Upgrading the Under Seat Leisure Battery to Lithium and Removing the 2nd Leisure Battery

[Wannabecamperman]

I had them installed in a reinbeck (Hamburg, Germany. It took them a day. During the day I visited Hamburg. It cost a bit but I am still very happy . Did not take the inverter or solar. https://www.camperelektrik.de/colle...ierung-autarkiepaket-vw-t6-1-california-ocean

Toll! ...Aber sehr teuer!!

 

[wildslammer22]

I am vaguely interested in doing this battery change.
I too have a 6 year old ocean. The leisure batteries are nearing end of life - probably because I (and maybe the prior owner) sometimes forget to regularly charge the batteries every couple of weeks when the camper is not used.

The advantages as I see it are Lithium can maintain it's charge for months and potentially I could increase the capacity of the batteries.

I did it last year when my original batteries in my T6 were end of life. Kept the existing charger - the AGM profile works well for LifePo4 batteries. I rarely use EHU now but the trickle charge function to starter battery is also retained when I do. I did replace the split relay with a DC-DC charger. I bought Xplorer Extreme batteries which are self heating and will charge/discharge down to -20°. The only issue I had was I to do a bit of DIY to get the rear battery to fit as they were a few mm longer and there is no leeway in the hatch width wise! The front battery under seat was fine with enough room for the DC-DC without having to move the fuse box, shunt etc. I believe Roamer now do 100ah batteries which are exactly the same size as the standard Cali AGM's. More expensive but they do have a higher spec BMS and will be easier to fit.

It’s worked great, I have the fridge on 24/7 all year round (I do have an 100w solar panel too). I can run Starlink all night if I want, lights, the heater in winter and charge phones etc and have never gone below 70% SOC in a single day. My only complaints is the hassle getting the rear battery in and the app that comes with the Xplorer batteries is crap!

 

[Dave Wickham]

Why do it?
Our nearly 6 year old T6 batteries are still working just fine , so why do they need changing? Lithium batteries are prone to combustion aren’t they?

I agree with this. I work for a company that has done a lot of fire tests on Li-ion batteries and they can be quite ferocious under any battery abuse condition (can release jet flames). Thats why I won't have Li-ion storage batteries in my house but only on an outside brick/block wall (at least 2m away from a window) or have them in an out-house. My T6 also nearly 6 years old now and batteries work OK - I get 3 days off grid running fridge at high (level 6) when its hot!! Mind you the charge drops to 60% but I think you are OK to let them drop to 50%, anyone know what is the 'safe limit' to avoid any leisure battery damage?

 

[WelshGas]

I agree with this. I work for a company that has done a lot of fire tests on Li-ion batteries and they can be quite ferocious under any battery abuse condition (can release jet flames). Thats why I won't have Li-ion storage batteries in my house but only on an outside brick/block wall (at least 2m away from a window) or have them in an out-house. My T6 also nearly 6 years old now and batteries work OK - I get 3 days off grid running fridge at high (level 6) when its hot!! Mind you the charge drops to 60% but I think you are OK to let them drop to 50%, anyone know what is the 'safe limit' to avoid any leisure battery damage?

 

[Kjetil]

Which vehicle do you have?
if you have a T5 SE, as your Avatar information states, you should have 2 leisure batteries. 1 under rear wardrobe and 1 under front drivers seat LHD.

(Sorry for late reply)
Yes, but I only have the one under the seat in front. And I have been searching for info on the easiest way to connect the red(+).

 

[WelshGas]

(Sorry for late reply)
Yes, but I only have the one under the seat in front. And I have been searching for info on the easiest way to connect the red(+).

So, you have an SE, the Full camper with kitchen and wardrobes and the rear Leisure Battery, below the rear wardrobe, has been removed together with the the large red wire that connected the rear battery to the front underseat leisure battery?

 

[Kjetil]

Yes, that is correct. Don’t ask me why but that is how it is. I read somewhere that in some markets the rear battery was optional.

 

[kave]

Not quite correct. Lithium-ion the older, far less safe batteries should go to 80% ideally.

The newer LifePO4 batteries that my newer Bluetti and Jackery power banks, and also my new Tesla Model Y have, are fine at 100% all of the time.

Anyone moving from lead acid or gel to lithium should ensure that they are buying the newer LiFePO4 batteries for the above reasons.

You do as you please. But the fact is you will shorten the life span of the batteries when charging to 100% all the time.

 

[WelshGas]

Yes, that is correct. Don’t ask me why but that is how it is. I read somewhere that in some markets the rear battery was optional.

Well you live and learn. Never heard of the California full campervan having an Optional 2nd Leisure Battery.
Have you owned this vehicle from new?
If not, have you checked the compartment below the rear wardrobe for any evidence of a 2nd leisure battery having been fitted in the past?

 

[Wannabecamperman]

You do as you please. But the fact is you will shorten the life span of the batteries when charging to 100% all the time.The 'simple fact' is that you are referring to the older Lithium-Ion vatteries

 

[Wannabecamperman]

The 'simple fact' @kave is that you are referring to the older Lithium-Ion which are absolutely recommended to charge to 80% to maximise charge cycles.

However, as I mentioned, the newer LiFePO4 batteries last just as long when charged to 100% and are actually recommended to do so in many cases, such as my new Tesla Model Y.

 

[Wannabecamperman]

Why Charging to 100% is Beneficial:

• Cell Balancing:
  LiFePO4 batteries consist of multiple cells. Charging to 100% helps ensure all cells are fully charged and reach the same voltage, a process called balancing. Unbalanced cells can lead to premature failure of individual cells.
• Maximizing Capacity:
  Charging to 100% ensures you are utilizing the full capacity of your battery.
• Solar System Considerations:
  In solar systems, batteries may not always reach 100% charge due to daily usage and varying solar input. Therefore, it's important to occasionally charge to 100% to facilitate balancing.
  
  
  
• - I hope this helps @kave

 

[yanathem]

(Sorry for late reply)
Yes, but I only have the one under the seat in front. And I have been searching for info on the easiest way to connect the red(+).

You must have one of these underneath your passenger seat (RHD) It is the split charge relay. Which connects the alternator and leisure batteries.

The split charge relay is not used when changing to a liFePO4 leisure battery. You will need a dc-dc converter.

 

[Kjetil]

Well you live and learn. Never heard of the California full campervan having an Optional 2nd Leisure Battery.
Have you owned this vehicle from new?
If not, have you checked the compartment below the rear wardrobe for any evidence of a 2nd leisure battery having been fitted in the past?

So it is. I haven’t seen any traces of a rear battery. But I might have to see what’s behind the walls. But anyway, my question is where the red cable connects, all the way to under the seat or, somewhere between. It’s not a big issue earth it and to draw the cables. I’m just wondering where to. I guess I need to connect it correctly where the N162 relay is fitted.

 

[Kjetil]

You must have one of these underneath your passenger seat (RHD) It is the split charge relay. Which connects the alternator and leisure batteries.
View attachment 139525
The split charge relay is not used when changing to a liFePO4 leisure battery. You will need a dc-dc converter.

Great, thanks! Is that the N162 relay? And are the two red cables from front and rear leisure battery respectively?

 

[SanderR72]

You must have one of these underneath your passenger seat (RHD) It is the split charge relay. Which connects the alternator and leisure batteries.
View attachment 139525
The split charge relay is not used when changing to a liFePO4 leisure battery. You will need a dc-dc converter.

Not true, my split relay charger is used while driving to charge my LifePO4’s (both of them). I’m not using a dc-dc converter. I’m just never on EHU.

 

[yanathem]

Great, thanks! Is that the N162 relay? And are the two red cables from front and rear leisure battery respectively?

It is. N162 relay is the split charge relay.
There is actually three cables, one is out of view. On the left hand side that’s the cable from the engine. The cable on the right hand side with the bare wire showing is one of the leisure battery cables. The other leisure battery cable is behind it. You can just make out a fabric sleeve on the bottom right of that photo. Both leisure battery cables are in that sleeve.
Photo below shows the three cables more clearly. Photo courtesy from a thread from Loz who made a post with instructions and photos showing how to change that split charge relay to a more modern dc-dc controller. Loz might have those speech bubbles the wrong way round. The cables that are together in the sleeve are from the leisure battery’s.

 

[Kjetil]

Great! This is info I’ve been searching for years(!). Now hopefully I know where to connect a rear leisure battery that was missing in my 2005SE Cali.
I’m not sure what you mean by ”…make out a fabric sleeve on the bottom right of that photo.”. Is it a function in the picture of the relay?

 

[Kjetil]

Great! This is info I’ve been searching for years(!). Now hopefully I know where to connect a rear leisure battery that was missing in my 2005SE Cali.
I’m not sure what you mean by ”…make out a fabric sleeve on the bottom right of that photo.”. Is it a function in the picture of the relay?

Hi again @yanathem. Disregard my previous post. I know what you mean by the ”…fabric sleeve…”. Google translate fixed it

 

[JMStockholm]

I changed both my AGM’s in my Ocean to LifePo4 from SuperVolt (the Polar version that charges below zero degrees as it has its own heating).

As a drop-in replacement.

No other wires, no DC-DC charger, just the existing split relay.

I do have to say I never use EHU, so my LifePo4 leisure batteries are only being charged while on the move with the existing alternator.

They were installed in February of this year. So far so good without any problems. Fingers crossed.

What happens with the charge display as they will have much more capacity or did you bypass the shunts having it always stay at 100%?

 

[SanderR72]

What happens with the charge display as they will have much more capacity or did you bypass the shunts having it always stay at 100%?

Charge display doesn’t work anymore, it doesn’t show any percentage. I get another symbol know and didn’t bother to look up what it means. I use the app on my iPhone that came with the batteries to know what the state is.

Note I have a T5.2 with the old fashioned not so smart display.

 

[Roger Boeken]

Hello, not shure what the gains would be in removing the rear battery. The space in almost unusable.
Perhaps consider an alternative:We have bought and have installed (not ourselves) two small 100 amp lithium. The package was VW approved and warranty remains intact. The new setup was even added to the vehicle configuration in the VW database.
We have now 200 amp usable lithium which last for a few days without external power. Driving for two hours charging the batteries completely because we added also a 70 amp battery charger.
We are using this now for two years and it works flawless. Battery is nicely indicated in panel and the app which comes with the battery

Who installed this ? Can you give a price indication ? I once found a german company but price was +/- 5000 euro…