Volvo S80 2001 doesnt charge the battery

[Matiss7]

So in short the Car doesnt charge the battery, or it does in very little amounts, i drove to a nearby city, what is about 35km away and it had no problems but when i drove back the car started to glitch and all electronics shut off in the car, including the fuel pump. could it be that some of the wiring is damaged or maybe just unplugged. The car has had similar stuff like this happen for example the turbo completely shutting off and not shutting back on even after turning the car on and off

[MoVolvos]

.
1) Check battery with the negative cable disconnected and you should see around 12.5 volts.
2) With the battery in the car and connected while running you should see at least 13.5 volts.
3) Check the acid in the battery chambers. I had replaced a 250K mile OE alternator in our 03 Odyssey. All systems check out but after a couple of days the van wouldn't turn over. Battery was at 8.5 volts. Put it on the charger and it's full amps going to the battery but just 15 minutes later when checking it's back to normal charge and good voltage. Checked the acid and one chamber was low. Filled with distilled water and it won't fully charge again. That cell had an intermittent open internally so only 8.5 volts from time to time. With the chambers fully filled it still won't take a full charge so just replaced it and all is well.
.