Chosen Solution
Hi all. After almost two years sitting in a drawer I wanted to give new life to my old boy macbook 13 inch late 2008 (unibody) which served me almost 10 years while I was upgrading RAM (8gb), SSD and taking care of it. Battery was completely flat (wasnt the original one) so I bought a new one. When I plugged the new one nothing happened. When I plug the charger I dont see ANY light on the AC charger. I thought it was a problem of the DC, so I changed the piece but it wasnt. Macbook starts perfectly if I force it to start off the AC charger. Checked with a multimeter the voltage, I get 12.5 volts on the plate where battery charge from. What I realised is the battery I bought was probably too weak, so I forced the macbook to boot on AC, then while powered on I connected the battery cable I saw the battery went from sending 10 volts to 12.56 (while AC charger on), but sending only 12.36 if the AC is off. Macbook is working in SMC Bypass mode, even from the battery! (No AC connected, unplug battery, press power button for 10 secs, connect battery and keep pressing for other 10 secs). If I connect the AC charger I suppose the battery charges, but I dont know. If I reset the SMC, it wont boot anymore from the battery. And the battery indicator (the small leds on the side of the macbook) will wave from left to right (which I understand it means no battery is installed). I suppose its a board issue. What should I do? Thank you
Yep! Thats a bad battery! Where did you buy it? I would contact them for a warranty replacement. Basically, the micro-controller within the battery failed. Update (11/20/2020) Seen this too many times! The clues are the lack of values and the odd value for temp
The upper part and lower part are from the SMC logic so we know that’s working. Resetting SMC alters the latch condition the failed battery caused. SMC is designed to go into a fail condition (latched in a No Go State) when the battery is in this state. When you reset the SMC it goes back to the Go State until the SMC discovers the failed battery and then sets the latch flag back to the No Go State so the next time it won’t startup. This is done to protect you from a failed battery which could fail explosively if the charging logic thinks its needs to be charged over charging it!
