leisure Battery Help

[Jammin40]

Hi All,

sorry if this has already been asked several times but I wondered if someone could please help me with the correct wiring setup for 2 leisure batteries connected to my existing starter battery via a split charge relay.
I’ve attached a picture to try to explain what I’m trying to achieve.

I’m not sure where to wire the solar panel into and where to take my positive and negative for my 12v devices.

can you help?

thanks in advance

 

[Phill D]

Hi welcome.

you need a bit more info than that . what set up do you have now? what control unit do you have for the liesure batteries, what solar regulator you got etc tec

 

[mitzimad]

you dont need to connect the grounds on the leisure and van batteries just both to chassis unless they are very close together lives should be fused close to batteries
what type of scr are you using ?
solar goes to live and ground on the leisure batteries best practice is one to each batttery but with just two its not crucial

 

[Jammin40]

Hi welcome.

you need a bit more info than that . what set up do you have now? what control unit do you have for the liesure batteries, what solar regulator you got etc tec

I’ve got a voltage sense split charge relay with no existing setup as I’m yet to connect anything.

 

[Jammin40]

you dont need to connect the grounds on the leisure and van batteries just both to chassis unless they are very close together lives should be fused close to batteries
what type of scr are you using ?
solar goes to live and ground on the leisure batteries best practice is one to each batttery but with just two its not crucial

it’s a voltage sense split charge relay.

Would this work then?

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[Phill D]

try this as a starter and remove the bits you dont want or need

 

[Jammin40]

it’s a voltage sense split charge relay.

Would this work then?

Or better still......

try this as a starter and remove the bits you dont want or need

View attachment 446716

thanks

 

[Phill D]

Good luck with the set up

 

[autorouter]

try this as a starter and remove the bits you dont want or need

This is an example of how NOT to wire a motorhome. The 'Load' terminals never have anything wired to them in a motorhome. The load terminals of the solar controller of a 200W panel will very likely only be good for about 15A, which is hardly enough for lights and water pump, never mind the inverter and heater shown in that diagram.

In motorhomes, the fusebox for the load circuits is connected direct to the leisure batteries (via a suitable isolator switch and a big fuse, of course). They are never wired to the load terminals of a solar controller.

And that's just for starters.

 

[Mikeco]

try this as a starter and remove the bits you dont want or need

View attachment 446716

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[autorouter]

Looking at your pair of leisure batteries, it's best to regard them as a battery bank, with one positive connection on one battery and one negative connection on the other battery. All external devices (SCR, loads, solar, mains charger etc) should go to these same positive and negative connections.

So on your diagram (post #7), move the load positive to the same as the SCR and solar. Move the solar negative to the same as the load negative and ground.

I'm assuming the 'Solar Panel' is really the solar controller. Any solar panel larger than about 20W needs a solar controller.

Voltage Sense Split Charge Relays are fine for simple systems, but cause problems for more complex systems like motorhomes. For example, you may in the future decide you want to charge the starter battery from solar. When its voltage rises, it triggers the VSR, which may not be what you expect or want. Similarly if you connect a mains charger to the starter battery.

Using a split charge relay triggered from the D+ signal of the alternator is a bit more effort with the wiring. However it has other benefits, apart from triggering the split charge relay. For example it can trigger a 3-way fridge to run from 12V when the engine is running, and back to gas when the engine stops.

 

[Phill D]

autorouter , I stand corrected..

 

[mitzimad]

Iwas going to point out the error on phils diagram fuse box should be run from the battery im not a lover of voltage sensing relays
another point is what type of fridge you are going to have? as this could need something different when i did a self build i used a smart com relay to feed the 3 way fridge and to trigger a normal relay for split charging this saves the need for a D+ signal
if your using a threeway fridge it needs two 12v feeds one for the controls and one for the element its the one for the elemnt that needs a relay to only cut in when engine is running

 

[mitzimad]

it’s a voltage sense split charge relay.

Would this work then?

yes assuming the box where you have written aux is a fuse box with a fuse for each circuit thats the basics you need heavy fuses on the inter battery connections minimum of 16mm cable and decent crimped ends if your near london i have a crimper you could use to make the leads

 

[mitzimad]

can i also suggest you pay to become a member its the best £15 youll spend on your van as a free member you can only post a few times

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