Battery fitting regulations

molly 2

molly 2

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IS their a legal or recommend limit on how many cables can be fitted directly to a habitation battery terminal before a bus bar has to be fitted , if a bus bar is fitted how should it be correctly fused .
 
I don't think there are any legal regulations in the UK on battery connections (Regs on DIY installation of anything on the UK is incredibly small compared to most other 'similar' 1st world countries). So the answer to the first part of the question is as far as I am aware, "no".

The second part, ref recommended limit, is another matter. Every cable connected to a power source should be protected by a fuse close to the source. So this means just about every cable that you might be connecting to the battery should have its own fuse. The neatest way to do this, IMO, is to have a fuse holder block rather than individual fuses on a whole stack of connectors on a +ve terminal.

Depending on what kind of current loads you have, you have a few options:

This is a multiway Mega-fuse holder. Good option for high power applications. This is from Victron Energy and available from Amazon at around £25
1665323553730.png


The type I use generally is a multiway Midi-fuse holder which has both +ve and -ve busbars and fuse indicators for failed fuses. Lots of "brands" but probably all from the same chinese factory and again around £25 or so on Amazon and eBay
1665323748232.png
 
wildebus said:
I don't think there are any legal regulations in the UK on battery connections (Regs on DIY installation of anything on the UK is incredibly small compared to most other 'similar' 1st world countries). So the answer to the first part of the question is as far as I am aware, "no".

The second part, ref recommended limit, is another matter. Every cable connected to a power source should be protected by a fuse close to the source. So this means just about every cable that you might be connecting to the battery should have its own fuse. The neatest way to do this, IMO, is to have a fuse holder block rather than individual fuses on a whole stack of connectors on a +ve terminal.

Depending on what kind of current loads you have, you have a few options:

This is a multiway Mega-fuse holder. Good option for high power applications. This is from Victron Energy and available from Amazon at around £25
View attachment 113524

The type I use generally is a multiway Midi-fuse holder which has both +ve and -ve busbars and fuse indicators for failed fuses. Lots of "brands" but probably all from the same chinese factory and again around £25 or so on Amazon and eBay
View attachment 113525
Click to expand...

They look quite nice, haven't seem them before...

Looking at eBay, this seems quite good as well. Mega to Midi and decent cover over the length of the crimps (y)

www.ebay.co.uk

COMBI MEGA / MIDI Fuse Holder - 12/24V - AUTOMOTIVE/TRUCK/MARINE - 4xMIDI 1xMEGA | eBay

M5 threaded studs and hex nuts to secure 4 MIDI fuses. Robust holder with cover attached.
www.ebay.co.uk
 
st3v3 said:
They look quite nice, haven't seem them before...

Looking at eBay, this seems quite good as well. Mega to Midi and decent cover over the length of the crimps (y)

www.ebay.co.uk

COMBI MEGA / MIDI Fuse Holder - 12/24V - AUTOMOTIVE/TRUCK/MARINE - 4xMIDI 1xMEGA | eBay

M5 threaded studs and hex nuts to secure 4 MIDI fuses. Robust holder with cover attached.
www.ebay.co.uk
Click to expand...
I used to use those before I switched to the one I linked to. I like the provision of the -ve Busbar on the one with the clear lid :)

Speaking how how many terminals can be stacked ... welcome to my VW 'Jenga'
What a mess!

LT-Battery-12V by David, on Flickr

A slight improvement using one of those 4 way Midi+ Mega boxes. Mercedes use a DIstribution box similar in function to this as standard on the Starter Batteries on the US T1N Sprinters (same van as the VW LT)
1665327389821.png
 
wildebus said:
Trev, they are good for the general distibuted 12V loads like USB, lights, TV, etc, but not for fuse protection for chargers or inverters. The maximum blade fuse size is 40A and blade fuses don't tend to be very good anyway at prolonged higher currents.
Click to expand...
Thats 100% true and thats what mine are used for, I have the other trip type but found as you said they are slightly over rated, so a 40ah is in fact better at 30ah
fuse trips.png
 
st3v3 said:
They look quite nice, haven't seem them before...

Looking at eBay, this seems quite good as well. Mega to Midi and decent cover over the length of the crimps (y)

www.ebay.co.uk

COMBI MEGA / MIDI Fuse Holder - 12/24V - AUTOMOTIVE/TRUCK/MARINE - 4xMIDI 1xMEGA | eBay

M5 threaded studs and hex nuts to secure 4 MIDI fuses. Robust holder with cover attached.
www.ebay.co.uk
Click to expand...

I have tried the multiway midi-fuse type in #2 but changed them for Combi mega/midi type in your link. I personally prefer the ring tag termination as I feel the contact area is greater. Just my personal preference.
 
xsilvergs said:
I have tried the multiway midi-fuse type in #2 but changed them for Combi mega/midi type in your link. I personally prefer the ring tag termination as I feel the contact area is greater. Just my personal preference.
Click to expand...
Given the choice, I like the stud+ring arrangement over a clamp-down screw as well. But the clampdown style is reliable enough I think and is fairly common place in the industry (the majority of Victron kit, such as the MPPTs, DC-DC Converters, Inverters and the newer Multipluses all use them - although as mentioned, if they had studs they would be better still IMO).
The advantages of having an integral -ve busbar and LED indications tilt the balance for me :)
 
Thanks Dave , I picked up the question from a will prouse vidio stating more than 3 leads need a buss bar , Baz
 
Another good supplier is vehicle wiring products, I used them a lot in the past, very knowledgeable staff and a good website
 
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