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2007 Toyota Camry Hybrid - ok to drive?

My '07 toyota camry hybrid was off the road (undriven) for 4 months; now when I start it, there is a “check Hybrid System” error message. The earliest Toyota can see it is in 5 days - can I drive it in the meantime (seems to drive fine) or do I risk doing serious damage?

Your vehicle manual most likely (same as my Prius) has a provision that vehicle has to be started/charged every 2 weeks for so, not to exceed 2 months, so I can assume your torque battery is damaged.

The prior owner of my Prius learned it hard way too: they let it sit for 3 months and torque battery was shot, dealer quoted almost $4,000 to replace battery.

As I purchased this vehicle, it showed “red triangle” sign and it could be driven, and although performance sucked, it made 20 miles to my garage, where I replaced failed cells in the torque battery and upon hybrid system reset it came alive with no ill effects other than it fried 45% of its cells while prior owner drove it to dealer and back and I drove it to my place, probably 40-50 miles in total.

I would not drive the vehicle unnecessarily in your state.

I have found at least 3-4 mobile companies “we will repair your hybrid battery at your place” around my area, service ranging in $400-600+ and providing next day appointments - this option will be substantially less expensive to compare to dealer (unless you do not DIY it).


What does the owners manual say about this message?

sounds like an interesting warranty question if you had a warranty that is.
i did not drive my car for 4 months and now the battery pack is damaged.
warranty is denied since you caused the damage by not driving it enough?
thats why my weedwhacker wont work? i left it sit over the winter?

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In the absence of knowing–I wonder if this could just be the battery pack being discharged–and if you drive it, it will run on gas and charge up the battery. Maybe someone will know…

The vehicle sat for 4 months so what is another 5 days . Why take a chance on causing damage that might be more costly than it needs to be .

There is a good chance this is covered in the battery warranty, and with a car this sophisticated, there is a good chance the computer recorded the neglect. The fact that rechargeable batteries age faster when neglected is pretty common knowledge.

I’d also be surprised if there is any remaining factory warranty on a 12-year-old car.

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This is quite right: battery warranty is long gone.
The only reasonable action from the dealer will be to sell a replacement battery, something like $2700 MSRP plus labor.

Most likely few individual cells out of 28 this car has were discharged to the point they are damaged by either shorted internal cells (I had of such kind) or by having internal resistance above normal (I had 2 such sells). In both cases, Toyota hybrid system will be able to start the engine, but system efficiency is out of whack and system tries to “train” the battery all the time, damaging more and more cells if they are substantially out of balance.

Gen2 Toyota hybrid system controls the state of charge with 14 interim points in battery chain, so it will not know the state of individual cell-packs, only state of every pair.
When it sees their charge out of balance, it pumps more juice in until it gets all 14 banks to the “proper” voltage.
If some cell-packs are out of balance, it results in their pairs getting substantially over-charged and gassing out, eventually destroying them if you drive your hybrid in this state.

Shops specializing in old hybrid repairs simply get individual cells charged/dicharged to measure effective capacity and replace only few cells out of 28, typically with other used cells of the capacity close to the original battery good ones.
That’s why their repair is way cheaper than dealer, but you get what you pay for: the battery is still usable, but it is unlikely to measure up against the new one.
Considering that hybrid batteries are well over-sized to compensate for eventual wear, it is not a bad trade-off.

As an example, in my battery of 28 cells I found 3 cells which were “dead dead”, then 9 were marginal capacity (5.5 Amph-hours or less), the rest made 6.5 Amp-hour or more (Toyota spec) with flying colors, some cells measured up to 7.4 Amp-hours.
The battery will perform as good as it’s worst cell, so I swallowed the bullet and bought 12 cells off recycler on eBay, from which I had to return/replace 2 back as they had under 6.5 Amp-hours in my test.

I bet the difference of my DIY approach and “mobile shops” one is that they would unlikely replace 12 cells in my case, they would have no time to measure up capacities. It would suffice to replace only 3 and car would start up and would run just fine, making for 6 months and 6000 miles of their warranty, but I wanted to put this problem to rest for good and I restored the battery to original specs at under $300 cost, including the specialized balance charger I bought.
It took me almost a week of work with setting up another set of cells on charger and repeating it every morning and evening until I had all tested and identified the ones to replace.

12 years? Yeah battery is gone. If you want to replace the battery yourself, ChrisFix on Youtube has a nice video on a Prius where he replaced the battery. I’m not sure how much different it is on the Camry, but watching this video honestly it’s just a long process but simple. The only hard part would be buying a good battery.

As far as I know, this generation of Camry uses the same cell-packs as Prius.
These are 7.2V 6.5+ Amp-hour NiMH blocks.