Solar panel manual switch between Lead/acid and Lithium

[M1EWK]

My Autotrail has a single solar panel and a manual switch to connect the controller to either the leisure battery or the vehicle battery (useful when in storage). If I go lithium for the leisure battery I will need to configure the solar controller to a lithium profile. If I occasionally switch the controller to the vehicle battery will this cause a problem with the voltage as the profile will be incorrect as the vehicle battery is lead/acid. Anybody come across this scenario ?

 

[rwg]

Hi,

I had the same switch and decided to deal with the problem by replacing the original solar controller with a Votronic one that will charge both batteries. All the correct wiring is present under the locker floor to do this. I have a Benivan improvements thread on here that covers this (the Benivan is made by auto trail and shares a lot of wiring with their vans)

Alternatively, leave the battery charger as is. Providing it is not set to provide more than 14.4v it will not harm a modern lithium battery, although it will perhaps not charge it as efficiently as possible..

If your van is recent and has start stop then you should also deal with the possible issue of a combination of a smart alternator on the van and an old fashioned split charge circuit in the auto trail wiring. That could feed 15v from the alternator to the lithium battery while running, which should be avoided.


Cheers


Robin

 

[VXman]

Or get a battery master that will automatically send a trickle charge from the leisure battery when it is higher than the starter battery.
[Broken Link Removed]

 

[Peregrinator]

Don't the controller have a separate feed to the starter battery?

 

[M1EWK]

Don't the controller have a separate feed to the starter battery?

It's got a manual rocker switch to go between starter and leisure, so it's one or the other

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[jwells]

It maybe worth your while doing a search of "lithium" threads, a great deal of information including many pitfalls! Think I have just got my new Auto Trail lithium hab battery /engine lead acid battery /"smart" alternator charging sorted!! I had to fit an isolation relay to disable the split charge relay, a B2b, and VanBitz Battery master!
Good luck!

 

[Peregrinator]

It's got a manual rocker switch to go between starter and leisure, so it's one or the other

Sorry I thought the rocker switch was separate to the Controller

 

[M1EWK]

Sorry I thought the rocker switch was separate to the Controller

It is separate. The output from the controller goes to the rocker switch which switches the charge to either the starter or leisure battery Normally I switch it to the starter battery when I'm not using the van for a while to keep it topped up and switch it back to the leisure when out and about. My concern was if the leisure and starter batteries were of a different technology and needed different profiles set on the controller

 

[poppycamper]

As rwg says... fit a Votronic Duo controller... has feeds to both hab and cab battery's..
Even if you go lithium and set controller to lithium setting that is only for hab battery..
The cab battery stays on a lead acid setting, regardless of what you have controller set to..
This is the arrangement we have

 

[Peregrinator]

You could purchase a dual charge controller for under £100, and then you no longer need to worry, it will switch and control the power for you.

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