"Emergency Battery" Under Seat

autostaretx

Erratic Member
The "emergency battery" (which is called "auxiliary" in some places) is quite small ... probably 2 inches tall, 4 inches wide and one inch thick.
It's near the rear wall of the driver's seat pedestal, near the back of the fuse panel. Sort-of lower right in this photo:

UnderDriverSeat150labels.jpg

--dick
 

RVCuisineScene

Active member
The "emergency battery" (which is called "auxiliary" in some places) is quite small ... probably 2 inches tall, 4 inches wide and one inch thick.
It's near the rear wall of the driver's seat pedestal, near the back of the fuse panel. Sort-of lower right in this photo:
I disconnected the negative post and pulled fuse #32 eight weeks ago to work on my van build. Yesterday I tried to start the van and it wouldn't start, power to wipers, seats, radio. Checked battery voltage, it was 12.1V so a dead battery. I'll charge the starter battery do you have a part number for the aux battery, 2022 VS30 diesel, any helpful hints to get the van running, thanks.
 

johnplyler

2020 4x4
I disconnected the negative post and pulled fuse #32 eight weeks ago to work on my van build. Yesterday I tried to start the van and it wouldn't start, power to wipers, seats, radio. Checked battery voltage, it was 12.1V so a dead battery. I'll charge the starter battery do you have a part number for the aux battery, 2022 VS30 diesel, any helpful hints to get the van running, thanks.
My van has cranked at 11.9 volts. I think you have another issue. You did reconnect the battery?
 

scoobync

New member
Not trying to Hi Jack this post but I have similar issue on 2021 sprinter 2500. I'm getting AUX Battery Malfunction and took off the driver seat and wasnt able to find any battery. My VIN :W1Y40CHY9MT061439 hopefully someone able to help me.
 

Happy29

2020 2500 OM642 4x2 170HR
Not trying to Hi Jack this post but I have similar issue on 2021 sprinter 2500. I'm getting AUX Battery Malfunction and took off the driver seat and wasnt able to find any battery. My VIN :W1Y40CHY9MT061439 hopefully someone able to help me.
2021 should have a super capacitor. No battery.
 

scoobync

New member
2021 should have a super capacitor. No battery.
thank you for the quick respond, I saw the super capacitor and still getting the aux battery malfunction and I believe the reason is fuse 32 unplug. So the 10amp should plug in to slot 32 right.
 

Happy29

2020 2500 OM642 4x2 170HR
thank you for the quick respond, I saw the super capacitor and still getting the aux battery malfunction and I believe the reason is fuse 32 unplug. So the 10amp should plug in to slot 32 right.
Yes, I don’t think the fuse position changed. It’s possible the super cap has failed and should be a straightforward warranty item.
 

Happy29

2020 2500 OM642 4x2 170HR
I have a 2021 3500 Sprinter Cut-away Chassis under a LTV RV Coach (See Avatar)

Happy29, can you please post a photo of this super capacitor's location under the drivers seat... and its part number?

Thank you.
Sorry, my 2020 has the little SLA battery. It’s under the drivers seat. I presume the super cap is in the same location but I really don’t know where it’s located.
 

RVBarry

2023 AWD 170 DIY CamperVan
I have a 2021 3500 Sprinter Cut-away Chassis under a LTV RV Coach (See Avatar)

Happy29, can you please post a photo of this super capacitor's location under the drivers seat... and its part number?
I'm not sure how much this helps, as the picture was taken of the relay I added, but here's the outer rear corner of the seat pedestal on my 2023.

1708900397786.png

Compare to Dick's picture below or an older VS30 with the battery:
The "emergency battery" (which is called "auxiliary" in some places) is quite small ... probably 2 inches tall, 4 inches wide and one inch thick.
It's near the rear wall of the driver's seat pedestal, near the back of the fuse panel. Sort-of lower right in this photo:

View attachment 266557

--dick
 

scoobync

New member
So even after replacing super capacitor, im still getting the same error message “auxiliary battery malfunction “, anyone has any idea what else it might be?
 

RVBarry

2023 AWD 170 DIY CamperVan
The fuse supplement for my 2023 says, in the driver's seat base fuse block (F55/4), that fuse 32 is for the transmission.
So I believe that is still the correct one.
 

autostaretx

Erratic Member
If it really thinks the Aux Batt (supercapacitor) is bad, it could be the charging circuitry itself at fault.

--dick
 

scoobync

New member
**UPDATE**
I was able to resolve issue, the issue was missing fuse #9 under driver seat. My super capacitor is good after all. Thank you everyone for all the suggestions . Cheers 🍻
 

Top Bottom