400h Auxiliary Battery Problems?

[Foxgoose]

Got my new 400h on Friday in the UK and it's great - except that, while sitting in the car transferring my phonebook, loading CD's and playing with the ICE video system for an hour or two - the auxiliary Battery went flat and wouldn't start the car.

Rescue truck driver said its because it has a very small auxiliary Battery for the size & complexity of the car.

When I finally jump started it the engine ran for a few seconds and then cut out because the traction batteries were presumably OK.

Seems weird that the car can be immobile because of a low aux Battery when there's all that juice sitting in the traction batteries.

Anybody know why the design doesn't allow for starting the engine from the main batteries via a voltage converter?

Anybody else had aux Battery problems?

[Loopster]

Hi there,

Got a 400h at the beginning of Oct 05 and had no probs with the main or aux Battery yet - I agree that it seems odd the juice from the traction batteries can't be used, in fact why didn't they just do away with the 12v system and use the big electric engines to start the petrol engine...

If you bought your car from Lexus Poole (as I thought I read somewhere) then be prepared to wait to have it looked at. I nmy car, one of the DVD screens in the back has never worked. Twice they have not shown up when they say and failed to fix it once may just be bad luck...

[Foxgoose]

Hi

After speaking to the recovery guy and taking a few voltage measurements I think I understand the problem a bit better.

The traction Battery does feed charge into the 12v Battery - but only in "ready" mode and only about 3 amps when the engine isn't running.

Bottom line is - if you want to sit in the car and use accessories, make sure it's in "ready" mode. (and don't do it in the garage in case the engine decides to start).

Because of the relatively small aux Battery it won't last long in the normal "accessory" key position if you use the hifi etc.

I actually got the car from Plymouth and they've offered to change the aux Battery just in case it's not holding full charge.

[billygarrett]

Hi

After speaking to the recovery guy and taking a few voltage measurements I think I understand the problem a bit better.

The traction battery does feed charge into the 12v battery - but only in "ready" mode and only about 3 amps when the engine isn't running.

Bottom line is - if you want to sit in the car and use accessories, make sure it's in "ready"  mode. (and don't do it in the garage in case the engine decides to start).

Because of the relatively small aux battery it won't last long in the normal "accessory" key position if you use the hifi etc.

I actually got the car from Plymouth and they've offered to change the aux battery just in case it's not holding full charge.

←

Thi has happened to me 3 times, twice because I was stupid enough to leave the key in Aux position all day so the display was on and once because I sspent 2 hours trying to work out the secret menus :)

I jumped stated it without any problems each time.

The first time I did it was when I was explaining to the Dealer on cordeless phone that my display was showing "Check VSC System". I forgot to turn it off and when I jump started it the problem had cleared itself. That happened the second time again about 6 weeks ago. I got the car on 1st Sept.

So it seems the cure is to flatten the Battery, or disconnect and reconnect it some time later!

There is a label inside the bonnet saying do not jump start and instructions in the manual on how to do it!!!:)

However I am DELIGHTED with the car