After a good 11 hour charge yesterday, we refitted the battery this morning and all is good. I educated my lad on the need to do the occasional long run, especially during lockdown. Basically, he uses it to go to Tesco or visit us and she uses it to get to the hospital and back. Maximum journey time is maybe 15 minutes, so the battery was probably suffering anyway.
As I have said before the battery is probably the most misunderstood and neglected part of the car - does not bode well for BEV, although because it is a major part of car maybe will be looked after better, but how many people know that both frequent fast charging and also leaving at over 80% state of charge will damage Li-Ion battery. I never even fully charge phone, shaver and toothbrush....
Thankfully what we used to call 'K-Mart specials' batteries are not very common ( cheaper due to a big case, lots of electrolyte and not many plates ( usually 7 or 9 plates per cell, which you could tell by light weight when you lifted them up ). Most batteries now are 11 and probably 13 plates per cell and makers have managed to give better performance and lighter weight with thinner plate frames / grids and thinner separators and different lead alloy combinations - lead/silver and lead/calcium make a battery really maintenance free and very low self-discharge.
If the battery has been kept in low state of charge for any length of time ( <80% ) and has been fully flattened and is =>4 years old, may be time to fit a new on for peace of mind.
