I'm sure that any battery service can replace your 12V battery. That shouldn't set you back more than 75 Euro.
Thanks, I found this , from a different thread on this forum:
It costs £53, inc delivery.
It has identical dimensions, terminal config and capacity, although it is a wet battery, and not ideal
for fitting inside the cabin, rather than outside in the engine bay.
I got fed up with jump-starting, so I purchased the above and fitted it, as a temporary measure.
It is working fine, as you would expect.
But I shall be round to the dealer ASAP, to get the original replaced under warranty. I only purchased the car in February, 2 years old, replacing my MY14 Phev.
This car has low mileage (only 5K), but I see from the service history that it had only done 20 miles(!) in the last 12 months. This probably did not do the battery any good at all, and I feel that the dealership should have considered this possibility before they sold me the car.
Mitsubishi say they’re >£500. The cheapest I could find the exact one for was on Amazon...£205
Thanks also for that info; I see no reason why Mitsubishi choose to fit such an expensive battery.