Why doesn’t anyone tell you this about self charging hybrids

Herzlos

It's definitely something that should come up during the sale, in the same way diesel particulate filters should have done, because there are some use cases that just don't work for them.

Very few cars do well with sitting for 3 weeks at a time not moving, but with hybrid/electric cars it's worse because the 12v battery is smaller.

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I charge my EV 12V battery every Sunday, unless it is raining, when I do it on the next dry day. It only does a couple of sub 20 minute trips a week normally. (I charge the ICE car battery every other week, and that does around 20 miles a week too)

I reckon the EV takes at least 1AH out of the 12V battery per day just sitting around powering the keyless entry while it is waiting to be stolen, and pinging the Wifi, never mind what all the computers find to do.

I was using the optimate, but it was taking too long- around 12hours, so I bought one of the Lidl 5A smart chargers that were in a fortnight ago for £12.99, now it completes the charge in a morning.

It is a 60AH EFB battery, so it might last a month standing and be ok to start it- or it might not.........

born_again

facade said:

I charge my EV 12V battery every Sunday, unless it is raining, when I do it on the next dry day. It only does a couple of sub 20 minute trips a week normally. (I charge the ICE car battery every other week, and that does around 20 miles a week too)

I reckon the EV takes at least 1AH out of the 12V battery per day just sitting around powering the keyless entry while it is waiting to be stolen, and pinging the Wifi, never mind what all the computers find to do.

I was using the optimate, but it was taking too long- around 12hours, so I bought one of the Lidl 5A smart chargers that were in a fortnight ago for £12.99, now it completes the charge in a morning.

It is a 60AH EFB battery, so it might last a month standing and be ok to start it- or it might not.........

Your battery bms should be taking care of keeping the 12V side topped up.

On the e-niro there are 3 green lights on the dash. When middle one starts flashing, that is BMS topping up the 12V side.

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born_again said:

facade said:

I charge my EV 12V battery every Sunday, unless it is raining, when I do it on the next dry day. It only does a couple of sub 20 minute trips a week normally. (I charge the ICE car battery every other week, and that does around 20 miles a week too)

I reckon the EV takes at least 1AH out of the 12V battery per day just sitting around powering the keyless entry while it is waiting to be stolen, and pinging the Wifi, never mind what all the computers find to do.

I was using the optimate, but it was taking too long- around 12hours, so I bought one of the Lidl 5A smart chargers that were in a fortnight ago for £12.99, now it completes the charge in a morning.

It is a 60AH EFB battery, so it might last a month standing and be ok to start it- or it might not.........

Your battery bms should be taking care of keeping the 12V side topped up.

On the e-niro there are 3 green lights on the dash. When middle one starts flashing, that is BMS topping up the 12V side.

It only charges the 12V when it is switched on. Then there is a 12V converter off the 400V battery available to power the car and charge the battery, it will be fairly low power, the 12V battery is 60AH, with a high CCA to supply any high current short term loads, it only need slightly exceed the draw of the lights, heater fan and the control electronics.

Around town, with the lights on, heater fan going, heated rear window on for half the trip, bangin' tunes out of the radio and all that twiddling of the power steering I'd be surprised if the average charge was more than a couple of amps.

Probably would need at least a couple of hours running time a week to keep it fully topped up.

It does raise the battery voltage to getting on for 14V when the car is on, it was the first thing I tested.

No doubt standing around for months before I bought it killed the battery though, (EFBs don't like to be discharged below 50%- which I estimate is around 4 weeks standing), and I will need a new one shortly.

Goudy

The Yaris/Yaris Cross have something like a 35 amp 12v battery and the typical, key off idle draw from the battery will be something like 20 to 50 milliamps.

Working out power usage is from those figures is a little misleading, after left sat for a while even with that small draw, it's not longer 35 amps as some has been used and there will be inhibited circuits (circuits on a timer that stay live a few minutes after key off) that will temporary draw more power even if everything is off. 

But the main upshot, a Hybrid like the Yaris/Yaris Cross doesn't have an alternator spinning away all the time.
The electrical management system has a convertor that diverts power that is harvested under breaking or when the engine is running to the various batteries.

This system is designed for efficiency and economy, the system is looking to shuffle power to where it thinks it's needed at any given time between the two different batteries.
The newer Toyota Hybrids tend to run in electric mode more of the time, all the low gearing, the pulling away is via the electric motor.
The system probably isn't stacked in favour of the operator turning off after a few minutes, then repeating that a few times which would deplete the 12v battery and not give it chance to recharge properly.
There has to be a compromise over which battery wants what, when and that will no doubt be efficiency focused when on the road.

With this and the normal pull of milliamps when left stood for long periods and it's easy to understand why the small 12v battery suffers even though it doesn't handle the engine cranking.

From what I understand, around a third or so of those 35 amps are needed just to get the car powered up in to "Ready" mode.

The "fix" isn't just to fall back on jump starter (though that should get you going again), you'll be doing that forever as the 12v is never getting enough charge in "your" normal use and batteries just don't like being left in any state, particularly not left flat.

You need to think about adding to what it's missing out on, those regular runs long enough to recharge the 12v system with some form of trickle charger.

Or you could force the system to charge. Periodically turning on the car to "Ready" will divert some power from the traction battery to the 12v system, but it's a bit of a slow process and you'll just force the electrical management system to lean towards recharging the traction battery when you do venture out again particularly if it's been stopped with a partially charged traction battery. 
These don't utilise all of the battery, even though it says "Fully Charged" on the dash, that is only around 80% of battery capacity.
It also doesn't want to fall bellow around 40% capacity, if it gets near it'll prioritise recharging that as soon as it can.

EnPointe

this is not a Hybrid issue specifically 

 There are, and have been, various vehicles over the past  30 or so years  where  the populous at large have got used to leaving  motor vehicles for  aperiod of weeks or even months and  being able to get  and  drive away, that  fail to achieve this. 

Sometimes it's by an omission in design  i.e. fitting the smallest + lighest  battery they can get  away with for packaging reasons ( lead acid batteries  whatever their exact type are  heavy / dense objects ) , other times it's a mild 'fault' in that there is a quiescent drain on the electrical systems  and while it's only a few milliamps instanteously, over hundreds of hours  it can make a noticable difference to the Starting  battery, especially once the starting battery  gets a little bit older - as the deisgn life for conventional lead acid car batteries  is  only  really 7-10 years

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EnPointe said:

this is not a Hybrid issue specifically 

 <snip>

Exactly, I have the same issue with the ICE car. Now I don't have to toil ceaselessly every day I don't drive enough for the modern emission reducing charging system to top the battery up.

A 50mA drain is hardly anything, but is just over 1AH a day, and when you only have 50 or so to start with it doesn't take long to kill the battery by over-discharging it even if you can still just manage to start the car.

born_again

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born_again said:

facade said:

I charge my EV 12V battery every Sunday, unless it is raining, when I do it on the next dry day. It only does a couple of sub 20 minute trips a week normally. (I charge the ICE car battery every other week, and that does around 20 miles a week too)

I reckon the EV takes at least 1AH out of the 12V battery per day just sitting around powering the keyless entry while it is waiting to be stolen, and pinging the Wifi, never mind what all the computers find to do.

I was using the optimate, but it was taking too long- around 12hours, so I bought one of the Lidl 5A smart chargers that were in a fortnight ago for £12.99, now it completes the charge in a morning.

It is a 60AH EFB battery, so it might last a month standing and be ok to start it- or it might not.........

Your battery bms should be taking care of keeping the 12V side topped up.

On the e-niro there are 3 green lights on the dash. When middle one starts flashing, that is BMS topping up the 12V side.

It only charges the 12V when it is switched on. Then there is a 12V converter off the 400V battery available to power the car and charge the battery, it will be fairly low power, the 12V battery is 60AH, with a high CCA to supply any high current short term loads, it only need slightly exceed the draw of the lights, heater fan and the control electronics.

Around town, with the lights on, heater fan going, heated rear window on for half the trip, bangin' tunes out of the radio and all that twiddling of the power steering I'd be surprised if the average charge was more than a couple of amps.

Probably would need at least a couple of hours running time a week to keep it fully topped up.

It does raise the battery voltage to getting on for 14V when the car is on, it was the first thing I tested.

No doubt standing around for months before I bought it killed the battery though, (EFBs don't like to be discharged below 50%- which I estimate is around 4 weeks standing), and I will need a new one shortly.

Really?
Mine charges 12V at any point it is sensed as too low.

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born_again said:

facade said:

born_again said:

facade said:

I charge my EV 12V battery every Sunday, unless it is raining, when I do it on the next dry day. It only does a couple of sub 20 minute trips a week normally. (I charge the ICE car battery every other week, and that does around 20 miles a week too)

I reckon the EV takes at least 1AH out of the 12V battery per day just sitting around powering the keyless entry while it is waiting to be stolen, and pinging the Wifi, never mind what all the computers find to do.

I was using the optimate, but it was taking too long- around 12hours, so I bought one of the Lidl 5A smart chargers that were in a fortnight ago for £12.99, now it completes the charge in a morning.

It is a 60AH EFB battery, so it might last a month standing and be ok to start it- or it might not.........

Your battery bms should be taking care of keeping the 12V side topped up.

On the e-niro there are 3 green lights on the dash. When middle one starts flashing, that is BMS topping up the 12V side.

It only charges the 12V when it is switched on. Then there is a 12V converter off the 400V battery available to power the car and charge the battery, it will be fairly low power, the 12V battery is 60AH, with a high CCA to supply any high current short term loads, it only need slightly exceed the draw of the lights, heater fan and the control electronics.

Around town, with the lights on, heater fan going, heated rear window on for half the trip, bangin' tunes out of the radio and all that twiddling of the power steering I'd be surprised if the average charge was more than a couple of amps.

Probably would need at least a couple of hours running time a week to keep it fully topped up.

It does raise the battery voltage to getting on for 14V when the car is on, it was the first thing I tested.

No doubt standing around for months before I bought it killed the battery though, (EFBs don't like to be discharged below 50%- which I estimate is around 4 weeks standing), and I will need a new one shortly.

Really?
Mine charges 12V at any point it is sensed as too low.

Kia must be the exception, they are quite good at making EVs.

There is of course no reason for an EV not to do this, at least until the 400V battery gets down to 20% or so.

It would actually be useful, hence it isn't implemented

Goudy

facade said:

born_again said:

facade said:

I charge my EV 12V battery every Sunday, unless it is raining, when I do it on the next dry day. It only does a couple of sub 20 minute trips a week normally. (I charge the ICE car battery every other week, and that does around 20 miles a week too)

I reckon the EV takes at least 1AH out of the 12V battery per day just sitting around powering the keyless entry while it is waiting to be stolen, and pinging the Wifi, never mind what all the computers find to do.

I was using the optimate, but it was taking too long- around 12hours, so I bought one of the Lidl 5A smart chargers that were in a fortnight ago for £12.99, now it completes the charge in a morning.

It is a 60AH EFB battery, so it might last a month standing and be ok to start it- or it might not.........

Your battery bms should be taking care of keeping the 12V side topped up.

On the e-niro there are 3 green lights on the dash. When middle one starts flashing, that is BMS topping up the 12V side.

Around town, with the lights on, heater fan going, heated rear window on for half the trip, bangin' tunes out of the radio and all that twiddling of the power steering I'd be surprised if the average charge was more than a couple of amps.

Yes, things have somewhat changes with modern cars 12v demands in recent years.
My first car had three or four fuses (often wrapped in tinfoil).
My current car has so many I just couldn't count them.

Electric power steering is pretty much standard now and can have a large electrical demand.
There are a couple of cars I know that the EPAS playing up is a first sign of a weakening battery as demand can peak at up to 60 amps.
It's not uncommon either for Hybrids to have electric heater elements same as EV's.

Then packaging comes into play. Manufacturers are chasing grams when it comes to weight savings as weight spoils everything, so fitting heavy duty batteries with thick copper wires isn't part of their plan.

Also as we all know, you can just pour power into a battery like filling a petrol tank (not wanting to start a different argument), even a 12v lead acid battery takes time to put the power back in it. Whether that's driving around or on a chargers, it doesn't fill up instantly.

The battery will have a charge rate and will be governed by all sorts of things like the battery it's self, temperature and again packaging.

So todays car will likely "just have enough" to met what the manufacturer thinks is normal/average usage.
It's designed to deal with excess, so you could drive it all day no problems, but it obviously can't cope with a lack and when you cause the lack due to underuse, it's an ever decreasing circle.
You take some power out and don't fully replace it, then do it again and again and again until you don't have enough anymore.