chargers and charging habits

[timc]

Hi Everyone,

I started driving a 2019 Bolt LT last month and have 3 questions:

1. Do there exist any level 2 chargers, other than JuiceBox and OpenEVSE, that allow the amperage to be adjusted?

2. Is there any consensus on what charging habits will maximize the battery life?

3. I've tried unsuccessfully to get "Speed Warning" off the DIC. How do I do it?

Thanks very much.

 

[xflow7]

The newer version of the ChargePoint (the Home Flex as they call it) allows variable current:

https://www.chargepoint.com/drivers/home/

It's pricey, though.

As for charging habits, I can't say comprehensively, but what I've gathered is:

1. Don't charge the battery to 100% unless leaving for/on a long trip where you really need the range (I have mine set to charge to 60% day-in/day-out)
2. Don't let the battery sit for extended periods either very full or very empty
3. Keep the car plugged in, with the charge limit set, especially in winter/summer so the battery conditioning system will kick in to keep the temp from becoming too high/low
4. Temperature-wise, excessively high temperatures will decrease capacity/life, while low temperatures will hinder performance as long as they last but don't tend to have permanent effects.

For the speed warning, If you hit the left arrow on the steering wheel and scroll down to one of the bottom menus, there's an option for Speed Warning on/off I think. If it's not honoring that, maybe theTeen Driver settings are on or something?

Dave

 

[marspilgrim]

Yeah, what xflow7 said. The general consensus on the Net has been keeping cars between 20-80% for best long term health. We don't have any 10 year old Bolts to provide us with historical data but at least it has active thermal management for peace of mind. I have a 2017 so it only has Hilltop Reserve that doesn't adjust, it's either off (so it would charge to full) or when on stops charging at 87%. I leave it on all the time when home. We got the ClipperCreek 40P because it's a great match for the car's built-in charger, and it's the car that controls how much amperage is passing into the battery. But you could get a stronger EVSE for a bit more future proofing if you change cars often but the Bolts inverter is the limiting factor.

One thing to note about the future. I am positive that utility companies will be wanting to better control home usage in the future. My house has a smart meter now but ComEd hasn't yet mentioned wanting to proactively adjust how much our home and the devices in it consume from the grid. I suspect that is coming soon so that they can better stabilize the grid and prevent local brownouts/outages. I don't know if new EVSE's will have features that let it integrate with the local power companies yet to do this but it won't be long. I see that the Bolt charging can be set to only charge at off hour rates, and we have just changed our plan from daily to hourly rates since we only charge the car overnight. Already saving a bit of money but it should help a lot more during the winter when I'll have the car plugged in every night for preconditioning.

 

[SeanNelson]

1. Do there exist any level 2 chargers, other than JuiceBox and OpenEVSE, that allow the amperage to be adjusted?

I can't speak for chargers intended to be mounted on the wall, but Tesla makes what is IMHO the best portable charger - it accepts interchangeable AC plugs and adjusts the charge rate it advertises based on the plug type. You need to buy a Tesla-to-J1772 adapter to use it, though, and that makes it expensive. Although it does give you the ability to charge from any conceivable AC plug and from Tesla Level 2 ("Destination") chargers.

 

[timc]

1. Don't charge the battery to 100% unless leaving for/on a long trip where you really need the range (I have mine set to charge to 60% day-in/day-out)
2. Don't let the battery sit for extended periods either very full or very empty
3. Keep the car plugged in, with the charge limit set, especially in winter/summer so the battery conditioning system will kick in to keep the temp from becoming too high/low

Dave

Dave, thanks for your reply.

Somewhere I read that the top and bottom "ends" of the battery are hidden from us, so we can never really charge the battery to 100% or deplete it to 0%. Do you know anything about this?

Also, I thought that the battery conditioning system would operate regardless of whether the car is plugged in. Am I mistaken?

 

[timc]

I can't speak for chargers intended to be mounted on the wall, but Tesla makes what is IMHO the best portable charger - it accepts interchangeable AC plugs and adjusts the charge rate it advertises based on the plug type. You need to buy a Tesla-to-J1772 adapter to use it, though, and that makes it expensive. Although it does give you the ability to charge from any conceivable AC plug and from Tesla Level 2 ("Destination") chargers.

Sean, thanks for your reply. Where can/should I buy this Tesla portable charger?

 

[SeanNelson]

I can't speak for chargers intended to be mounted on the wall, but Tesla makes what is IMHO the best portable charger - it accepts interchangeable AC plugs and adjusts the charge rate it advertises based on the plug type. You need to buy a Tesla-to-J1772 adapter to use it, though, and that makes it expensive. Although it does give you the ability to charge from any conceivable AC plug and from Tesla Level 2 ("Destination") chargers.

Sean, thanks for your reply. Where can/should I buy this Tesla portable charger?

I bought the Tesla charger (which they call a "UMC", or "Universal Mobile Charger") from a Tesla dealer, and the Tesla-to-J1772 adapter from this web site.

 

[timc]

If it's not honoring that, maybe theTeen Driver settings are on or something?

Dave

It's not honoring my OFF command, and I bought the car new so I don't think anyone has messed with the teen driver feature. When I go to that feature on the center screen, it asks me to set a PIN. So I'm stuck. Not only can I not turn speed warning off, but when I raise the speed warning level to 90 mph it still shows the warning regardless of speed.

 

[marspilgrim]

Yes, every vehicle I know of has the upper and lower buffer, the lower being the most important I believe I've read. So our 60 kWh battery is in fact something like 64+ and it's adjustable via software by GM. I think a recent update might have increased the buffer slightly on the Bolt, which some people could see as "degradation" due to a bit less kWh's being available for us to use as mileage.

Yes, the Bolt EV will moderate itself for protection in extreme heat and cold. But to be most effective, being plugged in at the time such as overnight in winter lets you use the utility power for that conditioning rather than consuming battery power. I installed a L2 at home just so I can precondition the cabin and have it toasty warm inside and defrosted every morning and still leave for work with a basically full battery.

Somewhere I read that the top and bottom "ends" of the battery are hidden from us, so we can never really charge the battery to 100% or deplete it to 0%. Do you know anything about this?

Also, I thought that the battery conditioning system would operate regardless of whether the car is plugged in. Am I mistaken?

 

[marspilgrim]

In case y'all haven't seen this.

https://www.torquenews.com/7893/3-takeaways-qa-chevy-bolt-ev-battery-expert

 

[JoeS]

If you're not fussy, there are plenty of low cost no-name brand EVSEs which offer both 120vac/240vac capability with various current settings up to 32A. Just google "EVSE adjustable current" in 'shopping'. Current adjustability is important when, for example, plugging into a 30A dryer outlet where the maximum steady-state current draw should not exceed 24A. Consider buying one with a NEMA 14-50 plug and make/buy a bunch of adapters for other sockets for those road trips. Just remember to never exceed 80% of an outlet's current rating.

Unless I'm in a hurry, I rarely exceed 16A on 240vac and 8A on 120vac - you never know the condition of the house wiring or outlet, and it's a good idea to touch a plug after the car has been charging for a while at an 'unknown' socket to ensure it's only mildly warm at worst.

Agree with xflow7's recommendations, I also normally charge to 60%, and I do recognize that there is a 'hidden' percentage in the Bolt's battery. For some insight, here's just one place which discusses battery longevity:
https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

BTW, you can't expect a GM battery engineer to say anything other than the party line on a public forum.

Edit 11/20/19: corrected one typo and fixed link.

 

[timc]

I also normally charge to 60%, and I do recognize that there is a 'hidden' percentage in the Bolt's battery.

If you recognize that some of the Bolt's battery is hidden, how do you know you are charging to 60%?

 

[JoeS]

I also normally charge to 60%, and I do recognize that there is a 'hidden' percentage in the Bolt's battery.

If you recognize that some of the Bolt's battery is hidden, how do you know you are charging to 60%?

Exactness doesn't much matter, as, if I understand correctly, operating the battery somewhere around its midpoint is better than at its extremes.