Split charge relay question

[Martin C]

Hi, quick one regarding connecting split charge relay, can I power it from the rear ciggy lighter in the back of the van rather than running a live from main battery through bulk head etc?

 

[ched999uk]

Normally cigarette lighters are only fused at 10amps. A split charge relay just connects both batteries together when the van battery voltage is high enough. There is no current limitation on what the leisure battery can 'pull' so it would most likely pull more than 10 amps. That said it might be ok if you mains charge the leisure battery each day.
What ever you do don't be tempted to put a larger fuse in the cigarette lighter as the cable will only be rated to 10 amps and a higher rated fuse could cause a fire!

 

[Martin C]

Normally cigarette lighters are only fused at 10amps. A split charge relay just connects both batteries together when the van battery voltage is high enough. There is no current limitation on what the leisure battery can 'pull' so it would most likely pull more than 10 amps. That said it might be ok if you mains charge the leisure battery each day.
What ever you do don't be tempted to put a larger fuse in the cigarette lighter as the cable will only be rated to 10 amps and a higher rated fuse could cause a fire!

Ok thanks ched,

 

[Mattlekim]

Hi, quick one regarding connecting split charge relay, can I power it from the rear ciggy lighter in the back of the van rather than running a live from main battery through bulk head etc?

We run a Duel split charge relay.
So we have a main fuse of 20amps
And then each batter is fed by a 10 amp fuse. If you are charging 1 battery technical it would be fine. As our 10amp fuse doesn't blow.

 

[Martin C]

We run a Duel split charge relay.
So we have a main fuse of 20amps
And then each batter is fed by a 10 amp fuse. If you are charging 1 battery technical it would be fine. As our 10amp fuse doesn't blow.

Ahhh, might be worth a try then, worse case scenario it will blow the fuse…correct?

 

[Mattlekim]

Ahhh, might be worth a try then, worse case scenario it will blow the fuse…correct?

Yep. And regardless you should always have a load of 10 amp fuse spair for the connection of pump to battery

 

[Martin C]

Yep. And regardless you should always have a load of 10 amp fuse spair for the connection of pump to battery

Thanks, I’ll give it a go ?

 

[Mattlekim]

Only other thing to look at is that if the sigarette lighter is always powered or only when engine is on. You want it only when engine is on.

It will work either way. Just easyer to calibrate that way

 

[Martin C]

Yep. And regardless you should always have a load of 10 amp fuse spair for the connection of pump to battery

Only other thing to look at is that if the sigarette lighter is always powered or only when engine is on. You want it only when engine is on.

It will work either way. Just easyer to calibrate that way

Yes, I did check yesterday & it’s only live with ignition on.

 

[Ian Sheppard]

I would agree with Ched here. While it is possible to use the 12V output in the rear of your vehicle it may not be rated sufficiently for a Charging circuit. Fitting the correctly rated fuse as specified by the manufacturer is an absolute must. Over rating fuses is not a good idea. This blog gives more info System Maintenance FUSE!! | Blog | Spring (Europe) Ltd

 

[Martin C]

I would agree with Ched here. While it is possible to use the 12V output in the rear of your vehicle it may not be rated sufficiently for a Charging circuit. Fitting the correctly rated fuse as specified by the manufacturer is an absolute must. Over rating fuses is not a good idea. This blog gives more info System Maintenance FUSE!! | Blog | Spring (Europe) Ltd

An interesting read, ok… I’m not gonna chance that now. Thanks for the reply, are you aware of any other power source I could tap into, or am I better of bringing the live off the main battery in through the bulk head?