Will just turning on the car without driving prevent battery damage?

Better to buy a Battery Tender Jr assuming you have power access. Otherwise running it will probably be ok.

 

And I imagine if you were in Brooklyn you're probably in an apartment getting a battery tender or a drop cord to your car would be a great challenge and then every street person in the area would be plugged up to it within an hour problems problems problems what you'd have to do with the Prius and city situation like that is bring the battery upstairs into the apartment maybe set it on a counter and connect it to the tender one or two Amp Max. To minimize any funny business out gassing or anything One or two amps you can't create enough gas in an apartment to really cause a problem You get in the 4 to 5 amp and up range and things can start happening.

 

Welcome!!!
IMHO; you don't have to do anything drastic (ie. pull the battery out and charge it in your living room). Turning the car ON every 3 days to a week should do it. If the ICE (gas engine) starts up; I would wait for it to shut-down, before turning off the car at the 20 minute mark. The ICE turning ON indicates that the batteries are low. The software automatically senses this, and fires up the engine to recharge the batteries. Allow the car to do it's thing, and you should be OK.

Hope this answers your questions....

 

Where is the car parked, street, parking lot, underground parkade, secure or open, access to 120 volt outlet?

assuming just street or similar, for 3 weeks the simplest approach would be to disconnect the 12 volt battery negative cable; this prevents the constant low-level drain the car imposes.

 

Unless you have reason to suspect the 12V battery is weak, I wouldn't expect a problem with 3 weeks inactivity.

Only thing I'd do is if it's got the smart key system, there should be a switch below the steering wheel to deactivate it, which reduces the 12V load.

 

yes, have him turn it on for an hour every couple days.

 

I would expect a 12v problem at three weeks unless the battery is very new. Better to be proactive. A battery maintainer would be ideal, while a twenty minute operation after ten days would be ok.

Disconnecting the battery is a pain since the hatch won’t open later. Plus the first restart won’t work but a second will. This can be a blood pressure moment particularly after crawling in from the back seat and attempting to remove panels.

If running the hybrid system to charge the 12v, remember the key fob won’t lock the doors with the system in Ready. The manual key will lock in Ready but must be used to unlock. Then you can power down. A “hold the fob to the button” restart is likely the next time. If you don’t immediately realize this it may look like a start failure.

Another option is a lithium jump pack. Be aware of how to use from the engine compartment if this is the emergency plan. Having one is a good strategy but store it under the seat because the hatch won’t open with the 12v dead. In this situation you unlock with the manual key as well.

It is useful to try the manual key in any case since its not 100% intuitive.

A 12v battery maintainer is my first choice, followed by periodic operation and backed up with a lithium jump pack for the unexpected, which will eventually happen.

By the way, three weeks is not an issue for the high voltage battery. In fact running the system while parked can actually leave the hybrid battery at a lower (but acceptable) state of charge.

 

Finally someone gives the correct answer in this thread...

Basically the hybrid power supply is based on antiquated NiMH battery chemistry that self-discharges when sitting there not being used. In older packs it's possible some batteries in the pack will discharge faster than others leading to an out of balance pack that will throw warning lights.

Running it every couple-few days as Bisco suggests will work, but you could use a more aggressive method and get by with just once a week. This method requires putting the car in drive with your foot on the brake and flooring the accelerator until the engine shuts off. This is called forced charging and will full charge the pack to help maintain balance between modules/cells.

 

FWIW, Toyota (Europe)'s long-term storage rules for dealers, for hybrids in general (from TSB PD-8002R) are:

* Keep "Ready ON" for 60 minutes just after unloading.
* Disconnect the 12V auxiliary battery negative terminal or relay box wire in storage.

* Keep "Ready ON" for 60 minutes every month.
* Disconnect the 12V auxiliary battery negative terminal or relay box wire in storage.

* Check the 12V auxiliary battery with the local recommended tool and charge if necessary before delivery to customer.

Mind you, that would be for brand-new batteries.

 

Thanks... Obviously brand new packs require less attention, but leaving a fleet of hybrids running on a dealer lot for that long sounds problematic. I bet few dealers follow these rules.

 

Am I missing something? That procedure will only address an aux. battery going low. Nothing about making sure there's gas in the car - so it can fire-up the ICE, if both batteries are low. Leaving a Prius in ready mode for an hour, only makes the traction battery charge the aux. battery.
I also wouldn't put the car in gear - there's no need to. There's also no need to 'rev' the engine - the ECU has control of that. If the ECU needs MEG1 to spin a litter faster for a faster charge rate - it could manage that on it's own.

 

That procedure covers both batteries. Leaving it in READY gives the hybrid system a chance to run the engine to charge the traction battery if necessary.

Filling up the tank if empty is normal procedure, so I guess they didn't think it was worth listing as too obvious. (The car isn't delivered totally empty - they've driven it off the production line onto a boat and onto a transporter...) Elsewhere in the doc they did mention something about ventiliation because of the engine running though.

 

Yes, that is correct.

Nope, it is instant.

Smart key – that is, you touch the door handle to unlock; press the black button on the door handle to lock – or remote lock/unlock where you press the buttons on the fob to lock or unlock?

 

Check the Owners Manual; that should be covered.

 

YES....BUT if your 12 V battery is healthy, it should easily last 3 weeks with no problem if you turn off the SKS.
Consider that this might be a round-about way to test and see if you are due for a new battery.