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

[andrew_kombilife]

Hi All,

I have a T6.1 California OCEAN and I am looking to upgrade the Leisure Battery System to Lithium from the AGM Batteries that are in the vehicle.

I can get far more useable capacity with just one Lithium Battery under the Left Hand Front Seat, so I am thinking of just upgrading the battery under the Left Hand Front Seat and am wondering if anyone has done a similar thing in the past?

To be honest my biggest concern is actually deleting the Second Leisure Battery which is installed in the Rear Cabinet. From what I understand the two Leisure Batteries are connected in parallel, however I am not sure exactly where the cable from the Rear Leisure Cable connects to the Leisure Battery under the Front Left Seat? I assume that it connects somewhere to Fusebox SH, however can anybody help me out here with identifying exactly where this connection is made?

Also, are there any ramifications that I should be aware of removing the Second Leisure Battery?

Thanks in advance!

Andrew

 

[WelshGas]

Hi All,

I have a T6.1 California OCEAN and I am looking to upgrade the Leisure Battery System to Lithium from the AGM Batteries that are in the vehicle.

I can get far more useable capacity with just one Lithium Battery under the Left Hand Front Seat, so I am thinking of just upgrading the battery under the Left Hand Front Seat and am wondering if anyone has done a similar thing in the past?

To be honest my biggest concern is actually deleting the Second Leisure Battery which is installed in the Rear Cabinet. From what I understand the two Leisure Batteries are connected in parallel, however I am not sure exactly where the cable from the Rear Leisure Cable connects to the Leisure Battery under the Front Left Seat? I assume that it connects somewhere to Fusebox SH, however can anybody help me out here with identifying exactly where this connection is made?

Also, are there any ramifications that I should be aware of removing the Second Leisure Battery?

Thanks in advance!

Andrew

On the T6.1 both Leisure batteries are monitored by the Control panel, so it may throw a hissy fit if it only sees one. The Mains battery charger may or may not be compatible with a Lithium battery.

If you follow the connections to the +tve pole on the front Leisure battery you should find a large red lead which comes from the rear battery. The earth's from both batteries are connected to a local chassis earth.

 

[yorkshiredave]

I believe the leisure battery under the passenger seat is dedicated to run the Auxiliary Diesel Heater and the Leisure Battery under the rear wardrobe runs the fridge, sockets and lighting, etc. in the rear habitation space of the vehicle, both managed by the charge control unit under the wardrobe/fridge (which also trickle charges the vehicle starter battery) and displayed via the main Control Panel. So deleting one of the batteries and running from a single Lithium battery would require some wiring changes to ensure the auxiliary heater and habitation circuits are correctly powered. Personally, if I was thinking about doing this I would retain two Leisure batteries but just change to smaller balanced (same capacity) Lithium to save messing with wiring. Though are there any considerations of using different Ah capacity batteries to the original, as will the Battery Charging Unit/Inverter not be calibrated in some way to battery capacity? I’m sure many people have done this before on this forum who can give you the low down.

 

[WelshGas]

I believe the leisure battery under the passenger seat is dedicated to run the Auxiliary Diesel Heater and the Leisure Battery under the rear wardrobe runs the fridge, sockets and lighting, etc. in the rear habitation space of the vehicle, both managed by the charge control unit under the wardrobe/fridge (which also trickle charges the vehicle starter battery) and displayed via the main Control Panel. So deleting one of the batteries and running from a single Lithium battery would require some wiring changes to ensure the auxiliary heater and habitation circuits are correctly powered. Personally, if I was thinking about doing this I would retain two Leisure batteries but just change to smaller balanced (same capacity) Lithium to save messing with wiring. Though are there any considerations of using different Ah capacity batteries to the original, as will the Battery Charging Unit/Inverter not be calibrated in some way to battery capacity? I’m sure many people have done this before on this forum who can give you the low down.

I'm afraid you are incorrect in your assumption.
The rear leisure battery is wired in parallel to the under seat battery to create a 150 amp battery. The only additional connection to the rear battery is the battery monitor module on the T6.1.

All the leisure electrics are connected to the under seat battery via a +tve bus bar and fusebox.

 

[yorkshiredave]

I stand corrected! Would this have been the same in our T5.1 Cali, as I could have sworn the under seat battery was dedicated to the heater??


Sent from my iPhone using Tapatalk

 

[WelshGas]

I stand corrected! Would this have been the same in our T5.1 Cali, as I could have sworn the under seat battery was dedicated to the heater??


Sent from my iPhone using Tapatalk

Yes, T5/5.1/T6 and T6.1
The Parking Heater, Fridge, rear habitation lights, water pump , inverter and rear 12v sockets are all wired to the Leisure battery under the front passenger seat.

 

[andrew_kombilife]

On the T6.1 both Leisure batteries are monitored by the Control panel, so it may throw a hissy fit if it only sees one. The Mains battery charger may or may not be compatible with a Lithium battery.

If you follow the connections to the +tve pole on the front Leisure battery you should find a large red lead which comes from the rear battery. The earth's from both batteries are connected to a local chassis earth.

Thankyou and great comments, where is the Mains battery charger actually located? Additionally, I am wondering if anyone has a photo of the large red cable coming from the front leisure battery +ve pole?

 

[WelshGas]

Thankyou and great comments, where is the Mains battery charger actually located? Additionally, I am wondering if anyone has a photo of the large red cable coming from the front leisure battery +ve pole?

Mains charger is located above the rear leisure battery.