Has anyone noticed their BMS counting more than one cycle per day, most times in quick succession, even though the charging & discharging has been largely continues (minimal micro-cycles)? I have two Hubble AM2's and a friend another one. Two of these three batteries do this most days.

The graphs below is for two batteries in parallel. The master mostly counts 1 cycles per day, yet the slave 2 (and less often 1 or even 3!) cycles per day. I'm baffled and can only assume they aren't configured correctly. I've reached out to Hubble and am waiting their response. Curious to know if this is a somewhat isolated case(s)....?

Edited February 26, 20233 yr by tertiuscpt
title fix

I've noticed same, sometimes counting 2 cycles per day

 

50% discharge is counted as a cycle. i.e. it seems they regard the 50% discharge means a 50% charge is needed to recharge which then makes up 100% (1 cycle).
Whether that is altered/fixed with later firmware remains a mystery. Mine is on original firmware since 2021 and I got the 50% 1 cycle count when I spoke to one of their technicians around a year ago.

I don't see how 50% can be counted as one cycle. In any definition a cycle is 0-100%, in fact that is what Hubble says in their brochures, I quote:

"Cycle Life @ 1C: +/- 3000 Cycles @ 100% DOD, Above 6000 cycles @ 50% DOD"

If the pack runs into issues few years from now what will Hubble then say? "Sir you are at 3000 cycles and your warranty is no more......." If they base their argument on that measurement then the way its calculated is dishonest. I have about 4 packs of which 3 is doing this, some like the one in question increasing sometimes 3 cycles in one day, with a single charge/discharge. Micro-cycles in this regard are minimal. One pack tracks one per day, which I feel is correct.

Even their "Cycle Life and DOD" graphs depict the 3000 cycles at 100% DOD to get to 80% remaining capacity. This implies a full discharge & charge = 1 cycle.

These batteries are expensive and I think we need to have this conversions to secure our investment and avoid surprises later on.

Hi @tertiuscpt,

I agree with you the way the cycles are counted is not accurate, and the only thing they will do when you have a warranty claim, is say "Sir you reached you 3000 cycle".  I want to connect to R9 2nd Life Revov batteries via the R9 C8 Pace BMS to monitor it.  Will send you a private message on how to get it working.

I think it is important that you gather more evidence and maybe let the battery run to complete DOD a few cycles while monitoring the count.  Then do a few 50% discharge cycles like you did and send through your results.  This is more than enough evidence to start an investigation.  I can even have people in my area I know contribute and I have them monitor the same on the batteries they have.  If this is a the norm rather than the exception, we have to speak up as it is a large investment.

 

AM-2 climbs faster than ZA inflation:

Blue line is the SoC.

AM-2 averages 1.5 cycles per day

Edited March 30, 20233 yr by system32

Also seeing about 2 cycles a day on my single AM2

same here, seeing a 2cycle increase per day across all my AM2's

FWIW, with the Freedom Won battery that I have, the BMS also count the charge and discharge separate as cycles.  The principle as confirmed by FW is that the BMS count a full charge and full discharge as two cycles (15kWh in my case x 2).  For warranty purposes they take the cycle count divided by 2 divided by 0.8 (80% DoD) and that is then the cycle count they use.

13 hours ago, system32 said:

AM-2 climbs faster than ZA inflation:

Blue line is the SoC.

AM-2 averages 1.5 cycles per day

Same here, LBSA does the same, once DOD drops below 80% counts a cycle. see last 7 days.

5 hours ago, PearlJam said:

FWIW, with the Freedom Won battery that I have, the BMS also count the charge and discharge separate as cycles.  The principle as confirmed by FW is that the BMS count a full charge and full discharge as two cycles (15kWh in my case x 2).  For warranty purposes they take the cycle count divided by 2 divided by 0.8 (80% DoD) and that is then the cycle count they use.

@PearlJam, It would be nice if we can have that confirmed by the supplier in some way.  The warranty wording on my batteries does not read like this.

Thinking about the way other BMSs are also counting it twice, makes me wonder why the one battery then counts only 1cycle and the second battery 2cycles.  If it should count 2 in practise, then it should be consistent on both.

16 minutes ago, lcj said:

@PearlJam, It would be nice if we can have that confirmed by the supplier in some way.  The warranty wording on my batteries does not read like this.

Thinking about the way other BMSs are also counting it twice, makes me wonder why the one battery then counts only 1cycle and the second battery 2cycles.  If it should count 2 in practise, then it should be consistent on both.

I agree that the information is non-existent or at best vague when it gets to cycle counting in the warranty documentation.  Hence why we asked FW to confirm, which I now have in writing from FW