Max. Charge and 80%?

[Carabiner]

Does the Max. Charge option do anything if the display is reporting >60h of leisure battery charge? Or are they fully charged already? I thought they charged to 80% normally. Does the >60h mean the batteries are 80% charged, or does it never report higher? Mine never shows anything more even with the Max. Charge option selected before a journey.

Thanks!

 

[dspuk]

Yes. Tops you up to 100%.
Yes. 80 is the norm. Keeps batteries working properly.
>60h means that. Under normal use. It never reports higher.

TBH the management system looks after it. Don’t sweat it.

 

[Californication69]

Yes. Tops you up to 100%.
Yes. 80 is the norm. Keeps batteries working properly.
>60h means that. Under normal use. It never reports higher.

TBH the management system looks after it. Don’t sweat it.

What @dspuk said.
Will drive you insane keep looking at blue bars and hours and amps and why when I’m driving it says -23 amps, then up to +30a
Who knows.
I believe the VW battery control panel algorithm is based upon chicken bones being thrown onto a dustbin lid.

 

[66tim99]

Does the Max. Charge option do anything if the display is reporting >60h of leisure battery charge? Or are they fully charged already? I thought they charged to 80% normally. Does the >60h mean the batteries are 80% charged, or does it never report higher? Mine never shows anything more even with the Max. Charge option selected before a journey.

Thanks!

I just press max charge for the last drive before camping without hook up for more than one night. Eventually (seems to take a couple of hours of driving) all the bars become blue and it probably gives you an extra day camping.
I also did that when I had to park it up for 3 months off hook up. I figured it would be better to have 100% battery slowly draining, than to come back and find the batteries empty. In the end, the leisure batteries barely drained.

 

[Roger Boeken]

What @dspuk said.
Will drive you insane keep looking at blue bars and hours and amps and why when I’m driving it says -23 amps, then up to +30a
Who knows.
I believe the VW battery control panel algorithm is based upon chicken bones being thrown onto a dustbin lid.

I agree sometimes it seems confusing and numbers displayed cannot be explained but most of the time it makes sense.
1. When driving and batteries being charged it shows charge /discharge current.
2. When motor not running and none or very little current drawn from batteries it indicates battery voltage and > 60h. Voltage is best indicator here for battery status.
3. When motor not running and a current of several amps is drawn from the battery it will tell you how many hours the battery can continue to deliver this current. In other words if you multiply the hours and current you get the leftover battery capacity in Ah. This will never be more than 80Ah because it is rule of thumb not to discharge batteries more than 50% and we have 2 batteries in parallel. According to VW our VARTA batteries have 75Ah capacity but if you look up the VARTA reference number on the battery at the VARTA website it says 80Ah. Limited accuracy and precison of current measurement makes it only rough estimation at low currents: display shows 0.0 A or -1.0 A when nothing is switched on. But if heater or refrigerator becomes active it gives you a good indication of capacity left in leisure battery.
I see many members here with questions about how much and how long heater and refrigerator discharge the batteries. Also many questions if current is taken from motor battery or leisure battery. If anyone likes to measure this himself I found a suitable DC clamp meter at amazon :

OWON CM2100B Mini Bluetooth Clamp Meter​

make sure to look for the bluethooth version : it can show/log measurements in app on our phone in real time. So you can monitor how much and how long any consumer discharges the batteries of your cali.Very usefull for troubleshooting electric circuits in the cali. Check also the reviews on youtube . If you want to measure/monitor more than one voltage or current at the same time you can connect more than one meter in the same app. One restriction: highest range is 100 A DC.

 

[sidepod]

Hopefully I’m understanding this correctly?
The extra 20% that max charge gives you means you can get a full weekend out of the fridge?

So far I’m 41 hrs in with just the fridge (setting 5) and battery showing 11.8. Charge now!

Bonus - control panel woke me up on the night to point out the system’s shortcoming!

 

[Corradobrit]

Hopefully I’m understanding this correctly?
The extra 20% that max charge gives you means you can get a full weekend out of the fridge?

So far I’m 41 hrs in with just the fridge (setting 5) and battery showing 11.8. Charge now!

Bonus - control panel woke me up on the night to point out the system’s shortcoming!

At setting 5 you must have a block of ice in the fridge. 2 is what I need (still get ice forming on the back surface) and 3 when I'm on the road and dropping the temp from ambient. Lower the thermostat setting and you'll get more life out of the batteries.

 

[Californication69]

Should do. Depends how many times you open it and what else you charging from usb and ciggie lighter chargers.
Also if you’re running night heater.

 

[Californication69]

At setting 5 you must have a block of ice in the fridge. 2 is what I need (still get ice forming on the back surface) and 3 when I'm on the road and dropping the temp from ambient. Lower the thermostat setting and you'll get more life out of the batteries.

Yep fridge 2 or 3,
Night heater on 7

 

[sidepod]

Ok so it’s opposite to what I’m used to? 5 is colder than 1?

 

[Corradobrit]

Ok so it’s opposite to what I’m used to? 5 is colder than 1?

Correct

 

[sidepod]

That’s odd. I had it on 4 and it was starting to ice up then switched to 5 and the icing stopped.
Must have imagined it.
Hey ho. Thanks chaps.