Speak EV - Electric Car Forums banner

1 - 20 of 21 Posts

·
Registered
Hyundai Ioniq Electric Premium SE 2018 Black
Joined
·
62 Posts
Discussion Starter #1
Hi there, thought I would check my 12v battery's green indicator on the battery itself and it's not green ... is that a sign it's about to go? No warnings on the dash and everything seems to be working normally (no dimmed headlights etc). Will check in a bit with a multimeter but what should it show when it's all good? Cheers!
127588
 

·
Registered
Joined
·
1,543 Posts
The first sign the 12V battery is about to die is the automatic window stopping to work.
Any garage can check the battery for you and you can buy a 12V battery over the internet on sites like
 

·
Registered
Joined
·
7,460 Posts
As said above, the missing green ball is a sign of impending trouble. But not terminal. I saw the same black hole of doom early in my Leaf 24 days and soon after began to experience bizarre events such as being locked out.

Back then advice from other forum members was to use a 'smart' charger that didn't just top up the 12v battery but went into a conditioning cycle after that to balance the cells and overcome sulfidation issues. And to use that charger once per month overnight, whether it seemed to need it or not, and to leave it plugged in well beyond when it was fully charged to allow the conditioning phase to take place. The very same battery that was giving trouble then went on to be trouble-free for the rest of the 3 year PCP period.

Such 12v DC 'smart' chargers are more expensive than 'dumb' chargers, but in my case it prevented being let down by the car at inconvenient times.

If you try a search in the forum at the heading for 12v DC battery issues you will find numerous threads over the last 4 years on this very subject.
 

·
Registered
Hyundai Ioniq Electric Premium SE 2018 Black
Joined
·
62 Posts
Discussion Starter #5
Hi thanks for the advice and info! I live in North East Wales haha, I don't think I can make the trip up to Scotland but thanks anyway. I need to last until the major service in June, wonder if they replace it as part of the service? I've no idea as it's my first car and first major service at Nissan dealership hah.
 

·
Registered
Joined
·
1,543 Posts
It will not be part of the service for sure.
Either they will tell you that you need a new one and will charge you an arm and 2 legs for it or maybe you will get lucky and they will replace it if under the warranty, which I pretty much suspect they won't...
 

·
Registered
Joined
·
7,460 Posts
I need to last until the major service in June, wonder if they replace it as part of the service?
Whatever you do don't just ignore it and cross your fingers that it won't cause a problem before June. A 12v Dc battery with a low voltage can cause all kinds of problems that seem to be unrelated to that issue. At the very least beg borrow or steal a basic battery charger and get the green ball back in view or you could be stranded at a very inconvenient time and place. You might have to jog the battery violently with the heel of your hand or bounce the car on its front springs after a good period of charge to persuade the ball to come out of hiding as it can get stuck down its hidey-hole. Trust me - driving a Leaf with a low voltage 12v battery will eventually cause any one of a series of bizarre events.

If you check other threads on this topic you will realise that this isn't a 12v battery problem at all- it's an elusive issue with EVs that fails to keep that battery charged up by normal use.
 

·
Registered
Hyundai Ioniq Electric Premium SE 2018 Black
Joined
·
62 Posts
Discussion Starter #8
Whatever you do don't just ignore it and cross your fingers that it won't cause a problem before June. A 12v Dc battery with a low voltage can cause all kinds of problems that seem to be unrelated to that issue. At the very least beg borrow or steal a basic battery charger and get the green ball back in view or you could be stranded at a very inconvenient time and place. You might have to jog the battery violently with the heel of your hand or bounce the car on its front springs after a good period of charge to persuade the ball to come out of hiding as it can get stuck down its hidey-hole. Trust me - driving a Leaf with a low voltage 12v battery will eventually cause any one of a series of bizarre events.

If you check other threads on this topic you will realise that this isn't a 12v battery problem at all- it's an elusive issue with EVs that fails to keep that battery charged up by normal use.
Thank you for the advice! I managed to borrow a basic charger from a relative, I've managed to tuck it under the hood to charge over night too. Fingers crossed!

127600
127601
 

·
Registered
Hyundai Ioniq Electric Premium SE 2018 Black
Joined
·
62 Posts
Discussion Starter #9 (Edited)
After a couple of hours the green indicator has come back! And it's gotten higher on the gauge too. Will unplug after a couple more hours, then check again in the morning.
127612
127613
 

·
Registered
Joined
·
7,460 Posts
After a couple of hours the green indicator has come back! And it's gotten higher on the gauge too. Will unplug after a couple more hours, then check again in the morning.
Great. Best advice in here is to buy an ebay 12v DC meter that plugs into the ciggy lighter outlet so that you can keep an eye on the voltage in future. And if the budget runs to it buy a 'smart' charger to regularly condition the battery. The dumb charger you have used could overcharge and cause a different problem if left on too long.

As I said, this tendency for EV 12v batteries to become discharged has been a thorny problem for some years. No-one has yet been able to fully explain why this happens. It is something related to the DC to DC charge systems. They sometimes fail to click on to maintain the voltage. If it happens often it can kill the battery. Even though it should not be necessary a bit of preventative maintenance solves the issue. Watching the voltage and using a smarty once a month overnight is a small price to pay for sanity. Life's too short to stress trying to solve this conundrum.
 

·
Registered
Joined
·
1,543 Posts
Great. Best advice in here is to buy an ebay 12v DC meter that plugs into the ciggy lighter outlet so that you can keep an eye on the voltage in future. And if the budget runs to it buy a 'smart' charger to regularly condition the battery. The dumb charger you have used could overcharge and cause a different problem if left on too long.

As I said, this tendency for EV 12v batteries to become discharged has been a thorny problem for some years. No-one has yet been able to fully explain why this happens. It is something related to the DC to DC charge systems. They sometimes fail to click on to maintain the voltage. If it happens often it can kill the battery. Even though it should not be necessary a bit of preventative maintenance solves the issue. Watching the voltage and using a smarty once a month overnight is a small price to pay for sanity. Life's too short to stress trying to solve this conundrum.
Keep in mind that when you turn the car off the ciggy socket goes off too.
I bought a trickle charger for the motorbike and comes with a plug so you can have a permanent connection directly to the battery and use it when you need it.
You can find excellent chargers here
 

·
Registered
Joined
·
7,460 Posts
Keep in mind that when you turn the car off the ciggy socket goes off too.
Quite. But as it only displays when I'm driving, at least it shows the voltage being delivered to that socket which should be the same as that being applied across the battery terminals. Meaning that the car is functioning properly and charging the 12v battery much like it would if there was an alternator.

I believe that by pressing 'start' without the brake pedal the car goes into a different admin mode. Perhaps that energises the socket and shows the resting voltage before starting the car fully. I must try that next time I'm in the car because that could be a better use of the 12v meter to look for a low resting voltage.
 

·
Registered
Joined
·
7,460 Posts
There are some lead/acid battery experts in here who pass the opinion that much of the drama over 12v DC batteries in EVs is caused by the OEMs fitting the wrong type of battery. EVs do not require an ICE battery as they do not need the high power delivery to crank a reluctant diesel in winter. Apparently a better choice would be ones normally supplied to the leisure industry that are more robust at handling low power demands and can cope with periods of deeper discharge. There are some threads in here where replacement batteries have been fitted with this in mind.
 

·
Registered
Hyundai Ioniq Electric Premium SE 2018 Black
Joined
·
62 Posts
Discussion Starter #14
Just a quick update, checking my battery every day after arriving at work, and so far so good. I've never seen it so green and luminous before haha. Going to keep checking every day anyway.

127669


Something to note.

I noticed this problem just after I decided to charge the car last weekend on the EVSE charger as I had only been using rapid chargers for a few months since a new one was installed between my work and home. I charged it on the EVSE from 25% to 100% and it was left plugged in overnight.

Would that have anything to do with the 12v battery I wonder.
 

·
Registered
Joined
·
7,460 Posts
Over the years if you ask any 10 pundits you will get 12 different suggestions about the 12v DC issues. Originally it was always blamed on a bad batch of cheap batteries and dealers just replaced them under guarantee. It's still a mystery but one thing is certain. The absence of an alternator that is constantly running when an ICE is running is a huge factor. That being replaced by a system that is supposed to keep the 12v fully charged from the traction battery has an inherent flaw. One that is random. It only affects some cars - and only some cars some of the time. I just declared defeat and kept a close eye on it weekly and used a smart charger monthly. One day they will track the culprit down and fix it.
 

·
Registered
Hyundai Ioniq Electric Premium SE 2018 Black
Joined
·
62 Posts
Discussion Starter #16
Mystery solved, noticed cat hairs on the battery clamp. It's stealing some charge from the battery, god knows what for :LOL:
 

·
Registered
Hyundai Ioniq Electric Premium SE 2018 Black
Joined
·
62 Posts
Discussion Starter #18
Battery update: Checked every day and can still see the green ball indicator. I haven't used the granny charger yet but will do soon, will see if it does it again.
 

·
Registered
Ioniq 38kwh 2020
Joined
·
256 Posts
With a multimeter check the voltage after the car has been off for a couple of hours. If it reads above around 12.5v it should be fine. 12.6-12.8 v is fully charged, depending on temp and battery type.
If the voltage drops below around 12.2/12.1 for an extended period of time, that is what can kill them prematurely. That and heat.
But they are pretty small batteries, you should be able to get replacements online for under £50 easily I would have thought.
"Dumb" chargers are fine in my experience, and last a lot longer than any of the smart chargers I've had. I've got one which must be 30 years old. Obviously don't leave them connected for more than about 12hours, but they shouldn't overcharge the battery as the voltage will just level out. That's all an alternator does in reality.
 

·
Registered
Hyundai Ioniq Electric Premium SE 2018 Black
Joined
·
62 Posts
Discussion Starter #20
It's happened again! Used the granny charger to charge from 60% to 97%. Unplugged and started car, works fine. All the lights work okay, noticed the boot light which I swapped with LED light is way brighter then before.

Odd stuff! I don't have a multi meter unfortunately.
 
1 - 20 of 21 Posts
Top