Battery OPTIMA or OEM BMW

If you really want to buy this one (I find the price quite high, but I don’t know the specific market in Norway), buy an OBD adapter and EVScanner app on iOS with the BMW module. You can check the SOH of the battery and the general state of it as the replacement could be quite costly (around 1500 per module and you could have to replace up to the six if all fail or the BMS). I’d guess the SOH would be at best around 85%, maybe less. The engine itself is pretty reliable as it’s a detuned B48 from the 330i. Go to the infotainment and check the stats from factory and the percentage of eDrive kilometers (full electric) compared to the total kilometers, it would give you an idea of how the car was used and how much charging it got. This specific model of car is great to drive if you can charge everyday and you drive mainly short distances. I do around 80 km daily, almost all highway and my average consumption on those drives is 3.5 liters and 10 kWh/100, so it’s about 2/3 of the cost of my previous car, while beeing a lot better to drive. I’d still buy a 320 or 330i instead because there will be less things that could fail and I would probably not want to get such a high mileage PHEV without knowing how it’s been previously used. Source: I have a 330e from 2021 with 112k km and the SOH of the battery is 90% with around 1400 cycles. Average consumption since factory is 4.9 l/100 km and about half of the distance have been made fully electric.

I took a drive in my i4 a couple of weeks ago that estimated I'd get home with 4% battery. Guess what I rolled into the garage with..... 4% battery. These modern systems are pretty damn accurate.

Yellow top , my recommendation ; I do carry multiple lights on the taco .size 35

I just replaced both batteries in my 2018 740iX. Was original battery (build date was Aug 2017) so actually lasted 8 years which was surprising given other problems I had with the car!

I still have the original BMW battery on my 2005 e46 325i , I used a battery tester on it and still say it’s good

I had 8 years on original battery on 2017 750i. I replaced it. It was barely holding 12V. Few functions were not working like stop/start and such.

I also just had a new battery installed by BMW, $600 for the honor.

DO NOT buy a red top Optima. They haven't been good or worth the price in like 15 yrs.

Those Optima Red, Yellow and Blue tops used to be the cat's ass 20 years ago, but quality has fallen off big time in recent years

Optima batteries have, in my experience, gone downhill over the last few years. For their price, I don’t think they’re worth considering.