Lithium LifePo4 12v Batteries - Time For An Upgrade?

[bobbybasic]

A second opinion is what I'm looking for too. A tear down would be good.

I'm not powering anything at the minute, I am researching and learning

Regarding AH numbers - isn't the question how long are you powering for, as well as "what are you powering"?

 

[bobbybasic]

I've been speaking to Steve at Roamer who would like to drop in here to answer any questions

 

[bobbybasic]

They use Prismatic cells and a custom BMS, and busbars to connect cells. Here are some pics from some other batteries in their range. Same tech thats in the underseat 200ah.

 

[RoamerBatteries]

Hi Guys! This is Steve at Roamer Batteries, happy to answer any questions

First off, I've had T4s and T5s for 10 years and currently have both a T5 4Motion and a Crafter 4Motion which I converted myself and now rent out for ski holidays in the Alps via Roamer Vans. You can see pics of our vans on our Insta page @roamervans So I know my way around off campervans and VWs in particular. The battery business was born from a love of off grid camping and frustration at the limited generic options available (and a lot of spare time over lockdown haha!).

Yes they are manufactured in China but on a quality controlled production line and we use high quality components - prismatic cells, busbars and 2 different customised BMS setups. We are a UK business, ship from our warehouse in Yorkshire and provide full UK warranty support.

We offer 3 capacity options (100Ah, 200Ah and 300Ah) and two BMS options. The first gives you Bluetooth monitor and the ability to tweak settings, but is only for single battery installs (no parallel or series connection) and limited to 150A continuous discharge. The second options is a more heavy duty BMS, we dropped the Bluetooth in favour of a higher continuous discharge rating and the ability to parallel or series connect. All batteries have standard protections - high/low voltage etc and we also added low temperature charge protection.

We can also make completely custom batteries - any case shape or size, voltage, capacity or power output. This has been really popular with overlanders in particular, as we can build a battery to fit a specific space. I've also been able to make some amazing batteries for people including a 24V 600Ah beast! The seatbase design started off as a custom battery but I decided to make this a main line product as it works so well. As far as I know, 200Ah of lithium is the biggest battery that can be fitted into a T6 seatbase?

This will be our second batch of seatbase batteries so I've been able to tweak the design slightly - the dimensions are now 330mm x 290mm x 180mm high so it'll now squeeze between the floor brackets, and beneath a swivel seat (the first design sat on the rails and it poked up slightly at one end). We had to reduce the size of the BMS from a 150A to a 120A continuous discharge but that seemed like a small compromise. I'm happy to do a teardown video when the next batch arrives (end of April) but in the meantime, you can see a typical layout and construction in BobbyBasics's post above.

 

[bobbybasic]

Thanks Steve!

 

[t0mb0]

Hi Guys! This is Steve at Roamer Batteries, happy to answer any questions

First off, I've had T4s and T5s for 10 years and currently have both a T5 4Motion and a Crafter 4Motion which I converted myself and now rent out for ski holidays in the Alps via Roamer Vans. You can see pics of our vans on our Insta page @roamervans So I know my way around off campervans and VWs in particular. The battery business was born from a love of off grid camping and frustration at the limited generic options available (and a lot of spare time over lockdown haha!).

Yes they are manufactured in China but on a quality controlled production line and we use high quality components - prismatic cells, busbars and 2 different customised BMS setups. We are a UK business, ship from our warehouse in Yorkshire and provide full UK warranty support.

We offer 3 capacity options (100Ah, 200Ah and 300Ah) and two BMS options. The first gives you Bluetooth monitor and the ability to tweak settings, but is only for single battery installs (no parallel or series connection) and limited to 150A continuous discharge. The second options is a more heavy duty BMS, we dropped the Bluetooth in favour of a higher continuous discharge rating and the ability to parallel or series connect. All batteries have standard protections - high/low voltage etc and we also added low temperature charge protection.

We can also make completely custom batteries - any case shape or size, voltage, capacity or power output. This has been really popular with overlanders in particular, as we can build a battery to fit a specific space. I've also been able to make some amazing batteries for people including a 24V 600Ah beast! The seatbase design started off as a custom battery but I decided to make this a main line product as it works so well. As far as I know, 200Ah of lithium is the biggest battery that can be fitted into a T6 seatbase?

This will be our second batch of seatbase batteries so I've been able to tweak the design slightly - the dimensions are now 330mm x 290mm x 180mm high so it'll now squeeze between the floor brackets, and beneath a swivel seat (the first design sat on the rails and it poked up slightly at one end). We had to reduce the size of the BMS from a 150A to a 120A continuous discharge but that seemed like a small compromise. I'm happy to do a teardown video when the next batch arrives (end of April) but in the meantime, you can see a typical layout and construction in BobbyBasics's post above.

Thanks for coming on, great to speak to someone making stuff like this on the forum.

I have a question about the warranty which I'd like to get your view on.

One theoretical advantage of lithium is the greatly increased cycle life. For example, you quote a cycle life of 8000 (at 80% DoD) which is huge, even assuming you were living in your van and cycling daily that would still be two decades of life! However, the warranty is only three years. Given I'm a naturally cautious type, then my conservative estimate as to the life of the battery is much closer to the period the manufacturer is willing to warranty it for than any theoretical cycle life. Given this, I find it very hard to consider lithium for my particular use case as I can get a much cheaper premium AGM with a 5 year warranty - others may have different requirements obviously, if you really need 200Ah with 80% DoD under the seat then I think you are the only game in town!

I can't help thinking of the LED lightbulb example. Every LED lightbulb I buy lists how many tens of thousands of hours it theoretically lasts but in practice I end up replacing them almost as frequently as the traditional type because they tend to just mysteriously stop working!

 

[RoamerBatteries]

I have a question about the warranty which I'd like to get your view on.

Yes fair point and cycle life is impossible to prove - it's unlikely anyone using a LiFePO4 battery in real life situations has had theirs long enough to see 8000 cycles. Of course, if you look after it then it will last waaaay longer than lead acid, that's been proven many times under test conditions. The BMS will also protect the battery from accidental damage, charging below zero etc so it's (almost) idiot proof.

There is no reason to think that it won't last you 10, 15 even 20 years but the warranty doesn't guarantee longevity, that's not the point. The warranty is to protect you from manufacturing faults, a dodgy cell or loose connection to the BMS, something like that. So in that context whether it's 3 or 10 years isn't particularly relevant. More important when you're handing over a large amount of money is knowing that if you have a problem then the company dealing with it will get it sorted out. A 30kg battery is not something you can ship back to China yourself so we have taken over the manufacturers warranty support - if you have an issue then send it back to us. We test the fault and assuming we can replicate the problem then we will issue a replacement from stock, or if this is not possible, a refund. We can offer an extension to 5 years at a 10% premium but my advice is that it's not worth it, if there's a manufacturing fault then this will be obvious well before the 3 years is up.

 

[DXX]

Not sure what weight the seat base foundations are designed to handle in a collision but an extra 30Kg might be pushing the limit with a large person in the seat.

 

[RoamerBatteries]

Not sure what weight the seat base foundations are designed to handle in a collision but an extra 30Kg might be pushing the limit with a large person in the seat.

I did look this up originally and a crash test simulates a 3T load per passenger - and that’s pulling from the frame and seatbelt which will put a lot more strain on the seat than at the base where it is securely bolted down. Of course you’d need to weigh up any risks for yourself but I really don’t see it as something to be concerned about. I’d be more worried about have 100kg of lead acid loosely strapped in the back

 

[DXX]

I did look this up originally and a crash test simulates a 3T load per passenger - and that’s pulling from the frame and seatbelt which will put a lot more strain on the seat than at the base where it is securely bolted down. Of course you’d need to weigh up any risks for yourself but I really don’t see it as something to be concerned about. I’d be more worried about have 100kg of lead acid loosely strapped in the back

Just so you‘re aware that 20Kg battery will have a mass of 650Kg if it stops from 60MPH within 10m. You might want to fit a different restraint instead of the wood.

So a 3T simulated test load equates to 92.5Kg stopping from 60 MPH within 10m. 92.5Kg minus 30Kg for the battery unit leaves just 62.5Kg for the driver.
Not many drivers in the 60Kg range I think.
I agree on the comment on battery security and the benefits of housing it in a CE approved unit.

 

[RoamerBatteries]

So a 3T simulated test load equates to 92.5Kg stopping from 60 MPH within 10m. 92.5Kg minus 30Kg for the battery unit leaves just 62.5Kg for the driver.
Not many drivers in the 60Kg range I think.
I agree on the comment on battery security and the benefits of housing it in a CE approved unit.

Thats good info and more than I found out. My logic was more in where the load was being applied, a pull test applies force at end of a lever (the seat) whereas our battery would be fixed to the floor next to the bolts. I’d be interested to know how much force the base on its own could handle, my guess would be at least 10-20x that of the seat. I’d written it off as a reason for concern but I’ll give some thought to recommended mounting options. The design of our battery allows room at the front and the back if you wanted to add extra brackets or straps to secure it to the floor so there’s a few options

 

[bobbybasic]

Hey Steve, do you have any pics of your under seat @RoamerBatteries in situ?

Would be great to see some install photos, or even drawings/renders etc

 

[RoamerBatteries]

Hey Steve, do you have any pics of your under seat @RoamerBatteries in situ?

Would be great to see some install photos, or even drawings/renders etc

Sort of. I’ve got a shoot lined up for when the new batch of batteries arrives next week so hopefully this will do for now.

This is the PREVIOUS version that was 335mm wide. We’ve managed to redesign it to 290mm wide so the NEW version will sit between floor mounting rails instead of on top like this pic. It will therefore sit nicer side to side and vertically but you can at least get an idea of remaining space surrounding the battery (terminals are out of shot on this pic but are accessible from the rear)

 

[Strettyp]

I've got a factory fitted leisure battery under the factory swivel base so the base seat battery looks really good as an upgrade, but is it as simple as just swapping them, and do I need to worry about leaving permanently in the van?

 

[RoamerBatteries]

I've got a factory fitted leisure battery under the factory swivel base so the base seat battery looks really good as an upgrade, but is it as simple as just swapping them, and do I need to worry about leaving permanently in the van?

You don't need to worry about leaving it permanently installed as the internal BMS will protect the battery, its got low temperature charge protection too which a lot of lithium batteries don't have.

When you say the factory fitted battery, is this a leisure battery for camper electrics or an aux battery for the factory engine preheater/winch etc? I'm not familiar with the T6 factory electrics setup so would need some help on this one.

Either way, you might need to consider the chargers you've got installed, recommended charge voltage is 14.6C and it can also handle a much bigger charge current so to ensure you fully charge the batteries in the most efficient way, you'll want chargers with a lithium profile and a high power output. If you can let me know what make and model of chargers you've got installed then I'll look into it for you.

 

[Strettyp]

You don't need to worry about leaving it permanently installed as the internal BMS will protect the battery, its got low temperature charge protection too which a lot of lithium batteries don't have.

When you say the factory fitted battery, is this a leisure battery for camper electrics or an aux battery for the factory engine preheater/winch etc? I'm not familiar with the T6 factory electrics setup so would need some help on this one.

Either way, you might need to consider the chargers you've got installed, recommended charge voltage is 14.6C and it can also handle a much bigger charge current so to ensure you fully charge the batteries in the most efficient way, you'll want chargers with a lithium profile and a high power output. If you can let me know what make and model of chargers you've got installed then I'll look into it for you.

It's the battery that is installed when you order the factory installed heater, I can try to dig out the spec but pretty sure it's the 75Ah, AGM one

 

[t0mb0]

I've got a factory fitted leisure battery under the factory swivel base so the base seat battery looks really good as an upgrade, but is it as simple as just swapping them, and do I need to worry about leaving permanently in the van?

The standard factory fit 2nd battery just charges via a relay so you’ll definitely need a lithium compatible DC-DC charger if you haven’t added one already.

 

[Strettyp]

The standard factory fit 2nd battery just charges via a relay so you’ll definitely need a lithium compatible DC-DC charger if you haven’t added one already.

Ok cool thank you

 

[RoamerBatteries]

It's the battery that is installed when you order the factory installed heater, I can try to dig out the spec but pretty sure it's the 75Ah, AGM one

Ah gotcha... I've seen Crafters with the same setup. Like t0mb0 says, the aux battery is on a smart relay. I know it works differently to a standard split charger but I'm still pretty sure this can't be used as a leisure battery in the way you're thinking.

I would keep it simple and leave the factory battery where it is, then run a battery to battery charger to the new lithium. If you don't have room under the seat then you'd need to find a space in the back but at least that way you'd know it's set up right and it's not going to interfere with the vehicle electrics. We sell 200Ah batteries in a couple of different shapes so sure we could find something that fits.

 

[RoamerBatteries]

The other standard shape 200Ah is L525 x W240 x H220. I'm also working on a new shape for a T6 converter that is only 180mm wide, so it'll fit in a side pod next to the wheel arch. So.... options