Even after charging my battery yesterday (maypole) the battery saver mode is still active?

im doing a 40 motor way drive today. 
 

when I arrive and do a battery test ( my son in law thinks he has one) I’m assuming the battery should show full charge. 
 

if I test tomorrow after overnight can I assume the battery ( if in order) should still be charged c. Full? 
 

any guidance appreciated 

You are testing the voltage with a multimeter I assume? You’ll need to test it after about an hour of the engine being off or you’ll get a false reading. You are looking for 12.4V or more ideally. If it’s less than that after charging and a long journey it’s probably on its way out. If it’s between 12 and 12.4 it probably still has a bit of life in it but not long. Below 12 I’d change it. 
 

The 60Ah Ford/Varta battery is known not to last long. 

12.4 v after 1 hour and 14.7v with car on.

sound ok? 

1 hour ago, Andyr55 said:

12.4 v after 1 hour

Sounds about what you would expect with the cars Smart charge still set at the factory default of 80%

see the battery SOC table in my signature line.

Is it an idea to reset the BMS after the battery was drained to 5.4v?

just done motorway trip and the battery charge shows 12.4v after standing for 1.5 hrs after trip. 
 

battery saver mode is still active so will a BMS reset resolve? 

1 minute ago, Andyr55 said:

Is it an idea to reset the BMS after the battery was drained to 5.4v?

just done motorway trip and the battery charge shows 12.4v after standing for 1.5 hrs after trip. 
 

battery saver mode is still active so will a BMS reset resolve? 

No. Never reset BMS unless you are fitting a new battery. It resets the battery age to zero. 
 

It should have already figured out the SoC by now. But if you want to force an SoC reset then just disconnect the battery for 10 mins. 

3 minutes ago, alexp999 said:

No. Never reset BMS unless you are fitting a new battery. It resets the battery age to zero. 
 

It should have already figured out the SoC by now. But if you want to force an SoC reset then just disconnect the battery for 10 mins. 

Negative only?

3 minutes ago, Andyr55 said:

Negative only?

That should be fine. 

Can this cause any other problems?

the battery saver mode is not going away on its own.

im temped just to leave the saver mode on if there is a possibility of other issues if the negative terminal is removed for 10 mins as suggested 

any expert guidance appreciated 

5 hours ago, Andyr55 said:

is a possibility of other issues if the negative terminal is removed for 10 mins as suggested ?

No.

It's standard practice, just like when your computer crashes and you switch it off and back on.

Just to update

removing the negative battery terminal for 5 mins or so appears to have resolved my issue. 
 

thanks

Disappointing to report the battery saver mode has returned despite charging the battery. 
 

multimeter shows 12.4v so not sure what issue can be? 

On 12/15/2023 at 11:40 AM, alexp999 said:

 

Battery internal resistance is too high. It can not maintain the voltage underload due to being excessively discharged. 

Replace the battery with a new one. Restart the BMS and all will be well again. 

Halfords here I come!