battery cable ?

[grafozz]

i am moving batteries on my boat and need 25 metres of battery cable . the runs are 2.5 metres each cable and its costly . can i use heavy 6 x core flex , industrial type, its only 30 cents a metre here ! obviously i intend to strip the ends and use as one cable . can anyone advise ,please ?, thanks.

 

[Evadne]

The important number for a cable is CSA (cross sectional area?). Two wires of 25mm2 will conduct the same current as one of 50mm2, the only hidden snags are
(1) the connectors, the resistance at a connector is often significant compared to the wire, so make sure your crimps are up to the current and
(2) bundled conductors should be de-rated, by up to 50% depending on how many there are, because of the heating that occurs within the cable.

Make sure your current requirements are well within the cable rating, there are plenty of online tables courtesy of Mr Google, and there will be nothing to worry about.

 

[pappaecho]

I rewired the boar 4 years ago, and used the cable used in Britain for "meter tails", that is the connection between the mains meter and the consumer unit. The cables are double insulated and the inner core is coded red or black for positive and negative, though the latest EU regulations probably require white and skybluepink.
The cable is certainly a fraction of the price of cable sold for cars, but I think the maximum amps was 150. Used it as a submains connection to the main distribution board which was about 12 meters away, but luckily the connection to the engine were in place anyway directly from the starter batteries

 

[noelex]

A single tinned cable in an appropriate size for the voltage drop is the best choice. 6 core industrial cable has the drawback that it heats up more than a single cable wont be tinned and if the connection fails, or the resistance increases on a few of the conductors the remaining wires will not be capable of conducting the current. The result is overheating / fire.
Will it work, probably at least for a while, is it safe possibly, but I would not use it.
If the boat is ever inspected the surveyor will condemn it. Considering the work involved I think its worth using the correct wire.
I am cruising in the Med and can give you a good source of marine cable, but it would be better to PM me. (No personal commercial interests just some issues I would rather discuss offline)