Multiple System Warnings

StickWare: Out of curiosity why didn't use the free Honda Road Side assistance for the Clarity. They would have provided a flat bed for free.
Also for extra security I pay for a AAA membership and that covers me for a 100 miles worth of towing.

24-hour emergency road service is available in the United States, Canada and Puerto Rico, and includes flat tire and lockout assistance, towing and more. ... For Clarity Electric and Clarity Fuel Cell, Roadside Assistance is available for 3 years/Unlimited Miles. Call 866-372-5139 for assistance or details.

 

You should also file a claim with the city/county responsible for maintenance of the road you were driving on. They may say "no", but it costs nothing to try.

 

17 months, 13000 miles and no issues. Had all of the required patches, all of the required maint. done. Now saying that, I have not been on a trip that required the car to sit for 3+ weeks. I'll make sure that I read through this before I do.

 

Most people seem to charge to full prior to leaving for a trip, which is understandable, however that means the 12V never gets charged because the current theory is that the 12V only charges when the main battery is charging. My idea is to leave for the trip with the main battery much closer to empty and then schedule charging for 30-60 minutes per day, whatever amount will result in daily charging for the entire duration of the trip. That might help keep the 12V from running down while you are gone.

 

There is not much prep you will need to do before your trip. I charge the car to 70% SOC, hook up the battery tender and feel comfortable leaving the car. I would not plug the car in unless you have surge protection (If power goes out while you are away and leave the car plugged in: when the power comes back on your car will charge to 100%). As an example I left my car garaged in Michigan for 3 months during winter and it only lost about 3% SOC. The telemetrics to the car will probably shut down after a week of inactivity of the car to protect the charge of the 12v battery. If the telemetrics shuts down you will not be able to tell your car to charge.

Sent from my SM-G955U using Inside EVs mobile app

 

I think you're right a battery tender would be a better solution. I have one that I use on another car that only gets driven every couple of weeks or so and the 12V has lasted for many years. So they certainly do the job without damaging the 12V battery like a cheaper battery charger can.

However if someone doesn't have a battery tender and is using the method that I suggested, scheduled charging doesn't require connection to a smartphone so I don't think it would stop following the schedule just because telematics shut off, although I can't say for sure. Also I'm not sure if your car works differently than mine but if power goes out, when it is restored charging does not resume. Actually that's kind of a bummer in case the power goes out briefly in the middle of the night while charging which has already happened to me once. But if using scheduled charging it will still follow the schedule for the next charge session.

 

Disclaimer: This is what I observed with my car when the 12 volts battery got discharged (after few days of ownership) because I sat in it for hours and hours in instrument mode trying to setup android auto and learn about the infotainment system. After 3 nights of doing this, my 12 volts battery got discharged and I started getting the multiple warnings system. So my disclaimer here is that this is what I observed but I could be wrong.

1- Even with the propulsion batter fully charged, and while the car is plugged in, the 12 volts battery did trickle charge itself back to around 12 Volts, but it took 2-3 days to go up to 12 volts. Again the main propulsion batter was not charging. This observation is 100% accurate, I took pictures and documented it for the sake of the local Honda Dealership.

2- My guess is that when I got the car from the dealership, the 12 volts battery was very discharged to start with (car sat at the dealership while not being plugged in and it was not fully recharged when delivered) and that is why I experienced the multiple system warning after sitting in it for 3 nights trying to figure out the Android Auto and infotainment system. Once I realized this, I started being careful on how much time I spend inside the car and when it is not plugged in. So, 1-2 hours is okay 6-9 hours may not be okay.

Hope this helps

 

That's good to know. The session when you ran down the 12V if I understood correctly you were not plugged in? I sat in my car for about 45 minutes one time going through screens, I had the fan on, I was plugged in but not charging. This caused EV range to go down about two miles, so apparently the HV battery powers things when you are in ACCESSORY or ON mode and plugged in, even if not charging. But if not plugged in then only the 12V is used. Not sure of the logic, Other than they figure if you are plugged in you are more likely to charge the HV battery in the near future.

 

Not necessarily. Could be that it is using the 12V battery and the HV battery, which is plugged in but not charging, is giving to the 12V battery like it is designed to do when turned on. Nothing we've seen anywhere says the car has to be out moving around, only that the 12V battery is charged by the HV battery when the power in the car is on.

 

2002: I was plugged in all the time, the HV battery was fully charged, but I think I was draining the 12 Volts battery faster than it could be trickle charged by the HV battery. My understanding is that some functions like the infotainment system and the dome lights inside the car use the 12 Volts battery, where as the Air Conditioner and the Heater use the HV battery.

rodeknyt: Please read my post above - I think, with high confidence, that the car does not have to be ON for the HV battery to trickle charge the 12 volts battery. It has to be plugged in though. It makes sense from a design perspective. The 12 Volts battery is cheap and replaceable, where as the HV battery is very expensive and hard to replace. So when the car is not plugged in, do not sacrifice the HV battery to keep the cheap 12 Volts battery alive.

my 2 cents - Hope this helps.

 

True but in some contexts we don't go into that level of detail since in the end the HV battery is ultimately providing the power even if the power is "passing through" the 12V battery. But yes in other contexts it is important to make that distinction.

Just to make sure that we are talking about the same thing, ON mode is two presses of the power switch without pressing the brake pedal. AFAIK all systems work in ON mode except the AC compressor and heater, and of course you can't actually drive the car. READY mode (press the brake pedal when pressing power switch) enables AC compressor and heater and the propulsion system.

We know that in READY mode the HV battery will keep the 12V charged. Our question is how it works in ON mode, which seems to depend on whether or not you are plugged in. OTOH we are doing lot of theorizing at the moment without a commensurate amount of testing.

But as I was mentioning earlier if you aren't charging there is no electricity flowing through the cable so it's really no different than not being plugged in. The only difference is that if you are plugged in there will probably be some charging going on at some point within the next 24 hours, but not necessarily.

I don't think the AC compressor or heater work except in READY mode. In ON mode only the fan will run, even if plugged in. At least that's my experience. But you may be right that the fan runs directly from HV battery not 12V, since the AC system (including fan) runs off of HV when you use the key fob or app to turn on climate when you aren't plugged in.

My only data point at the moment is sitting in my car plugged in, not charging, in ON mode with infotainment and fan running and I saw EV range drop 0.01 miles every few minutes. Also the daytime running lights were on. Maybe it was only the fan that was using the HV battery, I was running the fan relatively high as it was hot in the garage, but I was under the assumption that everything was running off of HV. Will need to do more testing.

 

ALL systems in the car - with the exception of the drive motors - run off of 12v. This includes the fans, lights, infotainment, computers, A/C compressor, heat pump (on the BEV).
The only question is when (and in what modes) does the car use the HV battery to provide energy to the 12V to charge/maintain it?

As an interesting note, Hyundai/Kia eliminated the AGM battery in the Ioniq and Kona (& Niro?) hybrids. They put a 12V lithium battery in the HV pack, and the driver can manually "jump" that battery from the main pack. They kept the lead acid setup in the PHEV and BEV versions . Not sure if I want to ask what it would cost to drop and open the main pack to replace a flaky 12v battery (original owner does have a lifetime warranty).

 

Correct but we were discussing the source of the power for specific devices in specific scenarios not whether or not these systems are running on the 12V system. Or another way to put it, which battery is drained in different scenarios when no charging is taking place.

 

The 12v battery is ALWAYS being "drained" in these scenarios. The question is when is the 12V battery being CHARGED.
This is an important distinction because many weird/odd issues crop up with a bad/low 12V battery, even if the vehicle is supplying charging voltage to the battery.

 

When running remote climate when your car is sitting in a parking lot the HV battery charge goes down. If you turn on ACC or ON in a parking lot and run the radio the 12V battery charge goes down. Turn on the radio in READY and the HV battery charge goes down. That's the type of thing we are discussing and trying to figure out for different devices in different scenarios and more testing is needed to determine this.

 

Exactly like I said. The question is: "Under what conditions does the car use the HV battery to charge the 12V?"
The 12V power NEVER comes directly from the HV. It always funnels thru the 12v battery. Charging the 12V battery will indeed drain the HV (or the gas tank if the ICE is running on the PHEV).

 

The discussion that Hanman and I are having is which devices in which scenarios cause which battery charge to go down. Adding to the mix whether or not the charge cable is plugged in but not charging, which from our initial tests seems to make a difference for an as yet unknown reason. Sorry if while my mind was on that subject I used terminology like "drained" and "powered by HV battery" that were too technically vague and could be misinterpreted as saying something it wasn't meant to convey. But yes the technical discussion is interesting and in the bigger picture is important in understanding the systems.

 

I was curious so just went out and put a voltmeter on the battery while trying different states. Generally, a car's 12V battery puts out around 12.6 Volts when not under load and not being charged. When you see 13+ Volts at the battery terminals, that means the 12V battery is being charged (either by the alternator in a regular car, or by a combination of the HV battery and the engine's generator through the DC converter). And that also means any 12V components are really using the juice from the HV battery or alternator just like the 12V battery is; it's not like the electricity passes "through" the 12V battery first.

Here's what I found (charging/draining refers to the 12V battery):

Off, not plugged in: <13V (not being charged)
Accessory (one press of power button without foot on brake): <13V (draining)
On (two presses of power button without foot on brake): <13V (draining heavily, especially when a loud cooling fan came on)
Ready to drive (press power button with foot on brake): >13V (charging)
Off, plugged in to L1 charger: >13V (charging)

This was a quick test, and I'll capture the actual voltages later -- the key is that "On" doesn't seem to engage the HV battery, and is really the worst case drain of the 12V battery. That's consistent with ICE cars where "On" without the engine just drains the 12V battery. If you're going to sit in the car for a long time, Ready is much better, plus gives climate control if you want.

The only real difference we have from an ICE car is that our 12V batteries get kept topped off during the charging cycle -- and that's most likely because charging requires computers and relays that would otherwise drain the 12V battery. A healthy 12V battery should be able to sit in an unused (off!) car for several weeks or more without issue, even with the small constant loads in modern cars. Longer than that, sure, consider a battery tender or other options.

 

Thanks JCA, this is very helpful. And confirms my personal observations.
So form now on, I will only put the car in Ready mode if I need to do some infotainment/Android Auto setup/update and the car is plugged in. This is in lieu of the Accessory mode or ON mode.

Thanks to all for the info. I didn't know about the ON mode (2 presses) until this thread, I only knew about Accessory mode, and Ready mode. Now I know.

Again thanks JCA.

 

Bought my clarity on May 28, 2019 and have 4,600 miles on it as of today.

After reading this thread in its entirety, I'm losing even more confidence in the Clarity after only 3 months of ownership, mainly because of what has already happened and that there are not many answers yet:

• This was my wife and my first serious concern and why she has told me, "Just so you know ... I am NEVER driving the Clarity!" There is a Dangerous Problem with the Honda Clarity https://iconnectdots.com/2019/06/there-is-a-dangerous-problem-with-the-honda-clarity.html

• The check-engine light has come on four times and each time I take it in to the dealership they are unable to detect any issues (and the Clarity does not have log files so they can't see any historical codes that have been generated). So I spent $100 to buy an OBDII connector so *I* could capture error codes as they were happening.

• Then, after being gone 5 days for the Labor Day weekend time, I jumped in to my Clarity to run errands on Tuesday and it was stone-cold dead. Had it towed to the dealership and they supposedly fixed it, but I'm very uncertain any meaningful analysis or deep troubleshooting was done.

• Just wrote this post which about sums up the latest: Is my Clarity fixed? https://iconnectdots.com/2019/09/is-my-honda-clarity-fixed.html

So what would you do in my situation?