Starting vehicles with a jump pack ?

[Misterg]

Apparently turning the ignition on then waiting for the warning lights to go out helps somehow?

Yes, I'd been doing all that, and the van is a camper with solar that trickle charges the cab battery, so it's always full (there is quite a bit of parasitic draw on these vans that will flatten a battery in a few weeks, as you probably know). So I was gutted when I bogged the engine and almost stalled it and the effin' airbag light came on! (Got it in 3rd rather than 1st leaving some traffic lights).

 

[JohnH]

There probably is something to it. I remember in the 1990’s having a E30 BMW 325is and that had a whole procedure outlined in the owners manual on what you had to do if you wanted to jump start it. Headlights on etc to load it up as much as possible, supposedly to protect all the ecu’s it had in it.

BMW E28 1985

 

[Pete.]

An advantage with EVs...if everything is working correctly they top up the 12v battery from the main traction battery I believe.

....if everything is not working correctly I've heard they too may need a jump start!

My company Toyota van runs the 12v battery down if left for more than 4 or 5 weeks because of the tracker and camera being permanently live. To charge it up you have to sit in the driver's seat and turn the ignition on as if you're going to drive it, then the charging inverter will charge it at 50A from the main battery. Gotta be sat in the seat though (I dump my rucksack on it) or it shuts off.

If it's gone dead flat though, no amount of jump starting will get it going. Even a normal charger takes a loooong time to bring it round.

 

[Pigeon_Droppings2]

Gotta be sat in the seat though (I dump my rucksack on it) or it shuts off.

I'd love to know what the designers logic was...mine dies it automatically...or more accurately it's "meant" to do it.

Think modern cars are just too complex...the jogger I bought goes nuts if I open the door when reversing to check the kerb. I don't think that's breaking any road rules (unless things have changed!)

 

[Bornfree]

The only thing electronic in my 25 year old ssangyong is the alternator regulator.

 

[Kram]

Jump packs are safer than jump leads from another car, they don't supply power till it senses power draw, jump leads and smart alternator throw out power instant it's connected.

Not quite. Theres nothing particually smart about a jump pack. You press the boost button, it outputs 16v.

I can’t see how it could possibly cook anything, it’s simply putting 12 volts or so into the system, like the original battery does.

A jump pack will be running on near 16v. Four * 4.2v = 16.8v, minus a bit for diode drop, if its fully charged.

Cars generally, can handle the increased voltage and is also the reason jump packs are so effective, the extra voltage provides extra power and spins it a little faster than normal.

Note that a car alternator generally puts out 14-14.7v which is the maximum a lead acid will generally tollerate long term without degrading. So its only 1.5v or so more than normal.

 

[sg66]

Not quite. Theres nothing particually smart about a jump pack. You press the boost button, it outputs 16v.



A jump pack will be running on near 16v. Four * 4.2v = 16.8v, minus a bit for diode drop, if its fully charged.

Cars generally, can handle the increased voltage and is also the reason jump packs are so effective, the extra voltage provides extra power and spins it a little faster than normal.

Note that a car alternator generally puts out 14-14.7v which is the maximum a lead acid will generally tollerate long term without degrading. So its only 1.5v or so more than normal.

The noco I have has reverse polarity and it has a cycle to go through or it times out, it has anti sparking whilst connecting too, it doesn't try to put 800amps into the battery as there is no huge power draw, it does have an override to attempt to jump start if battery voltage is so low that it can't detect it, that nocks off all the safety features, it's intelligent enough for me.