Lithium? The big con?

I'm still waiting for an explanation of how I went from 27 % to this?

Did the 8k spent include a regeneration system like on my Tesla...
Seems i can stay another day and a half




Screenshot_20250101_103843.webp
 
Abacist said:
Air fryers are very heavy users via the inverter!

You need a B2B and a non Smart alternator!
Click to expand...
Re the Air Fryer, Nope. Or more specifically...

An Air Fryer will use (roughly) 1500w for typically 20 minutes max. That works out at 1500/3 (60 mins / 20 mins gives you the /3) = 500wh. A 300ah 12v lifepo4 has 12v x 300ah = 3600wh capacity so the air fryer will use about 1/7th of the battery capacity.

The biggie appears to be the combination of a 3 way fridge and the inverter. The fridge 'should' be running on Gas, so the electricity consumption would be minimal, but it sounds like it is running on mains, so you have the draw of the fridge (over 24 hours) plus the overhead of the inverter (say add 20%).

Personally, I have a 150l Thetford compressor fridge - runs on 12v, consumes (per the manual) 470wh per 24 hours (so less that 20 mins for the air fryer) and has zero inverter losses as it is 12v. By comparison (per Thetford manual again) the N3141 141l 3 way uses 3.9kwh per 24 hours (seemingly irrespective of power source). So a three way fridge of 141 litres is over 8 times as power hungry as a 150 litre 12v compressor fridge. And the battery is 3.6kwh so ignoring the inverter overhead yiou get less than 24 hours from 3 way on 240v in that setup.
 
Tombola said:
3 way fridge running from batteries ?
Knock 70 + amps per day( guestimate)

Inverter left on 20 + amps per day.
Click to expand...
A thetford N3141 3 way is (per thetford) going to consume 3.9KWh per day. The 12v 300ah battery is 3.6KWh capacity, so running the fridge on 12v or (worse) 240v through the inverter will be the problem.

By comparison a Thetford T2152 150l 12v compressor fridge will use (per the manual) 470Wh (or 1/8th the power) in the same24 hour period.

Of course, the lack of a B2B is not helping as this will limit the charge rate.
 
haganap said:
Or am I expecting to much,

Or am I in the dark? No literally "I'm in the dark"

So I must be doing something wrong.....maybe I'm reading my stats wrong.

Bear in mind, I've been motorhoming for 20 plus years. My set up prior to this van was simply for 10 years, two x 120 amp batteries and an effoy, nothing more nothing less.

My set up on my new van that we've had since March is 3 x 110 victron lithium batteries,3 kw victron inverter charger, 200w of solar no B2B smart alternator. Never ever needed to think about power before, most places we stay a couple of nights, nikki uses hair dryer and we cook with an air fryer without issue.

We came away Friday, stopped the night in Stratford upon Avon, no hook up, arrived fully charged, lived our best lives and had an air fryer meal. I noticed we had hammered the batteries a bit, I noticed I was only putting in about 20-30 amps and the journey from Stratford to Portsmouth wouldn't be enough time arrive fully charged. I turned off the fridge, managed to get the charging rate up to 40 amps and arrived at Portsmouth with 98 percent battery.

We have stayed 3 nights with tonight being our 3rd and already the batteries are saying low charge. This set up comes in at over 8k factory fitted so I'm unsure why I'm in the dark?

My draw is about 3 to 4 amps even with everything seemingly switched off.
Nikki washed and dried her hair yesterday, we watched a bit of avtex tv.

How come I have had the worst performance ever when camping in the depth of winter?
Other than increasing the capacity to more than I have ever ever had, am i sat in the dark?

Seems to me I should have simply ordered two led acid batteries with an efoy?

Complete load of dreamers out there selling these off grid solutions to put you in a place that could have been achieved cheaper in the first place. Might be alright if you are slumming it in Spain l, but clearly we don't, but I would have expected to not have to worry for 4 nights away in winter in the UK...

Lithium "ain't all that" prove me wrong or tell me there's something wrong.
Or am View attachment 994946View attachment 994947i misreading something?
Click to expand...
Regardless of how your current (no pun intended) rig is set up, b2b or not 2b (I know, I’m a knob lol), you were spoilt by the wonders of methanol. In essence you had a generator of sorts chiming in and out constantly with the fantastic Efoy product.
It acted in exactly the same way as today’s smart generators do, so when the levels drop it kicks in to top your batteries back up without you having to interact.
I have a set up very very similar to yours, just with more solar and a b2b, same inverter, 400ah lithium, and it’s not as wonderful as I would have expected. Shamefully it’s my miscalculations and expectations as very much a newbie that lead (sorry) me astray, I didn’t bother to try calculate things anywhere near sufficiently or scientifically like the rest of you guys. I just had two batteries that didn’t afford me enough so added two more. When that wasn’t enough I doubled the solar. Then I found how the wizards at Carthago leave a chunk of drain on the vehicle battery rather than the habitation set, so my vehicle battery would drain while my hab side held on, so a battery master was added alongside a solar panel feeding the cab battery first before sending any leftover power to the hab side.
I’ve a couple of EcoFlow Delta Pro’s that are great as portable power sources, thus I can plug a hookup cable from one directly into the motorhome’s hookup port and the motorhome thinks it’s plugged into shore/mains 230v and it powers and charges everything back up. It’s like having x3 batteries and a 3k inverter sat in a portable box (still heavy though).
They’re great for me as I can use them independently anywhere, for multiple applications rather than tied to the motorhome. BUT where just servicing a motorhome is concerned I’d 100% go for a Efoy!
Best of luck going forward.
HNY 2025

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£8k for 300ah and an inverter? Makes me grateful for my DIY skills - currently fitting 600ah lifepo4 with Victron 3Kwh inverter, 2 B2B's plus 350W solar and a Cerbo to control, and that lot is coming in at around £3k mark (including an extra discount on the Fogstar batteries thanks to the codes available as a member of this very forum!)
 
Matt_e said:
£8k for 300ah and an inverter? Makes me grateful for my DIY skills - currently fitting 600ah lifepo4 with Victron 3Kwh inverter, 2 B2B's plus 350W solar and a Cerbo to control, and that lot is coming in at around £3k mark (including an extra discount on the Fogstar batteries thanks to the codes available as a member of this very forum!)
Click to expand...
Ticking them boxes on a luxury MH order form comes at a cost. Although if I understood correctly it was the previous owner doing the ticking so it might not be fair to compare to 2024 lithium prices given how fast the prices have been coming down past years.
 
Matt_e said:
£8k for 300ah and an inverter? Makes me grateful for my DIY skills - currently fitting 600ah lifepo4 with Victron 3Kwh inverter, 2 B2B's plus 350W solar and a Cerbo to control, and that lot is coming in at around £3k mark (including an extra discount on the Fogstar batteries thanks to the codes available as a member of this very forum!)
Click to expand...
Makes me greatful that the person that specked and bought it and used it for a few months had the good sense to know I would need it in the future.
 
The answer is you no longer have an EFOY pumping say 5A into your battery 24/7 if needed. Your electrical loads are all very significant, air fryer etc . Just compare your previous charges and discharges with your settup today.

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mikash said:
Ticking them boxes on a luxury MH order form comes at a cost. Although if I understood correctly it was the previous owner doing the ticking so it might not be fair to compare to 2024 lithium prices given how fast the prices have been coming down past years.
Click to expand...
It was 8k on the order sheet 4 years ago.
It's over 10 now, good job those prices went down...

It is a luxury though...

Lithium truly is great 👍 especially in my Tesla and Ebikes.
 
haganap said:
It was 8k on the order sheet 4 years ago.
It's over 10 now, good job those prices went down...

It is a luxury though...

Lithium truly is great 👍 especially in my Tesla and Ebikes.
Click to expand...
As Monty Python might have asked , What did Lithium ever do for us?? Torches! OK apart from the torches, what did lithium ever do for us?, power toll batteries!, OK apart from torches, and power tool batteries, ------------- add as you think of them uses.
Mike.
 
haganap said:
I'm still waiting for an explanation of how I went from 27 % to this?

Did the 8k spent include a regeneration system like on my Tesla...
Seems i can stay another day and a half




View attachment 995396
Click to expand...
mmm 12.64v isn't many V's for lithium, even when it has a 4amp draw. Whats it like with everything off and no draw?
 
bellabee said:
Exactly this!!!

Horses for courses, I suppose.

We have 2 x 7-year-old gels, can spend 6 nights on a Fun summer rally without problem.
We make 2 extended Continental trips per year, rarely stay in one place for more than a couple of days, stay on aires, campsites and free park, and have never, ever felt anxious about electricity.

We are light users of electricity, don't watch television when away, feel no need for an air fryer or a washing machine, or any of the other domestic gubbins which crowd our lives at home. We do use hookup to recharge batteries, but that's no hardship to us, as we move about so frequently. We also like to use some campsites so we can spread ourselves out in the sunshine.

I do understand that others have different priorities to us, and I'd never say 'never', but I really can't see how conversion to lithium would enhance our particular experience in any way.

On the other hand, we have been known to experience anxiety about cassette capacity. 😀
Click to expand...
I have a friend with an old Swift motorhome with a single 95AH lead acid battery and whatever split charge Swift originally fitted.
No solar, B2B or anything.
They don't have a TV and only use the battery for lights, water pump, and charging phones.
They go to Europe every summer for 2-3 months and don't plug in at all and have no problems as they move every day.
They have 2 weeks a year on a site in the UK and plug in to EHU.
As you say horses for courses, they are fine with their set up.

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haganap said:
I'm beginning to think your username is as much of a con as lithium :LOL:

I'll try harder in future...

Maybe it will become more informative on my upcoming YouTube channel whereby i discuss all the things motorhomers have been conned out of in over 20 years..


It's going to be a great watch...
Click to expand...
Don't think so!
 
I have the Hymer Smart Battery System fitted.

Spec …
  • 3 x 18 A mains chargers delivering max 56 Ah on hookup. - LAS 1218-S Lithium Chargers - Lippett
  • 1 x 18 dedicated starter battery charger. - LAS 1218-S AGM Charger - Lippett
  • 4 x 80 Ah Lithium - total 320 Ah - BOS -AG
  • 70 Ah B2B - Schaudt WA121545
  • No solar fitted as yet
I’ve only used it in late Autumn and early winter so far.

After two days usage in a cold December I was seeing around 60% battery left. This was with pretty careless use of TV, satellite, interior Blackpool illuminations, exterior awning light on, 12v compressor fridge and the diesel heater fan running most of the time.

I reckon I could get five or six days out of it with careful usage, but realistically, it’s more like four days.

Summer usage should be better as there would be less lighting, no heater and probably less TV use. So maybe five to seven days without Solar.

Hymer claim ten days self sufficiency with this system if 2 x 100w solar is fitted which in the summer is pretty realistic I reckon.

I’m not going to fit solar until I’ve lived with it for a while. I’m heading Morocco way at the end of the month and don’t want to hook up to Moroccan campsite electrics, so I’ll find out how long it lasts in better weather conditions.

If you move every couple of days then the B2B delivers 70 Ah so one hour’s driving for one day’s battery usage seems to be about the rule of thumb so far.

As a comparison my previous Hymer which I used extensively in all seasons, with diesel heating and 12v compressor fridge, had 2 x 95Ah AGMs, 70 Amp B2B, 36Ah mains charging plus 2 x 100 Ah solar, worked just fine. It did have much less in the way of lighting, big TV etc.

Pretty much I think bigger battery bank just means you use more power just coz you’ve got it!
 
Abgs said:
I have the Hymer Smart Battery System fitted.

Spec …
  • 3 x 18 A mains chargers delivering max 56 Ah on hookup. - LAS 1218-S Lithium Chargers - Lippett
  • 1 x 18 dedicated starter battery charger. - LAS 1218-S AGM Charger - Lippett
  • 4 x 80 Ah Lithium - total 320 Ah - BOS -AG
  • 70 Ah B2B - Schaudt WA121545
  • No solar fitted as yet
I’ve only used it in late Autumn and early winter so far.

After two days usage in a cold December I was seeing around 60% battery left. This was with pretty careless use of TV, satellite, interior Blackpool illuminations, exterior awning light on, 12v compressor fridge and the diesel heater fan running most of the time.

I reckon I could get five or six days out of it with careful usage, but realistically, it’s more like four days.

Summer usage should be better as there would be less lighting, no heater and probably less TV use. So maybe five to seven days without Solar.

Hymer claim ten days self sufficiency with this system if 2 x 100w solar is fitted which in the summer is pretty realistic I reckon.

I’m not going to fit solar until I’ve lived with it for a while. I’m heading Morocco way at the end of the month and don’t want to hook up to Moroccan campsite electrics, so I’ll find out how long it lasts in better weather conditions.

If you move every couple of days then the B2B delivers 70 Ah so one hour’s driving for one day’s battery usage seems to be about the rule of thumb so far.

As a comparison my previous Hymer which I used extensively in all seasons, with diesel heating and 12v compressor fridge, had 2 x 95Ah AGMs, 70 Amp B2B, 36Ah mains charging plus 2 x 100 Ah solar, worked just fine. It did have much less in the way of lighting, big TV etc.

Pretty much I think bigger battery bank just means you use more power just coz you’ve got it!
Click to expand...
Diesel heating and compressor fridge - just what I would have liked - would make a big difference
 
haganap said:
Fgs can someone explain what's happening here.?
Been out for the night, came back, checked batteries and I've more power than MisterB...

Never had this problem with AGM... when they were fooked that was that...View attachment 995335
Click to expand...
As Adrian says something not right with those readings 12.7v off load is about 15% SOC you only have a small load of less than 3 amps that shouldn't have much effect on your voltage.
A full charge 100% should resync the shunt.

As I said in my first post many pages ago a photo of your shunt settings would be helpful.
 
Last edited:
Matt_e said:
Re the Air Fryer, Nope. Or more specifically...

An Air Fryer will use (roughly) 1500w for typically 20 minutes max. That works out at 1500/3 (60 mins / 20 mins gives you the /3) = 500wh. A 300ah 12v lifepo4 has 12v x 300ah = 3600wh capacity so the air fryer will use about 1/7th of the battery capacity.

The biggie appears to be the combination of a 3 way fridge and the inverter. The fridge 'should' be running on Gas, so the electricity consumption would be minimal, but it sounds like it is running on mains, so you have the draw of the fridge (over 24 hours) plus the overhead of the inverter (say add 20%).

Personally, I have a 150l Thetford compressor fridge - runs on 12v, consumes (per the manual) 470wh per 24 hours (so less that 20 mins for the air fryer) and has zero inverter losses as it is 12v. By comparison (per Thetford manual again) the N3141 141l 3 way uses 3.9kwh per 24 hours (seemingly irrespective of power source). So a three way fridge of 141 litres is over 8 times as power hungry as a 150 litre 12v compressor fridge. And the battery is 3.6kwh so ignoring the inverter overhead yiou get less than 24 hours from 3 way on 240v in that setup.
Click to expand...
I have a 1,400 watt air fryer. Typical cooking time is 20 minutes.
The air fryer cycles the heating element on and off and the fan is on continuously for the 20 minutes.
The heating element comes on for 1 minute and draws 1,400 watts plus 35 watts for the fan so 1 minute at 1,435 watts, the element then goes off for 1 minute so only drawing 35 watts.
So for that 20 minutes cooking time my air fryer uses 10 minutes at 1,435 watts and 10 minutes at 35 watts so approximately half it's stated 1,400 watts as for half the time the heating element is off.

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haganap said:
I'm still waiting for an explanation of how I went from 27 % to this?

Did the 8k spent include a regeneration system like on my Tesla...
Seems i can stay another day and a half




View attachment 995396
Click to expand...
Probably Your neighbour ( van ) next to you has got fed up with your negativity , and connected his batteries to yours without you knowing to keep you quiet 😂😂😂
 
Abacist said:
Air fryers are very heavy users via the inverter!

You need a B2B and a non Smart alternator!
Click to expand...
Hello Abacist - I understand needing a B2B, but why a non smart alternator?

If fitting say 2 x 50 amp Victron B2B - is it necessary to replace the smart alternator with some other spec to get the full benefit of the Victrons?
 
Years ago I started with a cheapo inverter to satisfy the need for the hair dryer and curling tongs.

Then we changed vans and had a bigger inverter but still on lead acid but added a Nespresso coffee maker.

Upped to lithium and a bigger charger and B2B so we’ve added an air fryer!

From memory we now have 300ah of lithium, 2 solar panels of 130, a hefty 3kw inverter and a hefty Sterling B2B.

We are OK on the move and weekends etc without hookup or if there is plenty of sun in France or Spain for longer

Ideally I could do with doubling the solar and lithiums.

And there will be something else come along to help consume all that power - induction hob, compressor fridge freezer etc.

It’s a treadmill!

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Abacist said:
Air fryers are very heavy users via the inverter!

You need a B2B and a non Smart alternator!
Click to expand...
I suppose it depends on what you call heavy use.
A typical 20 minute cooking time with my air fryer uses about 20 amps.
 
Second morning of no EHU. We have used the electric kettle and hairdryer. We were out for a few hours in the day and all evening. I turned the inverter off when we went out. I think that is probably over cautious. We’ve watched a good bit of TV including a sound bar and fire stick. Plus of course heating. Surprisingly Solar delivered 70 Wh yesterday



IMG_5418.webp
 
Last edited:
Peter Clark said:
Hello Abacist - I understand needing a B2B, but why a non smart alternator?

If fitting say 2 x 50 amp Victron B2B - is it necessary to replace the smart alternator with some other spec to get the full benefit of the Victrons?
Click to expand...
My van is 2014 and not a smart alternator!
 
headlight said:
I suppose it depends on what you call heavy use.
A typical 20 minute cooking time with my air fryer uses about 20 amps.
Click to expand...
Sorry it’s the cumulative effect of adding another appliance on top of the TV, lights, pump, coffee maker etc when static without a hookup.
 
I was not aware of EFOY fuel cells - I would be glad to know more about them.

Are these a directly comparable option to a generator?

Would you use it to charge an onboard lithium based system - or as a separate power source - or both?

What are the pros and cons?

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