Disconnecting Power / Batteries for truck with dual batteries

[BartHarleyJarvis]

Hi all - I've worked on vehicles before, but never anything with two batteries.

Instructions say:

1. Disconnect the ground connection to the Battery Combiner.
2. Remove the Negative (-) terminal on both the Start and Auxiliary Battery. Never allow contact between the Battery Cables and conductive metal parts, for example, the vehicle body.
3. Perform Service Work.
4. Re-assemble in the opposite order.
5. Check that there is no fault indication on the Battery Combiner LEDs.

All I see on the batter combiner (or what I think is the battery combiner) is "in" and "out"

Here's the diagram from @Rok_Dr 's fantastic manual:

Can someone give me a bit more direction?

And you don't disconnect the positives at all?

Thanks in advance for sharing your expertise.

Matt

 

[Clark Kent]

Hi all - I've worked on vehicles before, but never anything with two batteries.

Instructions say:

1. Disconnect the ground connection to the Battery Combiner.
2. Remove the Negative (-) terminal on both the Start and Auxiliary Battery. Never allow contact between the Battery Cables and conductive metal parts, for example, the vehicle body.
3. Perform Service Work.
4. Re-assemble in the opposite order.
5. Check that there is no fault indication on the Battery Combiner LEDs.

All I see on the batter combiner (or what I think is the battery combiner) is "in" and "out"

Here's the diagram from @Rok_Dr 's fantastic manual:

View attachment 7880984

Can someone give me a bit more direction?

And you don't disconnect the positives at all?

Thanks in advance for sharing your expertise.

Matt

Hi @BartHarleyJarvis (Matt)

What instructions are you reading this from?

Confirming that the item with the CTEK branding in Rok Doc's pic is the battery combiner. Early deliveries got a fully featured Smartpass 120S as shown. Later deliveries got a stripped-down unbranded version that Ineos call the battery combiner.

The ground cable is a thin black wire at one end as shown in these pics. Maybe you're looking for a thick earth cable.

Call me old school but I routinely disconnect the positive and negative battery terminals to be sure.

Be aware you need to let the vehicle go to sleep before you disconnect the starter battery or you will cause an airbag error that needs to be reset by a dealer. The sleep instructions are in the owner's manual and Rok Dr's guide.
After you reconnect the batteries expect to get a couple of unexpected lights stay on, e.g. diff locks if you have them fitted. These will self clear within a few minutes of driving. No panic.

Cheers

 

[BartHarleyJarvis]

Thanks Clark - appreciate your help here!

I was in the Owner's handbook (the hardbound one in the glovebox and the online version), in @Rok_Dr 's manual, scanning through the forum, and frantically googling!

I had just hunted down that the ctek smartpass box was the battery combiner - and I was just looking through their documentation. And you're absolutely right, I was looking for a big boy grounding cable.

Vehicle is asleep - so I'll disconnect that small connection on the smartpass box, both battery negatives and both positives, because I'm in the same old school camp as you.

Thanks also for the note about the unexpected lights - future Matt thanks you for that!

Best,

Matt

 

[Clark Kent]

Thanks Clark - appreciate your help here!

I was in the Owner's handbook (the hardbound one in the glovebox and the online version), in @Rok_Dr 's manual, scanning through the forum, and frantically googling!

I had just hunted down that the ctek smartpass box was the battery combiner - and I was just looking through their documentation. And you're absolutely right, I was looking for a big boy grounding cable.

Vehicle is asleep - so I'll disconnect that small connection on the smartpass box, both battery negatives and both positives, because I'm in the same old school camp as you.

Thanks also for the note about the unexpected lights - future Matt thanks you for that!

Best,

Matt

There's been some variation in the owner's manuals according to the delivery region and at least one MY update hence my question. Steve @Rok_Dr has done a great job covering the system differences where known.

To be clear, that yellow arrow might be pointing at the temp cable but it's just a marker to get you in the ballpark. You'll find what you need at that end.

Sounds like you're good to go. Have fun with your vehicle.

 

[BartHarleyJarvis]

Just ran back out to the shop and got everything disconnected. I guess we won’t really know if I did ok until I plug it all back in, though!!

 

[Rok_Dr]

Hi all - I've worked on vehicles before, but never anything with two batteries.

Instructions say:

1. Disconnect the ground connection to the Battery Combiner.
2. Remove the Negative (-) terminal on both the Start and Auxiliary Battery. Never allow contact between the Battery Cables and conductive metal parts, for example, the vehicle body.
3. Perform Service Work.
4. Re-assemble in the opposite order.
5. Check that there is no fault indication on the Battery Combiner LEDs.

All I see on the batter combiner (or what I think is the battery combiner) is "in" and "out"

Here's the diagram from @Rok_Dr 's fantastic manual:

View attachment 7880984

Can someone give me a bit more direction?

And you don't disconnect the positives at all?

Thanks in advance for sharing your expertise.

Matt

Just confirming that the disconnection procedure wording came out of the grenadier owners manual.

Thanks @Clark Kent for the clarifications.

For the next edition I'll clarify that battery combiner and smartpass are the same thing and will also check the recently released V2 owners manuals that there is no change in the disconnection procedure.

Cheers
Steve