Can you advise me on the best configuration for connecting my Blue Smart IP65 12v 10a charger to my 2017 Range Rover. It has 1x AGM 95ah battery (hidden deep in the boot), there is no 2nd aux battery in this model.
The car has an Intelligent Power System Management (IPSM|) that shuts down non essential equipment when the car engine is not running and the battery voltage drops down. I bought the charger to use in Winter to make sure the battery stays at full capacity so the remote Fuel Burning Heater can be activated to warm the car up in the mornings.
I have read conflicting information on the best way to connect the charger to my car.
Connect conveniently via the permanent 12v aux socket inside the car with the cigarette lighter adaptor I purchased as this is a direct (via the fuse box) connection to the battery and the Blue Smart will be able to correctly read the condition of the battery to determine what charge status to apply.
or
connect via the terminal connections under the bonnet (used to connect jump leads if needed) as they run via the Battery Management System (BMS) controller and can take a higher amperage. Will Blue Smart send / receive correct battery status information when passing through the BMS?
The battery doesn’t need full charging from a 100% discharged state as it will be near full charge when I park the car up from driving it during the day. It just needs the Blue Smart to act as a trickle charger to maintain the full capacity for when the electronics that run 24/7 take some power (i.e. the active security monitoring system and dashcam/security cameras).
Have you verified that the 12v socket in the vehicle is always-on? I know my own 12v sockets in my vehicle are accessory-triggered, they’re not powered when the ignition is off, which means that a charger connected to them won’t do anything for the battery unless the ignition is on.
The battery charger will not itself send or receive any information to/from your onboard BMS, there’s no communication like that.
That said, most of the onboard vehicle BMSs that I’m familiar with just use a battery current and temp sensor that’s usually mounted to the battery terminal negative, so connecting the charger directly to the battery via clamps would bypass that sensor and probably is not what you want to happen… in which case, connection through the 12v socket is probably the best move as long as you’ve independently confirmed that it’s an always-on socket.
thank you Justin. I confirmed the socket stays live so will use that method then.
Is it ok to join 2 of the 2m extension leads plus the cigarette lighter adaptor lead to the lead from the charger so I can mount the charger on the wall?
It’s not a great idea overall just because of the voltage drop; 4m of extension plus roughly 1m of original cable equals around a 32’ round-trip circuit length which would equal (if I’m recalling that the extensions use 10AWG cabling, which I could be wrong about) around 5% voltage drop… but I think you can likely get away with it.
An alternative is to look and see if you have a good grounding post (besides the battery) under the bonnet, I know some vehicle manufacturers provide one for the purpose of jump-starting basically for this exact reason, so that the BMS can “see” the current from the jump-starter - in that case, you could connect the +ve gator clip to the battery and the -ve gator clip to that grounding post, and that way the onboard current sensor can see the current inbound from the charger.