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Re: keep the forum going!

Posted: Sat Nov 13, 2021 8:19 pm
by SunnySoCal
Glad to hear of all the high-mileage owners who plan on keeping the car for a long time.

I wanna keep mine as long as possible, too. So I’m keeping SOC between 30-80%

How often would you recommend charging to 100%?

Is there a benefit for battery health to charge to full on every month/quarter/etc?

Thanks in advance!

Re: keep the forum going!

Posted: Sun Nov 14, 2021 10:25 am
by f1geek
I believe charging to 100% will balance the cell voltages. Once a month or two months makes sense.

Re: keep the forum going!

Posted: Fri Jan 21, 2022 2:26 pm
by MichaelG
It is good to see owners that have a bit more mileage than the 32K that I have on my 2016. I have been monitoring the battery very closely. I arrive at capacity values two ways. I determine how much capacity the car needed to go from plugin (17%) to full charge (typically 80%). lets say 63%. I then determine how many kWh were needed on the last trip. 39 miles traveled at 3.5mi per kWh 39/3.5=11.14kWh. 11.14 / .63 = 17.69 kWh capacity. I am using Juicebox at home and they maintain fairly comprehensive website that tracks power consumption. For the same trip the Juicebox tells me that 13.144kWh passed thru the device. 13.144 / .63 = 20.863kWh. The difference can be attributed to efficiency loss during the charge cycle. I was a bit flummoxed by this initially, but a Google search tells me that 10-15% energy loss is typical. Not everything goes into the battery. Some is converted heat. The 17.7 capacity has been holding firm for about 16 months. It was at about 19.3 when I first acquired the car, but it dropped to 17.7 in about the first six months of ownership. Like I stated before. I hope that an industry pops up that installs fresh batteries into older cars. There is no reason that this car shouldn't last 300K miles if I am able to replace/renew the battery.

MichaelG
2016 e-golf

Re: keep the forum going!

Posted: Fri Jan 21, 2022 5:53 pm
by f1geek
Good first technique for pack usable capacity calculation, though you will get a more accurate value if you charge to full (top balance cells) and then drain to ~15% or less (if you feel comfortable). I do not think data from EVSE is reliable, considering unknown charging losses.

We’ll see if e-Golf pack refurbishment becomes a widespread business. I think there are already some shops that replace Leaf packs.

My car has 36,000 miles now and is holding steady around 28 to 30 kWh usable (varies a bit due to rounding errors in data I can get from car) in warm weather.