trickle charge vs. 240V

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user 162

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Hi -

Newbie where. We just got the RAV4 EV, but are awaiting the 240V charger. The trickle charge only seems to get to 92 miles. Are my electrons weak? :) Any thoughts?

I saw that by unplugging the 12 V battery one can re-set the gauges. Any down side to doing this?

thanks
 
Why do you care what the meter says? Have you ever driven a gasoline car without a GuessOmeter?

I don't know of a specific downfall to disconnecting the battery, provided you don't do it while the car is in READY (on).

I suspect that the your trickle charger is working perfectly, but your GuessOmeter spent a bunch of time sitting on a dealer lot with the power on showing off the car.

Congrats and welcome.
 
capod said:
Hi -

Newbie where. We just got the RAV4 EV, but are awaiting the 240V charger. The trickle charge only seems to get to 92 miles. Are my electrons weak? :) Any thoughts?

I saw that by unplugging the 12 V battery one can re-set the gauges. Any down side to doing this?

thanks

Those miles are based on your driving history, whether you have the AC or heat on, etc., and are variable. Resetting the guages probably won't change anything, although I've never tried such a thing. I haven't tried trickle charging the RAV, but I have trickle charged my Volt and Leaf.

One important tip: make absolutely sure nothing else is pulling current off that circuit, and a GFCI outlet is highly recommended. I had a bad breaker on my garage outlets before I had it all rewired and the L2 charger installed, not to mention the moron who originally wired our garage also had the dishwasher and disposal on the garage circuits. Thankfully I didn't burn my house down.
 
jspearman said:
Resetting the guages probably won't change anything, although I've never tried such a thing. I haven't tried trickle charging the RAV, but I have trickle charged my Volt and Leaf.

It resets to 3.5 miles/kWh, and shows 146 miles on a full charge, and probably about 117 on a "normal" 80% charge.
 
TonyWilliams said:
jspearman said:
Resetting the guages probably won't change anything, although I've never tried such a thing. I haven't tried trickle charging the RAV, but I have trickle charged my Volt and Leaf.

It resets to 3.5 miles/kWh, and shows 146 miles on a full charge, and probably about 117 on a "normal" 80% charge.

I did this reset without incident after a few weeks of driving my car like a rental. Gosh, those were the fun days! Prior to the reset, my GOM was only giving me 79 miles on the standard charge. Post reset, the GOM was 125 miles. Since the GOM takes into account your recent driving habits, the only practical application for this reset procedure would be if you were trying to sell the car to a newbie and you wanted to show that a full charge can get them close to 150 miles (you may not want to voluteer that those are accessory free miles, driven by an 80 year old in no traffic).
 
The odd thing about resetting the GoM by disconnecting the 12V battery is that when you "reset" the driving efficiency display on the center console, it does no such thing! I am of the opinion neither of these forms of resetting is a good idea. It is better to let the efficiency reading continuously accumulate and "build up" a history in the data base. I believe this will generally result in a more realistic reading on the GoM after charging, maintaining its accuacy rather well.
 
Dsinned said:
The odd thing about resetting the GoM by disconnecting the 12V battery is that when you "reset" the driving efficiency display on the center console, it does no such thing! I am of the opinion neither of these forms of resetting is a good idea. It is better to let the efficiency reading continuously accumulate and "build up" a history in the data base. I believe this will generally result in a more realistic reading on the GoM after charging, maintaining its accuacy rather well.

Honestly, the GOM will NEVER be accurate. It all depends on how I'll be driving as to the range, and if I want to drive 150 miles, I can do it, regardless of what the GOM says (I'll seen in the high 80's on the GOM when I drove 140)

By the same token, if I drive around town, I'll be lucky to get much over 100 miles of real driving. What the GOM says is strictly a matter of what I drove previously, which has zero bearing over what I will drive today.

I would prefer a "rated" range like Tesla uses, so that every time I charge up, it will show the same range. Ideally, however, it would have two ranges; around town at 2.7miles/kWh, and highway at 3.4 miles/kWh.

Thankfully, just like the LEAF, I completely ignore the GOM.
 
Tony, ideally, the car should have a battery gauge reading in real time exactly what the charge condition (or capacity) is to always be available to the driver to continuously monitor. This might take the form of an "amp-hour" or a killowatt-hour meter just like we all have connected to our houses from the utility grid. This would be analogous to having a gas tank with a "fuel remaining" gauge connected to a level detector in the tank.

Well, we're not going to get any more gauges at this stage, so we have to put our "faith" in what we already do have in the car, i.e. the so-called GoM. Like all "machines", the more we use them, the better we get to know them and their idiosyncrocies. Eventually, you get conditioned as to what to expect.

In my RAV4 EV, the GoM does seem to read out fairly accurately, although perhaps on the conservative side. I think the same would be true of most gasoline fuel gauges. The point being, if you unexpectedly run out of gas (or in our case, run out of battery charge), the driver will be cursing at his "fuel" gauge unmercilessly! The gauge is doing its basic function, if it warns the driver BEFORE that happens, even if there is a few more (emergency reserve) miles left to go at "EMPTY"!

If you drive in a reoccuring pattern - like commuting to work - and you are the SOLE driver of the vehicle, I contend that the GoM can be used to judge range fairly accurately. The only troubling thing I noticed about the GoM is that it does not seen to be a linear readout. That is, at the top of the gauge, each segment bar, especially for the first bar, varies quite a lot for miles driven before the next bar extinquishes. The miles driven denoted by each segment is non-linear, which is probably unavoidable since miles per kWH can be continuously changing. I think the lower the bar, the less mileage you get for that bar as you drop in range. Of course, this is obviously the case for the first bar, in large part do to the difference in battery capacities from an extended vs. standard charge.

The first bar on the gauge for an extended charge will extinquish after after ~25 or more miles, but after a standard charge, it should decrement after far less mileage. As the gauge decrements, the gauge tends to become more linear (or less non-linear might be a better description), decrementing every 5 to 8 miles driven. Down near the bottom of the gauge it seems to decrement at a faster rate, i.e. less miles driven per segment, perhaps only 4 or 5 miles, instead of 6 or 7 near the top of the gauge.

My point is the GoM still provides useful information and can be somewhat "trusted" (although certainly not 100%), but only if you do not "reset" the driving efficiency variable, thereby intentionally defeating its consistency from drive to drive. A RAV4 EV with a GoM that at first indicates 146+ miles (after an extended charge), but only actually travels 90 miles before the tow truck arrives, is far less accurate and certainly even less useful to the driver.

Just leave the gauge alone, not reset it (including the driving efficiency readout), and driving "normally", the GoM is probably going to maintain reasonably accurate. But, if you reset it, all bets are off!
 
Dsinned said:
Tony, ideally, the car should have a battery gauge reading in real time exactly what the charge condition (or capacity) is to always be available to the driver to continuously monitor. This might take the form of an "amp-hour" or a killowatt-hour meter just like we all have connected to our houses from the utility grid. This would be annologous to having a gas tank with fuel remaining level detector in the tank.


I guess I disagree that we won't get a "gas tank gauge". It just won't come from Toyota or Tesla. We've been using such gauges for about 18 months in the Nissan LEAF, and myself and others have been working towards a version for the Rav4.


Well, we're not going to get any more gauges at this stage, so we have to put our "faith" in what we already have in the car, i.e. the GoM.


I'm not new the GOM arguements, and you're welcome to figure it out to your satisfaction. I find that these debates always end in the same loop that looks like this:


big_headed_tiny_dog_chasing_tail_lg_nwm.gif
 
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