HV Battery Calibration Procedure

[Trick.Mach-E]

I think you should definitely watch two other sensors in Car Scanner:
HVB SOC module variation %
HVB voltage module variation V

https://www.macheforum.com/site/threads/battery-health-at-143-000-miles.39942/page-2#post-866068

What's an ideal number for the SOC variation and voltage variation? Looking at Snakebitten's post this is where I am at...

HVB SOC module variation - .36% (when I first looked at this number at 100% GOM SOC it was .46%)
HVB SOC voltage module variation - .01v

Snakebitten was mostly talking about his experience with a Leaf. I wonder what range do we need to worry about as Mach-E owners...

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[Mach-Lee]

What's an ideal number for the SOC variation and voltage variation? Looking at Snakebitten's post this is where I am at...

HVB SOC module variation - .36% (when I first looked at this number at 100% GOM SOC it was .46%)
HVB SOC voltage module variation - .01v

Snakebitten was mostly talking about his experience with a Leaf. I wonder what range do we need to worry about as Mach-E owners...

"Good" numbers are:
HVB SOC module variation less than 1%
HVB SOC voltage module variation less than 0.02V

You cannot do anything about capacity variation, it will increase up as the pack ages. If the numbers are higher, it does not mean the pack is bad.

 

[Machinator]

On this step, for NCM battery,
Leave the vehicle plugged in and let the battery rest for 3+ hours after 100% is reached.
Will it hurt if one is walking around with a cell phone and PAAK is enabled?

 

[Mach-Lee]

On this step, for NCM battery,
Leave the vehicle plugged in and let the battery rest for 3+ hours after 100% is reached.
Will it hurt if one is walking around with a cell phone and PAAK is enabled?

No, not unless you are hammering it with pings and it triggers a 12V recharge. Disable Bluetooth if concerned.

 

[kens]

Try to charge to 90% each day if you have time (100% nightly on Level 2 once you have that), and try to get the battery temp above +10ºC while doing so. If temps are low, shut off HVAC while charging until it warms up.

Seeking some wisdom on how to best use my limited level two access.

I've been using the level two since Sunday, and still have access for a few more days. I'm letting it go to 100%, such as it is, I know it's not actually getting there yet.

I do see that once it hits 100% displayed it shuts charging down and doesn't seem to do much without me drawing power down again. So far I've set rolling departure times to keep pack temp up, keep the duration with power flowing in up, and hopefully encourage a few more kW to eek their way in.

Temps here will be below freezing nightly and below 10ºC all week, I'm mostly keeping the pack in range with the departure times. I've been driving as needed, but if you say it'll help to let it sit on the charger for the next few days I'll let it be and drive another car. Alternately, if it's better to draw the pack down further daily I'll take some road trips.

So, what say you Lee? Leave it on the charger for a few days, or go wandering around sightseeing? Are the rolling departure times useful to continue?

 

[Mach-Lee]

Seeking some wisdom on how to best use my limited level two access.

I've been using the level two since Sunday, and still have access for a few more days. I'm letting it go to 100%, such as it is, I know it's not actually getting there yet.

I do see that once it hits 100% displayed it shuts charging down and doesn't seem to do much without me drawing power down again. So far I've set rolling departure times to keep pack temp up, keep the duration with power flowing in up, and hopefully encourage a few more kW to eek their way in.

Temps here will be below freezing nightly and below 10ºC all week, I'm mostly keeping the pack in range with the departure times. I've been driving as needed, but if you say it'll help to let it sit on the charger for the next few days I'll let it be and drive another car. Alternately, if it's better to draw the pack down further daily I'll take some road trips.

So, what say you Lee? Leave it on the charger for a few days, or go wandering around sightseeing? Are the rolling departure times useful to continue?

I don't have any specific advice other than to plug it in every night and let it finish charge to the same level. You can still drive it.

Is the voltage module variation going down? What's it at now?

 

[kens]

I don't have any specific advice other than to plug it in every night and let it finish charge to the same level. You can still drive it.

Is the voltage module variation going down? What's it at now?

A bit, it was 5.2% and .114V, yesterday it was down to 4.12% and .09V.

 

[Mach-Lee]

A bit, it was 5.2% and .114V, yesterday it was down to 4.12% and .09V.

That’s a lot slower than I expected. Are you giving it enough “off time” to balance the cells? Car needs to sit in the off state (not charging) to balance. Normally balancing happens after charging finishes for the night.

 

[kens]

That’s a lot slower than I expected. Are you giving it enough “off time” to balance the cells? Car needs to sit in the off state (not charging) to balance. Normally balancing happens after charging finishes for the night.

Should I unplug once it stops charging?

 

[Mach-Lee]

Should I unplug once it stops charging?

That’s not necessary, it will automatically go to sleep after it’s done and start balancing.

 

[Mache_Nor]

You mention balancing Lee; is this possible to see visible somewhere or is it something we just have to know happens? I initially thought that the hour or two it takes to charge from 99-100% (at very slow speeds) was this, but seems I might have been mistaken?

 

[Mach-Lee]

You mention balancing Lee; is this possible to see visible somewhere or is it something we just have to know happens? I initially thought that the hour or two it takes to charge from 99-100% (at very slow speeds) was this, but seems I might have been mistaken?

Balancing is automatic and we can't really monitor it other than the "HVB voltage module variation" parameter in Car Scanner. It occurs during the "off period" after driving or charging, regardless of SoC. The slow charging to 100% is really a constant voltage absorption mode rather than balancing.

For example, if you drive your car down to 20% and park it, you can check the voltage variation. Then come back to it in the morning and the voltage variation will be less because it balanced overnight. You can do the same at 100% if you want a really good top balance, charge to 100%, wait overnight, then cycle the plug and charge to 100% again, wait several hours (not recommended often due to cell stress). That's the EV equivalent of "topping off".

 

[lightningguy]

Just curious- will this HVB calibration technique work on an F150 Lightning? I realize that the battery packs are slightly different (though really quite similar), but I have no idea if the BMS is similar enough?

 

[mkhuffman]

Just curious- will this HVB calibration technique work on an F150 Lightning? I realize that the battery packs are slightly different (though really quite similar), but I have no idea if the BMS is similar enough?

Yes.

 

[Mach-Lee]

Just curious- will this HVB calibration technique work on an F150 Lightning? I realize that the battery packs are slightly different (though really quite similar), but I have no idea if the BMS is similar enough?

Yup, this is pretty much a universal procedure that works with any EV.

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