The boot has been playing up a bit, I noticed first thing in the morning it would only open halfway then it would be OK, I guess as the engine will have been running and topping the failing battery up...

I tested the voltage...

Is 10.2 volts a bit low......

The second battery was at 12.4 volts, with the car woken up and the lights on....

No other symptoms, started perfectly even at -7c, FBH stayed on for over 30 mins, No "charge battery" displayed.... no faults shown..

I had read that the second battery does a good job of backing up the main battery and disguising it's true state of health but I didn't think it would be that good....

Anyway, new battery ordered with a 5 year warranty...

If your boot starts playing up then check the voltage, the jump posts under the bonnet show the state of charge of the main battery, to check the second battery you remove the offside rear boot side cover... Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
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2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
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Sounds like you need a new one. I replaced both in mine to be sure.

The LR batteries are made by Exide.

The one in the spare wheel well is an EK950 and the one on the right hand side of the boot is an EK700. I paid £198 delivered for the pair this time last year from Tayna.

When you install it, remember to tell the car you've installed a new battery using the IID tool or SDD. It'll reset the charging algorithm. Kev

2014 L405 RR Vogue SE 4.4 SDV8 in Corris Grey
2010 L320 RRS HSE 3.0 TDV6 in Stornoway Grey

Thanks, new one on way from Tayna, like most things they have gone up a lot since last year, the Excide only comes with a three year warranty, so I bought the Enduroline, had a couple before and they lasted well.

It comes with a five year warranty...

The second battery appears to be fine and looks to have been replaced recently by the lack of dust on it, compared to other items nearby...

The IID will get to earn it's keep... Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
-Click here for Thread-
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
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I take it if you dont have the IID too for reset you could just pop in your local mechanic and they would do for you? overfinch modified

Lots of diagnostics will reset the BMS - you don't need to do it as the vehicle will eventually adapt to the new battery with no ill effects, if you have autostop, it will also re-enable once the charge level has been re-evaluated fully.

Thanks guys....


No stop/start to worry about.... Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
-Click here for Thread-
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click here for Project Fatty off roader-

Hi Pete,

There’s loads of threads on here if you search “battery” , but to save you the job, your battery is way too low on voltage, (should be about 12.6V if perfect, unloaded, i.e. disconnected from the vehicle) so if it’s more than 3-4 years old, may need replacing now.

You need at least a rating of 850CCA.

Tayna are recommended by many on here, and do many makes, good prices, and fast delivery.

I went for the Enduroline, because of the 5-year guarantee. V6 Vogue - “Less is More” - less to go wrong!

Phoenix wrote:

Lots of diagnostics will reset the BMS - you don't need to do it as the vehicle will eventually adapt to the new battery with no ill effects, if you have autostop, it will also re-enable once the charge level has been re-evaluated fully.

Great thx Phoenix.  overfinch modified

Gremlin500 wrote:

Hi Pete,

There’s loads of threads on here if you search “battery” , but to save you the job, your battery is way too low on voltage, (should be about 12.6V if perfect, unloaded, i.e. disconnected from the vehicle) so if it’s more than 3-4 years old, may need replacing now.

You need at least a rating of 850CCA.

Tayna are recommended by many on here, and do many makes, good prices, and fast delivery.

I went for the Enduroline, because of the 5-year guarantee.

Thanks, the post was tongue in cheek, it's amazing anything worked with such a low main battery voltage... as I said, a new one, an Enduroline, will be here tomorrow from Tayna who I have used for years...

The post was more to let folk know that the backup battery can mask a failed main battery very successfully, and if your boot opens to halfway or starts to play up then check the main battery voltage......  Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
-Click here for Thread-
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click here for Project Fatty off roader-

New battery fitted... I thought it would be a pain due to the location under the compressor under the spare wheel but I'd much rather change one on a 405 to a 322 any day....

Car starts just that little bit quicker, doors lock just a tad faster, and the boot opens and closes properly now....

Job done...  Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
-Click here for Thread-
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click here for Project Fatty off roader-

Good to hear Pete.  overfinch modified

Cool!

Glad you got it sorted, Pete.  V6 Vogue - “Less is More” - less to go wrong!