Solar Wiring

[JuanVecino2023]

Am I being belts & braces using 16mm cable to run between a Victron MPTT & my leisure battery? And should I put a fuse in the +ve cable?

 

[yossarian]

16mm cable to run between a Victron MPTT & my leisure battery?

That's good for about 110A / 1400W of panels...

I suspect your mppt won't have large enough terminals to accommodate.

 

[WelshGas]

Am I being belts & braces using 16mm cable to run between a Victron MPTT & my leisure battery? And should I put a fuse in the +ve cable?

That is definitely OTT. The cable, if you have 1 panel is carrying no more current than the wiring to your 12 v sockets which are fused at 15/20 amps and the sockets rated for 20 amps.
Under absolute ideal conditions and 100% efficiency the MPPT will be pushing out no more than 10 amps.
And yes, fuse at 10/15amps for 1 panel.

 

[JuanVecino2023]

That's good for about 110A / 1400W of panels...

I suspect your mppt won't have large enough terminals to accommodate.

It’s interesting. This was my suspicion. However, looking at various wiring diagrams, with MPPT 100/30 as the solar controller., 16mm cable is suggested.

 

[JuanVecino2023]

That is definitely OTT. The cable, if you have 1 panel is carrying no more current than the wiring to your 12 v sockets which are fused at 15/20 amps and the sockets rated for 20 amps.
Under absolute ideal conditions and 100% efficiency the MPPT will be pushing out no more than 10 amps.
And yes, fuse at 10/15amps for 1 panel.

I have 360W of solar. I would have thought 6mm sufficient.

Just lost by the suggestions on Victron kits. See previous

 

[wildslammer22]

I have 360W of solar. I would have thought 6mm sufficient.

Just lost by the suggestions on Victron kits. See previous

Please tell me you need all that solar to recharge your cordless chainsaw batteries and it’s not for a hair dryer…

 

[yossarian]

I had a look at the Victron 100/30 spec sheet and according to that the terminals can accommodate 6 AWG / 16mm wire max. Personally I'd use something more manageable but you can't go wrong by going large I guess.

Edit:

Interesting to note that the 3rd battery in an ocean/coast, originally fused at 75A I think, is wired with 16mm cable according to my diagram.

 

[JuanVecino2023]

Please tell me you need all that solar to recharge your cordless chainsaw batteries and it’s not for a hair dryer…

Hair straighteners. And foot spa.

 

[JuanVecino2023]

I have 360W of solar. I would have thought 6mm sufficient.

Just lost by the suggestions on Victron kits. See previous

I concur. Which is why I was scratching my head.

 

[Beaker]

The size maybe to minimise the voltage drop and not just for the current capacity.

 

[JuanVecino2023]

The size maybe to minimise the voltage drop and not just for the current capacity.

I would agree - a bit of both. 6AWG is definitely a sledgehammer to crack a walnut. With a 1.5m - 2m of cable max to the rear leisure battery, 10 AWG would probably be enough. 8AWG if you felt keen.

This is kind of useful.

 

[secret lemonade drinker]

Voltage Drop Calculator | 12 Volt Planet

Use our Voltage Drop Calculator to select the correct Cable for your campervan, motorhome or boat wiring application. Auto and Marine Electrical Components from 12 Volt Planet - Cable Size Calculator

www.12voltplanet.co.uk