battery musings?

[footpump]

hi all
I tend to do longer hilly trips in summer ,one of which is Watford/whippindale woods/flaunden/bovingdon open air market, which is about 25miles , 15 of which are hilly, or Watford to chipperfield hilly but slightly less miles
on the bovingdon trip 25 miles covered +5 next day on flat and ran out of battery completely.



this I would do on Carrera subway tdz2 250w cd drive 10.4ah yosepower bottle battery £160 and about 2000 miles of use.

I had a spare dolphin 09 battery 13.4ah which I fitted to subway instead of bottle battery in October but found range about 21-25 max flattish terrain.
I then purchased yosepower 17.ah dolphin battery and found range to be about 35 miles flattish terrain.
but wonder how did I get 30 miles including hilly stuff from my 10ah bottle battery and not that good from 13.4 and 17ah colder conditions.

so I refitted my original 10ah bottle battery the other day, and found I now get about 21 miles flattish terrain.
battery has been sitting around for a few months,but have recharged twice prior to a ride

10.ah charged multimeter reading 41.8v 21.6 miles now reads 34.9

so I have not ridden hilly terrain , been on the the flat but lost 9 miles?

the only real difference its been colder and windy

 

[Deleted member 4366]

Wind makes a lot of difference. I don't think cold weather makes a big difference to the battery, but it could make a big difference to your contribution. Also, your clothing is a lot heavier and less streamlined in the winter.

 

[flecc]

I don't think cold weather makes a big difference to the battery.

It's always difficult to tell on e-bikes, due to the rider contribution, but cold does seem to make a big difference to pure electric car lithium batteries.

Nissan on the 2018 new Leaf quote own ranges of 185 miles Summer and 125 miles Winter.

VW on the little e-Up model quote realistic ranges as 75 miles Summer, 50 miles Winter.

It seems they expect a third loss in cold weather.

Both use heat pumps now so not much loss due to heating
.

 

[Deleted member 4366]

It's always difficult to tell on e-bikes, due to the rider contribution, but cold does seem to make a big difference to pure electric car lithium batteries.

Nissan on the 2018 new Leaf quote own ranges of 185 miles Summer and 125 miles Winter.

VW on the little e-Up model quote realistic ranges as 75 miles Summer, 50 miles Winter.

It seems they expect a third loss in cold weather.

Both use heat pumps now so not much loss due to heating
.

They use heating systems to keep the battery at a constant temperature so that they can maintain performance figures, so battery range has little to do with ambient temperature. Instead, the heat for the battery has to come from somewhere, which can only be a wasteful source. We don't use battery heaters on ebikes.

The cabin heating might be assisted by a heat-pump, but the refrigeration unit would have to be massive to get meaningful cabin heating, and it's efficiency would drop as ambient temperature drops. On a day when ambient is 15 deg and you want cabin 20 deg, the heat pump might save you something, but it would be pretty useless once the temperature drops much below zero.

 

[flecc]

The cabin heating might be assisted by a heat-pump, but the refrigeration unit would have to be massive to get meaningful cabin heating, and it's efficiency would drop as ambient temperature drops. On a day when ambient is 15 deg and you want cabin 20 deg, the heat pump might save you something, but it would be pretty useless once the temperature drops much below zero.

You're right, their heat pumps are not very effective, nor the cabin heating overall. For that reason they rely on pre-heating, either using the built in user-preset timer, or a mobile phone app to trigger the heating on remotely.
.

 

[wheeler]

You're right, their heat pumps are not very effective, nor the cabin heating overall. For that reason they rely on pre-heating, either using the built in user-preset timer, or a mobile phone app to trigger the heating on remotely.
.

Having owned a Leaf for two years I can assure you that the cabin heating works as well as many ice cars. Along with the heat pump climate control the car has heated seats and steering wheel which all told provide a toasty experience throughout our Scottish winters.

I don't see where these cars "rely" on pre-heating, this is just a real convenience brought about by the fact that the heating works without an engine running so can be used with the car unattended.

I once had a Ford with a heated windscreen and I thought it was marvellous but it doesn't come close to comparing with coming out to the Leaf on a frosty night or morning when all the windows are clear and the cabin toasty.

wheeler

 

[flecc]

Having owned a Leaf for two years I can assure you that the cabin heating works as well as many ice cars. Along with the heat pump climate control the car has heated seats and steering wheel which all told provide a toasty experience throughout our Scottish winters.

I don't see where these cars "rely" on pre-heating, this is just a real convenience brought about by the fact that the heating works without an engine running so can be used with the car unattended.

I once had a Ford with a heated windscreen and I thought it was marvellous but it doesn't come close to comparing with coming out to the Leaf on a frosty night or morning when all the windows are clear and the cabin toasty.

wheeler

Thanks for the update Wheeler, my choice of rely wasn't the best, I was just showing that as it was from the mains when plugged in it could easily heat the car without relying on it's own resources.

There seems to be some mixed opinions though, since I've read a few moans about the effectiveness of the heat pump heating so was being cautious. I'll be able to find out for myself later once my new 2018 model arrives.
.

 

[wheeler]

They use heating systems to keep the battery at a constant temperature so that they can maintain performance figures,

The 2018 Leaf has no active battery temperature control, don't know about the VW.

wheeler.

 

[flecc]

The 2018 Leaf has no active battery temperature control, don't know about the VW.

wheeler.

Thanks, that was my understanding too from all my swatting up about it.

I didn't research the VW closely since it's current small battery is planned for replacement. VW had originally planned a progressive upgrade but it seems will now go straight to a doubling in battery capacity.

Skoda will be selling their e-Citigo version of it in 2019.
.

 

[Deleted member 4366]

The 2018 Leaf has no active battery temperature control, don't know about the VW.

wheeler.

"Cold temperatures primarily affect how quickly the energy can be taken out of the battery or put back in—that is, how much power it can deliver for acceleration, and how quickly it can be recharged. To compensate for this, automakers sometimes use an electric heater to warm up the battery. If that heater is powered by the battery itself, it uses energy that otherwise would go to propelling the car. Nissan’s Leaf is one such car."

https://www.technologyreview.com/s/522496/electric-vehicles-out-in-the-cold/

 

[wheeler]

"Cold temperatures primarily affect how quickly the energy can be taken out of the battery or put back in—that is, how much power it can deliver for acceleration, and how quickly it can be recharged. To compensate for this, automakers sometimes use an electric heater to warm up the battery. If that heater is powered by the battery itself, it uses energy that otherwise would go to propelling the car. Nissan’s Leaf is one such car."

https://www.technologyreview.com/s/522496/electric-vehicles-out-in-the-cold/

Possibly true in 2013 when the article was published and Nissan offered the battery pre-heating function on its old Leaf with the "Cold Weather Package", there's no option to spec this on the new model.

There is a battery warmer fitted to some models and this operates automatically at -17C, however this is to prevent the battery electrolyte freezing rather than improve performance, although I suppose a frozen battery means zero performance so preventing it freezing will improve performance. Sustained temperatures as low as -17C are virtually unknown in the UK.

For the UK market battery cooling is more relevant, with some reviewers of the new Leaf disappointed that Nissan hadn't included an active temperature control system similar to Tesla, BMW, and Chevy.

wheeler

 

[flecc]

"Cold temperatures primarily affect how quickly the energy can be taken out of the battery or put back in—that is, how much power it can deliver for acceleration, and how quickly it can be recharged. To compensate for this, automakers sometimes use an electric heater to warm up the battery. If that heater is powered by the battery itself, it uses energy that otherwise would go to propelling the car. Nissan’s Leaf is one such car."

https://www.technologyreview.com/s/522496/electric-vehicles-out-in-the-cold/

The new 2018 Leaf performance certainly doesn't seem to be affected, it's taken a marked step up. Previous model's 1 - 62 mph was a respectable 11.1 seconds, the new one 7.9 seconds.
.

 

[Deleted member 4366]

Whatever is or isn't in an electric car might or might not be relevant. I have a battery capacity tester and I need to test some batteries, so I'll do one at 20 deg and zero deg to find the difference. I'll let you know.

 

[bikey850]

Slightly on topic...

What is the recommended method to care for modern batteries? I have a 2018 Bosch Powerpack 500 and not sure if it's better to charge it fully, then run it to 20% charge (to condition and excercise the battery) or if better to charge each day?

A single commute (both ways) currently using 1 bar (20%) so could go 4 days without charging rather than top up every day.

I run the charger on a timer overnight so it cuts out after no more than 6 hours or so. This is more because I know it will be completed within that time as I am sure the supplier Bosch charger is smart enough not to overcharge.

What are others doing to try and care for their batters? Charge when nearly empty or top-up whenever possible?

Many thanks,

 

[flecc]

Top up since lithum types prefer that, but no need to do it after a very short run. In your case it seems first or second day would be both be suitable. Keeping the battery topped up gives the best performance from the full charge.
.

 

[Deleted member 4366]

! would go down to about 50%, then recharge fully.

 

[flecc]

Having owned a Leaf for two years I can assure you that the cabin heating works as well as many ice cars. Along with the heat pump climate control the car has heated seats and steering wheel which all told provide a toasty experience throughout our Scottish winters.

There seems to be some mixed opinions though, since I've read a few moans about the effectiveness of the heat pump heating so was being cautious. I'll be able to find out for myself later once my new 2018 model arrives.

I got my new 2018 Leaf in July but only now have low enough temperatures to comment. This morning with the outside temperature 4 degrees C and the climate control set to 21 degrees, it was very comfortable within a half mile.

So I agree and don't understand what the complaints were about, the car's heating is more than adequate with far greater comfort from the off than any i.c. car. And certainly no perceptible loss of performance with the battery at 4 degrees.
.

 

[georgehenry]

The 400wh battery on my sDuro Yamaha 2015 that I commute to work and back on is the original one and still performs almost as well as it did when new.

The bike has now covered 10190 miles. I charge the battery to full as close to departure as possible for my 14 mile cross country ride to work using 30% of the battery + or - about 5% dependent on route and conditions etc.

I charge back to full at work and use 35% to 40% on my 10 mile road ride home.

I always remove the battery from the bike and store it in a warm dry cupboard inside my house. I leave it in this cupboard at 60%/65% charge until I next need to charge it up to use. This will include wider time gaps when I am on holiday and could be up to three weeks before it next gets charged. Whatever the time gap I charge it back up to full as close to leaving on my next journey to work.

This regime seems to have kept my battery in really good condition. It is now three years and seven months old.

I think these batteries seem to prefer to be used regularly, not be regularly deeply discharged, stored inside the house not fully charged, and topped up to full before use.

My use as a regular commuter seems to fit well. I will be interested to see how long/far my battery will last/go.

The other thing about the way I use my bike is that when the capacity of my battery begins to noticeably reduce I should still have enough range left to complete my journey to work and back home again this should allow me to keep using a declining battery for quite some time before having to replace it. We will see.