Battery interchangeability
 

So after 10 mins the v60 shut off the radio saying "low battery etc"
I haven't got any history on the battery, with it being a genuine volvo one, I assume it's factory.
It's a 75aH AGM unit.
I have a good working spare lead acid 100aH from my 300c diesel. Which served as an admirable stop gap while my XC70 battery was incoming.

Will there be any issues using this?
I've fitted AGM batteries to my truck instead of lead acid but not the other way round.
Anything I might need to do?

You can go flooded to AGM going the other way is not so easy. AGM can handle higher heat in tighter space and depends if the charging system has been optimised to push a higher load for faster charging for AGM.

Flooded battery requires more ventilation should gassing occur.

The p3 battery tray should have enough room for ventilation? I see the agm battery is missing it's ventilation tube, and I kept the vent tube for the 100ah batt.

Considering the d5 XC has the same battery, with the 100/95ah capacity I'm hoping it shouldn't have issues. It physically fits and uses the last slot on the tray (same as the replacement in the XC). Wouldn't mind a higher capacity really, less strain, longer life!

Long term I will get a larger capacity AGM before the winter sets in. When I bought the car it had an absolute boat load of codes all pointing to the usual weak battery and being left stood.

Well, found a 90aH battery fitted very snug (temporary measure)

I think most cars see that message after about 10 mins or more of music with the engine off. More a precautionary measure I think. If the car still starts fine every time I certainly wouldn't be splashing out on a new battery just because that message appears after using media for a while with the engine off.

I've had my music on testing this battery for about 15 minutes until it defaults to powering off while giving her a polish today.
The best part of the battery swap, it was free!
I will load test the battery when I feel like wasting my local garages time. I'm guessing with its date code, It is original. Replace it now before it leaves me stranded in the winter!