Anyone replaced the under-seat battery with this 150AH KS-Energy Lithium?

[Lambeth Cali]

If your batteries catch fire, you won’t be insured.

Remember all those buses, phones, EVs and even aeroplanes that caught fire carrying lithium batteries?? You would have to be very confident in what you’re doing putting lithium batteries in your £70,000 van.

 

[Nand0]

@akprincehbd thanks for the details. Still not quite clear to me how you managed to secure those batteries in place. Do you happen to have pics?

@yanathem the strap method is one I considered. This could work to secure a custom battery that replaces the existing one under the driver's seat (left hand drive van), but I couldn't see how to do something similar in the compartment under the fridge. Mind you, with a large enough battery, one is probably enough, but I have to see the space under the fridge wasted

My AGMs are on their last legs, so it's time for me to do the LifePO thing. I know how to put a battery together, but securing it in place is what has me blocked at this point

 

[akprincehbd]

If your batteries catch fire, you won’t be insured.

Remember all those buses, phones, EVs and even aeroplanes that caught fire carrying lithium batteries?? You would have to be very confident in what you’re doing putting lithium batteries in your £70,000 van.

Yes thanks for the advice. It has to be very confident and professional, I'm a electrical engineer doing home offgrid conversions. Basically you just need to secure everything making sure there is no piercing or anything when emergency braking. The Epoxy fiber board surounding it should be at least 1mm thick.

The EVs that caught on fire is mainly very strong impact with direct hit causing the battery pack to be deformed and then shortened. And mostly they were Li-ions rather than Lifepo4.

@Nand0 ye I can take some pictures later one when I got time.

If you plan to put only 1x 314ah pack (4kwh) I suggest to put it under front seat, it will balance out the weight a bit. 4kwh is already too good enough for most ppl usage

 

[Nand0]

@Nand0 ye I can take some pictures later one when I got time.

If you plan to put only 1x 314ah pack (4kwh) I suggest to put it under front seat, it will balance out the weight a bit. 4kwh is already too good enough for most ppl usage

Much appreciated

I agree, 1x314ah would be enough, but quite frankly, given the prices, and that otherwise the space under the fridge would be wasted, I'd be very tempted to put a second one in there "just because"

What kind of "epoxy fiber board" are you using? I was thinking of using Bakelite boards, but open to better suggestions. I don't want to use wood like some people seem to be using.

 

[Lambeth Cali]

I suppose this is what forums are for, but it just seems a little more risky than most things.

The number of deaths in the UK with people charging lithium bikes and scooters in the hallway by the front door is quite high. They end up with a dodgy battery and then a fire whilst charging and its so quick with no way to escape. This seems a little like charging a scooter in your bedroom.

You two clearly know what you're doing but I worry all the same.

Having said that I live in a 1960s house with a garage on the ground floor with a very heavy 1960s fire door. In the 1960s they expected cars to catch fire. We have since converted part of that into a utility room where I charge our Dyson. After 2 Dyson batteries died I got a replacement from +amazon+amazon+amazon+amazon+amazon+amazon or Ebay. So I suppose I should practice what I preach. I'm glad its behind that door though.

 

[Kayleigh]

I suppose this is what forums are for, but it just seems a little more risky than most things.

The number of deaths in the UK with people charging lithium bikes and scooters in the hallway by the front door is quite high. They end up with a dodgy battery and then a fire whilst charging and its so quick with no way to escape. This seems a little like charging a scooter in your bedroom.

You two clearly know what you're doing but I worry all the same.

Having said that I live in a 1960s house with a garage on the ground floor with a very heavy 1960s fire door. In the 1960s they expected cars to catch fire. We have since converted part of that into a utility room where I charge our Dyson. After 2 Dyson batteries died I got a replacement from +amazon+amazon+amazon+amazon+amazon+amazon or Ebay. So I suppose I should practice what I preach. I'm glad it’s behind that door though.

Would that be an asbestos fire door being from the 60s?
If it were a Li-ion battery the resulting fire would be explosive and this is the battery chemistry those scooter and bike fires involve.
My concern would be with the BMS in DIY battery solutions. @akprincehbd what solution do you use for bms if adding the EVE cells in your Cali?

 

[Baldrick]

If your batteries catch fire, you won’t be insured.

Remember all those buses, phones, EVs and even aeroplanes that caught fire carrying lithium batteries?? You would have to be very confident in what you’re doing putting lithium batteries in your £70,000 van.

The batteries being discussed are LiPO4 - stable rather than the ones in our phones

 

[akprincehbd]

Puncture fire and charging fire are different:
Puncture file is battery physical being short ( car crash etc. ) You can easilly avoid by adding enough padding (wood/metal panel of your choice) and fully secure the battery to avoid that.

Charging fire is more or less charger issue/ BMS issue related. I use JIKONG 300A bms per 12v 314AH battery pack. I'm just using 8kwh pack to store the energy but I only use a victron 1200w inverter as I dont use very big appliance.

With a good BMS like JIKONG, if you have single cell exceed the max cell value, all charging shut down(which is what most the charging fire caused). Also you have to have active and passive balancing function, my BMS has 3A active balance. But based on the IR value I bought the EVE 314 from (www.fogstar.co.uk) they seems to be very consistant grade A cell, so I'm not expecting the active balance to kick in a lot of the time. That said with good A cell and good BMS you are on pretty solid safe system. Also this is Lifepo4 not Li-ion so much safer, you will be able to see if a cell is going worse everything is on monitor there is no chance of charing it into a fire.

You need to know what you are doing, basically when you make the pack isolate the + and - make sure they are not touching eachother at any occasion, when you full turn left or right or emergency brake, just make sure all wiring is tidy secured with enough isolation, also fuse it. Then after that the only thing can catch fire is short on a single cell

 

[Kayleigh]

Puncture fire and charging fire are different:
Puncture file is battery physical being short ( car crash etc. ) You can easilly avoid by adding enough padding (wood/metal panel of your choice) and fully secure the battery to avoid that.

Charging fire is more or less charger issue/ BMS issue related. I use JIKONG 300A bms per 12v 314AH battery pack. I'm just using 8kwh pack to store the energy but I only use a victron 1200w inverter as I dont use very big appliance.

With a good BMS like JIKONG, if you have single cell exceed the max cell value, all charging shut down(which is what most the charging fire caused). Also you have to have active and passive balancing function, my BMS has 3A active balance. But based on the IR value I bought the EVE 314 from (www.fogstar.co.uk) they seems to be very consistant grade A cell, so I'm not expecting the active balance to kick in a lot of the time. That said with good A cell and good BMS you are on pretty solid safe system. Also this is Lifepo4 not Li-ion so much safer, you will be able to see if a cell is going worse everything is on monitor there is no chance of charing it into a fire.

You need to know what you are doing, basically when you make the pack isolate the + and - make sure they are not touching eachother at any occasion, when you full turn left or right or emergency brake, just make sure all wiring is tidy secured with enough isolation, also fuse it. Then after that the only thing can catch fire is short on a single cell

Thank you for the explanation. Not sure I would personally use in the Cali, but I am interested in making something like this as a learning experiment. Fogstar seem to have everything you need to get started

 

[WelshGas]

Anyone know or is aware of the Insurance Companies take on ;
1. Replacing the VW approved AGM batteries for a 3rd party Lithium equivilent battery?
2. Doing a DIY install rather than a professional certified installation?
3. Assembling your own lithium battery from individual cells?

 

[Wannabecamperman]

If your batteries catch fire, you won’t be insured.

Remember all those buses, phones, EVs and even aeroplanes that caught fire carrying lithium batteries?? You would have to be very confident in what you’re doing putting lithium batteries in your £70,000 van.

Scaremongering based on the older lithium-ion tech. The replacement is LifePO4 - vastly safer.

 

[stim]

Much appreciated

I agree, 1x314ah would be enough, but quite frankly, given the prices, and that otherwise the space under the fridge would be wasted, I'd be very tempted to put a second one in there "just because"

What kind of "epoxy fiber board" are you using? I was thinking of using Bakelite boards, but open to better suggestions. I don't want to use wood like some people seem to be using.

I see you're in Switzerland. They don't seem to advertise it very well but AMAG will install a LiPO4 110Ah battery under the drivers seat to replace the AGM, replace the relay with a voltronic 30A charger, change something to make the electrical hookup work and do the necessary re-programming of the software. Their cost is about 1600chf, which is expensive but a LOT cheaper than any of the alternatives offered in Switzerland or Germany, plus it is VW authorised (since AMAG are the VW dealer for CH).

I've had mine for 6 months or so and it seems to work very well. A huge upgrade over the AGM:

• Charges faster, even with only 30A.
• Holds its charge better (after 2 weeks away, it did not drop by a single percent whereas the AGM was useless).
• It's lighter.
• Has a bluetooth app for checking the charge level.
• 2.5 times the usable capacity of the AGM.
• No more battery anxiety - my AGM sometimes struggled to last a whole night using the heater whereas this one has made me reconsider needing solar panels.

They work with Solar Peak for parts and installation. The battery they use is this which is 1000chf but for the extra 600chf you get all the other bits and installation, which I thought was worth it.

I hope that is useful for you!

 

[stim]

Oh, forgot to mention, it has an inbuilt heater so it can charge down to -20. Do these other options, including the DIY solution, have this feature? It's kinda necessary for winter camping in the mountains here.

 

[akprincehbd]

Oh, forgot to mention, it has an inbuilt heater so it can charge down to -20. Do these other options, including the DIY solution, have this feature? It's kinda necessary for winter camping in the mountains here.

Yes if camping in those sub zero temp then has to has the battery heating feature, a lot of the prebuild battery has this feature. Otherwise if you are DIY your own battery you can buy those lithium battery heating panels, insert them between cells and connect to a special temp control board it do the job. I bought all the parts from china each that heating panels cost £2, for a 4s batt you need 3 or 5 of that, but in UK kind of not need that.

If you don't want to DIY paying for the authorized dealer to do it is the best. But DIY is also fun if you know what you are doing and cheaper,

For me:
8x 314EVE A grade cells (12v 628ah total, however tested 660ah in reality) £480
JIKONG BMS 300A £30
Victron smart xs 50A charger £244
3x 100W Renogy solar £270 (mounting ALU bars and nuts, wiring £20)
Victron 75/15 MPPT £40
Victron smart shunt x2 (1 for each batt) £120
60A lipofe4 profile 220v charger (replacing the VW agm charger) £23
Victron smart battery sense x2 £60

Worked out under £1000 I'm quite satisfied

 

[Lambeth Cali]

Scaremongering based on the older lithium-ion tech. The replacement is LifePO4 - vastly safer.

Fill your boots.
And best of luck with the insurance.

 

[Nand0]

hi @stim . Thanks for the pointers. I know there are various options available here in CH for LifePO4 upgrades in the Cali. But the prices are a bit silly, considering I know my way around electrics.

A while back, before my Cali days, I put together a 100Ah LifePO4 battery I used for camping, which also served as an experiment. I still use this battery in my Cali to drive the laptop when I'm remote working, because the AGM struggles. And when I check the prices for a DIY job vs what they are asking, it's a no brainer.

I also already have a Votronic charger in place of the split charge relay (was part of the solar install), so all I really need to care about is the battery/batteries and the mains charger. Both my MPPT controller and the Votronic DC/DC charger already support LifePO4 profiles.

 

[akprincehbd]

So first assemble the pack EVC 314cell

I'm wraping it with tape, here you have to use non-stretch tape. put the Victron shunt in between batt- and BMS so it monitor everything.
Tidy up the cable. it will look like Above.

Left is original 75AH (only 30AH usable) Right is 314AH (10x capacity)

I know it looks like a bomb xD, so orignal AGM battery + going to Lithium batt + directly, AGM battery - going to BMS P- . Note that the t6.1 vw shunt is on the batt - terminal, I didn't rewire it leaving it in it's origianl place so the VW shunt is NOT monitoring BMS idle wattage, but the victron shunt as it's connected directly to batt- so it's monitoring everything.

Push inside it fits perfectly, left side there is like 7cm space I will slide in a 4cm thick 220V lithium charger to replace the oringal AGM charger. Also solar MPPT can be mounted on the left or top as well as it's only 4cm thick also. (75/15)

The battery will sit tight to the right side pannel, so emergency braking there is no issue, inside behind the batt is a fixing for the original AGM I didn't remove it and it can stop the lithium moving perfectly and it sits very close to the door , like 7-8mm to the door gap.
I know it doesn't look clean but I put thick foam to fit on top so that it will not move on bumpy road. it's very tight and it's not going any where. on left side I don't put too much padding as the accelaration of this car is like 11-14s 0-60mph, I'm not worrying about there is much force in the back. Also in the back is water tank very safe.


Finally on the door closing side I pad with thick foam to make it very tight, so no movement on left/right, back forth up down, very secure. There are 3 temp sensor I put on cell, BMS, wiring cable, either of them exceed the threshold temp will shut down the system.

Together with the same battery put under the passenger seat you have 8.5 kwh power usable, It will allow you harvest more from solar without wasting

 

[akprincehbd]

As you can see, when I install the battery into the wardrobe I use electric tape to insulate all the exposed point on the main wiring. The terminals on top of the batt are ok to be exposed as later on they will be covered with foam padding to ceiling

 

[akprincehbd]

Also on the side I wrap tape to be used as handle to pull batt out. As the battery is very wide now, without the strap it's hard to take it out

 

[stim]

@akprincehbd since pics and explanation, thanks, even if not useful for me now.

One question - how are you able to get 300+Ah capacity vs my 110Ah capacity for the same battery technology and what appears to be the same size?

Someone mentioned about the EHU charger. AMAG told me they "change a pin" (translated from german) to enable a lithium profile on the factory installed EHU charger.

 

[stim]

*nice pics an explanation (I can't edit the post)

 

[akprincehbd]

@akprincehbd since pics and explanation, thanks, even if not useful for me now.

One question - how are you able to get 300+Ah capacity vs my 110Ah capacity for the same battery technology and what appears to be the same size?

Someone mentioned about the EHU charger. AMAG told me they "change a pin" (translated from german) to enable a lithium profile on the factory installed EHU charger.

Thanks for the suggestion — I might take a look at that. However, I’m planning to move away from the factory charger, as it’s far too bulky for my setup. Instead, I’m exploring more compact, low-profile server chargers — possibly second-hand units — which are much more space-efficient and cost-effective.


As for the battery:


The prebuilt battery I looked at includes everything: terminals, BMS, safety padding, and a protective case. All of these components increase the overall dimensions — especially the padding, which tends to add bulk in all three directions. Prebuilt batteries are designed to be drop-in safe for a wide range of environments and use cases, so manufacturers often overbuild them to ensure robustness. That said, since LiFePO₄ batteries already have a much higher energy density compared to AGM or lead-acid batteries, the size increase isn’t usually a major concern. You can typically expect a 4x improvement in energy capacity for the same physical footprint.


However, my goal with this project was to maximize the amount of usable energy within the original compartment. For example, in the VW California, the rear battery compartment has a limited opening size — even if the internal volume is larger, you still have to fit the battery through that door. So I designed my setup to pass four cells (in series) through the opening and slide them to the right side of the compartment. That leaves around 7cm of space on the left, which I use for the breaker, shunt, and other components.


The housing for the rear leisure battery is already quite tight. I’m confident there’s no risk of piercing or damage to the compartment, as I’ve padded all six sides with thick foam. This ensures the battery is completely immobilized — there’s no play or movement, and it’s quite secure.


If you look at my battery dimensions, they reflect the pure cell size. In comparison, a typical 110Ah lithium battery — like the one you're using — might even be smaller externally, but often only half of its internal volume is actual cell material; the rest is padding, glue, and control electronics.