2006 Rx400H 12V Battery

[davetroup]

I have a 2006 RX400h which I bought new. I drive it regularly, but I don't commute in it and so it doesn't accumulate huge mileage (35,000 or so at this point.) Occasionally it will sit in the garage for a week without being driven, but that's fairly rare.

The only real problem I've had with this car is the 12V battery. I'm probably on my fifth battery, they just don't last. In early November I replaced a year-old battery (got a free replacement under warranty) and today I discovered the new battery was nearly dead (didn't have enough juice to start the car.)

I have heard that the '06 hybrid has an undersized 12V battery, and my experience bears that out. But this latest situation, with the battery dead after only two months, makes me wonder if I have a charging system problem. Anybody else having this problem? Any ideas?

[lenore]

When you get replacements is it the Lexus Toyota battery? Use of aftermarket batteries seem to hold up better. You might want to invest in a trickle charger since the infrequent driving...

[davetroup]

When you get replacements is it the Lexus Toyota battery? Use of aftermarket batteries seem to hold up better. You might want to invest in a trickle charger since the infrequent driving...

The first couple of times it was the Lexus battery but since then it's been third party brands. The last couple have been Kirkland arteries from Costco. I did buy a trickle charger and that helps - but surely a new battery should last more than a couple of months. And even though I may only drive it 2-4x/week, they are long enough drives that the battery should get well charged. And the trickle charger only helps when I'm at home. Back in November it died on me after parking at the airport for two days even though it had been fully charged on trickle charger the day I left.

I don't really understand the charging system on this car, there's no alternator and I guess it gets recharged through the hybrid system somehow, I fear that means a lot of expense and labor if I go to the dealer for diagnosis as its so complex.

Thanks for the thoughts and suggestions.

[RX400h]

My Costco battery was installed 2.5 years ago and is working, perfectly. I think it's safe to say that you need to have your RX tested. Something is not right.

[Jim Clark]

5th battery? Something is wrong.

[chand3]

I was away for two weeks on vacation and when I came back my 2006 RX400h did not start. It just needed a boost to get started but it is odd it would drain over a two week period. The only other time I had battery issues is when I did a few short back to back trips. I'm going to maybe try one of those Optima batteries or those glass mat ones next time.

The other option is to hook up a battery maintainer as someone said earlier.

[RX400h]

An Optima battery won't prevent the no-start condition, although a yellow top version can take deep discharges without permanent damage. You CAN extend the life of your present battery by using a battery tender when not starting the vehicle for an extended length of time.

[chand3]

My current battery is from the dealer and 2.5 years old and starts no problem even in -30°C weather. The only time it did not start was after my two week vacation, but it just needed a boost. It is odd that it would discharge to a point of not starting the car after two weeks.

[lenore]

I would check all of your lights, even in the cargo area to make sure they are not turned on. I personally changed mine to LED so if wifey leaves them on they draw very little.

[Stevenrx]

I have my rx400h. I had a battery issue like a year ago. I just bought a regular 55ah battery at the store with a 4 years warranty. The consol did not fitt top of the battery so I had to took one part off. Since than I had zero issue with my battery. I think this is one of the best car since 2005-2010. Mine have 110 000 miles and I only had little issues. I have to knock on wood. Thank you. Steven

[jim99w]

I had that trouble for a couple of years. On the third battery I discovered that the 12v is not charging when the car is in motion, but only when in Park and Ready, so I have been letting it do that for a minute or two when starting out, and again when parking. No problems since.

Jim