stephenhil

I am a new Lexus owner. I bought a 2013 RX450 in January. During delivery the salesman recommended a trickle charger be used to keep the battery charged during long absences as the on board computers will drain the battery after 8 weeks or so. Every summer we park our car in our marina parking lot and take off on our boat for 3 months or so. There is no facility at the marina to plug a charger into. Have any owners used one of those small solar panels to keep their battery charged? Any input / recommendations would be most welcome.
Thanks very much
Stephen

vlad_a

Well, you could just disconnect the 12V battery, or even take it out of the car and have it charged at a remote location. It is in the trunk, so it is more accessible than if it was under the hood. The locks and alarm won't work, though.

BertL

First, congrats on your new RX!

From reading other forums on the subject of trickle chargers in recent weeks, I believe one thing you have to watch out for is to ensure whatever device you use, it will in fact monitor the battery and stop providing a charge when the battery does not need it, and vice-versa. It needs to be "intelligent", and apparently some of the cheap panels don't have that that logic in them, say like plug-in CTEK, Deltran, etc that I've used, do. Some of the panels also have power ratings as if the sun is always shining, so owners have had varying degree of success keeping the real charge up, depending on the weather and direction they ended up leaving the panel. ...all that to say, it's going to take some research, and hopefully someone here has practical experience and more specific recommendations to get you started. Good luck. I'll watch this thread with interest, even though I'm fortunate and can plug my trickle charger in my garage.

vlad_a

Here's what the manual states:
Charging the hybrid battery (traction battery)
● As the gasoline engine charges the hybrid battery (traction battery), the battery does not need to be charged from an outside source. However, if the vehicle is left parked for a long time the hybrid battery will slowly discharge. For this reason, be sure to drive the vehicle at least once every few months for at least 30 minutes. If the hybrid battery becomes fully discharged and you are unable to jump-start the vehicle with the 12-volt battery, contact your Lexus dealer.
● If the shift lever is in N, the hybrid battery (traction battery) will not be charged.
Always put the shift lever in P when the vehicle is stopped. When driving in heavy traffic, operate the vehicle with the shift lever in D or S to avoid discharging the battery.
■ After the 12-volt battery has discharged or has been changed or removed
The gasoline engine may not stop even if the vehicle is running on the hybrid battery
(traction battery). If this continues for a few days, contact your Lexus dealer.

Cruiter

I think that might be a really bad idea, as the computers with the stored memory (a lot of 'puters on-board) run off the 12V. You probably don't want to lose that memory.

BertL

OP, for some crazy reason last night I was dreaming about leaving my RX450h for months in some harbor parking lot -- and I've never had a boat, although I lived in Hawaii for many years. (No wise cracks psychoanalyzing me, please!)

I agree if I were in your situation, I would try to find a trickle charger if I could that worked. If I couldn't, I'd explore if I could perhaps have a friend come once a month and take my beloved RX for a 30+ minute drive. If all that failed, I would just turn my truck off, lock it up, assume the alarm will eventually stop monitoring, expect I would not be able to start it upon my return, and I'd have to use the physical key to gain access to the driver's side door. Now, I prefer to always have a Plan B, so a couple of thoughts you could do upon your return to a dead RX:

• Jump the RX from a battery you take out of your boat. I don't know if that is even possible in your situation, but maybe?
• You have Lexus Roadside Assistance while you are under warranty, that you can call to get you on your way
• If you have AAA, that is another option to call

Worst case, you've got your boat to be on a little longer while someone comes to help deal with getting your RX started.

If it's not clear in the manual gobbly-d-gook about batteries, you have two -- the big hybrid battery under the back seat that is only used once you're going -- essentially for the electric motors (yes, I'm purposely over-simplifying techies). That one dies down too over time, but it's not your bigger concern getting the RX started. As mentioned by another poster, the battery in the rear cargo area is the one used to start your truck and that runs accessories when you have it locked, just like any car -- that's the real one you have to worry with. (Note if you need to jump your RX, you don't get into the back to do that -- look in your manual, and there are jump points under the hood that will do the job.) Your RX has some built-in things to try and conserve the battery when it's locked or forgotten, e.g. your 2013 unlike 2012 will turn off the headlights if you leave them on before completely draining the battery, but more importantly, your RX (not exclusive to 2013) will shut some things down in stages over the first few days and month after the truck is locked, like turn off the power and antennas used for keyless entry and remote opening. Eventually though, all power will go as it will with any modern vehicle.

My experience with several RX has been they can be left longer than some other modern vehicles, e.g. I once had to unexpectedly leave my RX400h for 5 weeks at the airport while a business trip was continually extended. Upon return at 12:15AM, I was worried about what I'd have to do to get home, but it started up. It wouldn't have lasted 3 months which your question was -- for sure. My previous BMW would only last 3-4 weeks maximum IF I remembered to physically unplug my iPod before locking it up. My new Mercedes arriving later this month actually has a statement in the owner's guide saying if the vehicle is parked longer than 4 weeks, the battery may be damaged by "exhaustive discharging". They go so far as to recommend a trickle charger in the MBZ owner's manual if you don't drive your car very often. That brings up one last point -- if your RX battery does get discharged completely and you do that many times, you're likely going to replace that battery earlier than those that are able to keep it with a charge. Batteries like to be exercised, but not fully discharged. Not a super biggie, perhaps in the scheme of things, but another something I was dreaming about.

Good luck with your new RX. I'll remain interested in what you do.

vlad_a

Computers are not people, they don't loose memory over time.
They don't care whether you unplug them for 5 minutes or 5 years, given the hardware is in a good shape. Anything important will be stored in a solid state form. All of other parameters will be relearned upon start-up.

Even Nonvolatile cache (RAM) in servers that is powered by Li-Ion battery in case of a power failure has an SD card to back its contents in case of long outages. Cars are much simpler than that.

BertL

Having spent more than 35 years in the IT and technical support business, I agree with most of what you say about computers in a general sense, but am sorry as I just can't agree if someone reading this were to inadvertantly walk away assuming all makes, models and years of vehicle computers operate the same way. They just don't. Things are implemented differently, programmed differently, and mfgrs make different choices that can impact the driver's vehicle experience.

The issue in the context of this thread, is some of the settings may disappear when the battery is disconnected or fully drained, or operationally a vehicle may do odd things when you reconnect a battery. e.g. my 2009 BMW, unlike my 2006 RX400h, lost all the radio presets when the battery was drained and an unexpected set of customization options (not all) needed to be reset when battery charge was restored in the BMW. Even in a 2013 RX450h, which from reading the manuals and TIS data (have not tested it yet ) appears to be pretty close to "remembering" everything it should when the battery is disconnected and then reconnected, I remember reading in the owner's guide that to get the power rear hatch to work properly, depending on the state the hatch was in when power was lost, one may have to open and close it manually one time to reinitialize that subsystem. There may well be other little things like that lurking in our RX that are perhaps not defects to some, but for others would be disconcerting when their vehicle didn't operate the same way it did before the battery was disconnected -- causing concern, someone making an infamous post about a "defect" in their Lexus here on the boards, a need for them to open the manual , or even contact their dealer.

Droid13

I'm going to put my 2 cents and say you definitely do not want to let your car just sit in a parking lot 3 months every year unused. With respect to the comments about the 12 volt battery, sure you want to make sure it stays charged even if it means removing it for charging elsewhere. Yea, a bunch of settings will need to be redone (radio presets, auto up-down windows, custom vehicle settings, etc.) but it's really not a big deal to redo the settings. My big, BIG concern is the hybrid battery itself. NiMH batteries are known for steady discharge rate when unused which increases with temperature (aka baking in a parking lot all summer long). If the hybrid battery falls below a minimum state of charge it will disconnect, there is no boosting, it will need to be towed to the dealer. Maybe the first years it will make it through the summer, but it will loose a little capacity each year. Letting a hybrid sit unused is like smoking 2 packs of cigarettes a day. Once in a while not a big deal, but doing it regularly year after year, expect a shorter life.

The best advice is what the manual says, find someone trusted to run it for 30 minutes every few weeks.

billy44bo

If you are using a first class marina let them run the car once a month for 10 to 15 min and then lock it back up. Problem solve before there is one.

doreencp

I just purchased a 2015 RX 450 H, and I am leaving on vacation to Europe for a month. How do I ensure that the battery will be good when I return?

Cruiter

There are various computers that keep track of stuff with a very low drain. Some folks have reported no problems if their battery was young and in good shape, others needed a jump. If you have a friend that could take it for a 15 or 20 minute drive every couple of weeks that wouldn't hurt. Normally a battery tender would do the job nicely but it doesn't get to the traction batteries. They need their exercise too ya know . Worse that could happen is you'd need a jump, if so carefully read the directions for jumping a hybrid.

RXSF

1 month is nothing, you should be fine. If you are really concerned, you would need to get a trickle charger

IS350atWOT

iTrader: (1)

I thought our hybrids had a second battery like those of regular cars. At least I thought that's what I was hooking to when I had to use the RX to jump my F. So if the hybrid battery is completely dead, the car won't start?

vlad_a

Traction battery cannot go completely dead. It has to maintain a specific charge rate, somewhere between 60% and 80%. If it does drop very low, a special device is needed to charge it up. I hear some dealers may have these, but never have to put them to use, so a month without starting will not be a big deal. I doubt dealers regularly start up their hybrids when they are sitting on the lot for months.

Now, the 12V battery that runs ECUs and most of electronics is the same as a regular car battery. If it is low or bad, the hybrid will need to be jump-started similar to a regular car. The difference is, there is no starter nor alternator.