TomT wrote:The 12 Volt DC-DC inverter can provide something like 100-150 amps (I forget the exact number now) so jumping is possible there too. I did exactly that with a friend's truck last winter, in fact.
The Leaf's DC-DC converter can supply up to about 1.7kW or 135a. This unit takes ~400v power from the traction battery and makes approximately 13 volts. (varies according to charge requirements of the 12v aux battery) It should be able to power up to 1.5kW of external load with no problems, provided most of the accessories are left off.
It operates ANY TIME the main battery contactor is closed, so this means when the car is in Ready, or anytime there is actual charging taking place over J1772 or CHAdeMO.
One interesting thing is, unlike the 12v system on a ICE car, there is almost no voltage sag. The DC-DC converter is a high-frequency switch mode converter, so it can respond very fast to high current surges, whereas a normal ICE car alternator cannot, and it's also RPM dependant for maximum output.
WARNING: NEVER connect anything directly to the negative post of the Leaf's 12v aux battery! This is a current sensor and doing so will disrupt the charging system! (Connect all accessories to the body ground, or, if high-current, the black wire screwed to the top of the DC-DC JB. (Behind the inverter)
Here's a picture during testing:
While Nissan doesn't condone it, you should have no issues jumping another car with the LEAF. Be absolutely sure to get the polarity correct, and connect the ground on the LEAF to the DC-DC converter, NOT THE BATTERY (-) TERMINAL!
Procedure: Connect the red/black jumpers directly to the Pos/Neg terminals of the dead car's battery first, then connect the red directly to the LEAF's Pos battery terminal, and then finally, connect the black jumper lead to the case of the DC-DC. The DC-DC is the large aluminum box behind the "engine looking" inverter. You can easily see the black negative terminal on top of it, which is a good place to grab. Once jumping is complete, disconnect in reverse order. Be very careful not to short the jumpers together when removing them from the LEAF.
The LEAF's DC-DC converter is about as powerful as an alternator on any normal car, and should charge a dead ICE battery enough to start it in a few minutes. No need to "rev" the LEAF! =)