mkhuffman
Well-Known Member
- First Name
- Mike
- Joined
- Nov 19, 2020
- Threads
- 24
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- 6,159
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- 8,130
- Location
- Virginia
- Vehicles
- 2021 MME GT, Jeep GC-L, VW Jetta
I am bringing this thread back up to the top of the active threads, because I think many new MME owners who have joined since this post have not seen this. @Administrator, this is definitely worth highlighting again.
I think this procedure should be done every 12 months to keep your LVB fully conditioned. Probably this should be done on ICE vehicles as well. In any case, if you are somewhat handy, do this every 12 months. And do this shortly after you receive your MME to ensure your LVB is ready to go.
Tonight I started the following process as @Mach-Lee described. The last time I did it was about 12 months ago. I am using an adjustable power supply, not a charger. So I am manually managing the voltage to follow the process Lee describes.
I am going to apply 14.5V to the LVB until the current drops below 1 Amp (or I am ready to go to bed) and then switch it to 13.6 V. All as Lee described below.
This is so simple, and it should be done by all of us.
"Set your supply to 14.5V at max amps and let it charge in CC (bulk stage). Check on it every hour and try to make a note of when it switches to CV at 14.5V (absorption mode). You can leave it at 14.5V timed for up to 6 hours, or monitor the current drop. When the current drops below 1A or 6 hours have elapsed, lower the voltage to 13.6V (float mode) and let it sit for as long as you can. The battery is done desulfating when the float current stops decreasing. This could take a day or several weeks. A battery in great shape will have a float current less than 0.1% of its C rating (<35 mA for the Mach-E 35 Ah battery). For comparison, I had an AGM sitting around at 75% SoC that hadnât been charged for a year or two, it took about 5 days of floating to reach a current minimum. Last little bit is very slow.
A note on temperature, the above voltages are for standard 25ÂșC/77ÂșF conditions. If itâs significantly hotter or colder than that in your garage you should adjust the voltage some. This is called temperature compensation, the adjustment constant is -0.024 V/ÂșC difference from 25ÂșC. So at 35ÂșC/95ÂșF your absorption voltage should be 14.26V. Do not exceed 15.2V in cold temps to avoid gassing. If at any time you hear high-pitched squeaking/farting noises coming from the battery, immediately reduce voltage as venting is occurring.
The below test was performed on a brand new BHAGM-H3 battery that appears to be about 6 months old, arrived at 12.83V (95% SoC). Power supply set at 13.60V, a current minimum of 14 mA was reached after about 24 hours maintenance charging as you can see below. Older or sulfated batteries will take longer than 24 hours to reach current minimum. The open circuit voltage after sitting 24 hours was 13.08V. The battery was then capacity tested and produced 43 Ah (35 Ah rated). "
I think this procedure should be done every 12 months to keep your LVB fully conditioned. Probably this should be done on ICE vehicles as well. In any case, if you are somewhat handy, do this every 12 months. And do this shortly after you receive your MME to ensure your LVB is ready to go.
Tonight I started the following process as @Mach-Lee described. The last time I did it was about 12 months ago. I am using an adjustable power supply, not a charger. So I am manually managing the voltage to follow the process Lee describes.
I am going to apply 14.5V to the LVB until the current drops below 1 Amp (or I am ready to go to bed) and then switch it to 13.6 V. All as Lee described below.
This is so simple, and it should be done by all of us.
"Set your supply to 14.5V at max amps and let it charge in CC (bulk stage). Check on it every hour and try to make a note of when it switches to CV at 14.5V (absorption mode). You can leave it at 14.5V timed for up to 6 hours, or monitor the current drop. When the current drops below 1A or 6 hours have elapsed, lower the voltage to 13.6V (float mode) and let it sit for as long as you can. The battery is done desulfating when the float current stops decreasing. This could take a day or several weeks. A battery in great shape will have a float current less than 0.1% of its C rating (<35 mA for the Mach-E 35 Ah battery). For comparison, I had an AGM sitting around at 75% SoC that hadnât been charged for a year or two, it took about 5 days of floating to reach a current minimum. Last little bit is very slow.
A note on temperature, the above voltages are for standard 25ÂșC/77ÂșF conditions. If itâs significantly hotter or colder than that in your garage you should adjust the voltage some. This is called temperature compensation, the adjustment constant is -0.024 V/ÂșC difference from 25ÂșC. So at 35ÂșC/95ÂșF your absorption voltage should be 14.26V. Do not exceed 15.2V in cold temps to avoid gassing. If at any time you hear high-pitched squeaking/farting noises coming from the battery, immediately reduce voltage as venting is occurring.
The below test was performed on a brand new BHAGM-H3 battery that appears to be about 6 months old, arrived at 12.83V (95% SoC). Power supply set at 13.60V, a current minimum of 14 mA was reached after about 24 hours maintenance charging as you can see below. Older or sulfated batteries will take longer than 24 hours to reach current minimum. The open circuit voltage after sitting 24 hours was 13.08V. The battery was then capacity tested and produced 43 Ah (35 Ah rated). "
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