question

Charge until the MultiPlus is through all charging stages (bulk, absorption and float), this can take 10-12h.

What are the settings of the BMV? Maybe it is jumping to 100% to fast?

Will try to charge for a longer time. State of charge is at 100 % but voltage only 11.82v

Here is the pictures from the bmv. Need to change some settings ?

Battery capacity in BMV should be 920, not 1120. (8*115)

Charge efficiency probably needs to be 90 or 85.

Need to see the charger/battery settings for the multiplus.

Sorry type error. 8*155 *0,9 becose they are old. will try to change charge efficience to 85

Here is some more pictures.

Thanx alot for helping.

Thanks

You need to think of charger and monitor separately.

Charger works on voltage and time. It charges at max current until absorption voltage reached, then keeps voltage constant until time limit reached, then switches to float voltage. Battery voltage should drop slowly to the float voltage. In general lead batteries are about 80-85% charged by absorption voltage. If the absorption voltage is reached quickly from start of charging, and start voltage was low, it indicates faulty/worn out batteries. In this condition the batteries hold much less power than when new.

Monitor works on current through the batteries. But resets to 100% charge when charged voltage is reached and the current drops to tail current or less for the detection time. State of charge is calculated on current measured and the capacity you enter. If batteries old/worn out SOC calcs will never be correct as capacity does not match the real capacity

Charged voltage is set below absorption in your system. But not too critical as current should remain high during most of absorption.

Your charging settings look good. Judging by what you're seeing, it's as you guessed. New batteries needed. But just try checking the charge current through the full absorption cycle. You might be undercharging. But regularly undercoating by switching off the charger will shorten the battery life.

Have charged for 3 houers now. shudent multiplus show state of charge. Still charging at 100 %.

I was thinking that the charge speed was going down when battery get 100 %

Multiplus bmv 712

No i have charged for 3 hours and 1 hour of this was absorption . Now everythings looks better.

Dont have this fast drop in voltage. Using aboth 30 w now and almost none drop.

So i will try to start charging for 12 hours when i am at the cabin.

Think i has bean charging to little. only charging for 1-2 hours when needed.

So hopefully this battery will work for a time now. Going to start looking for new batteries soon.Think i will go for litium.

Again thanx for helping

If you can, leave it on permanently. The charger will switch to float mode, then, if it's in you unit storage. This keeps the batteries at an optimal level and stops the deterioration from being undercharged.