Failed to start... again

[mitchelln]

This video takes one of the latest generation units apart. Very clever stuff!

[aphybrid]

My Crosstar has been left for up to 14 days at airport with no sign of battery deterioration/difficulty to start.

Seems silly to ask but has car always been left in P mode?

Also, make sure not left in accessory mode.

I know some alarms sound for both these but sometimes if stepped out of car order of shut down can result in one of these.

[Lord Voltermore]

I think its fair to point out that  this isnt  just a problem with Honda hybrids.  Most modern cars have a host of electrical standby systems that are running 24/7 and can drain a battery surprisingly quickly  if the car is only used infrequently or for short journeys  . Computers, alarm systems, security systems, keyless entry signals etc.    EV's and hybrids are particularly vulnerable because  their 12v battery is fairly small.  But even conventional  I.C.E cars with a large 12v battery can be at risk .   

Some Hybrids have an emergency starting procedure where if the 12v battery is flat you can switch it to obtain 12volts from the High voltage battery for long enough to initiate the start up procedure   (hybrids only use their small 12v battery to initiate computer systems etc.  The engine itself  is 'cranked over' and started using their big  HV battery . But no 12v  computer, no engine starting.)  utilising the hv battery to obtain 'emergency 12volts sounds a good idea  but there may be downsides  -such as perpetually running with a faulty 12v battery and possibly putting extra strain on the HV battery, which can be permanently damaged if its ever allowed to get too flat.  (so can a 12v battery if it happens too often or for too long , but thats much cheaper to replace )

My car was once left unused and unattended between 23 january to   15 march  .(about 7 - 8 weeks )  But I  took the precaution  of fitting a solar charging panel.  The car was outside,  and even in the winter months with short days the panel produced a tiny amount of charge.  It was enough to replace   the small perpetual drain  on the battery  and the car started no problem.    It might have started  anyway without the panel.   - I will never know.   But a possible solution for those who  do few miles and cannot use a mains trickle charger . It works for a hybrid anyway.  Not sure it would give enough charge for a conventional car with a duff battery that needs to crank an engine over on  regular cold mornings.   

I dont expect to ever leave the car that long again.  But I now also have a small 'power pack' jump starter  which in an emergency should be able to boost the 12v battery enough to initiate the  start up procedure  .   But it wouldnt necessarily reverse any damage done to the 12v battery if its been left too flat  for too long. 

[nowster]

There's also the stipulation in the manual that the car should be run for at least 30 minutes every three months. Some of that will be to keep the HV battery topped up and some will be to circulate the oil around the engine a bit.

Using a trickle charger will only top up the 12V lead-acid battery, not the HV battery.

As caravan owners will know, you also want to move the car every now and then to avoid flat spots on the tyres.

[andallthatjazz]

I Have a 2020 Honda E Advance @ 14800 miles I am on my 4th 12volt battery after approx 11 flat battery call outs to Honda rescue (the AA ) I would come back to the car after 2/3 Hours and the battery would be completely flat 8/9 volts, was always told that I had left something switched on ! After a week in the dealership again Honda came up with the reason is  that if the 12 volt battery when fitted was not fully charged to 100 percent the battery would only be charged to the state of charge when it was fitted ie. if it was only 75 percent charged that's what the car would charge the battery to not to 100 percent. Could that be the case with the Jazz  I have my doubts about the this is the reason why my battery goes flat. New Honda Jazz EX Style due I approx 3 weeks time in Crystal Red

[FMIB]

I Have a 2020 Honda E Advance @ 14800 miles I am on my 4th 12volt battery after approx 11 flat battery call outs to Honda rescue (the AA ) I would come back to the car after 2/3 Hours and the battery would be completely flat 8/9 volts, was always told that I had left something switched on ! After a week in the dealership again Honda came up with the reason is  that if the 12 volt battery when fitted was not fully charged to 100 percent the battery would only be charged to the state of charge when it was fitted ie. if it was only 75 percent charged that's what the car would charge the battery to not to 100 percent. Could that be the case with the Jazz  I have my doubts about the this is the reason why my battery goes flat. New Honda Jazz EX Style due I approx 3 weeks time in Crystal Red

I also had a Honda E, for 1 year and traded it in for a Jaxx EX Style, due late November. I was well aware of the issues of flat batteries for the Honda E as well as other EV's. Luckily I never experienced any issues over the first year.
I know full EV's only charge the 12V battery under certain circumstances when charging, depending on the state of traction battery charge and charges from the traction battery when driving. For an EV, sitting in it listening to the radio, playing with the screens etc etc, will soon drain the 12V battery and in these circumstances the main power must be switched on. Not sure how the hybrid battery system works, but I would assume sitting in the car with things switched on will also quickly drain the 12V battery. Being less than 1KW, I doubt the traction battery has sufficient capacity to to top up the 12V battery, so the only option i see would be to drive or run the engine to keep the 12V battery in good order.

[5thcivic]

Haven't had a problem with the E even though it is low mileage. The consensus on the E forum is the HV battery only charges the 12V below 80% level on the HV while charging. Why it does this is unknown unless the DC converter is so efficient or fast the 12V is always charged enough by 80%.

No problem with the Jazz so far, but I do trickle them both every couple of weeks because of the low use.

[5thcivic]

p.s. for andallthat jazz,
did the new battery solve your drain? If so it's a strange software design that requires a new battery to be fully charged before fitting, otherwise the system will only charge it to its initial voltage. Sounds like typical dealer talk to me, but you never know? 

[andallthatjazz]

After honda dealership had the E for a week and the 12 volt battery went flat twice overnight. extensive checks found no problem with the car just the 12volt battery was discharging. Dealer contacted Honda and was told to fit a new 12volt fully charged battery. I have a B2B monitor fitted which shows the battery discharging down to 9 volts in a matter of minutes as I approach the car after leaving it for a few hours but I think that the workshop ignored that fact and just followed Honda advice and fit a 4th fully charged battery 2 weeks on it seems to be holding up but I'm not holding my breath. will update if any change happens, apart from this it's been a fantastic car and the range much better than I expected.

[pauly58]

After the car failing to start on the morning we were going into our dealer, it was indeed a faulty battery. Of course they didn't have one in stock, so we had to make the hour's drive each way again today to get it fitted.

It took over two hours to get it sorted but at least they washed the car & there was an update done as well.

We've three years warranty on this battery, hope it lasts longer than three months.

All this state of the art technology relying on 1950's technology.

[nowster]

All this state of the art technology relying on 1950's technology.

Try 1850s!

https://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery

"The lead–acid battery is a type of rechargeable battery first invented in 1859 by French physicist Gaston Planté."

[Lord Voltermore]

You do hear quite a few reports  of the 12v battery having to be replaced under warranty. 

Mine has always had enough charge for the start up procedure (so far)  but  if I measure its voltage after sitting idle for more than a few days (the car , not me - well yes me too )   it  often  reads just under 12 volts. 
By conventional lead acid battery wisdom this indicates it is discharged and at risk of permanent damage.

I have tried to convince myself that its ok   because its some sort of modern gel technology or some such  . 
But I'm wondering if, due to the high draw 24/7 on modern cars , some cars discharged their batteries to the point of permanent damage during the long sea voyage from Japan.   Manufacturers dont normally fit rubbish batteries as OE.   

I did notice when I had a quick look around a VW showroom,  display cars were attached to what appeared to be a permanent 12v charging circuit incorporated in the floor.  (  Not HV charging.)    Looked to be the norm rather than a periodic top up, but I may be wrong.   

 So I'm coming round again to the idea of  attaching my solar trickle charger  if I anticipate the car may not be used for a while. (its parked too far from a power source to regularly use a  smart charger)   My power pack jump starter would probably start the car in an emergency but wouldnt prevent possible  damage meantime.   

[Kremmen]

My local Honda dealer had CTEK wired in to all showroom cars.

When I visited they weren't fully connected but the orange black connector on the end of the wire coming from under bonnet was a giveaway.

If I haven't used mine for 2 weeks, not uncommon, then a full CTEK for me and never had any issues.

[Bristol_Crosstar]

I did put a trickle charger on my Crosstar last winter a couple of times when I hadn't used it much but other than that nothing and I've never had problems even when it's gone a week or more without any use. I keep mine in the garage and have the parking brake off, the interior courtesy light off and I don't lock it all to save on battery drain.

[Neil Ives]

Generally, how long should we expect a 12v battery to last;  surely five years at least?

My car is used most days. If my Jazz battery fails early I'll be looking for a free replacement.

https://www.mastervolt.com/determining-the-lifespan-of-a-battery/#:~:text=12%20Volt%20Gel%20or%20AGM,80%20%25%20of%20its%20original%20capacity.