Split Relay / DC to DC for Lifepo4 300Ah

[PughGlobal]

Hey all,

I am looking at connecting up my Lithium 2 x 150Ah to the Van as a secondary charge.

Do we have anyone here who've already connected LiFePo4 to their vans?

I am thinking that the Split Charge Relay isn't any good as I have a 2014 Transit.

I was partly thinking, could I put switches to select Leisure or AUX to power the my inverter then use the 240v Victron Charger (but thats DC to AC back to DC) which would be a waste.

I'm new to all this.

Thanks in advance for any advice.

Cheers

Ian / Pughy

 

[SquirrellCook]

DC AC DC easy and adaptable too.

 

[wildebus]

The DC-AC-DC conversion could be a bit wasteful but the extra energy is there from the alternator so not really an concern.
Using an inverter on the starter battery to then feed a mains battery charger connected to the lesiure battery is perfectly doable (https://www.wildebus.com/blog/products/uber-cool/use-of-an-inverter-as-a-split-charger/)

Lots of people have LifePO4 batteries here yes (not me though ) A Relay won't really cut the mustard if you are wanting to get a full recharge when driving, but it will give a good boost to the batteries

 

[SquirrellCook]

Very good report Dave.
I just guessed it would work that way and it's nice to see it proved.
Before going solar, the alternator via an inverter would provide all the 240 volts to the habitation needs including a domestic fridge. So when we parked up the leisure battery would be fresh for our stay.

 

[PughGlobal]

Great! thanks Dave.
FYI the Amazon link on your page points to an unavailable item; but hopefully you'll still get kickback from the near £50 order I just placed

The DC-AC-DC conversion could be a bit wasteful but the extra energy is there from the alternator so not really an concern.
Using an inverter on the starter battery to then feed a mains battery charger connected to the lesiure battery is perfectly doable (https://www.wildebus.com/blog/products/uber-cool/use-of-an-inverter-as-a-split-charger/)

Lots of people have LifePO4 batteries here yes (not me though ) A Relay won't really cut the mustard if you are wanting to get a full recharge when driving, but it will give a good boost to the batteries

 

[wildebus]

Great! thanks Dave.
FYI the Amazon link on your page points to an unavailable item; but hopefully you'll still get kickback from the near £50 order I just placed

Cheers The kickback will be around 50p if I'm lucky.
Are you going to use an inverter then? After doing my test I would revert to that method if I had a standalone inverter rather than the multiplus. You shouldn't really need more than 1 charger but there is a distinct lack of integration on this aspect (There are a couple of B2B/Solar/Mains all-in-one units, but they run over £1,000!)

 

[PughGlobal]

Cheers The kickback will be around 50p if I'm lucky.
Are you going to use an inverter then? After doing my test I would revert to that method if I had a standalone inverter rather than the multiplus. You shouldn't really need more than 1 charger but there is a distinct lack of integration on this aspect (There are a couple of B2B/Solar/Mains all-in-one units, but they run over £1,000!)

Whoop whoop don't spend it all at once!

Yep, I am going to run with the cheaper inverter, I can then plug my Victron 30A Blue Smart IP22 mains charger (https://amzn.to/3248EBC) into the inverter or into my Petrol Generator if I need a boost and I am not planning on driving anywhere.

I had my Genny running at the Stratford U-Avon meetup as my batteries died the first night.

 

[wildebus]

Whoop whoop don't spend it all at once!

Yep, I am going to run with the cheaper inverter, I can then plug my Victron 30A Blue Smart IP22 mains charger (https://amzn.to/3248EBC) into the inverter or into my Petrol Generator if I need a boost and I am not planning on driving anywhere.

I had my Genny running at the Stratford U-Avon meetup as my batteries died the first night.

Sounds good.
If you get a hi-current isolation switch such as this one - https://amzn.to/32fkrxe - you could very easily change the inverter DC input between the Starter Battery and the Leisure Battery to give extra versatility with yout Inverter useage (You could also, if you put the switch at 1+2, also directly link the two batteries together for emergency jump starting - but maybe that bit is not a good idea if you have Lithium one side and Wet Cell the other )

 

[wildebus]

Oh, there are other options to get a controlled charge profile as well if you have a more powerful Solar Controller than a Mains Battery Charger ...

1) Starter Battery ==> Inverter ==> 24V or 48V PSU ==> MPPT Solar Controller (this setup: http://www.motorhomebuilder.com/threads/40a-smart-mains-battery-charger-for-under-£15.66708/)

2) Starter Battery ==> Voltage Booster ==> MPPT Solar Controller.

These are alternatives but a bit more fiddly when the solar controller is used for panels as well (which is usually the case )