Battery Management

fberube said:

Is there a way to limit the charge to a specific percentage, ex. 80%.
Or, is it possible to receive an alert indicating specific percentage of charge is reached, knowing that recharging time is longer after 80%.
Thanks

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The car allows you to charge to approx 90% (if you set the 'hilltop charging' option). The % isn't variable - you get what you get.

I don't think that you can set anything to get an alert when you reach a specific percentage of charge.

You could buy a JuicePlug from eMotorWerks, which would work on any vehicle. The software allows you to track all sorts of things, and comes with an app for your smartphone that allows you to stop charge at a particular % (and lots of other features, including utility rebates). But it costs $200.

https://emotorwerks.com/store/residential/juiceplug-a-universal-smart-ev-charging-adapter

$100 in parts of CA.

DNAinaGoodWay said:

$100 in parts of CA.

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Please add more context so I can understand your post. Thx.

SparkE said:

DNAinaGoodWay said:

$100 in parts of CA.

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Please add more context so I can understand your post. Thx.

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It's in the article you linked to:

If you are in SDG&E, PG&E, or SCE territories in California, you can get one for just $99 (less $100 rebate when you sign up for our JuicePoints rewards program).

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Hi guys
New to the forum with my 2017 Bolt EV
I come from the hybrid Honda Insight world where NIMH Battery deteriation is a huge problem

I also have played with Ford plug in hybrid battery packs which I suspect are similar chemistry nmg cells
All I have found about the Bolt cells is that they are Nickle rich lithium cell
The Ford pack as well as most lithium packs seem to have continuous voltage based BMS
This means that the cells are constantly being balanced at the cell level to a uniform voltage per cell
With a simple bypass resistor to drop the cells that are higher in voltage to a common cell voltage
The packs use a multi cell management chip set
That not only reads each cell but can activate the balancing resistors
Analog devices makes the chip set used in the Ford packs
Linear , MAxim make similar chip sets
The Ford balancing is very accurate and the cells have
Virtually no self discharge
A 340 volt pack with ~ 84 cells that was removed from a junk and sat for a year
showed less than 0.01v difference cell to cell
The balancing currents were quite small so the system seems to balance continuously
During driving or charging where high currents are flowing the balancing system can't do much so I expect the majority of the balancing takes place when the car is just sitting
Based on a battery manual lithium cells degrade when stored at high SOC and with repeated deep cycling as well as elevated temps
When frozen the ability of the lithium cells to produce current is very temperature related so driving could severely unbalance the pack as the cells try to produce the required current and warm up differently based on the position within the pack
Thus the need to keep the pack in the correct temperature zone

I use the hilltop mode which seems to get the pack to ~ 85%
I never get the pack into the very low SOC zone or empty as getting the SOC that low could over discharge a cell
Just to be clear we don't know what is really going on because there is no service manual to give us the real picture
I am not ready
To dig deeper until I have a manual in hand
Bottom line
I'm sure that Chevy has tried their best to manage the battery , so for now we can try to limit full charge and deep cycling if possible but I suggest we dont get too hung up about it until we have a few years of real world data and we use the forum to share our experiences
I love my Bolt and hope it last at least as long as my 2000 Honda Insight
Mike

fberube said:

Is there a way to limit the charge to a speficic percentage, ex. 80%.
Or, is it possible to reveice an alert indicating specific percentage of charge is reached, knowing that recharging time is longer after 80%.
Thanks

Click to expand...

Back to this user's question. A recent article by Tesla battery expert, Jeff Dahn, recommends charging the battery in an EV only to about 70% normally and only to 100% when it's needed for a long trip. Given that, and the same information I've read from other battery experts, I'm wondering if there is a way to code the Bolt to change the hill top charge option to charge to 70%. Even an alert, as suggested, would be helpful.

https://electrek.co/2017/09/01/tesla-battery-expert-recommends-daily-battery-pack-charging/

I do have a Juicebox Pro, which has many options accessible through an app, but there is no option to set the charge to a certain percentage. I'm currently charging an i3 with this EVSE, which doesn't have an option to set a maximum charge level. I also frequently charge at work, which has 2 EVSEs that are not 'smart enabled' devices.

I am the proud owner of a Chevy Bolt for one week! Love it so far. I have been reading this list serve for weeks while waiting for my Bolt's arrival. Issues related to proper battery charging seem to be all over the place. Our EV salesman at Roseville Chevrolet in St. Paul, MN, David Troy, is very knowledgeable about Bolt battery technology. I asked him when we took ownership of the Bolt if there were issues related to charging the battery that I should be aware of. He stated Chevy has designed their battery to be charged as often as I want, daily is fine and there is no decline in battery performance if I charge it fully every time, nor any risk of battery damage if it is discharge to very low status. He told me that Chevy engineers set the battery to be "fully" charged is actually 85% of full capacity and even when "discharged" it has 10% of capacity remaining. I have no way of verifying these statements but Dave is a well trained salesperson in the world of EV's.

hardy001 said:

He stated Chevy has designed their battery to be charged as often as I want, daily is fine and there is no decline in battery performance if I charge it fully every time, nor any risk of battery damage if it is discharge to very low status. He told me that Chevy engineers set the battery to be "fully" charged is actually 85% of full capacity and even when "discharged" it has 10% of capacity remaining. I have no way of verifying these statements but Dave is a well trained salesperson in the world of EV's.

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I would never trust anything a salesman says but what he claims is, at least in broad strokes, true. I wouldn't put too much stock in the actual percentages and the battery will actually degrade at least some, but it's not something you should really spend too much time worrying about, IMHO.

Sean: Are you getting a Bolt EV any time soon?

Hardy: Welcome to the forum! Enjoy your Bolt EV! I have 12,700 miles and have enjoyed every one of them! I charge every night to 100% until I read something from GM that tells me otherwise.

michaellax said:

Sean: Are you getting a Bolt EV any time soon?

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I'm getting ready to order one with the hope that I'll end up actually getting it some time in the spring. I'm kind of holding on to see if they're going to announce the 2018 models, I figure if I've waited this long I can wait a bit longer.

SeanNelson said:

michaellax said:

Sean: Are you getting a Bolt EV any time soon?

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I'm getting ready to order one with the hope that I'll end up actually getting it some time in the spring. I'm kind of holding on to see if they're going to announce the 2018 models, I figure if I've waited this long I can wait a bit longer.

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I'd be surprised if 2018 had anything substantive added to it.

Well, many Canadians have posted that if they order now, they won't get it until 2018 anyways ...

The other (possibly) good thing about waiting is that once the LEAF2 appears in your area, you might get a better price on the Bolt.

michaellax said:

SeanNelson said:

michaellax said:

Sean: Are you getting a Bolt EV any time soon?

Click to expand...

I'm getting ready to order one with the hope that I'll end up actually getting it some time in the spring. I'm kind of holding on to see if they're going to announce the 2018 models, I figure if I've waited this long I can wait a bit longer.

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I'd be surprised if 2018 had anything substantive added to it.

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Yeah, me too. Still, it seems to me that information ought to be available pretty soon, so that's why I've been waiting.

Hi. Brand new to this forum. I’ve just read through all eight pages of “Batteries and Charging.” Learned a lot. Here’s the deal:

I live in two places; Cape Cod, June through October, and just south of Tucson, end of October through end of May. So, my cars sit for long periods of time.

In AZ I have a garage. If I do go with an EV (and I like the Bolt, after researching the lot of them), I am very concerned about leaving the auto in a garage that will likely reach temperatures (from June through July at least) of over 100°!

Does this make any EV a no-go for me? At least at this stage of the technology.

Thanks,

Rich

Hunted around more and found this:

Four Weeks to 12 Months

. Discharge the high voltage battery until two or three bars remain on the battery range indicator (Battery symbol) on the instrument cluster.

. Do not plug in the charge cord.

. Remove the black negative (−) cable from the 12-volt battery and attach a trickle charger to the battery terminals or keep the 12-volt battery cables connected and trickle charge from the underhood remote positive (+) and negative (−) terminals. See Jump Starting - North America Page 295 for the location of these terminals.

Those instructions are for long term storage, but don't take into account high garage temps. If your hot location gets cold at night like many desert climates, then the car may do fine, as the mass of the pack tends to even out extremes in temperature. If the garage will be hot around the clock, though, you definitely have a problem. No one really knows how a Bolt at a low state of charge will do when the pack is kept hot for long periods.

Yes, those are my concerns as well. Although daytime "hot weather period" temps go up to over 105° at night the temperatures drop into the eighties. If I read the owner's manual correctly, a SmartCharger (already have one on each of my four cars when they sit for half a year at a time. Work great!) would go on the 12V battery.

Is the 12V used to power the temperature control unit (for the main battery) in the Bolt?

Rich

I can't answer that question, but I can say that the daytime/nighttime temps are too hot to do without battery cooling. Have you considered leaving the car plugged in, with a charge timer set to add, every day, roughly what the battery cooling will use? A PITA, but it might work if the starting state of charge was low and the timer setting erred on the side of getting some net charge added. The other option would be to air condition the garage to 80F or so.