EV cars are thick!

I posted about my Suzuki Vitara and this behaviour a few weeks back. Lithium battery on 4 bars (of 5) but car needed a jump start.

The problem isnt that it hasnt been charged, the problem is that its passed its useby date and won't start the car.

Some EVs can charge the 12V battery from the traction battery even when shut down. Some have no way to access the traction battery when the contactor is open and so cannot charge the 12V battery.

EVs may be thick, but still more intelligent than the pricks that buy them.

In message snipped-for-privacy@4ax.com, Cursitor Doom snipped-for-privacy@notformail.com writes

Admiral Insurance now have an advert on LBC Radio (and probably elsewhere) offering cover in case (or for when?) you run out of juice, and need to be recovered. It doesn't give you much confidence, does it? [Yes - I know that the motoring organisations (AA, RAC etc) will bring a can of fuel to drivers that happen to run dry, but I've never heard of insurance being offered specifically for this service.]

No, just like petrol cars, if a car sits for an extended period, the vampire loading on the 12V will drain it. Such things as alarm systems can do that.

And you don't want to drain the traction battery trying to keep the supervisor 12V charged, because of the issues if a traction battery is drained below 0% (damage).

Every lithium battery you buy, represents maintenance responsibility. If they're allowed to drain too low, their charger will refuse to fill them again.

A BEV is not particularly a good candidate for "storage" the way some ICE vehicles were treated. It needs too much attention to be treated that way. Putting it in a shipping container for three years, would be a very bad idea. Some people have stored their posh ICE vehicles that way.

Paul

Paul snipped-for-privacy@needed.invalid wrote

But if the traction battery is used to charge the 12V battery, it will take much longer to end up with a flat 12V battery.

Trivial to stop charging the 12V battery when the traction battery gets too low.

That's a different matter.

The cost of the insurance will indicate how likely this is. It's probably an optional add-on so if the cost of the insurance is low the insurance company doesn't think the risk is high and are trading on peoples fears about range. If the cost is high it's likely to be a real risk for a fair proportion for EV drivers.

I think that they are different systems. I've heard this complaint before. Also some of my friends though driving petrol cars have those than stop the engine idling when the car stops, then starts it again, but when they had to replace its battery recently, found that its a special one for such cars and twice as expensive as the old style car battery was. Is this just a con to sell expensive batteries or is there a real difference? Brian

Some EVs *will* charge the 12V battery from the traction battery when the vehicle is not used for some time, but will stop doing so when down to a certain percentage in the traction battery, to both preserve the traction battery and retain sufficient power that after a normal 12V jump start, the car has enough range to reach a charging point.

After I had called out the AA to start my hybrid twice during the 2020 lockdowns I invested £20+ in a solar panel that is connected to the battery terminals, lies on the passenger-side dash and trickle charges the battery. Leave it connected all the time and not had a problem since.

The AA have a charger they can bring out anyway, you don't need your insurance to do that aswell.

Why doesn't it give you confidence? I've run out of petrol (in a new (to me) car which had no fuel warning light, never come across that before), and LPG on Christmas Eve in an old converted Range Rover which refused to run on petrol anymore and a lot of garages were out of LPG. Both times the AA / Greenflag appeared. Green flag with 5 litres in a jerry can, AA with a truck to take me 5 miles down the road to the next station.

Indeed, they're buying them because they're climate change alarmists. At the moment, the cost of petrol saved (minus the cost of electricity) is equal to the higher price of the car, so you save precisely nought, and have to pay for it earlier. Unless you can charge for free (there's a public car park here which does so at the council's expense, or you can wire it the wrong side of your meter). Also, there's f*ck all 2nd hand ones available yet, and since only morons buy new....

In an electric car, the little 12V battery (to run wipers, lights, stereo, and the computer which controls everything) is charged from an invertor from the 400V battery. Since people have had the 12V battery end up flat, presumably it's not doing this unless you have the keys in the "ignition". An old/dodgy battery self discharges, or you leave something draining it, but don't use the car for a while, and you end up with it flat. If the car was designed properly, this would charge up from the 400V battery even without you being present.

The other weird thing I hear is you can damage the battery or the electronics if you try to jump start someone's petrol car from it. I don't see why. I've looked them up, they tend to be 16Ah LiIon. I can jump start my car from a LiIon emergency boost pack the size of my phone. It's about 3Ah. And I doubt the invertor topping up the battery from 400V would care, all it would see is a dropped voltage on the battery and try to charge it at whatever current it's capable of. It would just think you had a low battery and not know you had someone's starter motor connected to it.

Those stupid stop start cars to save a millilitre of petrol have a larger battery and a stronger (to be used more times in it's lifetime) starter motor, and a stronger alternator to charge it more. If I'm stopped and know I'll be there for a long time, I switch off the engine. I don't want it going off just for 30 seconds at some lights to please some stupid treehugger walking past. I have a catalytic convertor, some cars even claim they clean the air so much the air coming out of the exhaust is cleaner than the air going into the engine air intake.

Schoolboy design error. Why are designers total f*****ts?

I'd find the contactor and rig something to turn it on. You could probably get a relay with a 400V coil (you can get 240V ones), and simply use it to short the contactor using the main battery to power the relay through a manual switch, and turn on whatever is required to get the 400V to 12V convertor running.

I'm surprised that a 3 Ah LiIon donor battery can start a car. Maybe it supplies just enough energy that after being connected for a few minutes, the dead car's battery is charged up just enough to turn the engine over. I doubt very much whether the 3 Ah battery will be able to supply anywhere near enough current to turn the dead car's engine on its own ;-)

My dad had a Toyota hybrid and he was always having problems with the starter-motor battery going dead. Sometimes it would only affect the alarm, so the siren would go off even though he'd correctly unlocked the car with the key (either the remote transmitter or the key in the lock). Or else if the car had been left a day or so, the battery would be too flat to start the engine, and that was a "computer says no" error - ie the logic refused to even apply any current to the starter motor, as opposed to trying to turn the motor but failing to do so at all or with enough speed for the engine to fire.

When dad had to stop driving, it so happened that mum's car (a

If it had been me. I'd have kicked up a real stink with the Toyota garage and (if that failed) Toyota head office for a car that had a serious problem (maybe something drawing more current that it should when the car is turned off) and which needed to be fixed. The garage had already replaced the 12 V battery, so it wasn't that. It was the usual "it was fine when we tested it" sort of fault.

The only reason a battery would be more expensive, is if it was a different chemistry.

When there are after-market parts for cars, there is a bit of competition on price. For a regular petrol car, I can go to the hardware store and get an automotive lead acid battery for the job. If the dealer wants too much, then the alternatives are available.

Knowing the make and model of car, would allow a search for "whining about the battery" for the car, and figuring out what type it is.

For a general article, you can try this. "battery types for start/stop" It lists AGM and EFB (Enhanced Flooded Battery, whatever that is), as the types.

Lead-acid is not known for a high number of charge-discharge cycles, so it's a bit of a weird choice. The depth of discharge in this case, probably isn't that large. It's not like each cycle is a "full recharge cycle". But even the tiny cycles add up.

You can find 4S-4P lithium iron phosphate batteries as a replacement for cars, but I have no idea how safe that is. Those might be $400 or so. If the mechanic for your car, jammed the field winding on the alternator, I expect that battery type would be in serious pain at

The AGM and EFB, they'd probably work in Siberia.

Paul

The two VW cars we have that have this feature use AGM batteries.

In fact that is precisely what does happen, essentially because of the massive surge current it can provide.

The proof of that is that you can start the car instantly the jump starter is connected, no need to wait for it to charge the 12V battery.