odd battery behaviour

[Anonymous]

36 hours to charge! I think that tells the whole story - I regularly discharge a 120A Lead acid battery to around 10.9 V, it takes less than 12 hours to recharge with my excellent Lidl C-Tek clone.....

im using a motorcycle battery smart charger using a lead at the under bonnet connector, designed to charge much smaller batteries but as a trickle charger works fine if somewhat slower than a car specific charger.

Ive removed the battery this weekend and charged it directly, its holding fine now at 12.9v a day later.

I think what caused my initial concerns was lower voltage when connected to the car and it still does have me wondering if thats the same on all e89s with a pull from the canbus, I wasn't expecting the increased voltage when removed from the car

Sounds like all is well..that voltage reading with a smaller charger all makes sense..nothing wrong with using a smaller charger, just takes longer..the only catch is if it doesn’t have the ability to flip to float charge mode then you will cook the battery if you leave it for a very protracted period...but that sounds unlikely..

I think many cars are suffering from their batteries running flat to damaging levels due to lack of use and then only ‘essential journeys’

 

[mr.tourette]

Just reconnected now.. battery has been off charge a day and a half, solid 12.94v off the car, put it on and reading 12.60, got to assume the bus ecus and some interior lights are pulling that current. Ive also noticed my amp fires up when the canbus wakes but goes back to sleep around 2/3 mins later if the key is not put in the ignition, this perhaps is also causing some drop on the readings when connected

 

[mcbutler]

36 hours to charge! I think that tells the whole story - I regularly discharge a 120A Lead acid battery to around 10.9 V, it takes less than 12 hours to recharge with my excellent Lidl C-Tek clone.....

So was that direct on battery or via the under bonnet contacts?

I doubt that battery’s fitted to Marks e89, it’s 120A so probably wouldn’t fit? :?
Rob

Nope its a leisure battery, lead acid AGM in my camper van