Ongoing 12v issues

[s2ke]

Background: My car is a launch model, 20 reg. It was a demo and I got it in Jan 21. It's done c20k miles and had a new battery in Oct 23. It went flat once while we were on holiday, probably in April/May 22 but it didn't happen again till the end of last summer

I replaced the battery, new one is fine (tested)

I noticed the passenger side handle was not behaving, I removed it, cleaned and greased. It's better but I think maybe still an issue

This week the car hasn't been used much. This morning 2.6v..

My Noco couldn't notice it was connected - the I button held for 3s is a manual over ride I learned

Putting a BT battery monitor on it but I am contemplating unplugging the ps handle power to the passenger side as it's not the family motor.. anyone done this? Will it chuck an error?

[s2ke]

So the BT monitor is on and the handle thoroughly greased. It moves better 100% and seems normal but the lights do odd, inconsistent things when I lock the car (staying on for several seconds being one)

I can leave my phone on charge overnight monitoring the 12v as the car is close enough

Noticed on a short run today it does an odd thing, if you drive with a fully charged 12v the e won't put any charge across it, so my accessory socket voltmeter says 12.5v steady, running

After a little while it then kicks in and goes up to 14.5v which is where you would see a not clever ICE system when the car was running.

Tonight, having been charged earlier it is sat at a perfect 12.64v

Let's see tomorrow, otherwise I will start to remove fuses, the door handles have 10A each - alarming!

[mrdo]

Noticed on a short run today it does an odd thing, if you drive with a fully charged 12v the e won't put any charge across it, so my accessory socket voltmeter says 12.5v steady, running

How long do you think it took to start charging the 12v on your short run?

[EEEE]

So the BT monitor is on and the handle thoroughly greased. It moves better 100% and seems normal but the lights do odd, inconsistent things when I lock the car (staying on for several seconds being one)

I can leave my phone on charge overnight monitoring the 12v as the car is close enough

Noticed on a short run today it does an odd thing, if you drive with a fully charged 12v the e won't put any charge across it, so my accessory socket voltmeter says 12.5v steady, running

After a little while it then kicks in and goes up to 14.5v which is where you would see a not clever ICE system when the car was running.

Tonight, having been charged earlier it is sat at a perfect 12.64v

Let's see tomorrow, otherwise I will start to remove fuses, the door handles have 10A each - alarming!

When the 12v is especially 'full' , you will get journeys where the charging voltage is not applied, and the car 'runs' at close to battery voltage, so the battery does not gain (nor lose significantly) any charge.

I think this happens when the temperature rises. The 12v battery is 'charged' during running or during HV charging overnight. Then the following morning, the temperature goes up, and the 12v battery goes up to about 12.85/12.9 , and I think the car senses this and says 'Im not going to charge now as the resting voltage is too high', and it runs it at 12.65ish to just take the edge off and draw out a little bit from a full/overfull 12v battery.

I'm not sure i have ever experienced issues with the interior lights, it does sound like perhaps there are door switch issues. The handle mechanism I can imagine is only 1 of the components, I believe there must be other microswitches in the door latch and interior handle assembly which could affect the operation.

When I powered my spare handle on the bench with a bench PSU at 13v , they would have a massive instantaneous/inductive current draw. Well over 3 amps for sure, big sparks (whilst I have a spare handle, I do not have a spare multiplug connector!)

[EEEE]

Noticed on a short run today it does an odd thing, if you drive with a fully charged 12v the e won't put any charge across it, so my accessory socket voltmeter says 12.5v steady, running

How long do you think it took to start charging the 12v on your short run?

I have observed an entire 30minute commute in which the 12v system is not 'charged'.

just 8 days ago:

HV charged from 12:30am to 2:40am, 12v held at 13.3v float
HV charging ends 2:40am, 12v battery now at 12.98v
12v rested/dropped to 12.86v by 6:45am
Commute started at 6:45am
Voltage dropped the first 10min to 12.61v
Voltage maintained at 12.6v until 7:17am
Commute ends, voltage slowly recovers over 10minute rest period to 12.74v

I observe this maybe once a week/10 days. I suspect this is 'correct' operation as the 12v battery is new and now oversized compared to OE (65ah Yuasa 5000 series).

The decision to charge is not based solely on the voltage of course. The negative battery terminal clamp incorporates a current meter (unsure if it is a shunt, CT or hall affect type). We only get half the picture looking at the voltage. If the battery is in good condition, we can mostly assume the expected behaviour of the battery, but a faulty battery would make interpreting the BM2 voltage graphs slightly useless.

[s2ke]

Some interesting insight here

For me, I drove 1.7 miles last night, no charge was applied (in the rain and dark), on my return journey I think it charged at the end.

It's currently getting something as the traction battery charges, it was over 13v but has now reverted to 12.58v - this is good for me as I plug in a lot

My battery has been tested so voltage is useful insight and I can see if it drops I have a drain

I think having fixed the pass handle and removed my old OBD2 device I may have solved that. Amazing to hear the draw is that high but it explains how it can go flat so fast

[londiniumperson]

Putting a BT battery monitor on

What is the make/model of your BT battery monitor.

I have just replaced a CTEK Battery Sense with a SizzApp that monitors the battery as I had a spare from another car.
Here's a summary of 3 trip made today (times from MyHonda+ app):
A - Started at 0840, parked at 0900.
B - Started at 0951, parked at 1010.
Then between 1020-1030 & 1036-1040 returned to the car and powered it on, but didn't drive anywhere.
C - Started at 1113, parked at 1119 & then drove again from 1120 until 1128.

[555djx]

2022 Advance in Crystal Black Pearl on 17's - 08/2020-Current

2015 VW Tiguan (Pure White) - 04/2018-Current
1991 Honda Beat PP1 (Festival Red) - 11/2022-Current

Have you been tweaking your signature? First line, a slight typo has slipped in.
I can’t sleep (jetlagged as just back from Australia) and catching up with recent posts.

[Hondaprone]

anyone had this dashboard warning ?

[555djx]

New battery required in keyfob.