I want to relocate my battery, wiring info required

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kingoftheroad

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2006 Hymer A Class
Hi
I want to move my Lithium battery from the outside locker and put it inside the seat compartment (directly above) its current location.
Currently all cables (dc dc charger/solar/inverter)with their relevant fuses go straight to the battery terminals my question is:
Can I connect all the current set up of cables to neg/poss busbars and then run a negative and a positive straight up from the busbar and onto the battery terminals in its new location.
 
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No reason why not providing all new wires are same size and length as each other.
I would use the size of the thickest cable as a minimum, Probably inverter, to size new cables
 
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Which Hymer have you got?

Is it really an outside locker, or is it like mine and just accessed from outside (or from the inside as well?)
 
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pappajohn said:
No reason why not providing all new wires are same size and length as each other.
I would use the size of the thickest cable as a minimum, Probably inverter, to size new cables
Click to expand...
The existing cables will hardly move, I can mount the relevant busbars, just above the position they are currently in on the battery terminals and yes, aware of cables size.
 
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kingoftheroad said:
Hi
I want to move my Lithium battery from the outside locker and put it inside the seat compartment (directly above) its current location.
Currently all cables (dc dc charger/solar/inverter)with their relevant fuses go straight to the battery terminals my question is:
Can I connect all the current set up of cables to neg/poss busbars and then run a negative and a positive straight up from the busbar and onto the battery terminals in its new location.
Click to expand...
Just to be clear. Are you going to mount a bus bar in the location of the current battery and connect all the incoming cables to that bus bar.
THEN move the battery and have a single cable going from the new battery location to the old battery location and connect it to the bus bar?

If so then I see no issue with this. Providing you have a fuse right at the battery on the terminal to protect the cable that runs from the battery to the bus bar.
 
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Gromett said:
Just to be clear. Are you going to mount a bus bar in the location of the current battery and connect all the incoming cables to that bus bar.
THEN move the battery and have a single cable going from the new battery location to the old battery location and connect it to the bus bar?

If so then I see no issue with this. Providing you have a fuse right at the battery on the terminal to protect the cable that runs from the battery to the bus bar.
Click to expand...
Yes exactly that.
What size fuse would you advise please
 
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kingoftheroad said:
Yes exactly that, I was going to ask if this cable would need to be fused, so thanks for that. What size fuse would you suggest
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Depends on the load and cable size. You will need to work out highest of amps in/out in total then choose an appropriate cable size, then fuse accordingly.

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herald_400rl said:
Depends on the load and cable size. You will need to work out highest of amps in/out in total then choose an appropriate cable size, then fuse accordingly.

Cable Size Calculator - Cable sizing and selection | 12 Volt Planet

Cable Size Calculator - Read our guide to selecting cable of the correct type and size for your automotive, marine or leisure wiring application. Auto and Marine Electrical Components from 12 Volt Planet
www.12voltplanet.co.uk
Click to expand...
I knew this was going to get more complicated, I can do the physical part of the job, no problem, but the technical side goes right over my head.
If i duplicate the cable and fuse size, that's currently fitted between my DC-DC charger and my battery, that should be ok shouldn't it
 
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kingoftheroad said:
I knew this was going to get more complicated, I can do the physical part of the job, no problem, but the technical side goes right over my head
Click to expand...
Do you use an inverter? If its less than a meter you could just use a 70mm2 cable and stick a 300a fuse on it and a 300a mrbf on the battery and it'll cover all eventualities. But then you need to think about fusing the smaller wires coming from the bus bar.
 
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herald_400rl said:
Do you use an inverter? If its less than a meter you could just use a 70mm2 cable and stick a 300a fuse on it and a 300a mrbf on the battery and it'll cover all eventualities. But then you need to think about fusing the smaller wires coming from the bus bar.
Click to expand...
All current cables are fused and not altering or moving them
 
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herald_400rl said:
Do you have an inverter? Most other loads aren't going to be significant.
If you have no inverter you will  probably be ok with 16mm2 cable and an 80a fuse, depending on cable length.
Click to expand...
Yes, think it's 1500w, with a fused, 20mm cable about 500mm long
 
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kingoftheroad said:
All current cables are fused and not altering or moving them
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Are you sure they are all independently fused.

Where cables join it is important to note that if the size of the downstream is smaller than the upstream it needs a smaller fuse at that junction.

In case you weren't aware the fuse is there to protect the cable not the device at the other end of the cable.

So if you move the battery and put a bus bar in. Lets say you don't have an inverter and use 25mm² cable from the battery to the busbar 50cm away and this is just powering low current stuff. You could put a 50A fuse in at the battery logically speaking.

However, If from the bus bar there is for example a 1mm² cable for the light circuit. If that light circuit gets a fault that pulls 20A. That 1mm² wire is going to melt and perhaps start a fire. So the 1mm² wire from the bus bar needs it's own fuse of say 5 or even 10A,
Which would blow at that 20A fault level. This fuse NEEDS to be directly at the point where the 1mm² start not even an inch further.

I hope that makes sense?

I have had a few drinks so if my explanation is not clear please feel free to ask.
 
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Gromett said:
Ah, sounds like you need a fused distribution block rather than a straight forward bus bar.
Click to expand...
That is what the EBL and other existing wiring is doing.

This thread is making a mountain out of a mole hill.

All the OP should need to do is what was suggested in the original post, but with a fuse in the posititive at the battery.
The value of the fuse should be set so that it is correct to protect the new cable.

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To answer 'can I put in a busbar ......' - yes!
If everything is working to your satisfaction then 2 x busbars and 2 x 50cm x 25mm2 cables with a MRBF fuse on the positive battery terminal is good for a 100 amp load.
If your load (inverter + everything else) needs more amps and the battery can provide them then go for bigger to 35mm2 with the appropriate fuse size.
 
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Gromett said:
Are you sure they are all independently fused.

Where cables join it is important to note that if the size of the downstream is smaller than the upstream it needs a smaller fuse at that junction.

In case you weren't aware the fuse is there to protect the cable not the device at the other end of the cable.

So if you move the battery and put a bus bar in. Lets say you don't have an inverter and use 25mm² cable from the battery to the busbar 50cm away and this is just powering low current stuff. You could put a 50A fuse in at the battery logically speaking.

However, If from the bus bar there is for example a 1mm² cable for the light circuit. If that light circuit gets a fault that pulls 20A. That 1mm² wire is going to melt and perhaps start a fire. So the 1mm² wire from the bus bar needs it's own fuse of say 5 or even 10A,
Which would blow at that 20A fault level. This fuse NEEDS to be directly at the point where the 1mm² start not even an inch further.

I hope that makes sense?

I have had a few drinks so if my explanation is not clear please feel free to ask.
Click to expand...

LithiumConvert said:
That is what the EBL and other existing wiring is doing.

This thread is making a mountain out of a mole hill.

All the OP should need to do is what was suggested in the original post, but with a fuse in the posititive at the battery.
The value of the fuse should be set so that it is correct to protect the new cable.
Click to expand...
I must admit, even with my limited knowledge, I thought this is getting crazy, so thanks for getting me back on level ground.
My current set up is fine works great and has been checked over, I basically want to move my battery less than a foot, from under the floor section to above it, without having to extend all the cables that's currently connected to it, plus I thought getting them all off the battery terminals as they are now, onto two bus bars will tidy things up a bit.

It was just the two extension cables, so to speak, (negative & positive) from the new bus bars to the battery, i was asking, is this doable.
 
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Gromett said:
You can do it without fusing, but it would be at your own risk.

Raul any thoughts?
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Thats why I left it as OP would have to think about fusing the smaller wires - I have no experience with a Hymer B524s wiring so don't know how supply gets to whatever from the battery as it stands.
It might have en existing fuse for the inverter, and the EBL supply cables - it might not.

But the new supply cable should definitely be fused and id just use a 50mm2 cable with a 250a fuse and have done with it. Would be fine for an upgrade to a 2000w inverter if needed in future.
 
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herald_400rl said:
Thats why I left it as OP would have to think about fusing the smaller wires - I have no experience with a Hymer B524s wiring so don't know how supply gets to whatever from the battery as it stands.
It might have en existing fuse for the inverter, and the EBL supply cables - it might not.

But the new supply cable should definitely be fused and id just use a 50mm2 cable with a 250a fuse and have done with it. Would be fine for an upgrade to a 2000w inverter if needed in future.
Click to expand...
Yup, I am going to bow out now as well. I have given my advice and the reasoning behind it. Not much more I can say.

Raul and autorouter are the ones I would listen to on this.
 
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herald_400rl said:
Thats why I left it as OP would have to think about fusing the smaller wires - I have no experience with a Hymer B524s wiring so don't know how supply gets to whatever from the battery as it stands.
It might have en existing fuse for the inverter, and the EBL supply cables - it might not.

But the new supply cable should definitely be fused and id just use a 50mm2 cable with a 250a fuse and have done with it. Would be fine for an upgrade to a 2000w inverter if needed in future.
Click to expand...
Hi
Sorry, got involved with other stuff.
Yes, all current CABLES & FUSES serving everything i have fitted (including Hymers wiring) are at the correct spec/size, I had the Lithium fitted and the system checked by EcoTree Lithium at Oaktree Motorhomes, it all works great and happy with it, except now, a couple of years on, I just want to move the battery, less than 300mm, from under the Hymer floor, to above it, inside the van. I could extend all the current cables, but thought, it would be easier and a tidier setup, if all the cables stayed put, attach them to a couple of bus bars and I just run a positive and a negative from the bus bars to the battery terminals, at the battery's new position. It appears, by most that this will be ok to do, if i use the correct cable size for the new cables and its fused
Example:
50mm2 (the cable run will be under 500mm)
Positive cable to incorporate a 250a fuse
 
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The only thing I have not seen mention of is to use an insulated bus bar for the positive.
i.e. one with a cover.

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kingoftheroad said:
Hi
Sorry, got involved with other stuff.
Yes, all current CABLES & FUSES serving everything i have fitted (including Hymers wiring) are at the correct spec/size, I had the Lithium fitted and the system checked by EcoTree Lithium at Oaktree Motorhomes, it all works great and happy with it, except now, a couple of years on, I just want to move the battery, less than 300mm, from under the Hymer floor, to above it, inside the van. I could extend all the current cables, but thought, it would be easier and a tidier setup, if all the cables stayed put, attach them to a couple of bus bars and I just run a positive and a negative from the bus bars to the battery terminals, at the battery's new position. It appears, by most that this will be ok to do, if i use the correct cable size for the new cables and its fused
Example:
50mm2 (the cable run will be under 500mm)
Positive cable to incorporate a 250a fuse
Click to expand...
0.5m 12v 250a
You could use 25mm2 and a 250a mrbf on the battery terminal. I would use 35mm2 though but im paranoid.
 
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