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Jump Starting A Hybrid

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How do you jump start a Hybrid? Is it the same as any other car.

Got a 400H last month, and saw a few posts regarding the drain of the 12V battery...Just curious.

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Because I was too lazy to check my manual, I found this on a AAA site:


The Lexus RX400h has one battery which is located under the hood. It is positioned on

the right (passengers) side of the engine compartment behind the right front headlamp


Figure 11

The RX400h uses the high voltage system to start the gasoline engine. If the 12 volt

battery is discharged, the high voltage system does not function so there may be the need

to jump-start these vehicles.

The following jump-starting procedures should be followed when rendering assistance to

a Lexus RX400h:

Never use jump-starting equipment that can exceed normal 12-volt charging

system voltage.

Ensure that all electrical accessories and the ignition switch are turned OFF

before connecting jumper cables or a jumper box to the discharged vehicle.

If using jumper cables, make connections in the following order:

1. Connect the positive (+) jumper cable to the positive battery terminal of the

discharged vehicle and to the positive (+) battery terminal of the donor vehicle

or jumper box.

2. Connect the negative (-) jumper cable to the negative battery terminal of the

donor vehicle. (Skip this step if using a jumper box.)

3. Connect the negative (-) cable to a good ground on the engine of the

discharged vehicle. NOTE: You may have to remove the decorative engine

cover to access a good connection location.

Allow the discharged battery to charge for a few minutes before attempting start the

vehicle. Since the high voltage system actually starts the gasoline engine, there may not

be any cranking that takes place. The computers on this vehicle decide whether or not

the gasoline engine needs to run to charge the high voltage battery which in turn charges

the 12 volt battery through a connection in the systems inverter/converter assembly. The

RX400h usually moves at low speeds and in reverse under electrical power only.

By the way, when your 12V battery is getting weak, you will probably see a message telling you to shift the gear shift selector into Park. This is most likely to happen in the morning when it is cool/cold in the garage or outside. When you see this message, you should plan on buying a new battery sooner, rather than later.

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Here's more info regarding how the RX should be jacked up, towed, fueled, etc:

Most, if not all of this is in the manual but it's good to review every once in a while.

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That's all interesting reading (where did you find that?) I love reading about the RX - here's another good link It has nothing to do with's just interesting.

To answer the original question in layman's terms, though, yes, you boost the RX400h the same way you would boost any other non hybrid vehicle.

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Nice info as well! I did a Bing search to find the AAA site.

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