Toyota Rav4 EV Forum

It is currently Tue Oct 22, 2019 7:31 pm

All times are UTC [ DST ]




Post new topic Reply to topic  [ 45 posts ]  Go to page Previous  1, 2, 3, 4, 5  Next
Author Message
 Post subject: Re: Storage / Long Term Parking
PostPosted: Mon May 20, 2013 3:39 pm 
Offline

Joined: Wed Nov 14, 2012 9:50 pm
Posts: 4075
Location: San Diego
occ wrote:
What about disconnecting the 12v terminal for 2-3 weeks? Would this suffice? What's the 12v battery self discharge rate when unconnected?


Of course that works. You just get to setup everything again.

_________________
Tony Williams
QC Charge
1780-104 La Costa Meadows Drive
San Marcos, California 92078 USA
tony@QCcharge.com
www.QCcharge.com
Twitter: QCPower
1-844-EV-PARTS
1-844-387-2787
1-760-798-0342 Office
Hours M-F, 9-5 Pacific Time


Top
 Profile  
 
 Post subject: Re: Storage / Long Term Parking
PostPosted: Mon May 20, 2013 6:38 pm 
Offline

Joined: Sat Feb 23, 2013 2:43 am
Posts: 114
Location: Tustin
TonyWilliams wrote:
occ wrote:
What about disconnecting the 12v terminal for 2-3 weeks? Would this suffice? What's the 12v battery self discharge rate when unconnected?


Of course that works. You just get to setup everything again.


Yeah, that's a pain.

So did anyone gone on extended 2+ weeks, and left the rav4ev, as-is, w/ no battery tender, or plugged in, or anything like that, and parked outside yet?

I'm planning a summer vacation, and wonder if 1, 2 or 3 weeks parking in the sun without anything would be doable.

_________________
Blizzard Pearl Rav4EV VIN 1324
Nissan LEAF VIN 4873
Tustin w/ 4Kw Solar PV


Top
 Profile  
 
 Post subject: Re: Storage / Long Term Parking
PostPosted: Mon May 20, 2013 8:20 pm 
Offline

Joined: Sun Jan 20, 2013 9:34 pm
Posts: 62
occ wrote:
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.

Side story: I was at a Livermore, CA auto shipper this past week. Surprisingly, there was a quite new Tesla Model S hooked up to their 120VAC service (they didn't have the default 14-50P on the lot). I asked about the situation and was told the Tesla had arrived (from where, I do not know - surprising since it had less than 150 miles on it and surely came from Fremont at some point). The shipper had quite a problem just getting the Tesla off his truck.

Tesla service was called and they came out, dismantled the front of the car to gain access to the 12V battery (this is a 1st gen car!) to trickle charge it. After a little bit, they were able to get it off the truck and then hooked up the portable EVSE to their 120VAC service.

I also learned an alarming fact about the Tesla that occurs when the battery (presumably the 12V) is very low. Since the door locks have no place to insert a physical key, the safety measure Tesla took was to automatically roll down the drivers window! Just imagine the auto shipper's surprise when they arrived in Livermore only to find a dead Tesla with the driver's window lowered. Having seen the muck that can accumulate on (unenclosed) shipped cars, this could have been disastrous.

Although there seems no reason - other than the common but seemingly unrelated components - that the Rav4 EV would have this horrible behavior. But it would be good to know from any of those that have reported having killed their 12V Rav4 EV batteries...


Top
 Profile  
 
 Post subject: Re: Storage / Long Term Parking
PostPosted: Mon May 20, 2013 8:52 pm 
Offline

Joined: Thu Jan 17, 2013 11:13 pm
Posts: 1791
Location: Los Altos, CA
edmc wrote:
occ wrote:
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).
I believe you are wrong on these points. First, I believe the traction battery is used for conditioning. Second, I believe that the 12V battery is only charged when the car is "ON", not while charging from the J-plug. The cars have gone dead on dealer lots when connected to charging stations because nobody turned them on. The problem is the "dark current" required by the car when it is turned off. If you disconnect the 12V battery, it will have exactly as much energy as you left it, many months later, so it's not "self discharge".

_________________
2012 Shoreline Blue #1462 w/JdeMO | 2018 Tesla Model 3 LR | 4.32kW Motech/Enphase PV Solar + 2x Powerwall 2 AC| Leviton EVB40 40A & Jesla Home Charging | 2015 e-Golf LE (returned)


Top
 Profile  
 
 Post subject: Re: Storage / Long Term Parking
PostPosted: Mon May 20, 2013 9:02 pm 
Offline

Joined: Thu Jan 17, 2013 11:13 pm
Posts: 1791
Location: Los Altos, CA
TonyWilliams wrote:
I killed the 12v today the old fashioned way... I left the car on. I think this is my first time in 50,000 total EV miles. Naturally, the car didn't charge either, since the car was left on READY.

Honestly, the horn should blow if the car is plugged in while the car is in READY (or powered ON or ACC).

The funny thing is that it didn't drain the traction battery. In other words, the 12v was not getting charged, even though power was available to do so.

I jump started it today, and pushed the POWER button to OFF as the car came to life. Naturally, the clock set to default 12:00 and eastern time zone (even though the car isn't even sold there).

I lost all the radio presets, of course, and all the charge timers. The address book remained, thankfully.
Wait a minute. Now I'm confused. The car was left "ON" and it did not drain the traction battery, but instead the 12V died. Was the key in or near the car? If you took the key away, it probably shut down, but left a bunch of accessories on. Does this sound right based on what happened Tony?

_________________
2012 Shoreline Blue #1462 w/JdeMO | 2018 Tesla Model 3 LR | 4.32kW Motech/Enphase PV Solar + 2x Powerwall 2 AC| Leviton EVB40 40A & Jesla Home Charging | 2015 e-Golf LE (returned)


Top
 Profile  
 
 Post subject: Re: Storage / Long Term Parking
PostPosted: Mon May 20, 2013 9:45 pm 
Offline

Joined: Sat Mar 30, 2013 9:20 am
Posts: 694
Location: Seal Beach, CA
miimura wrote:
Wait a minute. Now I'm confused. The car was left "ON" and it did not drain the traction battery, but instead the 12V died. Was the key in or near the car? If you took the key away, it probably shut down, but left a bunch of accessories on. Does this sound right based on what happened Tony?
I don't think the car would shut down based on taking the key away. Tony's experience is pretty strange, as one would think that while the car is "READY" the 12v is getting charged. It must be that plugging the car in took it out of "READY" mode and into something like "ACC" mode, where it wouldn't allow charging from the wall and also wouldn't supply power to the 12v system.

_________________
ImageRavCharge.com | 2012 Classic Silver | 2011 Leaf | Clipper Creek CS-60 | 40 amp openEVSE | 3.84kw PV


Top
 Profile  
 
 Post subject: Re: Storage / Long Term Parking
PostPosted: Mon May 20, 2013 11:49 pm 
Offline

Joined: Sun Jan 20, 2013 9:34 pm
Posts: 62
Hmm... seems to me we have a lot of conflicting speculation going on... along with conflicting experience. It sure would be nice to have a definitive answer. Anybody have a relationship with a Toyota Service department that could answer?

Here and elsewhere, we've seen postings of 12V going dead when not plugged in... one where "ignition" was left on in fact.
This would seem to support the claim (not mine, I'm just repeating) that the 12V is only charged when plugged in.
As for 12V drainage when not plugged in, we also have conflicting reports alas.

Oh, well... my trip is in four days so my window for a solution is rapidly closing. The PV panel to USB was admittedly a Hail Mary :-(.


Top
 Profile  
 
 Post subject: Re: Storage / Long Term Parking
PostPosted: Mon May 20, 2013 11:57 pm 
Offline

Joined: Wed Nov 14, 2012 9:50 pm
Posts: 4075
Location: San Diego
The 12v died because that battery is not serviced by the main traction battery through the DC-DC converter while the car is plugged in.

This is common to the Nissan LEAF, which does exactly the same thing. If it's plugged in, and you leave it in READY, or even if it's turned off, the 12v is not being serviced.

_________________
Tony Williams
QC Charge
1780-104 La Costa Meadows Drive
San Marcos, California 92078 USA
tony@QCcharge.com
www.QCcharge.com
Twitter: QCPower
1-844-EV-PARTS
1-844-387-2787
1-760-798-0342 Office
Hours M-F, 9-5 Pacific Time


Top
 Profile  
 
 Post subject: Re: Storage / Long Term Parking
PostPosted: Tue May 21, 2013 12:01 am 
Offline

Joined: Sat Mar 30, 2013 9:20 am
Posts: 694
Location: Seal Beach, CA
edmc wrote:
Hmm... seems to me we have a lot of conflicting speculation going on... along with conflicting experience. It sure would be nice to have a definitive answer. Anybody have a relationship with a Toyota Service department that could answer?
Haha, I'd take speculation in here (appropriately filtered, of course) over "official" word from Toyota anytime.
edmc wrote:
This would seem to support the claim (not mine, I'm just repeating) that the 12V is only charged when plugged in.
There's absolutely no way this is true. The 12v system must be powered via a DC/DC converter from the traction battery while you're driving, otherwise an hour-long drive with the headlights on would kill the battery.
edmc wrote:
Oh, well... my trip is in four days so my window for a solution is rapidly closing. The PV panel to USB was admittedly a Hail Mary
The safest bet is just to disconnect the 12V battery, or connect a battery tender direct to the battery if you have one.

_________________
ImageRavCharge.com | 2012 Classic Silver | 2011 Leaf | Clipper Creek CS-60 | 40 amp openEVSE | 3.84kw PV


Top
 Profile  
 
 Post subject: Re: Storage / Long Term Parking
PostPosted: Tue May 21, 2013 12:03 am 
Offline

Joined: Wed Nov 14, 2012 9:50 pm
Posts: 4075
Location: San Diego
fooljoe wrote:
miimura wrote:
Wait a minute. Now I'm confused. The car was left "ON" and it did not drain the traction battery, but instead the 12V died. Was the key in or near the car? If you took the key away, it probably shut down, but left a bunch of accessories on. Does this sound right based on what happened Tony?
I don't think the car would shut down based on taking the key away. Tony's experience is pretty strange, as one would think that while the car is "READY" the 12v is getting charged....


No, the car won't shut down if you take away the key. What if the battery to the FOB died while you were driving down the freeway... the car would die, if that were the case.

If you ever find yourself driving off and somebody else had the key (happens to me all the time), DO NOT SHUT THE CAR OFF UNTIL YOU GET HOME !!! It will not restart if you turn it off, or until a key returns.

_________________
Tony Williams
QC Charge
1780-104 La Costa Meadows Drive
San Marcos, California 92078 USA
tony@QCcharge.com
www.QCcharge.com
Twitter: QCPower
1-844-EV-PARTS
1-844-387-2787
1-760-798-0342 Office
Hours M-F, 9-5 Pacific Time


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 45 posts ]  Go to page Previous  1, 2, 3, 4, 5  Next

All times are UTC [ DST ]


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
cron
© Toyota Rav4 EV Forum - part of the MyElectricCarForums.com Group