Sorry complete newbie here. I have installed Lifepo4 battery (640Ah) in my motorhome. I was told it is not safe to charge from my ignition/battery and use a DC to DC 12v/30a charger, which I have done. But since disconnecting the 12v feed and adding the charger in between the load, my 12v Lifepo4 batteries do not feed the motorhomes 12v system back to the vans 12v consumer/fuses so nothing 12v works in the van? Can somebody please let me know if I’ve cocked up somewhere?
No This is normal.
DC / DC converters pass power in one direction only.
If you have circuits that you need to power in the van from the House battery (in the motor home), then you need to move the DC/DC converter upstream of these loads, i.e. to move it into the van closer to the alternator.
Thank you makes sense. If I leave the DC charger where it is, will it do any harm just running a new 10AWG positive to the vans 12v fuses/consumer units main input. Also if this is ok, will I also need to run a negative with it?
This is ok. No, you should not need to run a new negative.
Hi
I have just run the 12v positive back to the 12v fuses from the LifePo4 Leisure batteries. On opening the back of the 12v fuse housing it has a 12v permanet live in dont know what this powers? and a seperate 14v ignition power, which I am guessing is the alternator? as it is the two same brown wires going into my DC to DC charger at the back of the Van.
If I wire into the latter direct back to battery will it not bypass the DC charger and atempt to charge direct from the alternator? My heads fizzled out.
Can anyone please advise on which live I need to be in at the back iof the 12v consumer fuses?