Charging my Fogstar Drift 230ah LiFePO4 Under-seat Battery

[Tel Jenkins]

I am going to replace the 2 85ah LA batteries with an underseat Fogstar Drift 230ah lithium. Firstly I'm trying to find info on removing the swivel seat but there is little info out there on how to do it. Also I need to find out if the leisure battery charger that's in the Westfalia, is it powerful enough to deliver 14.4a to the Fogstar?
There is also a Victron MPPT pushing power from 275w of solar in to the LA batteries. Another thing I can't seem to find is, are the batteries being charged when on hook up?

 

[Lenny HB]

The seat is held in by 4 bolts the seats are very heavy best to have help to lift it out.

It will have a charger and 12v distribution unit often under the other seat or hidden in a locker. It will charge the leisure battery when on EHU and normally they charge the starter battery as well. It will probably be either a CBE unit or an Elektroblock unit.
You will probably find the charger won't support Lithium charging so if you are going the use EHU a lot its best to fit a suitable mains charger.

There are loads of threads on the forum about fitting Lithium.
These are the results from just a quick search there are far more.

https://www.motorhomefun.co.uk/forum/search/649705/?q=Fitting+Lithium&o=relevance

 

[MichaelT]

Just set your onboard charger to gel setting which will be OK so long as you don't hook up all the time. If like us you are nearly always off grid so long as your mppt controller supports lithium that will keep you charged. If you have a smart alternator you'll need a b2b also.

 

[Dorwyn]

What especially is the issue with continuous hookup? I've never understood.

 

[Rogerwyn]

There should be 4 bolts that secure the seat to the base and a plug to disconnect but be carful it’s a heavy lump, as for the rest someone will be on to advise you on that.

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[Jev88]

What especially is the issue with continuous hookup? I've never understood.

I think that lipo battery don't like being sat at 100% charge long term for best life expectancy.

 

[Lenny HB]

What especially is the issue with continuous hookup? I've never understood.

Not good for Lithium unless you have a proper Lithium charger, still best to not leave them on charge when not using the van.

 

[MichaelT]

What especially is the issue with continuous hookup? I've never understood.

If you don't have the correct profile it may not charge correctly but it's OK for the odd day or two.

 

[Dorwyn]

Ok, I'll be charging every couple of weeks with a mains lithium charger in any case. I do have a Victron mppt to install. Another thing I don't understand is why b2b chargers are so expensive. They don't even need a mains supply. And you have to disable your onboard splitter.

 

[LithiumConvert]

Another thing I don't understand is why b2b chargers are so expensive. They don't even need a mains supply

They are basically two units in one. Battery to Battery power transfer.
More usually wired as alternator to leisure battery.

The input battery side doing the work which would otherwise be provided by the mains supply,

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[Speve]

We have a victron multi plus and it will keep the battery to storage when on EHU also victron mppt smart solar will do the same.im not sure what that means but my take is it will charge until full then as it recognises you are on EHU it will let battery drop to a storage capacity.

 

[Tel Jenkins]

If you don't have the correct profile it may not charge correctly but it's OK for the odd day or two.

I am only planning to use hookup very occasionally, so hopefully this wont be an issue.
I need to remove the seats first to see where the consumer unit/fuses/wiring all goes to. There is a monitor on the wall for tank levels and batteries but it's very basic, only showing 4 levels from empty to full.
Also I'm wondering if I should fit a B2B charger as at the moment, I'm not sure where the leisure batteries are being charged from (smart alternator?) when driving. Also they are being charged from the Victron MPPT which I can at least change the profile on that unit.
Have to see how it goes.

 

[The Artilleryman]

B2B, yes is the answer, can be a problem to find and disable split charge relay, but is a must for LiFePO4.

 

[treblid]

Seat removal. It may differ slightly but this will give you a guide: Thread 'X290 - step by step access to the under driver seat leisure battery compartment' https://www.motorhomefun.co.uk/foru...iver-seat-leisure-battery-compartment.250152/

 

[Lenny HB]

Also I'm wondering if I should fit a B2B charger as at the moment, I'm not sure where the leisure batteries are being charged from (smart alternator?) when driving

You probably already have a B2B installed but settings on it will changing.
If you monitor the leisure battery voltage while driving and start with a partly leisure battery down below 75% the voltage should go up to 14.2-14.4v until the battery is charged then hold there or drop back to 13.8v depending on the B2B, If it varies up and down dropping to 12.4v you don't have a B2B.

You could use one of these to make checking easy.

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