Range has dropped after I drove through some deep water

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Dave Fundakowski

New Member
Yeah, I know turn around don't let your range go down..

A few months ago I was stuck on the other side of town during and after a couple of good size downpours and drove through some 4-in water. My range, which used to be about 300 and or so miles, is now only about 250 on a full charge.

As an engineer this has my mind churning about all kinds of problems that could have been created in my EV from Deep water. The service guy at the dealer said not to worry about it: 'he frequently has to reset mileage range calculators on cars and that it's no big deal'.

A few questions come to mind: has anyone else experienced something similar?

If so, tell me what you know..

My mind goes to a couple of things: one I actually got water into my high voltage battery pack and it has either corroded some connections or damaged cells themselves and isn't allowing the battery to charge fully. Which brings up another interesting question: exactly how does an EV know how charged it is? Is there a charge accumulator or effectively a current integrator? Or, does it just look at battery voltage and know that when it's at its full Voltage it's fully charged in that should give you the range specified? This seems like a likely cause if I charged it when it was wet and that caused some cell connections to corrode and only fraction of my cells are being charged, While others do not have a connection to the charging source, from corroded connections. That seems fairly likely to me; but the dealer says 'no there's no way for water to get in there'. But, if it has connections going into the battery pack for heating and cooling as well as charging and operation, there are certainly opportunities for leaks.

The other possibility is that I got water in some of my 12 volt circuitry and that has caused some leakage paths that is making my high voltage battery have to charge my 12 volt battery more frequently, thus decreasing my range?

Any inputs would be welcome. Right now, I'm just waiting for the summer heat to get here when I can be relatively assured that anything that was once wet in my car is now completely dried out, as routine temperatures are 100+ here
 
Here are a few technical facts that might help you reason your way through this and avoid catastrophizing.
1. 4" is about 102mm. The ground clearance is 160mm.
2. The battery pack is sealed with the only vent located high up under the rear seat.
3. All the HV electrical connectors are sealed.
4. The battery potential operates completely isolated from the chassis at all times. If that isolation is reduced such as due to water splashing around inside the battery pack, motor or inverter you'd get a 'Check EV' error on the dash.
5. If the settled voltage of any of the 98 series cell groups (of 3 parallel cells each) differed from the others more than 0.1V you'd also get a 'Check EV' error on the dash. (If you have a gen-2 it's 96 single cells in series.)
6. The car always knows the charge level by reading the settled voltage when parked, or by counting coulombs (Ah) while charging or driving.
7. If the 12V battery was charging more than normal the amount of energy involved is still miniscule compared with the traction battery capacity.
8. The GoM is not a good source of diagnostic information. Use the OBD port to read the isolation resistance and cell balance using a dongle and smartphone app.
 
KiwiME said:
Here are a few technical facts that might help you reason your way through this and avoid catastrophizing.
1. 4" is about 102mm. The ground clearance is 160mm.
2. The battery pack is sealed with the only vent located high up under the rear seat.
3. All the HV electrical connectors are sealed.
4. The battery potential operates completely isolated from the chassis at all times. If that isolation is reduced such as due to water splashing around inside the battery pack, motor or inverter you'd get a 'Check EV' error on the dash.
5. If the settled voltage of any of the 98 series cell groups (of 3 parallel cells each) differed from the others more than 0.1V you'd also get a 'Check EV' error on the dash. (If you have a gen-2 it's 96 single cells in series.)
6. The car always knows the charge level by reading the settled voltage when parked, or by counting coulombs (Ah) while charging or driving.
7. If the 12V battery was charging more than normal the amount of energy involved is still miniscule compared with the traction battery capacity.
8. The GoM is not a good source of diagnostic information. Use the OBD port to read the isolation resistance and cell balance using a dongle and smartphone app.
Click to expand...

1. well, I might have understated, possibly significantly, the depth of the water. No way for me to really know; but I felt just like Bud or Sandy racing my skiff thru the Gulf of Space-X Debris on Flipper, with water shooting 3-4' into the air from the wheel wells -and I was only going a few mph. Popped the hood today and can 'see' the apparent high-water mark -about 1/3 of the way up the motor housing. Soooo,....
2. I understand the battery is air-cooled possible from the A/C heat pump. Is this location under the seat where this occurs?
3. Yeah. As a Chem E. with extensive industry experience, I have a pretty good understanding of how this might have been designed. But, as we all know seals can fail....see e.g. "Go with Throttle-up.".
4. NSS. But, luckily was able to stop wrenching on cars in my mid-late 20s and more-than-capable (& happy to) of paying others to do it, I have not ever done any OBD scanning. Tempted; but already have TOO MANY toys... I certainly hope the diagnostics and idiot lights are as good as you say they are...and will take comfort in the fact that I haven't gotten any. Yeah!
5. Please. Tell me more of the battery pack layout, schematic, cell grouping, wiring [whatever you can] about how the charging/running battery sub-group voltages are individually monitored and reported to the diagnostic system [Is there any current monitoring]. This is EXACTLY the kind of detail I'd love to know more of.
6. see 5. above... Ah, yes counting coulombs (or integrating current) is an area of concern. I would assume this occurs thru some type of voltage divider thru a shunt or maybe an amp probe; if these circuit elements got wet and experience DC current leakage paths during charging -possibly even fairly small leakage currents could lead to large errors in the integration of current and therefore range calculation errors.
7. That would completely depend on the amount of energy being dissipated through any short or leakage path.
8. GoM & how its relates to my personal FUoM. I didn't list the exact range values -because I don't record them; but typical numbers from the car's system would be 296 or 298 to 304, 306 or 308. Granted these are from the car's display based on its battery and energy consumption (again from the battery) data and calculations for estimated range. But they were fairly tightly grouped and quite repeatable, as well as in agreement with the 300 mile marketed range.
 
How has the temperature varied in your area recently?
Has your usage changed of late?
The GOM range can vary easily 30 percent from max to min comparing springtime driving around town to winter highway driving
The car has an EPA range of 260ish, so depending on your location it would not be expected to actually get 300 miles of range
It does seem unlikely that there is water damage without an error message.
 
ENirogus said:
How has the temperature varied in your area recently?
Has your usage changed of late?
The GOM range can vary easily 30 percent from max to min comparing springtime driving around town to winter highway driving
The car has an EPA range of 260ish, so depending on your location it would not be expected to actually get 300 miles of range
It does seem unlikely that there is water damage without an error message.
Click to expand...

Well, it's spring now, so getting warmer (both high and low temps are increasing gradually), which should mean LESS (winter) battery heating, -if anything increasing range.
Usage has not changed. I typically see my displayed range change (decrease) when Heat or A/C is turned on and then comes back up when they are turned off.
As far as estimated range goes, I have the 64kWHr battery, which I believe is larger than a previous model. I believe it was estimated at 300; but maybe that's just what they were saying people were typically getting (on the Range GoM). I see on my window sticker that it IS listed to have a 256 estimated range to empty, as a previous poster mentioned.

Perhaps it is just some sort of range estimate anomaly based on some unusual unexplained measurement(s); but it is strange that after charging there was always a ~300 mi estimated range, and suddenly that estimated range has dropped by ~15%, with no obvious attributable cause.
 
other thoughts:
HOw long have you had the car?
HOw many miles do you usually drive?
How often do you charge?
things that can change the GOM range...driving mode....hvac settings...just reaching for ideas...
 
ENirogus said:
other thoughts:
HOw long have you had the car?
HOw many miles do you usually drive?
How often do you charge?
things that can change the GOM range...driving mode....hvac settings...just reaching for ideas...
Click to expand...

I am coming up on 3 years with this car and typically drive about 300 Mi a month. This typically came to about one full charge, which I would do in three sessions using the included level 1 charger, simply by plugging it in when I got home in the afternoon or evening and unplugging it when I went somewhere the next day. Essentially, I've done very little level 2 or DC charging

With regard to driving style and HVAC usage: yeah, they might be different from one day to the next but on average they stay about the same, as it's in a round town car and I typically do the same mix of low speed surface street and high-speed freeway to the other side of town trips. In fact, I typically see my car displaying a 4.8 mile per kilowatt hour energy deficiency; so, it kind of puzzles me how range after charging can be different.

I guess at this point I'm just going to chalk it up to some anomalies -mostly because I don't see any error codes or service requests- and watch it for a while.
 
Does seem odd
I guess check what your actual range looks like
We do call them the guess o meter, so it could be some odd glitch in that
 
ENirogus said:
Does seem odd
I guess check what your actual range looks like
We do call them the guess o meter, so it could be some odd glitch in that
Click to expand...

That's difficult to do accurately as a I don't do long trips, where I could easily compare my car's measured distance to a map distance. Car measured distances are usually pretty reliable unless one starts messing with their tires and wheels -and nothing would explain an abrupt change. About the closest I could do is compare my phone's trip distance to the Kona's meas'd distance. I've been contemplating doing something like that lately.

I'll just see what it looks like as the summer progresses.
 
Dave Fundakowski said:
That's difficult to do accurately as a I don't do long trips, where I could easily compare my car's measured distance to a map distance. Car measured distances are usually pretty reliable unless one starts messing with their tires and wheels -and nothing would explain an abrupt change. About the closest I could do is compare my phone's trip distance to the Kona's meas'd distance. I've been contemplating doing something like that lately.

I'll just see what it looks like as the summer progresses.
Click to expand...
What I do is just compare the trip odo miles to the miles of the GOM.
 
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