[NWH]

Grippa do a split charging unit for stop start vans.

[Simon Trapani]

The Sterling one I have is also, but thanks.

[Spruce]

Grippa do a split charging unit for stop start vans.

The trouble with stop start is that when the engine stops the alternator stops charging.  But the connection between the b2b charger and the starter battery remains for a bit. The b2b charger continues to draw power from the starter battery to charge the leisure battery during this period.

When I switched my engine of last night I monitored both batteries. The b2b charger remained on charging the leisure battery at 4 amps until the starter battery dropped to 12.5v under load. At that point the starter battery climbed back up to 12.6v. It's at 12.62v this morning. So over the course of the day yesterday my starter battery has lost 0.1v . As my starter battery was fully charged on Monday morning 12.6v means it's now 75% charged. My leisure battery is showing 12.93v which is 100% charged, although again its 0.1v down on what it was yesterday morning from fully charged.
I did 10 miles yesterday. As the batteries were both fully charged the only real charge the leisure battery got was the 5 miles home.

That battery is original with the van so could well be that its on its last legs and has lost capacity, but it tells me that some of its loss is due to the b2b charger. If I was in traffic yesterday with a van having stop start then I would be worse of with regards to my starter battery.
Later on this week I'm going to fully charge both batteries again and then switch the b2b  charger off for the day and see what the van battery does.

[Simon Trapani]

Would fitting the optional ignition wire or reducing that timer to zero in the settings help?

[Spruce]

Would fitting the optional ignition wire or reducing that timer to zero in the settings help?

It won't help you with stop start as the ignition will still be on triggering the unit to remain connected to the starter battery.
This is why I was thinking about the trigger wire to be connected to the alternator.
If you have your ignition on to listen to the radio at least the B2b charger remains disconnected.

[Simon Trapani]

Is the trigger wire the ignition wire? I wouldn’t know where to fit it at the vehicle end.

My stop/start stopped working after lunch today. Hasn’t worked since. I had the radio on for 20 mins or so, my phone was charging & the dashcam was on. I’ve only done 7 miles.

Does the dashcam eat much battery do you know & would it help to piggyback it onto a position ii fuse?

[Spruce]

Is the trigger wire the ignition wire? I wouldn’t know where to fit it at the vehicle end.

My stop/start stopped working after lunch today. Hasn’t worked since. I had the radio on for 20 mins or so, my phone was charging & the dashcam was on. I’ve only done 7 miles.

Does the dashcam eat much battery do you know & would it help to piggyback it onto a position ii fuse?

The suggestions are that a dash cam uses between 1.8 watt and 2.5 watt. (12w is an amp over an hour. I think my starter battery is 90 amph.) That's not very much but over a period of time it will flatten a battery. A customer has a Ford Ranger and he accidentally left his dashcam on whilst the vehicle was parked on his driveway for a 'few' days. The battery was flat. He called the AA who charged it a bit and then jump started it. They eventually had to reprogram the ecu as it had lost a few settings, according to the AA guy.

If you are prepared to recharge your leisure battery every night you might try and switch the b2b charger off and see if the stop start reactivates without that additional draw.

They warn you that having the b2b charger linked to the ignition switch is the only way if you have regenerative braking but that it will be active with the ignition on and could flatten the starter battery.
There will be plenty of fuses in the fuse box that are only active with the ignition on, radio, cigarette lighter/ auxiliary power socket, wipers, reverse lights, etc so a piggy back fuse can be linked into any of those fuses with it own low rated fuse. Ive done this with my reverse camera.



 

[Simon Trapani]

Ok thanks for all your time Spruce. Lots for me to think about.

I've got a double outside socket right next to both vans, two extensions made up & two ctek chargers but I'm reluctant to bench every night, even in situ, as I just know I will drive off forgetting to disconnect!

[Spruce]

Ok thanks for all your time Spruce. Lots for me to think about.

I've got a double outside socket right next to both vans, two extensions made up & two ctek chargers but I'm reluctant to bench every night, even in situ, as I just know I will drive off forgetting to disconnect!

Tie a towel onto the steering wheel so you don't forget.

[windowswashed]

The b2b will automatically drain the main battery overnight to charge the leisure battery in normal automatic setting unless you wire the b2b through the ignition feed. The only way around it if you don't plan to wire b2b through ignition would be to fit an isolation switch before the leisure battery to stop the b2b charging it overnight or any time your vehicle is switched off.

[Spruce]

The b2b will automatically drain the main battery overnight to charge the leisure battery in normal automatic setting unless you wire the b2b through the ignition feed. The only way around it if you don't plan to wire b2b through ignition would be to fit an isolation switch before the leisure battery to stop the b2b charging it overnight or any time your vehicle is switched off.

The sterling b2b unit doesn't remain constantly on. Sterling says it should switch the unit off when the input voltage drops to 13.0 volts. I've watched mine on my battery monitor and it only disconnects when the starter battery drops to 12.5v under load.

Once the unit has switched off there is no charge input from the starter battery to the leisure battery.

The instructions say that with vans with regenerative braking you must have an ignition trigger wire which disconnects the unit when the ignition is switched off.