Solar Charge to Cab Battery (1 Viewer)

Silver-Fox

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Sep 5, 2014
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I hope this isn’t going to sound too stupid.

Am I correct in saying I can trickle charge the cab battery from my Solar Controller, picture below.

If correct is it just a simple case of running a live cable to the Cab Battery.

Assuming the above where does the cable go into the Controller.
What size cable is needed, the length is around 9m

32A4822C-A534-487C-9F19-7A4160A1F338.jpeg


TiA

Edit

what a plonker I forgot the picture ?
 
Last edited:

pappajohn

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Depends if the connection is a simple load connection, it may be limited to 2 amps.

If it is a proper battery charge connection I reckon cable size over 9mtrs should be 16mmsq or more.

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Dec 2, 2019
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Providing that, controller settings will allow you to set the float charge suitable to just maintain the battery and not going to absorb every day, yes you can float charge a battery indefinite. UPS and telecom batteries that's what they do, spend most of they life in float/ storage charge mode, ready to be deployed when needed. Usually that's 13.2v to 13.6v. Depends on the battery spec.
As for the cable size, need to know the max power(W) that is going to be used; ie solar panel Wp. Then I can advise on cable section needed to prevent to much of a voltage drop.
 
Jan 19, 2014
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Our Votronic controller maintains the starter battery with a small current. I used a 0.5mm cable and it works great. I would have gone with a 1mm cable but the 0.5 was already in for the BM2 monitor so used that ?
 

Jaws

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I hope this isn’t going to sound too stupid.

Am I correct in saying I can trickle charge the cab battery from my Solar Controller, picture below.

If correct is it just a simple case of running a live cable to the Cab Battery.

Assuming the above where does the cable go into the Controller.
What size cable is needed, the length is around 9m

TiA
Errrr.. picture ???
Did you forget or is it another Krimble miracle ?

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Dec 2, 2019
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The 0.5mm2 is capable of carrying a 0.5A for about 3m length. Any longer than that or more A, it will heat up pretty quick. I hope you have a fuse on that, just in case your starter battery will ask more than the cable can carry at any given time, and the supply its got the potential that exceeds the cable capabilities for that load.
 
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Silver-Fox

Silver-Fox

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Please see original post as I have now added the picture.

I know what a n*b ?

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Jan 19, 2014
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The 0.5mm2 is capable of carrying a 0.5A for about 3m length. Any longer than that or more A, it will heat up pretty quick. I hope you have a fuse on that, just in case your starter battery will ask more than the cable can carry at any given time, and the supply its got the potential that exceeds the cable capabilities for that load.

1amp fuse. Rough rule of thumb is x 10:

0.5mm = 5a
1.mm = 10a
1.5mm = 15a

Depends on allowed voltage drop though so only rough.

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Jan 19, 2014
9,395
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Derbyshire
Funster No
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since 2014
I hope this isn’t going to sound too stupid.

Am I correct in saying I can trickle charge the cab battery from my Solar Controller, picture below.

If correct is it just a simple case of running a live cable to the Cab Battery.

Assuming the above where does the cable go into the Controller.
What size cable is needed, the length is around 9m

View attachment 350586

TiA

Edit

what a plonker I forgot the picture ?
That's the same as ours, it goes in one of the small connectors on the right of the main ones. Just use a piece of 1mm² wire with a 5a fuse, run it straight to the cab battery positive. No need to connect a negative ?
 
Sep 28, 2015
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It’s the ll start + connection and you don’t have to take the cable all the way to the battery as the positive cable from the battery will come back to the, in my case, EBL. I just connected it to where the vehicle battery positive wire entered the rear of the EBL. I used 4mm squared (auto) wire.

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Mar 26, 2009
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I'm sure it will only supply 1 amp. Lenny HB will put you right.

Capture2.JPG


Two Battery Charging Ports: Automatic charging of the main battery or board battery (Board I): Support charging and trickle charging (max. 1 A) of the vehicle's starter battery (Start II) with overcharge protection.
 
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Silver-Fox

Silver-Fox

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It’s the ll start + connection and you don’t have to take the cable all the way to the battery as the positive cable from the battery will come back to the, in my case, EBL. I just connected it to where the vehicle battery positive wire entered the rear of the EBL. I used 4mm squared (auto) wire.

Thank you.

Dumb question EBL?
Would the cab battery cable be obvious.

Thanks
 
Sep 28, 2015
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Thank you.

Dumb question EBL?
Would the cab battery cable be obvious.

Thanks
Yep, wherever you can get access to the + battery cable.
Ours has an EBL 29 that controls all the electrical stuff and the + battery cable connects at the rear so it was only a two foot length of cable needed from the Votronic.
205CB765-434F-40CC-8A71-03E09F60BFD5.jpeg

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Lenny HB

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Yep it will only supply 1 amp. I didn't bother with it on mine I fitted a CBE Solar split charge relay which can supply 4 amps.
I would have probably used the Votronic output if I hadn't had the relay in my spares box.
 

Jaws

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According to the spec on their web page it supplies 1 amp
Be enough to counter any alarm drain and keep things nicely topped up
 
Sep 28, 2015
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I think 4mm2 solar is too thick for the terminal block on the Votronic. I used 4mm2 auto because I had some, though Votronic state 1.5 - 2.5mm2.

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Silver-Fox

Silver-Fox

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Sep 5, 2014
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According to the spec on their web page it supplies 1 amp
Be enough to counter any alarm drain and keep things nicely topped up

That’s partly my thinking.
Especially after the very cold snap we had last year.
 
Sep 29, 2019
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Just wired mine in, max size is 2.5mm. You can’t fit bigger, it won’t go in.
 
Apr 27, 2016
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Since the 80s
0.5mm2 would be big enough to carry the current and avoid voltage drop, but as a rule of thumb 1.5mm2 is the smallest you should use, just for general mechanical strength and resistance to vibration in a moving vehicle.

If you're using the terminal on the back of the EBL, make sure you do it up nice and tight. The main charging current from the alternator to the hab batteries routes through these terminals, and can be well over 30 amps. I'd put a 5 amp inline fuse in the wire too, as shown in the manual diagram.

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