just to clarify the reasons for an aux battery,

my understanding is that for 2013/14 years JLR fitted a 90ah battery as a main.
the aux battery is a 70ah which is for 3.0 in cold climate countrys and standard for 4.4 engines..

in roughly 2015 when the stop/start was introduced the aux battery was reduced to a 14ah ..i think this was due to better engine tech and emissions..

this is from the WM,

Click image to enlarge

My 14 AutoBio 5L SC has the smaller motorcycle style battery. I checked the voltage when off and it read 13v when off and 14 with engine running. It was hooked up to the leads but my start stop is somehow not working (I don’t mind having no start/stop). But I get “low battery warning on the dash”. I just changed my main Bart like 3 months ago (did not have it programmed) and it reads 12.x volts when off and 13 with engine running. Is this normal? Why am I getting the battery errors…bc I didn’t get the new main battery registered? Or is the AUX battery malfunctioning with the read-outs it’s giving me? 2014 FF Autobiography 5.0 SC
2008 FFRR (sold)
2008 BMW M5

its recommended to get the BMS reset so your FF knows you have a new battery...doing this should solve the dash errors, if it doesnt the you know that this process can be eliminated from your problem search... ... - .- -.




Y. O. L. O.
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Agree with Stan. I replaced both main and auxiliary batteries last Friday after ‘low battery warning’ on my L405. My ecu was then remapped to receive new batteries and warnings disappeared.

Having to "tell" your FF it has a new battery makes me chuckle.

It's like emailing yourself to say you've had breakfast, after you've had breakfast  What do I put here then?

This practice is just another money spinner for JLR. Is the same applicable for the pollen filter to the new LRRR? 🤣🤣

[quote="GAC23"]Having to "tell" your FF it has a new battery makes me chuckle./quote]

AFAIK it's pretty common with many makes thesedays.

Thanks for the replies guys. I’m do for inspection this month so I can have them register the new main battery I got a couple months ago. Hopefully this didn’t mess up the new main battery.

Assuming I don’t need to re-register the aux battery that’s been in there (still registers 13v engine off so didn’t replace it) 2014 FF Autobiography 5.0 SC
2008 FFRR (sold)
2008 BMW M5