The MIMA pack whack could be a huge new advantage to owning MIMA for the many people struggling with limited capacity battery packs due to recalibration's.
The pack can also be balanced with the grid charger described below.
*****DANGER, THE BATTERY AND THIS PROPOSED CHARGER CAN ELECTRICUTE YOU, DO NOT ATTEMPT THIS IF YOU DO NOT HAVE THE PROPER TRAINING*****************
As many of you know, I have been using MIMA on my pack since 80K, and as I approach 180K, the pack still runs fully from top to bottom, on each cycle. Since I do not have recal's, it is something that I was not able to examine. On my trip to Hybridfest, I flew out to MI,to ride out with Ed Zandee,a very savvy auto technician who owns his own service center in Grand Rapids. Ed purchased a used 2000 Insight with 130K on the clock.Like many older Insights, he was getting a typical recal whenever his pack reached 5-6 bars from the bottom. Ed Installed a MIMA system the day before we drove the 350 miles to Madison. I drove some of the way, and got to experience recals first hand for the first time. Ed and I started to experiment and analyze what was happening. We noticed that the recal point seemed to move up the scale one bar as the pack temp increased.We also found that full regen could be applied with MIMA, even though the SOC guage was showing full and limiting the standard IMA regen.
I have since confirmed that my pack will stop MIMA charging near the top bar, so it is synchronized with the SOC display.
Most of us with MIMA will stop regen when the SOC is at the top, since we fear overcharging.
This is where we do the PackWhack.
Just let the ABC keep charging until it is limited, even though the SOC is at max.
Drain it down till no assist is available, and you have given it a stop to stop full charge.
On the way back, we again took turns driving,We decided to push past the SOC top end and using MIMA we continued to freely charge, for quite some time while the SOC was pegged at the top. A good pack will stop excepting charge from MIMA when full,even if the MIMA system request it, so this was a new experience for me.
We decided to keep jambing charge into the pack to see if it would eventually start limiting, and eventually it did, but only after putting in the approximate equivalent of charging to about 6 more bars.
We then switched on PIMA, and started running a lot of assist. We were drawing full assist for several minutes, before the SOC finally began to drop, and it dropped smoothly to the recal point, and then recalled as normal, but this time, even with no bars of SOC, we were able to draw the full 100 A of assist for several minutes as the photo above shows, until the assist finally became limited. We ran the pack through the cycle another time, with the same results.
We got back to Ed's place, feeling that the pack was outputting a lot more capacity than before.
The real surprise came the next day, when Ed brought me back to Detroit for my flight home.
The recals were gone. We cycled the pack several times, and the SOC ran from the top,right to the bottom.
Ed will do some more test runs with his Honda factory scan tool and get us more information. Making some assumptions which still need to be tested, my read of this experiment is that the SOC limits that stop normal IMA action at both ends are different that the BCM top and bottom limits which are based on actual voltage measurements on both ends.
When a pack starts having limited capacity issues due to the memory effect, the SOC in normal IMA mode will stop regen when the guage is at the top,even though the pack is really not charged fully. The MIMA forced charge is limited instead by the BCM when it determines that the battery voltage has reached the max. So this MIMA PackWhack as Ed and I began to call it, allows the pack to be fully charged past the SOC gauge limited point that the standard IMA is limited by, and is only stopped when fully charged, therefore doing the equivalent of a equalization charge on a lead acid based pack.
I suggest that any of the MIMA owners that have recals give this a try. Just stay in an ABC forced charge, or manually do regen until the charge is limited even though the SOC bars are full. Then do assist with PIMA or MIMA until it starts to be limited on the bottom end.
Do several of these cycles, then see what happens with your recals the next day.
Of course you are doing this at your own risk, as it will take some time to see if this effect is temporary.
This blog will be where we will put the results of further testing of this experimental procedure.
All recals are not the same, so this procedure is for the standard regular recal at a specific SOC that seems to be the most common.
A long time MIMA user from CT drove up on DEC 13 2008. He was getting repeated P1568 codes.(Battery Module Individual Voltage problem) If the car was allowed to sit, it would sometimes clear and things would work normally for a while. This was happening on a daily basis, sometimes more than once. We looked at all of the pin plug MIMA connections and found that they were solid and all were firmly plugged in.Wiggling the harness did not cause any issues.
Since the code would indicate that a subpack was showing a voltage match problem compared to the rest,I suggested that he try the pack whack on the way home. He did a full MIMA induced charge until limiting kicked in, then did a discharge to the bottom, then started driving normally.
He has put over 300 miles on the car since then with no further codes.The pack whack can definitely help
many problem battery packs, and for all of the MIMA owners, it is very simple to do.
This blog starts at the page bottom.