GC600 2021 – AGM to Lithium battery swap (house battery at the front)

[hohe]

Hi everyone,
I have a Grand California 600 from 2021 and I'm planning to replace the habitation (house) battery with a LiFePO4 lithium battery.
On my van the house battery is located at the front, in the engine bay under the hood — not inside the vehicle. I'd like to hear from anyone who has done this swap on a similar setup.
My specific questions are:
Did the OEM 230V charger accept the lithium battery without any issues, or did you have to change/adjust anything?
Did the OEM DC-DC booster (the one that charges the house battery from the alternator while driving) work correctly with lithium, or did it disconnect too early?
Did you have to change any settings or replace any components, or was it literally a straight swap?
For context, I also have 200W of solar panels with a Victron SmartSolar MPPT controller already installed.
Any feedback from GC600 2021 owners who have made this switch would be really appreciated!
Thanks all!!!

 

[GordonH]

There are a few threads on this and the various Facebook groups on this topic. It’s certainly done by folks who report positively but here are some gotchas to be aware of. You cannot change the hookup charger charging profile so it will charge on the assumption of an AGM chemistry battery which may not be ideal for whichever lithium battery you choose. The alternator charger is a very simple split charge relay affair, not a dc:dc system. When closed it places the starter and leisure batteries in parallel. You are then by default connecting different chemistry batteries in parallel which is not ideal. On from this you may need to reduce the alternator output current (factory set to 180A) to below the maximum threshold of your lithium battery, I believe that can be done via the OBD2 port. Even with that tweak as the split charge relay creates a low impedance link between the two batteries depending on relative states of charge you may get high current surges between batteries that could cause the lithium BMS to cut off abruptly. There was a post last year about someone who had done this swap and their lithium BMS over current protection triggered which ended up damaging the GC battery shunt likely due to transient voltage spikes due to the high speed switch off. Changing the split charge relay for a dc:dc charger would avoid the issues with the factory alternator charging setup.

 

[hohe]

There are a few threads on this and the various Facebook groups on this topic. It’s certainly done by folks who report positively but here are some gotchas to be aware of. You cannot change the hookup charger charging profile so it will charge on the assumption of an AGM chemistry battery which may not be ideal for whichever lithium battery you choose. The alternator charger is a very simple split charge relay affair, not a dc:dc system. When closed it places the starter and leisure batteries in parallel. You are then by default connecting different chemistry batteries in parallel which is not ideal. On from this you may need to reduce the alternator output current (factory set to 180A) to below the maximum threshold of your lithium battery, I believe that can be done via the OBD2 port. Even with that tweak as the split charge relay creates a low impedance link between the two batteries depending on relative states of charge you may get high current surges between batteries that could cause the lithium BMS to cut off abruptly. There was a post last year about someone who had done this swap and their lithium BMS over current protection triggered which ended up damaging the GC battery shunt likely due to transient voltage spikes due to the high speed switch off. Changing the split charge relay for a dc:dc charger would avoid the issues with the factory alternator charging setup.

Ty Ty Ty so much for the info! Could you share the links to the comments you're referring to? Id love to read them myself
Thanks

 

[GordonH]

You will need to do a search so find the comments.

 

[mr pg]

Two lithium suppliers I spoke to when reaserching this both both recommended not fitting lithium under the bonnet due to the temperature changes in this area.

 

[Hammer]

I have fitted a Titan Lithium 180ah under bonnet, and I coded the battery to lithium via OBD so charging rate stays at around 70amps. I did have some water ingress issues to start but Titan sorted battery and told me its not issue having under bonnet.
So issues to be aware of:
1. Your VW touch screen display will no longer show correct battery level, its stays at 100% (most of time) but most decent batteries have good bluetooth monitoring that’s far better than the display anyway.
2. Temperatures could cause issues, check specs of the battery you are looking at Titan unit I have has a heater so will help in cold climates. As for overheating I haven’t seen this yet, the Titan unit spec says up to 60 degrees and most I have seen in 30 degrees South France few days ago was 46 on battery and that was stationary with mains hook up charging from VWs mains charger which as mentioned doesn’t have lithium charge profile but the battery BMS handles it ok.
3. Water ingress can be issue as VW crafter seems to dump water onto battery area. Even through my battery is IP65 water pooled around the coms ports and managed to seep into ports causing me few issues. Again Titan sorted this and have added extra waterproofing internally to my battery and told me not issue to have in bonnet. I would prefer battery with no ports but instead made a cover for top of battery just to keep water off as much as possible.
4. Doesn’t automatically charge when engine running, you have to press the boost charge button on dash. This isn’t major issue as I have so much more available power with new battery doesn’t always need to be 100%. Also bear in mind if you forget with standard battery often only goes to 80% anyway with lets face it is useless in winter!
5. Ideally you need to code the lithium battery type via OBD, I found without this you get drain between batteries as Gordon has mentioned above plus charge current is very high at around 180A (Titan can handle max 250A) and i didn't like the behaviour if the charging/discharging. With type changes to lithium I never get more than 70A and there appears to be no drain between batteries.

So with above in mind I personnel find the positive of having more than 3 times the useable capacity worth the compromise. It’s not perfect by long stretch and there are certainly things you need to consider and some people are very anti installing lithium in this location but it works for me.

I haven’t written lot about my experience on this yet as its only been 8 Months and wanted to fully test in hot and cold climates. I am still not 100% sold on keeping it up front and still have option of installing in rear cupboard if it causes me any issues going forward. Chris on this forum has good guide on installing lithium in rear cupboard but keeping stock battery in place so that is still option.

hope this helps a little and doesn’t create too many more questions

 

[Rostman]

Test: Supervolt Lithium Battery / Update Lithium in the Grand California

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www.grandcali.com

 

[Blue Grand Driver.]

Hi Hohe, see my recent post "AGM to Lithium". Might help if you haven't already upgraded. Happy to answer any questions. Cheers.

 

[G-A-R-Y]

I have fitted a Titan Lithium 180ah under bonnet, and I coded the battery to lithium via OBD so charging rate stays at around 70amps. I did have some water ingress issues to start but Titan sorted battery and told me its not issue having under bonnet.
So issues to be aware of:
1. Your VW touch screen display will no longer show correct battery level, its stays at 100% (most of time) but most decent batteries have good bluetooth monitoring that’s far better than the display anyway.
2. Temperatures could cause issues, check specs of the battery you are looking at Titan unit I have has a heater so will help in cold climates. As for overheating I haven’t seen this yet, the Titan unit spec says up to 60 degrees and most I have seen in 30 degrees South France few days ago was 46 on battery and that was stationary with mains hook up charging from VWs mains charger which as mentioned doesn’t have lithium charge profile but the battery BMS handles it ok.
3. Water ingress can be issue as VW crafter seems to dump water onto battery area. Even through my battery is IP65 water pooled around the coms ports and managed to seep into ports causing me few issues. Again Titan sorted this and have added extra waterproofing internally to my battery and told me not issue to have in bonnet. I would prefer battery with no ports but instead made a cover for top of battery just to keep water off as much as possible.
4. Doesn’t automatically charge when engine running, you have to press the boost charge button on dash. This isn’t major issue as I have so much more available power with new battery doesn’t always need to be 100%. Also bear in mind if you forget with standard battery often only goes to 80% anyway with lets face it is useless in winter!
5. Ideally you need to code the lithium battery type via OBD, I found without this you get drain between batteries as Gordon has mentioned above plus charge current is very high at around 180A (Titan can handle max 250A) and i didn't like the behaviour if the charging/discharging. With type changes to lithium I never get more than 70A and there appears to be no drain between batteries.

So with above in mind I personnel find the positive of having more than 3 times the useable capacity worth the compromise. It’s not perfect by long stretch and there are certainly things you need to consider and some people are very anti installing lithium in this location but it works for me.

I haven’t written lot about my experience on this yet as its only been 8 Months and wanted to fully test in hot and cold climates. I am still not 100% sold on keeping it up front and still have option of installing in rear cupboard if it causes me any issues going forward. Chris on this forum has good guide on installing lithium in rear cupboard but keeping stock battery in place so that is still option.

hope this helps a little and doesn’t create too many more questions

I think what you have done is wrong, you've coded the van to a lithium profile but you still have the original AGM battery.

The "dumb" relay under the bonnet still joins the two batteries together, the lithium profile is for vans fitted with a lithium engine battery. It can't separately charge two different batteries with the OEM relay.

Also under the bonnet is not a good place, I did a lot of long term testing, under the bonnet get too hot for lithium, more than 10c warmer than ambient and spikes when stopping engine due to latent heat.

Just swap out the dumb relay for a B-B, fit the battery in the rear and use the original cable as your charge supply. I did a lengthy post if you search back.

 

[Coachella]

There are a few threads on this and the various Facebook groups on this topic. It’s certainly done by folks who report positively but here are some gotchas to be aware of. You cannot change the hookup charger charging profile so it will charge on the assumption of an AGM chemistry battery which may not be ideal for whichever lithium battery you choose. The alternator charger is a very simple split charge relay affair, not a dc:dc system. When closed it places the starter and leisure batteries in parallel. You are then by default connecting different chemistry batteries in parallel which is not ideal. On from this you may need to reduce the alternator output current (factory set to 180A) to below the maximum threshold of your lithium battery, I believe that can be done via the OBD2 port. Even with that tweak as the split charge relay creates a low impedance link between the two batteries depending on relative states of charge you may get high current surges between batteries that could cause the lithium BMS to cut off abruptly. There was a post last year about someone who had done this swap and their lithium BMS over current protection triggered which ended up damaging the GC battery shunt likely due to transient voltage spikes due to the high speed switch off. Changing the split charge relay for a dc:dc charger would avoid the issues with the factory alternator charging setup.

I had put a Lithium under the bonnet (only for festival trips) and added a Victron shut. It stopped working last year and from this attached post it must have been that. Didnt blow fuse but my shut is now dead.
I am 6months in on getting the battery boost button fixed in my MAN TGE, but once done i think that is the way to go - DCC charger as the relay replacement.
The battery charger in the rear is a new Dometic charger and has Lithium setting.
One notable thing was MAN had pulled from an old document they dont support Lithium in the 2nd battery location under the bonnet, due to temperature. Doesnt say temp of the battery or the engine.
But then goes to talk about retrofitting a Lithium.
Seems as clear as mud.