This a Healthy Battery? Subpack Voltages Included!

[Artric]

Howdy,

I made a friend on the forum with a HCH1, and last night helped him pull his pack, and we put it on a grid charger for about 12 hours.

It started at 163v (from the battery), and ended up at 167v (both measured from the same source on the battery). It's pretty cold here, so the numbers seemed a little low, but not bad.

I disassembled the battery and measured subpack by subpack, then measured again to confirm no mistakes, finding all measurements within .01v of the original.

From the junction board side, read left to right and top to bottom (like a book) the voltages were as follows:

8.48
8.36
8.31
8.26
8.20
8.22

8.43
8.32
8.24
8.23
8.12
8.11
8.29

8.41
8.34
8.30
8.22
8.18
8.21
8.32

I'm sure it could benefit from cycling, especially the weaker cells - but we don't have three weeks to work on a battery.

I'll give more info later, but could anyone with experience with the subpacks give me an idea of how healthy this battery might be? I have a charger for subpacks, and I'm wondering if it'd be a good idea to "attack" those showing weaker voltages, or if they're all pretty much "in spec".

Thanks so much!

FYI: I'm not charging anything for this, it's not my new business venture, I'm not stepping on the toes of hybrid-battery-repair. Just being a nice dude.

[gderian]

My battery pack came up to 174 volts after about 18 hours of charging at 350 mA. I could not get them to 177 like Mike Dabrowski showed. Mine held 174 volts for many hours. It was 20F in my garage at the time. The cooling fan was off and the batteries never felt even warm.

I would expect those battery sticks to me more consistent than that but have no experience to know for sure.

[MN Driver]

You really can't tell battery health from the voltages at all. You would need to cycle the pack and measure capacity, which you said you do not have the time to do. ...therefore you won't have that answer. If you measure capacity you usually have to cycle multiple times to get it and also to correct some of the memory imbalance, otherwise if you don't you end up with a pack in worse shape if you cycle it in such a way without cycling it to find the max capacity.

I've got a dozen cells laying downstairs that when I measured discharge capacity to where every 6 cell stick came at different voltages and even every cell came with different voltages after each full charge and a decent wait afterwards before measuring voltage.

If this was a Lithium chemistry, things would be easier. It isn't. You aren't going to find your answer by doing what you just did. If you want to do it the right way, there are threads dating at least two years back and going father where this was being done in pretty much the same way I would do it myself. With my own equipment, I'd be spending about a month to find out.

The grid charger is really a band-aid keeping the cells charged to the top but whatever stick pair triggers the BCM that that pair of sticks is empty is going to be the one that will trigger the negative recal. So essentially its the voltage profile(trend) under load or shortly after a large amperage draw that determines the negative recal.

Determining health(the better part of my response to this thread):
You didn't even say the obvious stuff that is needed. IMHO you are better off putting this grid charged pack(assuming you grid charged it long enough to be balanced, not sure if you did), and getting it to the top once, then drive it down to the bottom of the gauge until it stops allowing assist, then going straight back to the top with charge, back to the bottom, watching for the negative recal or bottom of the gauge again. If you can run it all the way down the gauge and back without it stopping on the way down and going into a recal, I would call it healthy. ...or at least healthy enough as far as the car is concerned. In the Insight the car hits 3 bars, waits for its standard cue to be empty, then goes through the same routine as a negative recal. Not sure what the HCH1 does at the bottom but if its not getting to 1/4 of the battery gauge before it stops assisting, I'd say there is an issue.

Not sure if this was the answer you were looking for, but its my way of going about it.

[Hybrid-Battery-Repair]

Art,

Why don't you see what the numbers are tomorrow. You haven't really given it a chance to settle yet. This soon after charging, the varying voltages are directly related to the IR of each stick.

Originally Posted by Artric

Howdy,

I made a friend on the forum with a HCH1, and last night helped him pull his pack, and we put it on a grid charger for about 12 hours.

It started at 163v (from the battery), and ended up at 167v (both measured from the same source on the battery). It's pretty cold here, so the numbers seemed a little low, but not bad.

I disassembled the battery and measured subpack by subpack, then measured again to confirm no mistakes, finding all measurements within .01v of the original.

From the junction board side, read left to right and top to bottom (like a book) the voltages were as follows:

8.48
8.36
8.31
8.26
8.20
8.22

8.43
8.32
8.24
8.23
8.12
8.11
8.29

8.41
8.34
8.30
8.22
8.18
8.21
8.32

I'm sure it could benefit from cycling, especially the weaker cells - but we don't have three weeks to work on a battery.

I'll give more info later, but could anyone with experience with the subpacks give me an idea of how healthy this battery might be? I have a charger for subpacks, and I'm wondering if it'd be a good idea to "attack" those showing weaker voltages, or if they're all pretty much "in spec".

Thanks so much!

FYI: I'm not charging anything for this, it's not my new business venture, I'm not stepping on the toes of hybrid-battery-repair. Just being a nice dude.

[Hybrid-Battery-Repair]

Originally Posted by MN Driver

So essentially its the voltage profile(trend) under load or shortly after a large amperage draw that determines the negative recal.

When that trend under load is significantly different in one or more pairs of sticks, you'll trigger a P1449-74.

[Artric]

Originally Posted by Hybrid-Battery-Repair

Art,

Why don't you see what the numbers are tomorrow. You haven't really given it a chance to settle yet. This soon after charging, the varying voltages are directly related to the IR of each stick.

I wish I could, but the thing is that I don't really have that kind of time. I wasn't initially planning on doing a stick-by-stick analysis.

I'd stay longer, but my family just happens to be going through a major crisis (not going to get into the details here), and I need to get to them ASAP. If I wouldn't have found out about it right before I left, I would have put this trip off.

By the way, I think that I failed to mention that he's 445 miles north of me (where I am now), and my family is about an extra 170 miles south. Not a great situation...

At this point, I think we need to get it back in the car, reset all codes, and see what we can do with it. In a perfect world, I'd take it home with me and go through all of the bases, but that's not a realistic option.

[MN Driver]

Getting it back in the car and doing something with it when time is available will be your best bet.

[E27006]

The Amp hour capacity of each stick when measured under load of is a keystone of a healthy pack. The voltages do not have much of a tale to tell.

You need to run charge and discharge cycles at 10 amps using an intelligent charger such as a Robitronics Overloader to have those figures.

Alternatively send the pack to Ron at Hybrid battery Repair for testing/refurbishing

[Artric]

Thanks for the help guys. Just returned home from the trip at 6AM this morning - WHEW!

Anyway, as you suggested, we put the car through the paces. Previously, he was reporting that it was dropping significantly at certain points, and a bit unpredictable. But I drove it 180 miles round trip, and the discharged and charged gracefully.

I really had to work hard to get the battery down low. I mean I really had to step on it repeatedly. It would give full assist and recharge all the way back to the top.

I did run into an issue, but it was because of a stupid mistake. I did get an IMA light, as although we installed everything on the front side (the battery is located behind the back seat - far more space efficient than the Insight), we didn't reinstall the fan and ducts in the trunk. When I got out of the car, I could feel that the vents were quite hot.

It seems to be fine now, so thanks again. I obviously need to learn more about proper cycling and measurement of sticks - so time to hit the books! (After I get everything else out of the way).

[MN Driver]

Not only is it far more space efficient, it is a 20 minute removal versus the Insight's hour or more time to remove it, with most of the time being used to actually get everything out of the way covering the bolts and connectors to get the battery out.