Storage / Long Term Parking

[TonyWilliams]

What about disconnecting the 12v terminal for 2-3 weeks? Would this suffice? What's the 12v battery self discharge rate when unconnected?

I very much doubt the issues folks are having concern the self-discharge of the 12V battery. Plenty of ICE cars do quite well in long term parking lots for very extended periods.

The issue for our Rav4 EV is two-fold:

1) It appears the 12V battery is used to keep the traction battery "comfortable"... even when not charging or even connected to a J1772 live plug.
2) The 12V battery is not "recharged" while driving... and is only charged during J1772 charging sessions (unlike ICE cars that have alternators charging the 12V battery).

The first problem is what I'm most concerned about.
The second problem concerns what happens when your 12V battery is dead. Unlike in an ICE car, a "jump start" is not sufficient. You need to get enough of a charge into the 12V battery to make it to a J1772 charging station.

1. I'm not even sure what this says. The 12 volt isn't doing anything for the traction battery.

2. Of course, the 12v is charged anytime the car is in READY (or else the red battery light will illuminate). It's a great way to know when the traction battery stops powering the vehicle (due to low traction battery cell voltage)... the red battery light will illuminate when the main contactors open, thus disabling the DC-DC converter.

3. Yes, you can easily "jump start" the Rav4 EV, and I did just that.

 

[edmc]

Just wanted to post that following 7 days and change in an airport parking lot, I returned to find the GOM at 85 miles (same as when we left if memory served) and the Rav4 EV turned right on with no apparent issues.

 

[pchilds]

Three weeks unplugged, start 12.56 volts, end 12.3 volts. No need to disconnect the 12 volt battery for three weeks or less storage.

 

[occ]

Just wanted to post that following 7 days and change in an airport parking lot, I returned to find the GOM at 85 miles (same as when we left if memory served) and the Rav4 EV turned right on with no apparent issues.

Three weeks unplugged, start 12.56 volts, end 12.3 volts. No need to disconnect the 12 volt battery for three weeks or less storage.

Whew! That's great to know guys! Thank-you! Can I ask if you parked outside or inside or covered, and what were approximate average temperatures? Thanks.

 

[edmc]

Can I ask if you parked outside or inside or covered, and what were approximate average temperatures? Thanks.

My Rav4 was parked in SFO's "Lot D" (outside, where the old extended parking used to be before the now-always-full parking structure was built) May 24th thru 31st. Not having been in the area, of course, I only recall that folks have said this was a warm week... possibly 80s there on the black asphalt outside.

 

[pchilds]

Can I ask if you parked outside or inside or covered, and what were approximate average temperatures? Thanks.

Garaged, high 70s to low 80s.

 

[occ]

Great, thanks guys. So at highs of 80s, BMS doesn't kick in to "cool" the battery and use up energy yet. I'm hoping it stays like that up to low 90s, as LA doesn't usually get more than that in the summer. I need to park long term (2 weeks) at LAX, outdoors for summer vacation, but need at least 60 miles range to get home after the trip. Will be coming back late, so don't really want to stop anywhere for a charge with my family with me. Looks like doable with extended charge to begin trip.

 

[Incredulocious]

Great to know that a couple of weeks at the airport unplugged is okay!

However, does anybody know yet if RAV4 EV has the LEAF behavior where it's bad to leave it plugged in for more than a week or so or it will drain the 12V battery? In other words, in the LEAF, you counter-intuitively need to leave it unplugged.

 

[jgblair]

You can also carry a "jumpstart" self-contained battery with jumper cables. They also often have a air compressor, inverter, and other goodies built-in that make them useful for all kinds of things. I carry one on trips in my ICE for example. They cost $100 + or -.

John

 

[branstone]

I left me car n the driveway for about 17 days. Upon return the car had same charge and started right up, no issues.

 

[krestel1]

Went on vacation out of the country for 4+ weeks, we parked both a 2012 leaf and a 2012 Rav4 EV in the garage unplugged.
After we got back, both cars started with no issues. The GOM showed the same range as when we left. We did charge both cars to 80% full before we left.

We are in San Diego, temp in Nov and early Dec ranged from 50s to 80s when we were gone. Things may be different if we parked outside, but they seemed fine for long term parking inside the garage.

 

[smkettner]

So should I bother charging to 80% or just leave it 30% to 60% and go?
No immediate need to drive upon return as it will be parked at home eight days.

 

[TonyWilliams]

So should I bother charging to 80% or just leave it 30% to 60% and go?
No immediate need to drive upon return as it will be parked at home eight days.

I would do the latter. If you have one of those solar powered battery chargers, I'd plug that in to keep the 12 volt topped off.

http://www.walmart.com/ip/Cyclops-Solar-6W-12V-Solar-Battery-Maintainer/17480876?action=product_interest&action_type=title&placement_id=irs_middle&strategy=PWVUB&visitor_id=72865232789&category=0%3A91083%3A1045959%3A1074767%3A1043587&client_guid=9630531f-9746-4921-aa12-3d840168b710&config_id=0&parent_item_id=16550320&guid=41cf6cd1-4316-4d97-9ebd-d3fc03f579ee&bucket_id=irsbucketdefault&findingMethod=p13n

 

[Jorge A. Santana]

Charging my Rav4 during a two month absence? I will be away for a lengthy period and would like to know if keeping my car plugged in continuously for one week and the second week not plugged in during the two months. My neighbor would plug and unplug it during my absence. Any suggestions on this? Thanks.

 

[miimura]

This is discussed in the thread "Storage / Long Term Parking"

The recommendation for your case is:
1. Don't charge the traction battery full. In fact, leave it between 4-12 bars on the gauge.
2. Don't plug in the J1772.
3. Do use a maintenance charger on the 12V battery. It is also called a battery tender. These are available for $25-$50.

If you use the maintenance charger, nobody has to touch the car during your absence.

This recommendation is different than for a Tesla vehicle. The RAV4 will not wake up and maintain the 12V and traction battery, charging from the EVSE every couple days like the Tesla. The RAV will just quietly drain the 12V battery and will probably be dead after 2 months. The only way to maintain the 12V battery without driving it or using a tender is to turn it on to READY for a short time (maybe 10-20 min) each week or every 2 weeks. When the car is ON, it will charge the 12V from the traction battery.

 

[Solar PWR Rav]

I am a C-10 electrical contractor and hobby electric scooter builder.

In general, with just about every lithium batter manufacturer they recommend storing batteries at 40%-65% of full. Stored full batteries tend to build up gasses inside the battery when left on a shelf full. It degrades or can even ruin them if stored at 100% for long periods of time. I would have to assume Tesla Lithium batteries follow the same rules.

If I was going away for 2 months I would leave my Rav4 EV 50% to 60% of full. Charge it when you get home. I am no Tesla battery expert. I can only speak from Lithium batteries in general. They take a long time to discharge on the shelf. I do not think there is a significant ghost power draw when the car is just sitting there would take the battery low enough to damage it.

As far as the 12v battery goes. I had no idea they would bother putting one in a Rav4 EV when it has such a ridiculously large Lithium battery. I agree, the 12V battery will go dead in 2 months without a battery tender or similar device.

Could you help me out and tell me if this is a good deal? I am going to go sign a lease for a Rav4 EV this weekend.

Thanks,
John (619) 894-95 twelve

Retail Price Dealer Price Total Price
Vehicle Base Model 49,800.00
50 State Emissions
Special Color 395.00
Carpet Floor Mats/Cargo Mat 225.00
Total Accessories 620.00
Destination Charge 860.00
TDA (dealer advertising) 926.00
Gasoline
Total Price 51,280.00
Memo - Total Amounts included above :
Wholesale Financial Reserve 502.00

 

[Michael Bornstein]

As a slight variation, I will be gone for two weeks later this month. Do I have to worry about the 12V battery or will it have enough juice left to start the car when i get home?

 

[n3ckf]

i always put my car on a battery tender when leaving it > 1 week.

I have several of them (one for each car). I do it with gas cars too (although you're a bit less likely to have this problem with a car that doesnt have a cell phone in it that has to wake up and phone home every now and then).

 

[DevinL]

Does anyone have a particular battery tender they'd recommend? I'd likely get one for each car.

 

[arnolddeleon]

http://www.amazon.com/dp/B006CQ9BMO