Dead Honda e

[EEEE]

Does it matter how fast the AC charging is or any AC charging applies the 13.3v? There are charges with variable amperage, so, technically, it is possible to greatly slow down the charging process and it would take way longer than an hour for the HV to get from 80% to 100%. Maybe, with such a charger, it would be possible to trigger some sort of preservation mode where the HV is charged slowly keeping the 12v topped up? I don't think that it would be necessary to constantly reduce the amperage, but doing it like once in a couple of weeks to boost the 12v should do it. Or am I missing something here?

I have tested this and can confirm the assumption is correct.

I set my hypervolt to 6A charging rate (1.3kw, normally 32A 7kw), and charged from 70% to 100%.

The charging lasted into the early hours, and the 12v battery was 'floated' at 13.3v for over 8hours. There were no other voltages noted. This isn't charging as such, but floating which should be performed after the battery is fully charged using the bulk charge voltage of 14.4v. The battery will never really be charged at this 13.3v voltage. I admit, it will gradually top up a flattish battery, but since many of us use a 7kw charging rate, I suspect that the odd hour or 2 at 13.3v doesn't do much to keep the battery in decent condition.

[EEEE]

Was the test performed with the battery still connected to the vehicle?

Perhaps the batteries that have depleted are a little more resilient than we had expected...

Yeah, both tests were with the battery connected. Should I have questioned this?

Well well...I found my old multimeter, and decided to check the battery voltage myself. I connected it to the battery terminals and ran the cables to the charge port so that I could close the bonnet and thus lock the car properly.

When I unlocked the car and opened the driver's door, headlights turned on, and the voltage semi-slowly dropped down to 12.07 V.

When I powered it on, to ready to drive state, voltage stayed at 14.74 V.

I then shut the car down and locked it, took the key a suitable distance away to keep the car from reacting to it, and the voltage dropped to around 12.50 V or so. It started climbing, however, and 10 minutes later it was at 12.72 V and appeared to stay there.

I then went to the key, started preconditioning, and walked back to the car (still keyless). Voltage was now at 13.62 V, indicating that the 12 V battery is being charged during preconditioning.

After stopping preconditioning, I connected my Defa SmartCharge charger to the 12 V battery, and observed the multimeter. The charger started at 1/5 bars with another bar blinking, as it did before, at around 12.50 V. However, over a few hours the voltage kept steadily climbing along with more bars becoming lit, all the way up to 14.80 V at 4/5 bars with the 5th blinking. By morning, the charger indicated 5/5 and voltage held at 14.08 V. I turned off the charger, and the voltage dropped to 13.24 V. About 7 hours later it was still 13.12 V! Sure doesn't seem like a battery that's on its death throes.

Even more weirdly, something good appears to have happened to the battery/car during my visit to the dealership, even though they said they only checked the fault codes and ran a battery test (with their Honda-branded Midtronic EXP-1030). Thing is, as I've written, after the battery death the Defa charger couldn't charge the battery even overnight, still indicating 1/5 bars. Also, the only problem I noticed with the car after said incident was with the steering wheel heater; it would warm up as normal, but cool down soon after until it was cool to touch, despite the light staying on. However, after the dealership visit, the battery is accepting charge from the Defa charger, and the steering wheel heater is back to normal as well. Hell, it seems the ambient temperature sensor misbehavior has stopped, too! I'm also now getting a "it's cold, charger connection recommended" message upon parking, which I don't think I've seen before.

The instruction manual for the battery tester you mention says it can be used with the battery connected to the vehicle. However, since the infotainment is always powered, I wouldn't necessarily trust it. Out of the car or disconnected removes all variables... The small digital battery testers don't really pull massive current so I'm always a little suspicious by their extrapolation. They seem to report the cranking amps possible, not really the capacity which is more important in the e's application.

Your other observations match mine. The voltages takes a little while to recover after the load is removed (eg after stopping and locking).

Some digital multi stage battery chargers can struggle to get over the first stage of a flat battery. Its almost as if they give up too easily and are scared to proceed. This sounds like what happened to you - its worth keeping an older battery charger on hand also, which just increases its voltage until it gets current flowing up to its max. These generally don't tend to get stuck.

Your observation about the steering wheel heat and the ambient temp sensor is an interesting one. Its quite possible a software bug in the temperature handling is at fault, and a reset of the infotainment has corrected it. I would say my heated wheel output is variable, sometimes it is toasty and pleasant, other times it seems to be wanting...

My next question is is the 12v charging method dependant on the temperature? Could a fault in the recognition of the ambient temperature be the cause of incomplete charging? The voltages for charging are affected a reasonable amount by the battery temperature. Yesterday was especially cold for me in the UK, car reported ambient of 3degrees C, and the window was iced up, as was my wifes car.

I guess the hunt is on for the real cause of:

1) 12v charging does not take place even though the car is on (This has happened to most of us).
2) What is causing the drain over night that so many of us have experienced? (is it sticky door handles, is it infotainment, is it ambient temperature sense related?)

I'll get to the bottom of it even if it kills me, can't stand stuff that doesn't work properly.

[5thcivic]

Am I correct in assuming that if you do short journeys and continually charge up from say 80% to full every night, you not only risk harming the HV battery by not cycling in its optimum operating area, but it is possible the 12V is not getting a full charge anyway always at the top of the HV charging cycle?

When I got the car in those first enthusiastic weeks I used to top up to max straight away, then got wise, set the max at home charge to 90%, 100% when away, and now run down to 20 or 30% before plugging in. I do few miles, 2 and 1/2 years in and 1300 miles, and use a smart charger on the 12V every couple of weeks because of it. Touch wood no battery problems yet, we'll see what happens after the 3 years are up!

[londiniumperson]

However, since the infotainment is always powered

I doubt that the infotainment itself pulls any power whilst the car is powered down & locked, though I would expect some current draw for other 12 systems (e.g. the inbuilt sim to wake up the car when the MyHonda+ app requests data - this is probably the cause for most people's flat battery).

Some digital multi stage battery chargers can struggle to get over the first stage of a flat battery. Its almost as if they give up too easily and are scared to proceed.

Definitely agree here because only yesterday I checked on my Beat's battery and it was down to 7v; when I put it on charge with a CTEK 5A charger, it repeatedly error'd as not seeing the battery connected, however I left it overnight and it is now charging.

Your observation about the steering wheel heat and the ambient temp sensor is an interesting one. Its quite possible a software bug in the temperature handling is at fault, and a reset of the infotainment has corrected it. I would say my heated wheel output is variable, sometimes it is toasty and pleasant, other times it seems to be wanting...

Same for me, the heated steering wheel is another annoyance with it not always being very hot/warm even on cold days & it's light on.

I guess the hunt is on for the real cause of:
1) 12v charging does not take place even though the car is on (This has happened to most of us).

This has NEVER happened to me, I can guarantee that people are not ensuring that there car is actually ON. Unless specifically turned ON, it will auto shutdown by itself after a short while.
I have experienced a fully drained 12v battery many many times (yes intentionally added 'many' twice) and every time without fail that this has happened with the car unlocked I have determined the cause being that the car was not specifically turned ON.

[MaXPainT]

Some time ago there was an EV youtuber who has experienced similar issues with his Ioniq 5. Turned out that the drain was happenning due to the app requesting data from the car too often. Each request was waking up the 12v system and since the car was technically off the 12v battery was not charging. This got fixed with a software update. I wonder if the people with the dead Es are also using the Honda app.

[Verone]

Some time ago there was an EV youtuber who has experienced similar issues with his Ioniq 5. Turned out that the drain was happenning due to the app requesting data from the car too often. Each request was waking up the 12v system and since the car was technically off the 12v battery was not charging. This got fixed with a software update. I wonder if the people with the dead Es are also using the Honda app.

This is an interesting point. I don't use the app as the car's e-sim is not support in Iceland and the app isn't available here, and I've never had 12v issues so far.

[londiniumperson]

Some time ago there was an EV youtuber who has experienced similar issues with his Ioniq 5. Turned out that the drain was happenning due to the app requesting data from the car too often. Each request was waking up the 12v system and since the car was technically off the 12v battery was not charging. This got fixed with a software update. I wonder if the people with the dead Es are also using the Honda app.

Just as I suggested in the previous post and also several times on other topic threads.
Also just because an owner is not using the app does not mean that the car is not 'phoning home' or that Honda are not interrogating the car remotely for their own use.

[EEEE]

Small update.

My battery flats have happened both when the app was in use, and when not. My reminder to prove ownership expired ages ago and I never bothered relinking it. I guess the TCU would need to be completely deactivated so that it cannot be awoken by Hondas servers.

Did a quick capacity test by charging up the original Panasonic battery and the new yuasa 55ah same size battery, then left them a few days. Discharged both with a very light constant 2amp load until they dropped to 12.00v. Not a perfect test as the discharge tester is crap. Eitherway, the new battery gave me a hell of a lot more then the OE one. Got 24.5ah out of the new battery, and only 4.5ah out of the OE Panasonic by the time they hit 12v cutoff.

When my higher capacity tester turns up, I'll do a better test. I think it's probably safe to say that an OE battery that's gone flat 2 or 3 times in the past has lost a chunk of its capacity.

[Verone]

Just as I suggested in the previous post and also several times on other topic threads.
Also just because an owner is not using the app does not mean that the car is not 'phoning home' or that Honda are not interrogating the car remotely for their own use.

This could be the case, depending on the market.
In Iceland the eSIM in my car is completely disabled as none of the carriers in the country support it or will provide a data plan for it.
I might be wrong, but I don't think Honda will be able to connect to it remotely if that's the case, as the dealer has told me any time I need diagnostics or any software updates, I'll have to either use a wifi hotspot from my phone, perform a USB update, or take it to the dealer to have them do it.
Whenever I try to use any of the features in the car that need internet (Honda Personal Assistant, Update service, app center - although this is dead and gone now, or anything else that needs data) I just get a pleasant middle finger from the car that tells me I don't have any connectivity and need to visit my dealer to have it set up.

It's super shitty, but I'd love to have the car connected to enable more features. Not sure if Honda can even talk to my car with it in this state.

That said, maybe it's better if it's protecting my 12v battery's lifespan. I'm guessing that I'm not missing much with the App or the connectivity outside using my phone as a hotspot when needed?

[keithr]

The 12V battery going flat is a problem that a lot of BEVs have had, or have, and it's not unique to the Honda e. The original Nissan LEAF had a problem with 12V batteries going flat, which was much less of a problem with the second generation (40kWh) LEAF. I have had both so I was in the habbit of charging my 12V battery once a week using a smart charger (battery remaining in the car during charging), and I've continued doing that as preventative maintenance with my Honda e (now 3 years and 2 months old) and I've never had the 12V battery go flat yet on any of the three BEVs that I've owned. I don't do many miles a week (typically only about 20 miles a week during winter months), and so it can take over 5 hours to charge the 12V battery (with a 5A CTEK charger).

I've heard of Hyundai's, Kia's, Volkswagen ID.3's and other BEVs having 12V problems too. Even Porsche Taycans will let the 12V battery go flat if you park the car for two weeks, as this video shows - My EV BATTERY DIED and I was left TRAPPED INSIDE my ELECTRIC CAR with NO OXYGEN SCREAMING for HELP! . At least the Honda e doesn't lock people inside the car (as far as I'm aware)!

I blame the fad of allowing people to communicate with their car over the mobile phone network, keyless entry (so it's constantly transmitting radio signals), immobiliser and alarm, and even the BMS (battery management system), which mean that the 12V battery is constantly in use and the car is never truly turned off when parked, and the fact is that most cars are left parked for at least 95% of the time (nearer 99% of the time for my car).