clarity PHEV dead after 3 weeks in garage

No. If the battery can't hold a charge, it can't hold a charge. Trickle charging or jump starting will get you running, but it won't magically fix the battery. FWIW I had to replace my battery within 6 months of getting the car, presumably because one of the dealers had left it sitting on a lot for months. If you're still on the original battery, knowing how little they tried to sell these (i.e. test drives to exercise the system), you're lucky your has lasted this long. I bought this and have used it once to get a CR-V recharged and out of my garage after not driving it for months.

 

It would be interesting to check the voltage of the 12v battery, before you do anything else.

 

That new? I wouldn't screw around with Auto Zone load testing unless you're bored and curious. Honda will just give you a new battery. Just tell them it's dead after sitting only 3 weeks. With the car being that new I am very certain the dealer will replace it for free under warranty. If you don't want to jump start and drive it there, have Honda Roadside assistance tow it there free.

If it was a year+ old and had more mileage? I'd just buy a new battery and install it myself to save some money. A battery that has been fully and deeply discharged is damaged and needs replacement. Load test is waste of time.

 

I agree, 3 weeks isle should NOT kill a battery. I’d forgo any other triage and call your dealer who sold you the car and get some love. Silly...

 

A premature battery death should not be expected with the Clarity or any other car. That said, there have been a few reports of early 12V battery failures. One plausible explanation for the failures is that some vehicles may have sat in dealer lots for months without being “started” or driven to charge the 12V battery.

As suggested, you could have the car towed to a dealer or remove the battery yourself and take it to the dealer for testing, and probable replacement under warranty. It all depends on how much of a scene you want to make.

My experience, with no added electronic gadgetry, is that there is virtually no parasitic draw on the battery while it sits unused.

 

If the voltage gets low, it will light up all kinds of warnings on the dashboard and threaten that your car will explode. It's mildly distressing to have that happen while you're driving 55 mph down a country road. I was able to get mine replaced before it actually prevented me from starting the car, though.

 

It is interesting that a low voltage warning would occur while driving, as the HV battery would be sending ~14V to the battery. Much like an alternator in a normal car.

 

Early in the life of our Clarity, we had two of the multiple system warnings episodes. The Clarity still started up but the second tine I noticed that the 12V battery was in a low charge state (the charge eye was white with a red dot). For whatever reason, sometimes our Clarity would get a low 12V battery. The software update fixed the issue with a low 12V battery causing the multiple system warnings.

However, tonight before I hooked up the charger, I plugged in an OBDII scanner to run the tests that Cash asked about. While sitting in the car doing various preparations, I noticed that the low 12V battery red light was on. I saw that the 12V battery voltage was less than 12.2V. I hooked up a 4A 12V charger while I finished the tests. After removing the 12V charger and before plugging in the the HV battery charge cable, I tested the 12V battery and found a 15% SOC at 12.1V. Luckily, the battery health was still excellent. I then plugged in the HV charge cable. We have driven the Clarity only short distances the past ten days for a total of 25 miles over eighteen short trips. These trips were apparently not enough to recharge the 12V battery.

The 12V battery also charges when the HV charging cable is plugged in. I then measured the 12V battery to have 13.4V and an input current of 3.7A. This about what I would suspect for the voltage at a 3.7A charge rate for a 15% SOC. So, when recharging the HV battery, the 12V battery charges at less than 4A (a safe rate). I suspect that at that rate, the 12V battery would take ten or more hours to fully charge.

Tomorrow morning after a full charge for the HV battery, I will remeasure the 12V battery (voltage, SOC, and health). I will also put the Clarity in drive mode and measure the 12V battery voltage and current just to see how the 12V battery is charging when the Clarity is in drive mode (turned on). Finally, after the Clarity returns home from a trip, I will measure the 12V battery current when the Clarity is turned off, turned on, and when it is in accessory both modes as I am curious.

LeoP

 

@leop Are you using the 120 volt stock EVSE? It stands to reason the slower charging stock EVSE would give the 12 volt battery more hours of charge. With the small amount of driving we are doing during the pandemic it might make sense to switch back to the stock EVSE cord.

 

I have a Duosida 16A EVSE that I run off a 120V circuit (I keep the stock EVSE in the trunk). It pulls about 14.5A. However, it appears that the charge voltage to the 12V battery stays at 13.3V-13.4V the whole time the HV battery is being charged. Thus, the charging amperage to the 12V battery falls off as the 12V battery recharges. After about four hours the charging current is only 0.7A. My battery still shows low charge and I suspect the 12V battery will be no where near fully charged when the HV charging is completed. Tomorrow I will the check the 12V battery SOC and voltage. I do not know if the system will keep charging the 12V battery after HV battery is fully charged and the HV charging cable is still plugged in. That is easy to check tomorrow after the HV battery is fully charged.

BTW, 13.4V to 13.5V is the float voltage range for a typical flooded lead acid battery.

LeoP

 

Correct. And the resting voltage should be 12.7V. This should be measured after at least 1 hour has elapsed of no charging and no loads placed on the battery.

A battery at 12.0V would be at ~40-50% SOC.

 

The charging completed overnight and I measured things again. The 12V battery was not completely charged at 12.6V but I did not expect this with only 13.3V-13.4V while the EVSE was plugged in and the HV battery was charging. I then had my wife sit in the Clarity and turn the vehicle on to the drive mode (Ready to drive on display). The voltage at the 12V battery was now 14.6V and the charging current was over 14A. So, the 12V battery needs the vehicle to be in the drive mode for other than float charging to take place. So, one needs the car to be in the drive mode to get a good 12V charge. I just connected a good charger to the 12V battery to top it off this morning.

The clarity does seem to drain the 12V battery but this is expected in a hybrid vehicle. Toyota recommends protecting the auxiliary battery by powering on a hybrid vehicle for 20 minutes once every two weeks if the vehicle is stored. It is also recommended that the hybrid vehicle be started and run for 30 minutes every two month to charge the traction battery. I think that Clarity owners need to take similar precautions if their Clarity is not driven regularly. I measured the battery drain while our Clarity was off. The drain usually ranges from 15mA to 75mA with some periods where the drain is over 100mA. If we assume that the average 12V drain is 75mA and that the Clarity 12V battery has a 45 AH capacity, the drain will completely discharge the 12V battery in about 25 days. A decent 12V maintenance charger is probably a good thing to have at this time.

LeoP

 

I believe it is important to remember one thing with these newer connected cars. With convenience comes systems, and with systems comes power. A lot of curious people are checking on their car's location, status, etc. The parasitic load on the vehicle is very much as @leop describes. Note that it will substantially increase every time the car has to respond to a "server" request from Honda for telemetry. This is very infrequent and Honda seems to only ping the car when it is ON, Charging, or has just shut off (location and mileage info). However if you "refresh" your Hondalink, the radio transceiver goes from listening (like your cell phone on "standby") to transmitting (talking, and using more "talk time"). The car also has to power up some systems to get the info requested (GPS, state of charge, environmental etc) then send the info. This takes 12 volt power, not much - but it is still "activity" that is not standby. Something to keep in mind if you car is in storage. Stop asking it questions! Think of the Clarity as Schrödinger's cat - it is sometimes better to not know.

However that rate is actually LESS than the self discharge rate of most lead acid battery designs (like everything there are exceptions to this rule, but for car batteries...). So it is really not much concern. What is a concern is charging. The battery is floated when the car is charging, but the 12 volt battery is not bulk charging for that time. Now, if you are level 1 charging then you are preserving your 12 volt battery better than short Level 2 charges would allow. Most lead acid batteries need 4+ hours to actually absorb a charge. There is a lot of information on lead acid charging on the web, however the bottom line is that unless you are driving the vehicle regularly - you have to fully charge it, before any "maintainer" at 13.x volts will actually do much good. As Landshark says, you need to have a well charged battery before any storage longevity will be reasonable. @petteyg359 is right that we have seen a lot of Clarity issues that seem to be reasonably traceable back to dealer storage issues DEPENDING on your market. Some Clarity markets sold like hot cakes, others - well... they sat for long periods of time and were often very neglected vehicles both 12volt/ICE/and HV conditioning. My battery listed a reserve capacity of 85, so my Ah rating is only 35 (Honda Group 51R). However, even with minimal driving I find that level 1 charging is maintaining it at 85%+ SOC (using a hydrometer and load tester). The batteryminder I have keeps it at 100% SOC using only 1.3 amps max no issue.

I think we have a lot of early failures similar to the OP, and for that reason having the dealer replace the battery for FREE with a "new" one (that has been sitting on their shelf without a tender on it) is the best course of action. I doubt anything is wrong with the car.

As I have said in another thread - there is no monetary reason why a problem cannot be solved... So there is this! https://antigravitybatteries.com/products/starter-batteries/automotive/ag-51r-rs/

Think I will just keep a $50 jump pack in the trunk though...



Cheers,

Cash

 

@Cash Traylor , you had me at Schrödinger’s cat! You also forced me to Google how to get the umlaut over the “o”. Thanks, I learned some new electrical and some new grammar info.
Seriously though, the take home for me is that I don’t have to plug in my battery tender unless my wonderful Clarity is going to sit for more than a couple of weeks.

I do have a question for all you electrical wiz kids on this thread. I got out my Battery Tender Plus and decided to train on it so I’d be ready to use it, if and when necessary. I also got out my trusty little freebie Harbor Freight VOM.
Here’s what I found:

Voltage at battery terminals was 12.7 V on a day and week with normal driving and charging with temps in garage and outside in the mid 60s F.
Hooked up the Battery Tender Plus (1.25 A) and got the red LED that means charging and within 30 seconds got the green flashing LED which means battery greater than 80% charged and reads 13.7 V. It turned to solid green after 6 minutes which is charge complete and on storage cycle. Battery now reads 13.3 V while on Battery Tender Plus and with it disconnected.
Obviously my battery is fine and I wasn’t worried about it. After all it’s only 2 years and 17K miles old (95% EV). I was just wondering what, if any, you electrical Brainiacs can infer from this. I would also ask why the cable with clamps for attaching to the battery posts is fused but the cable for the quick connect (which I’m using) is not.
Inquiring minds want to know.

 

@KentuckyKen ,

Kentucky, you had me at being able to name what those two dots are called!

Hello, battery voltage is an ok method for determining state of charge, called "open circuit voltage" if done without the battery connected and having let the battery rest for 24 hours (no charge or discharge). However, it is not a good measure of State of Health/capacity. What I mean is that a battery can be sulfated, but NOT shorted (an internal cell) and therefore produce voltage or accept voltage as measured under no load that would lead you to believe it is fully charged (12.6+ volts). However, that battery may have very little "capacity" available for use. Meaning that if you put a load tester on it - something that put a known load (for car "starting" batteries this is normally a hundred amps or more briefly) it will immediately fail the test. You can also do something called a "capacity check" (this is never used in automotive, and rarely used on deep discharge/cycle batteries for testing) where the battery is loaded for a period to time at a known constant draw of amperage. It is how automotive batteries are tested for reserve capacity (normally a constant 25 amp load for x number of minutes until reaching a manufacturer defined cut off voltage, normally around 10.5 volts or so). Aviation lead acid batteries used in turbine equipment must, on a certain schedule, be checked at the C/1 rate (42Ah battery is discharged at a constant load of 42 amps) for a period of time. To pass, it must make 85% of its rated capacity (in time, or at least 51 minutes), if not it is removed from service.

Putting a fuse on the connectors that have clamps is likely to protect the device from a short/reverse polarity connection. However, almost all manufacturers put fuses on the connectors (quick connects) that are designed for "permanent" installation, as they are more prone to shorting over time. The fuse, on the positive side very close to the battery terminal, protects your installation from the fire risk of a wire shorting for any reason and igniting. Why your unit doesn't do this is perplexing, and I would recommend a fuse. I checked my unit, and the OEM's product list, and all of their units that have the quick connect feature are all fused on the harness that "bolts" to the battery. https://www.batteryminders.com/accessories-3/

I didn't get to log data that is statistically significant (over a 24 hour period), however have a hypothesis going back to the PDI (yep, that amazingly useful document). I have been checking the telemetry loads and standby in my garage at my house, which has apparently adequate cell coverage for the Hondalink to use. The data hits are not heavy current loads, however the telemetry system seems to be powered by the same fused sources that the PDI shows Honda removed for shipping the vehicles. I would guess, that like our phones when in locations with poor service (they use up their battery power more quickly searching for signals) that our cars in transit over the ocean would unnecessarily waste power searching for signals. When I pulled number 21 and 22 fuses the parasitic load drops, and I also do not see the current pulses from the telemetry system.

So here are the numbers: In a garage with good TCU signal, Standby after the vehicle calms down for a few minutes are like leop describes at 25 ma or so (0.025 amps). However, when I ask for a battery/mileage update it jumped to 240-650 ma for a few minutes. HOWEVER, when I asked for a fresh vehicle location (gps location) you can hear systems come on, and the current spiked to 3.75 Ah for almost 90 seconds. Here is the kicker, today I had to go to the airport and where I park in the hangar there is only ~1 TCU bar. I often cannot get a "status update" on Hondalink. So I repeated the test... everything was essentially the same except for the time periods. It seems the car can occasionally receive the call for data, but like getting a call where your phone rings but they cannot hear you, it was having a lot of trouble responding. It spent over 10 minutes off and on, for the same requests at the same currents. The 3.75 Ah draw stopped at less than 5 minutes once but then continued for 3 minutes the next time. Maybe the car was giving up, maybe it was getting through eventually. Either way, if your car is in storage - and maybe in "deep storage" where signal may be weak - don't ask for Hondalink updates as that will eventually kill your 12 volts battery. Also, at no time did I see the HV system start a charge cycle during these tests and did not expect one, however again I did not do any cumulative tests for hours or days to confirm.

Cheers,

Cash

 

I think Cash has come up with a possible reason why the Clarity 12V battery sometimes is drained quickly when the Clarity is not in use. I understand that the Clarity communicates over the AT&T 3G cell network. People have already asked what will happen when the AT&T 3G cell network is discontinued in 2022. AT&T is already cutting back on the 3G network and this is especially so in my local area. We are down to two accessible 3G equipped towers near my home and the effective 3G channels have been reduced. I suspect that repeatedly not being able to get a 3G cell connection (especially when the TCU needs one) may be causing the excessive 12V battery drain at times. Also, I am not so sure that the Clarity only connects to the HondaLink network when the owner queries HondaLink. I suspect there may be other reasons for HondaLink to connect either at the vehicle's or Honda's request.

If the above is true, it seems that Honda will need to provide a 4G solution especially for the owners of Clarities with long term HondaCare warranties.

LeoP

 

Do you have to use/activate Hondalink to connect to the 3G Dial-up network?

I don’t. Maybe that’s why my battery didn’t die after being parked for 4 weeks.

 

@Landshark

That is an interesting question and hypothesis... I don't know, and am not 100% certain I understand your statement/question. Are you not using Hondalink? Never activated it with a Honda account/VIN etc?

If that is the case, based on what I observed today, I would completely agree with you. That may greatly reduce your vehicle's standby power use. I activated mine, never really thought about it as I know the vehicle TCU sends Honda all kinds of info anyway. I wanted the long range climate and power state info. Of course, later I find I don't use it as much as I initially thought I would. The Clarity definitely "calls home (Honda)" when it is first turned on, turned off, and anytime it begins or ends a charging cycle (there is a minimum time limit I think, of 10 or more minutes between scheduled automatic "calls"). As to the data that is being sent, I am still digging through that. This is part of Wiresharking that I am still learning, with a layer of Fiddler running on top, and well, let's just say I need to watch more youtube instructional videos. I think the panda may be an easier solution, but that is more coding making my head explode. We can assume they know everything, and Hondalink tells us just a few variable.

I do not believe that "not activating" Hondalink turns the info Honda itself can get remotely from the car off. However, it would effectively eliminate "owner" information requests (pings), and that would reduce load, maybe substantially. If Landshark's long term storage success ends up being a rarity compared to others, this may be a real thing. Since most apps on phones run in the background (unless you specifically turn that service off), and can update in the background (ie, send a request for status/data to your car without you asking) it is possible that just having HondaLink installed on your phone and activated (enabled) can cause info requests you did not actually initiate. I haven't seen the source code so this is speculation! However, based on a hack report I read on Nissan regarding the LEAF and remote feature servers for their phone app, this is not that far out in left field for a possibility.

I don't want to create a panic situation about Hondalink and this 12 volt draining behavior. We need more data, and this kind of data would require a current logger and, although I have one - I am really not looking forward to doing that (it is a data feed, and boring as hell). We would be looking for needles in a haystack of where your phone requested an update in the background, and we knew it wasn't Honda. I am continuously annoyed with any developer, OEM, etc when they put out a software update (mostly for mobile devices, but even in general) and just say "Bug fixes and performance improvements..." in the version description. This goes back to "Right to Repair" stuff, as without a change log you are in the blind. It is possible that if this is the case, it may get fixed, either on the car via software bulletin - or your phone via an app update (assuming you do it or it is auto). That is, of course, assuming this is a real issue and not a figment of my imagination....

The bottom line is that the TCU is the tattle tree for Honda and the Clarity is talking a lot. I keep my cars a long time, and as someone who once manufactured a tech device, I understand the warranty-telemetry deal. However, once my warranty is up, I am pulling the TCU cable, and the black box FCAN as well. No, I don't have that little insurance snitch device plugged into my OBDII port or on my phone either. Everyone here knows my driving would exclude me from any discounts anyway! I am also becoming less concerned about the TCU/AT&T 3G obsolescence deal the more I think about it.... but I will have to think about it...

Cheers,

Cash