Hello,

Is anyone using an auxiliary battery to support engine starting?
Is it worth making such a modification? I’ve found that it’s feasible with a battery isolator featuring a start-assist function, controlled by the ACC/ON signal.

Best regards,
Greg

Point of this exercise being?
The original single battery has enough cranking power itself to start the engine. In more extreme cases, any 2nd battery expedition kit would provide double that, although the second battery is mostly used for prolonged acc power supply. Unless you use the car around the Arctic Circle, this would be rather pointless. Regards etc.,

Wojtek

---
WAS: 2006 RRS Supercharged
IS: 2010 RRS TDV8 HSE

If you're having trouble starting it and you know the main battery is a good one, that suggests glow plugs. If you don't fancy changing those, you can get a remote starting kit for the fuel burning heater which helps warm things up and will then help with starting in cold conditions. It's an old fix for this issue. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed

Hi,

No problem with cranking or starting the engine. The battery was tested and seems to be fine.
However, when starting the engine, the battery voltage appears to drop low enough to trigger errors and turn on the warning lights on the dashboard, which quickly disappear.
I described this here:

https://www.rrsport.co.uk/forum/topic62642.html

I’m just wondering if it’s really a battery issue (anyway, it’s probably time to replace it) or something else.
Also wondering if adding an auxiliary battery for engine cranking could help get rid of these electrical gremlins.

Anyway, I’ll start by changing the battery.

Cheers,
Greg

If the symptoms and use case is as your previous post then that suggests the battery is knackered from being discharged too deeply. If you're going to do lots of short trips and things like car washing (with doors open at times and thus the ECUs all awake and drawing current), you need to use a charger frequently.

Also check that the generator is working properly by looking at the voltage when the engine is running. If the battery is getting used heavily and the generator is weak then you're doubling down on your problem. 2012 SDV6 - it's missing a couple of cylinders
2008 TDV8 - it was a labour of love and is much missed