How much lithium is enough?

[Gordo]

Looking at getting lithium and a Victron inverter (3000w) for our Carthago.

This is partly driven by me hating the CBE charger it has now (unreliable) but partly as we've added an air fryer (2000w single) as well as wanting to be able to happily work off grid when we're away (i.e. Starlink/ laptops etc) and recharge e-bikes amongst other bits and pieces.

We have 520w of solar on the roof and tend to drive most days so will get a better b2b installed as well (e.g. Victron Orion).

We can get 300A of lithium batteries in the existing battery box but it won't take much more than that, replacing 200A of lead acid. Now I know that roughly gives me 3x what we have now but I'm a) bothered 300A might not be enough (esp if weather average) and b) given the overall cost, the cost of an extra battery is relatively marginal.

Soooo - what are peoples' thoughts - just put 300A in and it'll be fine or do people with that wish they'd fitted more?

Thanks in advance!
Gordo

 

[Jim]

I have 600AH –– and its enough. (for me).

 

[Abacist]

We have 300AH and our single air fryer knocks quite a big hole in it along with the other usual stuff so I would like another 150Ah for peace of mind. I only have 260 solar so could do with doubling that.

 

[suavecarve]

Immediate thoughts are, if 200 ah of lead acid was sufficient then 300 ah of lithium is, as you recognise, shed loads, on the presumption your usage hasnt changed.
Winter, will cause an issue if you are permanently in your van and charging e bikes and using air fryer regularly.

Being a TFG, another 300 ah of lithium will cost about 700 quid to put in, and ease the battery anxiety, but in reality, from my point of view, in winter, will only increase the amount of time prior to requiring a hook up (If your 300 ah is going to run out your 600 ah will run out only take longer to run out) The question then comes (to me) how much is it worth to lengthen the gap between 240 top ups ?

I would be tempted to run the 300 ah and see how long it takes before adding another.

I reckon on 50ah for air fryer use and about 60 ah for recharge of both bikes on an average day (50 km cycle). So that would be 3 to 4 days worth of electric and really hammering the battery before some external source (solar of 240 or B2B were to be required (for us)) whereas your solar might only put in 50 ah in those 4 days. On the same scenario 600 ah will run out after 8 days (or give you longer to get more solar and no need for external electric input)

I also think it depends where and when you are using your motorhome and for how long. France/Spain/Germany etc is dead simple to get a cheap fill up of electric, maybe 5 euros a fill up, if organised. whereas UK you need to go in a campsite and thats going to cost 20 quiddish (so I am told). So if in Europe it would take me 160 visits to a recharge facility for the battery to earn its keep, which isnt enough to justify my wallet coming out. It may be different for yourself.

 

[Al n Val]

I have 560ah lithium, 830w of solar and 90a B2B, we are heavy users of electricity but manage quite well

Would I like more lithium, hell yeah

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[MisterB]

'Enough lithium' is the max you can fit within your budget ....so long as you have a process to charge it up

 

[Al n Val]

'Enough lithium' is the max you can fit within your budget ....so long as you have a process to charge it up

and this is very important, the charging up bit i'm referring to

I've 90a B2B whilst driving and 120a whilst on ehu, the most i've seen whilst driving is 134a, this being a combination of b2b and solar

 

[WESTY66]

I have a Carthago and I too could only fit one battery in the original battery locker. The solution? I had Offgrid power solutions put TWO 300ah lithiums in the underfloor locker in the kitchen area, all the victron gear in the garage, binned the CBE charger and it’s great, by the end of this weekend I will have 885w of solar and early next year there there will be another 300ah lithium going in, why? Cos Mrs Westy thinks it’s a domestic house

 

[LithiumConvert]

We can get 300ah of lithium batteries in the existing battery box but it won't take much more than that, replacing 200ah of lead acid. Now I know that roughly gives me 3x what we have now

I think the reality is better than that.

Also you can run additional LiFePO4 batteries in an adjacent locker (just make sure the positive lead is fused at both ends)

so will get a better B2B installed as well

Why not get another B2B installed as well.

--------------------------------

We run the fridge on gas whilst driving, giving another 15amps into the batteries.

 

[Gordo]

I have a Carthago and I too could only fit one battery in the original battery locker. The solution? I had Offgrid power solutions put TWO 300ah lithiums in the underfloor locker in the kitchen area, all the victron gear in the garage, binned the CBE charger and it’s great, by the end of this weekend I will have 885w of solar and early next year there there will be another 300ah lithium going in, why? Cos Mrs Westy thinks it’s a domestic house

Thanks Westy - I'm eyeing up maybe putting two Fogstars on their sides (so 600Ah) in the wardrobe next to the garage. Can't use the kitchen locker as that's full of booze!

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[Gordo]

I think the reality is better than that.

Also you can run additional LiFePO4 batteries in an adjacent locker (just make sure the positive lead is fused at both ends)


Why not get another B2B installed as well.

--------------------------------

We run the fridge on gas whilst driving, giving another 15amps into the batteries.

Good shout - was thinking about just turning the fridge off on the move. I guess with the auto cutoff it could run on gas safely enough instead.

 

[Gordo]

I think the reality is better than that.

Also you can run additional LiFePO4 batteries in an adjacent locker (just make sure the positive lead is fused at both ends)


Why not get another B2B installed as well.

--------------------------------

We run the fridge on gas whilst driving, giving another 15amps into the batteries.

Another b2b is an intriguing idea - not sure that would make any difference as the smart alternator caps its output?

 

[Lenny HB]

I fitted 460ah of lithium in my CompactLine, wish I'd fitted 600ah the Fogstar 230 ah & 300ah are the same size.
I would have thought it would be easy in a C Tourer.

 

[Gordo]

I fitted 460ah of lithium in my CompactLine, wish I'd fitted 600ah the Fogstar 230 ah & 300ah are the same size.
I would have thought it would be easy in a C Tourer.

Thanks Lenny. Annoyingly the battery box will only take one (300ah) Fogstar, on its side with the handles cut off. That's why I'm checking on how much people have/ wish they had as it's easy to put one battery in, but harder to find places I'm happy to free up for two alongside ideally keeping the inverter in proximity to them.

 

[Al n Val]

I think the reality is better than that.

Also you can run additional LiFePO4 batteries in an adjacent locker (just make sure the positive lead is fused at both ends)


Why not get another B2B installed as well.

--------------------------------

We run the fridge on gas whilst driving, giving another 15amps into the batteries.

we always run the fridge on 12v whilst driving, it saves using gas, surely thats the way to be doing it isn't it?

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[Guigsy]

I've got 280Ah of Lithium... it's waaaay more than I need. Most trips, I'm not even touching the sides. I probably could have got away with half. The battery is under the driver's seat, and I knew I'd only ever be able to fit one battery in there, so I squeezed in as much as I could 'just in case'.

 

[Lenny HB]

We run the fridge on gas whilst driving, giving another 15amps into the batteries.

Dangerous and against construction and use regulations.

 

[jumar]

We've got 400 amp lithium and 400w tilting Solar...just upgraded B2B to 50amp...charge daily 2 eMTBs...and have a small 1400w airfryer...(Edited)
Sorry forgot to add 300 sunny days in España.. suppose that helps..

 

[Lenny HB]

and have a small 140w airfryer...

Must take hours to cook anything.

 

[jumar]

Must take hours to cook anything.

Not in the hands of a professional it doesn't..I've just realised my typo..
2 Salmon steaks. (Seasoned)
Asparagus.(That's that green stuff)
Potatoes Croquettes.(Carb loading)
20 minutes...start to finish
Not a single Chip in sight I might add

Jamie Oliver 30 minute meals, he got the idea from me..
Lenny can be my proof reader for my next book

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[Lenny HB]

Not in the hands of a professional it doesn't..
2 Salmon steaks. (Seasoned)
Asparagus.(That's that green stuff)
Potatoes Croquettes.(Carb loading)
20 minutes...start to finish
Not a single Chip in sight I might add

Jamie Oliver 30 minute meals, he got the idea from me..

Just not possible with 140 watts of energy

 

[jumar]

Just not possible with 140 watts of energy

OK.. well spotted..

 

[WESTY66]

Thanks Westy - I'm eyeing up maybe putting two Fogstars on their sides (so 600Ah) in the wardrobe next to the garage. Can't use the kitchen locker as that's full of booze!

As was ours but I figured I’d use more electricity than alcohol

 

[LithiumConvert]

against construction and use regulations.

This point has been discussed ad nauseum, but I have not seen any references to such regulations which backup the statement.

 

[Lenny HB]

This point has been discussed ad nauseum, but I have not seen any references to such regulations which backup the statement.

Read the construction and use regulations you are not allowed to travel with a naked flame.

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[LithiumConvert]

Read the construction and use regulations

Reference, please.

 

[Lenny HB]

Reference, please.

Easy to find with avggoole search.

 

[Carpmart]

I invested in lithium nearly four years ago now! I went for two 204A packs, so 400A in total and aside from it being bloody expensive back then, the point everyone was making on MHF was how ridiculous I was and that I would never need that much power! Fast forward to today and it’s almost an arms race to get more lithium capacity and more solar panel fitted…

 

[Gordo]

Thanks all - I think the answer is 2 x 300Ah in that case. Just need to decide where to put them now.....

 

[WESTY66]

Thanks all - I think the answer is 2 x 300Ah in that case. Just need to decide where to put them now.....

In the booze locker, keeps them warm when the heatings on
They fit perfectly

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