Cab Battery Wiring (1 Viewer)

Silver-Fox

LIFE MEMBER
Sep 5, 2014
9,289
29,325
Cheltenham Spa
Funster No
33,201
MH
Rapido
Exp
im a not so newbie
Good afternoon fellow Funsters.

I’m looking for a pointer from one of you clever lot how to wire in and charge my cab battery from the MPPT controller.

Prefer not to run a cable from the back of the van where all the electrics are.

I have been reliably informed I can do the above using a connection via my CBE unit.

I have a Rapido 995M van.

Pictures of my set up below.
5B59C3A7-4BDD-4BBE-93FA-A7A1D8354925.jpeg
8373C2FA-0B22-4E07-8B18-01FD777859AA.jpeg


Thanks
 
OP
OP
Silver-Fox

Silver-Fox

LIFE MEMBER
Sep 5, 2014
9,289
29,325
Cheltenham Spa
Funster No
33,201
MH
Rapido
Exp
im a not so newbie
Hab battery and all solar/wiring is in the garage at the rear.

If I need to I can run a cable to the front but would prefer not to.
 
Upvote 0

Two on Tour

LIFE MEMBER
Sep 16, 2016
10,429
51,946
Near the junction of the A14 and A1, Cambs
Funster No
45,145
MH
Elddis Autoquest 175
Exp
Since 2010
Hab battery and all solar/wiring is in the garage at the rear.

If I need to I can run a cable to the front but would prefer not to.

Can't help you unfortunately with your CBE setup as I know bugger about that system, but as ever your easy option might be a Battery Master, one small single wire to your cab battery run under your van.

Subscribers  do not see these advertisements

 
Upvote 0
Oct 10, 2018
2,023
1,147
Bracklesham Bay, West Sussex
Funster No
56,646
MH
PVC
Exp
Since 2005
The large terminal on the far lower left in the photo if marked +B1 could be the Starter (Cab) battery connection positive side and there may be another marked -B1 for the negative side (I cannot see them in the photo but if they are there you can confirm things with a meter , the+B2 terminal shown on the far right may well be the positive supply from the leisure battery) )
 
Upvote 0
OP
OP
Silver-Fox

Silver-Fox

LIFE MEMBER
Sep 5, 2014
9,289
29,325
Cheltenham Spa
Funster No
33,201
MH
Rapido
Exp
im a not so newbie
Can't help you unfortunately with your CBE setup as I know bugger about that system, but as ever your easy option might be a Battery Master, one small single wire to your cab battery run under your van.

I can run a cable from my MPPT controller as I have a spare out I can use apparently.
 
Upvote 0

Two on Tour

LIFE MEMBER
Sep 16, 2016
10,429
51,946
Near the junction of the A14 and A1, Cambs
Funster No
45,145
MH
Elddis Autoquest 175
Exp
Since 2010
I can run a cable from my MPPT controller as I have a spare out I can use apparently.

That's only good for topping up your cab battery as long as the sun shines, whereas a Battery Master keeps your cab battery topper up all the time. (well pretty well all the time - to keep the pedantic's happy :giggle: )
 
Upvote 0
OP
OP
Silver-Fox

Silver-Fox

LIFE MEMBER
Sep 5, 2014
9,289
29,325
Cheltenham Spa
Funster No
33,201
MH
Rapido
Exp
im a not so newbie
The large terminal on the far lower left in the photo if marked +B1 could be the Starter (Cab) battery connection positive side and there may be another marked -B1 for the negative side (I cannot see them in the photo but if they are there you can confirm things with a meter , the+B2 terminal shown on the far right may well be the positive supply from the leisure battery) )

Pictures below

204D783E-229A-4739-AAF4-9F4B2474A9C4.jpeg
204D783E-229A-4739-AAF4-9F4B2474A9C4.jpeg
BE629D07-2D37-494C-8197-A835E731ACA2.jpeg


It looks like
 
Upvote 0
OP
OP
Silver-Fox

Silver-Fox

LIFE MEMBER
Sep 5, 2014
9,289
29,325
Cheltenham Spa
Funster No
33,201
MH
Rapido
Exp
im a not so newbie
Another picture

To confirm +B terminals to the right and negative to the left.
DD8BCD58-20BC-474A-835B-C461420536E9.jpeg

Subscribers  do not see these advertisements

 
Upvote 0
OP
OP
Silver-Fox

Silver-Fox

LIFE MEMBER
Sep 5, 2014
9,289
29,325
Cheltenham Spa
Funster No
33,201
MH
Rapido
Exp
im a not so newbie
That's only good for topping up your cab battery as long as the sun shines, whereas a Battery Master keeps your cab battery topper up all the time. (well pretty well all the time - to keep the pedantic's happy :giggle: )

Hi Paul

Yes as you say only when the sun shines.

I have very little drain on the cab battery when the van is laid up.
And as we know the sun always shines in Gloucestershire 🤔😂
 
Upvote 0
Oct 20, 2010
2,251
37,619
Burry Port South Wales
Funster No
14,190
MH
A Class
Exp
Since 2003

This will do what you require, it will top up the cab battery with a small charge when the leisure batteries are at 12.5v or above. It is relatively easy to wire in, only 3 connections required. I have fitted mine connected direct from leisure batteries to cab battery as they are both at the front of our van.
 
Upvote 0
OP
OP
Silver-Fox

Silver-Fox

LIFE MEMBER
Sep 5, 2014
9,289
29,325
Cheltenham Spa
Funster No
33,201
MH
Rapido
Exp
im a not so newbie

This will do what you require, it will top up the cab battery with a small charge when the leisure batteries are at 12.5v or above. It is relatively easy to wire in, only 3 connections required. I have fitted mine connected direct from leisure batteries to cab battery as they are both at the front of our van.

This is what I’m trying to avoid, running a cable the length of the van.
Cab battery is at the front and hab at the back in the garage.

I’d also be using solar with that set up.

Thanks for the suggestion though 👍

Subscribers  do not see these advertisements

 
Upvote 0
Oct 10, 2018
2,023
1,147
Bracklesham Bay, West Sussex
Funster No
56,646
MH
PVC
Exp
Since 2005
You need to check with a meter but I think you should find that the +B1 is starter battery positive connection and +B2 is the leisure battery positive connection and also you may find that the -B terminal is a negative connection for both , If this checks out these connections could also be used for wiring in a battery master if you decided to fit one.
I cannot see the solar control connections but , if it is a duel controller , you could connect the second output to the points +B1 and -B to send a solar charge to the starter battery.
 
Upvote 0
OP
OP
Silver-Fox

Silver-Fox

LIFE MEMBER
Sep 5, 2014
9,289
29,325
Cheltenham Spa
Funster No
33,201
MH
Rapido
Exp
im a not so newbie
You need to check with a meter but I think you should find that the +B1 is starter battery positive connection and +B2 is the leisure battery positive connection and also you may find that the -B terminal is a negative connection for both , If this checks out these connections could also be used for wiring in a battery master if you decided to fit one.
I cannot see the solar control connections but , if it is a duel controller , you could connect the second output to the points +B1 and -B to send a solar charge to the starter battery.

Thanks for your help.

I can check in my user manual which +B is the cab battery.

I’ve been told the battery + output from the solar controller can be used to trickle charge to the cab battery.
It’s the first of the smaller outputs on the controller.
 
Upvote 0
OP
OP
Silver-Fox

Silver-Fox

LIFE MEMBER
Sep 5, 2014
9,289
29,325
Cheltenham Spa
Funster No
33,201
MH
Rapido
Exp
im a not so newbie
Just had a thought if I connect to the correct place to trickle charge the cab battery.

Could I damage the MPPT controller when on EHU?
 
Upvote 0
Oct 10, 2018
2,023
1,147
Bracklesham Bay, West Sussex
Funster No
56,646
MH
PVC
Exp
Since 2005
No it will not damage the MPPT, connecting in this way is an often used method of connecting duel solar controllers (and battery master units) into the battery systems.
 
Last edited:
Upvote 0
OP
OP
Silver-Fox

Silver-Fox

LIFE MEMBER
Sep 5, 2014
9,289
29,325
Cheltenham Spa
Funster No
33,201
MH
Rapido
Exp
im a not so newbie
No it will not damage the MPPT, connecting in this way is an often used method of connecting duel solar controllers (and battery master units) into the battery charging systems.

Many thanks for your posts.

I’ll check which point on the cbe is for the cab battery and get it wired up 👍

Subscribers  do not see these advertisements

 
Upvote 0
Apr 27, 2016
6,924
8,086
Manchester
Funster No
42,762
MH
A class Hymer
Exp
Since the 80s
There's probably no need to run a negative for the starter battery trickle charge, the two battery negatives will be connected to the chassis. The trickle charge amps is very small, so no problem with voltage drop. Note 'MASSE' next to the negative bolt on the circuit board means chassis.
 
Upvote 0
OP
OP
Silver-Fox

Silver-Fox

LIFE MEMBER
Sep 5, 2014
9,289
29,325
Cheltenham Spa
Funster No
33,201
MH
Rapido
Exp
im a not so newbie
There's probably no need to run a negative for the starter battery trickle charge, the two battery negatives will be connected to the chassis. The trickle charge amps is very small, so no problem with voltage drop. Note 'MASSE' next to the negative bolt on the circuit board means chassis.

Thankyou for the above.

It sometimes looks a bit daunting when you delve into these boxes.

I’ve never liked 12v electrics.

Happy to get inside a consumer unit though 😊
 
Upvote 0
Apr 27, 2016
6,924
8,086
Manchester
Funster No
42,762
MH
A class Hymer
Exp
Since the 80s
It sometimes looks a bit daunting when you delve into these boxes.

I’ve never liked 12v electrics.
While you are looking at it, the small black box with '70A 12V' on it, between the B1 and B2 terminal bolts, is the famous split charge relay, that connects B1 and B2 together when the engine is running.
 
Upvote 0
OP
OP
Silver-Fox

Silver-Fox

LIFE MEMBER
Sep 5, 2014
9,289
29,325
Cheltenham Spa
Funster No
33,201
MH
Rapido
Exp
im a not so newbie
While you are looking at it, the small black box with '70A 12V' on it, between the B1 and B2 terminal bolts, is the famous split charge relay, that connects B1 and B2 together when the engine is running.

Ok thanks

Do i need to do anything other than connect a cable from the MPPT controller "starter" out put connection?
Just checking :giggle:
 
Upvote 0
Apr 27, 2016
6,924
8,086
Manchester
Funster No
42,762
MH
A class Hymer
Exp
Since the 80s
Do i need to do anything other than connect a cable from the MPPT controller "starter" out put connection?
Yes, I think that's all you need to do. Doesn't have to be thick wire either, it's only about an amp, so very little voltage drop even for ordinary 1.5mm2 wire.
 
Upvote 0

Join us or log in to post a reply.

To join in you must be a member of MotorhomeFun

Join MotorhomeFun

Join us, it quick and easy!

Log in

Already a member? Log in here.

Latest journal entries

Funsters who are viewing this thread

Back
Top