HCH1 A123 60ah Pack Install

[retepsnikrep]

Off for a test drive now with IPU interceptor in and working.
Time to give the battery a good workout.

Installation of all the parts has turned out to be pretty neat in the end IMHO.

HCH1 Honda Civic A123 60ah Pack Install Video 13 - YouTube

HCH1 Honda Civic A123 60ah Pack Install Video 14 - YouTube

As the car SOC now goes up and down normally. I will have to manage that to get best use out of the A123 pack and avoid forced charge due to low SOC etc.

Unlike in the G1 Insight where the BCM and MCM are seperate units, you can't use the BCM interceptor to fake the SOC as you can't get to the data passing between them.

However I can use the OBDIIC&C to keep sending the reset SOC to 75% command.

I will modify the OBDIIC&C code so that when SOC is < 65% or > 80% it resets it to 75% which keeps regen functioning and avoids hidden charge kicking in etc.

[retepsnikrep]

Did 75 miles today in two hours over my hilly yorkshire moors route at 88mpg and flattened the pack.
Now on charge. It's a bit out of balance so need to set a balancing charge overnight.

Pack temp was about 8C when I set off and is now 12C. I don't think heating or cooling will be an issue as the cells are hardly stressed at all and my max assist is currently ~57A. That might not sound much but you have to remember 57A x 180v under load = 10kw+
So each 20ah cell in each 3 cell group is seeing less than 1C discharge at the moment.
For comparison the cells in my G1 A123 conversion see upto 120A which is 6C.

No surprise the packs are a bit wayward as they were all bought from the far east with no history or warranty. I can swap them about if needed with the two others packs I have and find the best two out of the four. Lots of tinkering/tidying up to do but the main thing was no errors or issues and regen worked as required.

Jobs List.

1) Sort out the OBDIIC&C for the HCH1 now to get the auto Soc reset written and get Ah counting working so I can check the pack capacity.

2) Change voltage pot on resistor fooler board to get larger range of adjustment.

3) Install the Zivan charger remote tri colour Led so i can see what it is doing once I have the seats all back in.

4) Sort out the cooling air exit vent to ensure charger exhausts correctly.

5) Sort out the BMS pwm voltage control of the charger.

etc etc

[samwichse]

Looks amazing!

The HCH1 computers don't barf at the differing voltages being told to them?

Also: You deserve an award for cleanest use of zip ties in your Zivan install.

Sam

[retepsnikrep]

Originally Posted by samwichse

The HCH1 computers don't barf at the differing voltages being told to them?

The voltages are the same, as both the resistor fooler and the IPU interceptor are adjusted to match each other.
The whole point is to keep them matched but at a lower value than the actual battery voltage!

The interceptor etc would not be needed if I had opted for less cells but I was stuck with the A123 packs 28S x 2 = 56 in series.

The Charger is actually bolted in I need to get rid of the zip ties

Edit

Pack absorbed 6.5kwh before BMS tripped out as one cell group had reached maximum 3.65v.
Now on 250ma overnight balancing charge, might have to bring the weak cell group back in line manually.
Should be able to put 4ah into the weak groups overnight will see how that looks in the morning.

[retepsnikrep]

Should have done this before but I'm now testing my spare packs so I can eventually match them and select the best two out of four for use in the car.

HCH1 Honda Civic A123 60ah Pack Install Video 15 - YouTube

Edit

First three cell groups all just over 52Ah Capacity between 3.5V & 2.7V at 60A load.
At a more reasonable 20A load that would possibly equate to 55ah+

Interstingly as the test progresses along the block the next group is slightly higher Ah than the previous. probably because the cells have been warmed by the heating of the previous cells in the block under test and so are slightly more effcient The whole block was at 6C to start off with and the third cell group is at around 15C after test has finished. This will be warming the fourth block about to undergo the test.

I won't be losing much sleep so long as the groups are within a couple of ah of each other

[retepsnikrep]

Cell group testing still progressing done 10 now in the first block all over 50ah capacity at 60A load and freezing here last night, so testing affected slightly by the temps of cells when load first applied

Car now on 250ma balancing charge for next 24hrs to see how far that brings up the lower voltage cells in the two installed packs.

I also added some code to my mini BMS Master to scroll through all the cell groups and display the voltages on command.
All are pretty well in balance apart from group 43 & 44 which are lower.

If the balancing charge, which will put in 2-3ah overnight, does not pull them up i will remove the battery cover and manually balance them directly with my little high current charger. Once in line then we can start proper road testing. Also written to my insurance to inform them about the mods.

[aisbell]

Originally Posted by retepsnikrep

Also written to my insurance to inform them about the mods.

If they're anything like American insurers, they were probably thrilled to learn of your modifications

[retepsnikrep]

Touch wood I didn't have too much bother when i informed them about the Grey A123 car mods. These are virtually the same and it's on the same policy.

The overnight grid balancing charge pulled all the cell groups into line except two which are low 44 & 45. So they are now on direct 20A charge (one at a time) with my little high current charger. Once they are back in line be interesting to see how long/if they take to drift off and if the BMS can keep them in line. Also be interesting to see how pack performs with full pack and balanced cells. Cold here though -2C last night

Half way through the first spare block now in the bench capacity testing all around 52ah at 60A load.

[retepsnikrep]

After some more testing I think cell group 44 in my second block in the car has a duff cell and it's capacity is about 2/3rds of the others. Anyway still plodding through testing one of the other blocks. I'll swap in a different one tomorrow I think.

Changed the pot on my BCM fooler matrix from 20k to 100K so I can increase the range of voltages seen by the car. Gives me much more flexibility for the voltage power mods.

I might build a special BCM fooler that also incorporates a relay so I can have a max ima mode activated by full throttle to fake 120-125V when max power is requested. This will work in conjunction with the IPU IGBT interceptor so both fake the low voltage at the same time.

The special circuit will be another 12F683 pic which sits watching the MOTA line in the IPU compartment, when it detects a max assist request it commands the IPU interceptor and BCM fooler to change the voltage to the low one which causes a corresponding increase in system current. When the max assist request ends the system returns to normal.

[retepsnikrep]

Nearly finished the block testing so will swap a better one into the car tomorrow with luck. I'll check the dodgy cell group in more detail once i have the weak block on the bench. Might split the pack and remove the bad cell, replace it with one of my spares (solder it in) and strap it back up again.

I've closed up the IPU put the seats back in the car and tidied it up as need to use it soon and lots of stuff going on in next few weeks. Seems to work pretty well. Lot's of potential for more tweaking over the summer. Just need to use it now.