General Charging The Battery

[Watchman077]

I have recently bought a new Carado Camper Van based on a 140 bhp Ducato Panorama with an auto-gear box and stop start. We took it to the nearest Fiat dealers for them to sort out a few minor niggles and no stop/start. The technician said the battery was only 45% charged & the top start will only work once the battery is above 85% charge. I told him we don't use the van regularly.
He said that if I wanted to charge the battery, open the bonnet & connect the negative charger clip to the earth terminal thread in the centre and the positive clip to the a terminal under a black plastic hinged unit on the RHS.
I bought a charger and read the manual - that tells me to disconnect the negative battery terminal and a sensor for the stop start before charging.
You Tube videos also show the battery being accessed under the cab floor and the the earth terminal being removed first.
Also that the terminals under the bonnet are just for jump starting.
Any ideas?

 

[Reg 65]

Welcome to the forum
Discussed on another thread
https://www.fiatforum.com/ducato/486776-new-ducato-stop-start-alternator-2.html?p=4600025
Nobody has come up with an answer so far. My guess is that a very powerful boost charger could raise the charge voltage above 15 volts and do some damage.
I have charged it in situ with a 10 amp charger, like the Fiat technician suggests, with no noticeable ill effects.
PS: I have the same 140 Ducato but manual. How do you find the auto box?

 

[RS3100]

If you use a microprocessor controller "smart" battery chareger, such as a Ctek or Noco (there are others) there is no need to disconnect the battery negative lead. That advice is aimed more at the use of old-fashioned single-stage or unregulated chargers.

When charging vehicles with stop/start systems, the main thing to ensure is that you never connect the negative charger lead to the negative terminal of the battery. Connect it to an appropriate part of the chassis or body, or on the Ducato the remote earth post under the bonnet is fine, as advised.

The reason is that the battery management systems on these vehicles monitor battery SOC via a sensor on the negative connection to the battery (a shunt). If you bypass the shunt by connecting the charger directly to the battery terminals, the battery SOC will be out of synch with the BMS calculation, which can lead to all sorts of undesired effects including various systems on the vehicle being shut down and less than optimal charging, until the BMS has been able to resynch.

Don't get hung up on stop/start. The systems are designed prioritise the actual use of the vehicle, and will often be disabled by the ECU when conditions dictate that continued use of certain systems is more important. I don't have stop/start on my Ducato, but I have it on my car and the handbook has three pages of conditions under which the system will not stop the engine or may restart it unexpectedly depending on vehicle use and the systems in use at the time, such as climate control, radio, headlights, screen demister, etc. Yet forums are full of posts complaining that stop/start doesn't work all the time