Battery to Battery charger

[Raul]

I think you might be suggesting that the 16mm cable could overheat and set fire to it’s insulation before the 150A fuse blows to save the battery from damage.

Something like that, a 150a mega will blow at 1,6 times the value in the best case scenario. That’s 240a running on a 16mm. Try run 100a on a 16mm and see how hot the cable gets within minutes the insulator will go soft. The max on a 16mm would be 50a, but since 30a is needed, the 30a would be perfect choice.

 

[autorouter]

Maybe swap the 150A Megafuse for a smaller one. I think the smallest Megafuse is 40A.

 

[Tombola]

lockdown Has been an expensive time I do agree. I have fitted the Victron B2B charger. Directly from the vehicle battery, I fitted a 150A Mega fuse to the vehicle battery 16mm cable to a 30amp circuit breaker then to the B2B then 16mm cable out of the B2B into another 30amp circuit breaker then to the Victron shunt for the negative connection to the leisure battery’s and the positive to the positive battery terminal I haven’t disconnected anything and it works a treat. No issues with the step or fridge. My control unit is the sargent EC500.

I have similar but with ec176.
Engine running without b2b has 7a going to leisure from alternator...with b2b 37-38. I have fitted a switch to the b2b in my cab so I can disable if I like.

Mine was assumed to be a "smart" alternator being a 2019van but it isnt.

 

[msyd]

as Lenny says SAP are here

Broken Link Removed

i’m not confused as such regards the wiring but after speaking to Mick there’s quite a bit more involved on my particular vehicle, the dc to dc charger is very easy but if it’s just wired as the video posted, then other things happen.

Relays are needed to stop one charger working against the other

Similarly now i’ve fitted an inverter, if left as is, the fridge, truma heating and the charger. once recognising there’s a 240v supply attached, will all go over to 240v (as in EHU) and drain the batteries rapidly

The Sargent split charger for instance will automatically want to charge the batteries so i’ve create a loop where the inverter is on drawing off the batteries and so is the sargent charger whilst it’s trying to charge them.

Also same for the fridge and Truma, so unless i have something fitted within the electrical system i’ll need to make sure that all those 3 items are turned off or on to gas whilst the inverter is on

It’s not so simple as I thought and has been made out

Al

I broke into the circuit behind MCB 1, which just supplies the mains sockets around the van, but not including water heater, fridge, stove etc which are served by MCBs 2 and 3. Using a 240V relay, which n/c connects the inverter to that circuit but when energised by EHU connection connects n/o contact to the circuit instead. Works perfectly.