Lifespan of the Cellmate-K9

FAQ
1

Hi Renzee,

First of all THX for your detailed answer.

Regarding your answer I’m with you that balancing every day or all the time does not make too much sense. And off course I don’t even plan to do so.

You wrote that Cellmates-K9 do not last long while balancing all the time.

I have two questions about this:

  1. How many operating hours is the Cellmate-K9 balancer designed for?
    (With fan mounted and never above 40 degrees Celsius temperature.)

  2. And if the balancer fails one day… Sh(W)ould the measurement part of the Cellmate-K9 still work ?

Regards
Benno

2

@Energywalls we moved your question to a new topic as we believe this is different from the original topic where it was first posted.

Please see the response below:

  • Assuming a 10-year life expectation (3650 days) this equates to one hour a day or up to 1000mAh balancing per day, which is far beyond the typical expectations of 20 to 50mAh per day. This target will achieve recovery of 40mA self-discharge on a single cell per day, being a damaged cell. With our balancing algorithm, it is able to do 6000mAh per day (continuous for the day).

  • For accelerated design verification testing, we tested the CellMate-K9s for five months of continuous running of multiple systems (20 weeks, 140 days and 3360 hours).

  • Whilst we are still doing this, we had a couple more systems where the K9s were removed from service and placed in a sealed container in a freezer (-20 degrees C) and then returned to forced balancing (60 degrees C) on working days to verify the freeze/thaw thermal cycling.

  • We have projects using LongMons that don’t have bonded heatsinks and are more likely to fail but have been running now for 12 years (since 2011) without incident with these typically balancing for less than 5-10mins per charge cycle.

  • We have had failed CellMate-K9s where they have been wired incorrectly and this has impacted the balancing functionality. Yet the K9 was still able to measure the voltage.
    Unfortunately, in those cases, the balancing was permanently on so the K9 module needed to be replaced.
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