Automate charging to a certain level

[daseth]

To prolong battery life i am looking to charge between 20-80%.
Can anyone suggest a way to automate charging until 80%? I keep bouncing ideas in my head, but i cannot get further than a smartplug with a timer set for the approximate time when the charge would hit 80%. Other ideas: HomeAssistant to control the smart plug. But how would HomeAssistant read the charge of the CE04 battery?
Or maybe a smartplug with an integrated meter and HomeAssistant to stop charging when current drawn is at a certain level. That would mean I would need to hope that current drawn changes when battery hits 80%, something i am not confident would actually happen.

 

[Tux]

To prolong battery life i am looking to charge between 20-80%.
Can anyone suggest a way to automate charging until 80%? I keep bouncing ideas in my head, but i cannot get further than a smartplug with a timer set for the approximate time when the charge would hit 80%. Other ideas: HomeAssistant to control the smart plug. But how would HomeAssistant read the charge of the CE04 battery?
Or maybe a smartplug with an integrated meter and HomeAssistant to stop charging when current drawn is at a certain level. That would mean I would need to hope that current drawn changes when battery hits 80%, something i am not confident would actually happen.

Firstly thats a great charging set up in your display pic.

I have the same issue as you, wanting to automate end charge at 80%. For the moment I’ve been setting a timer on my phone to go turn it off. I’m glad that the UI gives and estimate for 75%.
If you find a good solution let us know.

 

[daseth]

Nothing so far. I've also asked on a Facebook group. No ideas are being thrown, just as on this forum. So i am guessing no one knows a solution.

Does anyone have experience charging with a Smart wall box? Like the BMW smart wall box. Is the wall box aware of the charge level of the CE04?

Maybe this can be achieved with a Smart wall box that can be programmed itself. So take the problem to the wall box instead of the scooter itself.

 

[triangletom]

IMHO, it's probably a waste of time to optimize the state of charge on the BMW CE-04, as the scooter already manages spare capacity behind the scenes. The battery management unit only allows you to charge 8.5 kWh of the 8.9 kWh battery, presumably to preserve the lifetime of the battery. I figure if BMW didn't want you to charge up to 100%, they would have added a limiting option.

 

[Tux]

IMHO, it's probably a waste of time to optimize the state of charge on the BMW CE-04, as the scooter already manages spare capacity behind the scenes. The battery management unit only allows you to charge 8.5 kWh of the 8.9 kWh battery, presumably to preserve the lifetime of the battery. I figure if BMW didn't want you to charge up to 100%, they would have added a limiting option.

It wouldn't be in BMW's best interest to say "keep the charge between 20% and 80 %" as that take the usable real world range down to about 60km.

Charging to 100% wont kill the battery just speed up its degradation, an as long as the battery is still above 70% after 5 years BMW doesn't really care.

As BMW doesn't give guidance we can use proxies.
Both the BMW IX (uses the same battery), and the Nissan Leaf (air-cooled NMC): both recommend keeping the SoC charge between 20%-80% for optimal battery logevity.

Also low slow charging is better than quick charging and reducing demand on the battery in very cold and very warm conditions will also help.
I suppose it depends on how much the longevity of the battery is important to you whether it is a waste of time or not, if you have the means and inclination to upgrade often, it probably isn't worth the hassle, but if you intend to keep the bike for years and don't want to drop the cash on a new battery, it might be worth the hassle.

 

[Low On Cash]

While charging to 80-90 % is a great idea for EVs with 250-300 miles it severely limits the CE. As most know there already is a buffer so you’re never fully charging or discharging the battery. Chargers like the Juice box allow charging to any level. If you do decide to short charge, every 5th charge or so you should top it off to allow the cells to balance.

Mike

 

[Tux]

While charging to 80-90 % is a great idea for EVs with 250-300 miles it severely limits the CE. As most know there already is a buffer so you’re never fully charging or discharging the battery. Chargers like the Juice box allow charging to any level. If you do decide to short charge, every 5th charge or so you should top it off to allow the cells to balance.

Mike

I have noticed that the range estimate becomes less accurate if you don't do the full charge every now and then, also noticed ,when I have the CE 04 on a quick chgarger it looks like the amperage goes up just before it finishes, would that be the BMS balancing ?

 

[Jojo]

I like to limit routine charging to ~80-90% also. Yes, a charging limit setting would have been sensible and it annoys me that our Fiat 500e doesn't have one either! I use one of these outlet timers and with the charge rate set to 10 amps I know whatever percentage of battery I want to add I just set it for double the percentage in minutes. i.e. if I need to add 40%, I set it for 80 minutes. This is fairly accurate. Note I'm using a 240V charger and have the optional fast charging. Without fast charging I think you're limited to 8 amps which makes the maths not as simple.