I have been considering using a Lithium battery , and wiring the rear lighter outlet to it so I can run a fridge full time. Space looks large enough to fit a larger battery perhaps a 48 a.h. Can anyone see an issue with such an idea? M16 SVD8 ,4.4 HSE with a few extras, Sold R50 , Wife SQ5 , BMW R1200GSW.

Li of LiPO batteries are a great idea as they pack alot of punc however they are also quite volatile, so you would have to be careful with reagrd to charging as they often need to be discharged to around 20%, also if not maintained with a proper intelligent charger the battery could be a potential fire hazard ( Iguess if it was kept inside like a lipo container then that would solve that issue, but not sure about car insurance if there was a fire.

The fires from them are pretty severe as its a chemical fire and not easily extinguished.

Maybe using the battery and capictor idea could work for that where is uses the cap first then the battery?

On our boat the firdge whislt its not huge drain the batteries pretty quick, if the lipos were set up properly and safely then I guess it could be a great mod, if it only kicked in once the engine was off and when it was on the lipos charged and the main car battery was used while the engine was running to allow maximum charging to the offline batteries?

Be interesting to try it I guess If a jobs worth doing, get a someone who knows what they are doing to do it!

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Thinking of using this as my second battery, reckon I can squeeze it in. Will have the 12v connector wired direct so that I can run a fridge , fridge draw should be around 2 amps when cold.

https://itechworld.com.au/collections/lith...-slim-line M16 SVD8 ,4.4 HSE with a few extras, Sold R50 , Wife SQ5 , BMW R1200GSW.

Wiring direct should be fine as the car doesnt need this battery to be fair its there to assist the main one during stop starts, it will be tight getting that in there though, I thought that one was tight to get the cables on but you might need to get some cable extenders.

Ive fitted Cetk quick connetor charger to both my main and aux battery so I cna charge them up prior to any long trips, and the small batts are pretty quick to charge the onyl problem you might have with that from a charging perspective is the the main battery has priority so as far as I am aware until the main has suffcient charge then the aux get topped up so if you are doing lots of stop starting or etc... then that little one might not get charged o topped as as often and factor in running a fridge it might drop fair bit so and easy way of charging would be a good idea (otherwise you might get the low battery warnings)

The car will still run though as others have said their battery has been dead for a longtime and if you are nto bothered about the stop start then it shouldnt matter.

Id swap out the main battery for a nice new one if you are gonna do this that way they are both at full cap.

If you are running a fridge, I found in my old car I did the same, I'd buy a load of those flexible cold packs and get some to take with and some to prep the fridge, I used some of the big ones to get the fridge cold inside the day/night before and then use some more to help during the day so it used less power (its was just using 12V in the boot) It helped keep it really cold when we came back to to the car, as the car gets pretty hot too (sunroof open a bit to vent) does the trick and works well, the one in the arm isnt that bad either but is more of a chiller, i used the littel square ice back in the there to sit on top so it take longer to warm up but as the top cover is grey it attracts the sun unless using a sun shade.

Good luck and plenty of pictures if you do If a jobs worth doing, get a someone who knows what they are doing to do it!

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OK I have another question, can I replace the big starting battery with a Lipo4 battery. My battery is 5.5 years old and I am thinking replace both so both batteries have a similar chemistry. Seems the question is will the smart charge system charge a Lipo4 battery?/



The plus side of doing this will be weight saving mainly . M16 SVD8 ,4.4 HSE with a few extras, Sold R50 , Wife SQ5 , BMW R1200GSW.

Good question and the honest answer is I'm not sure, Lipo charged differently and so not sure how the BMS would would react or if it would charger properly.

I did look at Lipos to repalce mine with but couldnt really find anything the right size, and anything I could find was expensive.

Not sure about hoem charging either as most car battery chargers work on LA or AGM batteries not that if its 12 V it should maybe matter.

There is also the fire consideration LIPO tech is great but but not sure on maybe a jump start either unless it had its onw reserve so to speak, but if there was an accident and it got punchered by something it's almost a right off as thermal runnaway could happen and you have no real chance of stopping it and the car would burn away easily.

I thought about them purley for the punch they would have and probably power the fridge etc.. in the car for much longer but were expensive and would require modding to fit at the time.

I would go for it if they were a little bit more but the ones I looked around for were all £750+ and when you consider the battery I bought to my other post of battery replacing was only about £125 I went donw that route, I think the weight saving would be nice but on a 2.5T car probably not noticeable at all.

Id be interested in the leanring about the mod if you go ahead of if you have found sensible priced batteries.

I did wathc a Youtube video of James May moaning he had to take the bumper off his Tesla during lock down as the battery went flat, the main car batts to drive the car are LI but the one that runs the door locks and all the others things around the car like ours is a normal 12V battery the LI ones provide power to the car but do not "top up the 12V" which seems strange they did go down the LI route "unless it is an LI battery that went flat I dont think it said"

Keep us posted If a jobs worth doing, get a someone who knows what they are doing to do it!

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Brilliant write up thanks.

I just changed my auxiliary battery as the stop/start light would not go out. Battery voltage was around 10.5 even after a run.
Followed your instructions (including the supplier) and it was fairly easy.
I think its the original battery from new! No way to know, but it did have a LR label. 10 years is pretty good for a battery in my opinion.
Hopefully the main battery has already been changed but so far so good.
Main issue was the clips on the trim panel. All broke on removal. According to my parts list they should be LR035841 but the ones that broke looked different to the pictures, plus I struggled to find any in stock. In the end I went for LR013135 and they seem to have worked fine. I recommend vehicleclips.co.uk
Good website and quick service.
Thanks for the write-up, plain English, no acronyms/abbreviations and plenty of clear pics. If only more could be like this. RRS HSE Dynamic SDV6 2014

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no probs chap the main batt is under the floor and will be the cause of most pains! EK950 is oem brand.

the biggest killer of them is lack of use really If a jobs worth doing, get a someone who knows what they are doing to do it!

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I am having issues which I believe are battery orientated. I have already changed the main battery and done a BMS reset which seems to have partially helped, but it seems things are not initialising and then throwing up errors etc which when cleared remain clear for a while.

SO I am convinced the aux battery also needs replacing and followed the instruction in this thread to find I have a larger battery installed than the EK151.

My RRS is a 2017 4.4d one of the last with the round DRLs

The battery fitted is as follows:

FK72-10655-AD 12v 70ah 760a AGM (LR branded but with Exide label)

This is an 096 battery and the required replacement is Exide EK720



I will purchase one in the next few days and install it and fingers crossed my random electronic issues are resolved.
 MY17 RRS 4.4d V8 Autobiography - Aintree Green (also referred to on Topix as British Racing Green)

Thats a pretty big battery to fit, that said if you can get a larger one to fit in the space and the cables all fit then there is no down side really aside price and weight.

Even changing the batteries might not mean the low battery warning goes away though as it still depends on how much charge gets put back in and if it still only short trips you do the low charge will come back.

It worth checking earth strap in front wheel arches but also getting a charger and fitting a quick connector so you can top the main one up which is what trigger the low warning. the aux only gets charged once the main reaches a certain level the BMS is happy with If a jobs worth doing, get a someone who knows what they are doing to do it!

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Just to clarify - the larger battery is what appears to have been fitted by the factory back in summer 2017(literally the car is one of the last with round DRLs produced before they went rectangular with MY18), I am the second owner, having owned her since early 2019.

I replaced the main battery last week - so replacing both at just under 8 years old makes sense. MY17 RRS 4.4d V8 Autobiography - Aintree Green (also referred to on Topix as British Racing Green)

Yeah I get that just saying it’s more like a main battery so may have used whatever was available at the time as it’s was an out going model, they have played to capacitors and the. Back to batteries as well. So it could just be that replacing like for like is best but if a bigger battery could be fitted then it not a bad thing as it will have a higher capacity, that said it will also take longer to charge If a jobs worth doing, get a someone who knows what they are doing to do it!

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