Jump Start

[barrychan]

Hi
Not sure if this has been mentioned....
How do you jump start a gas vehicle with our i3?
Last week i came across a car on the road with a dead battery and i have a battery car and didn't know how to help her.

 

[Sparky]

I don't think it's possible, but read the manual anyway. The i3 has a very small 12v motorcycle battery embedded in the frunk. It only powers the ready electronics, and can't be charged through power outlets. I'd forget about helping others with this car.

 

[alohart]

I don't think it's possible, but read the manual anyway. The i3 has a very small 12v motorcycle battery embedded in the frunk. It only powers the ready electronics, and can't be charged through power outlets.

I haven't been able to find the capacity of the standard 12 v. battery in U.S. i3's, but I would be surprised if it did not have plenty of capacity to jump start another car except maybe in very cold winter weather. But I would not try it without first disconnecting the negative cable from the i3's battery and then connecting the negative jumper cable directly to the i3's battery post so that the other car's electrical system could not potentially damage the i3's electrical system.

However, disconnecting the negative battery cable would result in information being lost (e.g., memory presets, clock time), so I would only do this in an emergency. I'll know by the end of this week the effects of disconnecting the 12 v. battery (our i3 has been in storage for almost 6 months). Hopefully, not much of importance will have been lost.

 

[barrychan]

Maybe BMW will consider putting a positive terminal somewhere for this purpose!

 

[alohart]

Maybe BMW will consider putting a positive terminal somewhere for this purpose!

Even if a positive terminal were more easily accessible than now, I wouldn't want to connect my i3's electrical system to another car's electrical system through jumper cables. Once the other car starts, its alternator would send power back to the i3's electrical system which could cause problems.

 

[Stevei3]

Hi guys,
also keep in mind that the i3 has no 12v starter battery in the conventional sense. The REx, for instance, is started from the HV battery. The 12v system is only used for board electronics and lighting. I would't dare to provide a jump start however lovely the damsel in distress
Regards, Steven

 

[alohart]

Hi guys,
also keep in mind that the i3 has no 12v starter battery in the conventional sense. The REx, for instance, is started from the HV battery. The 12v system is only used for board electronics and lighting. I would't dare to provide a jump start however lovely the damsel in distress

Honda hybrids have a conventional 12 v. starter motor that is used at low temperatures when using the high-voltage NiMH battery pack might be damaging. Our 2000 Honda Insight has a tiny absorbent glass mat (AGM) battery which is the same battery design as the i3's battery but considerably smaller physically, so it almost certainly has a lower capacity and cranking power than the i3's 12 v. battery, yet it is able to start an Insight's engine using the 12 v. starter motor. So there's no reason to believe that the i3's 12 v. battery wouldn't have sufficient power to jump start another car unless the i3's 12 v. battery is dying.

Because the i3's 12 v. battery never has to produce the momentarily high current necessary to power an ICE starter motor, it can be very difficult to determine when an i3's 12 v. battery is dying. One jump start attempt could kill a weak i3 12 v. battery. The poorly-worded low battery power warning that some i3 owners are reporting might be the only early warning of a dying 12 v. battery. Gasoline-electric hybrids have the same problem since their 12 v. batteries rarely or never power a starter motor.

This is why I would jump start another car using our i3's 12 v. battery only in an emergency, but I would be quite confident that the jump start would succeed without damaging our i3.

 

[Schnort]

I'd rather carry and use something like this:

http://www.amazon.com/DBPOWER-12000mAh-Portable-Starter-Battery/dp/B00YE5Q132/ref=lp_318336011_1_11?s=automotive&ie=UTF8&qid=1443039100&sr=1-11

(mind you, I don't own this product and I'm not endorsing this particular one. it just came up on amazon when I searched).

 

[imolazhp]

Read your owners manual; it specifically says no jump starting, in either direction.

If you come across someone that needs a jump, make a phone call for them or help them flag someone down with a vehicle that can give them a jump. If you attempt to jump their vehicle and mess up yours are they going to pay for the repair bill? Because BMW will not cover the damage under warranty, you will be stuck with the repair bill.

It simply isn't worth the chance, even if it were easily accessible.

 

[jadnashuanh]

It's not worth the risk. Disconnecting it first might protect the i3, but that's a lot of work. In that time, you could probably take them somewhere to get help if they're out of cellphone coverage. FWIW, that's what something like AAA is for, or some other road service provider, depending on where you live.