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One car not used in weeks - battery gone flat
Other car is a PHEV. Only has positive terminal, no negative.
1. Can I charge the other car with out some how damaging the PHEV ?
Where the hell do I put the negative lead? Googling says the negative terminal must be attached !
These days they don't want you connecting battery to battery, it's live (red) to the battery and negative (black) to an earthing point on the body somewhere. It's usually a goldish unpainted bit of bodywork near the battery.
I've never used a PHEV to jump a car, I know they keep the high voltage batter system completely separate to the 12v system for obvious reasons so you should be able to do it. what are the cars?
Yeah, you'll be fine using a PHEV the DC/DC charges the battery just like an alternator would and the 12V is completely isolated from the HV for safety.
As P-jay says, red to batt+ and black to any good earth point should be fine.
It’s BMW 330e charging Vauxhall Corsa
So live to live
Bmw (bit in engine) to negative on Corsa battery ?
It's Red to Red first.
Then Earth to Earth (my car has a big lifting eye on the end of the engine which is convenient).
Reason is the last thing you connect creates a spark which you don't want near the battery. It also makes it much harder to create a short circuit (unless you dropped the first jump lead into the 1st cars engine bay, easily solved by leaving the other end on the floor).
Disconnect in the opposite order, earths first, then positive.
Managed to get through to BMW. They said not to do it as would void warranty.
Not sure that was the Truth, or the bloke actually didn’t have a clue!
When I did our flatted little Mazda from the van, it was +ve (van) to +ve (Mazda), -ve (van) to metal suspension brace wotsit (Mazda). Remove in reverse order
Managed to get through to BMW. They said not to do it as would void warranty.
Brilliant 🙂
"press 1 for parts, press 2 for sales, or press 3 for bullshit information from someone who really cant be arsed"
Ah but this was BMW Uk, not the local dealer
Of course they're going to say no. There's no upside for them and possibly damaged electrics if you do something stupid.
Your Corsa isn't going to know what the donor car is and your BMW isn't going to know where that battery charge is going.
Buy a battery pack jump leads. You charge it on the mains and then disconnect, carry it to where its needed and connect and start the engine. A fantastic bit of kit. Some will also charge your phone and laptops etc. Pricey but worth it.
Personally, I wouldn’t unless it was a last resort and the other option is being stranded. Your BMW probably still has a 12V battery which is removable - my preference would be to remove the battery and jump directly from it (or park close and just disconnect the positive from the donor battery).
I have a li-ion battery pack. I’ve never actually seen it start a car that’s totally dead but it will get an engine going that has some, but not quite enough, charge in the battery.
the high voltage batter system
Eel on the menu at your local chip shop tonight?
There is usually a red plastic flap under the bonnet which covers the positive terminal.
The negative terminal will be on the the drivers side of the engine bay which will be a little metal cylinder sticking out from the side
Jump leads – how to use
Right nipple first.
You don't want to give them a heart attack too soon.
I have a li-ion battery pack. I’ve never actually seen it start a car that’s totally dead
I started my Yaris from complete dead using one, several times on the same charge. Good to keep in the car for emergencies, has a built in light/emergency beacon and can charge phones etc.
Been thinking about getting one of these battery packs.
Does anybody have any recommendations for a particular brand/size etc?
I read this review:
https://www.carbibles.com/best-jump-starters-reviewed/
And bought this:
https://www.amazon.co.uk/Starter-External-Automotive-Motorcycle-Flashlight/dp/B01DVSSCG6
Online reviews and batteries from Amazon are prime scammer territory, but it seems to work fine, hasn't exploded and killed me yet.
Managed to get through to BMW. They said not to do it as would void warranty.
Bollocks. I’ve lost count of the number of times I’ve had to jump-start BMW’s at work, or pretty much any other make of car you care to mention, it’s just a fact of daily life when there may be several thousand cars on site, and some/many are sitting still for ages, months even. The battery is quite often in the boot of many BMW’s, which can be a royal pain if the car’s parked in the middle of a group of cars, more usually back to back in paired rows. There are still many cars with both + and - accessible, although many now have the battery recessed under the scuttle below the windscreen, and the - terminal is a little bare rod sticking out somewhere, and others don’t have anything at all, so finding a good contact on bare metal can be a bit of an issue.
Now, don’t get me started on Mercedes with flat batteries... 🤬
Turn lights on as soon as it catches.
Stops the surge.
Working in the motor trade, christ knows how many I've started
The battery is quite often in the boot of many BMW’s, which can be a royal pain if the car’s parked in the middle of a group of cars, more usually back to back in paired rows
There's a +ve terminal (usually under a red plastic cover) and a dedicated earthing point under the bonnet on BMWs where the battery's in the boot.
Been thinking about getting one of these battery packs.
Does anybody have any recommendations for a particular brand/size etc?
I bought a really cheap lead-acid one from halfords, the charger socket broke so I have to bodge it from a car charger, but still does the job.
They're basicly a motorbike battery and jump leads, shoddy charger connectors aside there aren't really any features to go worng.