Honda Insight Forum banner

41 - 52 of 52 Posts

·
Administrator
Joined
·
12,445 Posts
If your pack if not a complete basket case with duff cells, it will perform better after some hard use.
The chemicals wake up, it gets warmer so you have less internal resistance etc

Like us it gets lazy and weak sat around most of the time on the couch watching daytime TV and snacking.
But you put it on a treadmill for a bit and a sensible diet of electrons and it gains strength and endurance.

OK forgive the dietary analogy but that's the bottom line.
It sounds like your pack is not as bad as first thought.

Some sensible grid charging and cycling will likely improve it further so I suggest follow EQ1's regime.
The OBDIIC&C will allow you to keep an eye on what is going like the calorie counter on that gym equipment.
 

·
Registered
Joined
·
36 Posts
Discussion Starter #42
So a question Peter while you're here...I set the SoC on the OBDIIC&C at different points; first at 75% so I would prevent overcharging, then just to see what would happen to 60 and finally 40% while driving today, and in these cases I was looking for the ASST to keep functioning as normal and the CHARGE to slow or cease to allow the SoC to drop to 60 or 40%. But things kept on functioning as before, with the SoC increasing back to the 70% range. Why would the SoC limit not be kept?
 

·
Registered
Joined
·
36 Posts
Discussion Starter #43
PS, I did put the pack on the treadmill today! These big hills are challenging to manage with this car, but it's kinda fun. I even drove for a bit in leanburn. In general aviation that is called "leaning past the peak", where we lean based on EGT. Most pilots still will stay rich of peak, but the new technology shows leaning a bit lean of peak saves fuel and doesn't effect power, and won't detonate the fuel and blow a hole in your piston!
 

·
Registered
Joined
·
7,193 Posts
The OBDIIC&C SoC reset doesn't hold the state of charge at whatever you reset to, it simply resets it to that level at that point in time. SoC movement will continue normally thereafter, moving up or down depending on regen and assist usage...

Re. your post a few up: Like Peter said, sounds like your pack isn't as bad as thought, sounds likes it's actually working.

I don't see what swapping MCMs would do, but maybe 'something' about that could have changed operation... Or maybe it was reset since it was powered down, don't recall if you ever did any resets with your computers...

In any event, take some tap voltage measurements at some point. If it were me I'd pull the #18 fuse underdash or the 12V neg to reset all the computers, charge the pack up via long drive or just sitting there holding RPM above 3000 until the BAT gauge reaches 19 bars (or your OBDIIC&C reads 75% or 80%), then drive for some days and see how things go. At the end of all that you might try to drain the pack to neg recal as we talked about and measure tap voltages.

But, if you're not having problems, might be better to do nothing.
 

·
Administrator
Joined
·
12,445 Posts
The OBDIIC&C SoC reset doesn't hold the state of charge at whatever you reset to, it simply resets it to that level at that point in time. SoC movement will continue normally thereafter, moving up or down depending on regen and assist usage...

But, if you're not having problems, might be better to do nothing.
As EQ1 says the SOC setting is not a limit.
 

·
Registered
Joined
·
36 Posts
Discussion Starter #46
OK guys, thanks for the clarification. FYI eq1 I did do those things today before I drove off...fuse, and 12V neg. I will continue my exploration of this neat little car and stay in touch..Thanks!
 

·
Registered
Joined
·
36 Posts
Discussion Starter #47
Before I put the battery pack cover on I made some measurements. I think I read that you guys just want the 10 pack measurements without the A-B, C-D, etc:
Unloaded, breaker on:
16.8
16.23
16.2
16.16
16.22
16.28
16.26
16.25
16.21
16.22

Loaded using the Prolong discharger
Beginning load 160V 1.55A
16
16.02
15.96
15.9
15.93
15.98
15.95
15.93
15.87
15.86
Ending load 157V 1.568A (took <10min)
 

·
Registered
Joined
·
7,193 Posts
^ That first "16.8" must be a typo, right? Other than that, nothing majorly untoward...
 

·
Registered
Joined
·
7,193 Posts
If your pack if not a complete basket case with duff cells, it will perform better after some hard use. The chemicals wake up, it gets warmer so you have less internal resistance etc. Like us it gets lazy and weak sat around most of the time on the couch watching daytime TV and snacking. But you put it on a treadmill for a bit and a sensible diet of electrons and it gains strength and endurance....
In case someone were wanting a...more technically-oriented explanation of this, I happened to come across a passage from an old thread (the 'Tinkering' thread) that describes probably the most important way our cells 'get lazy'. It's a pretty excellent explanation:

"Chemically, active stuff is the same or very similar to crud. The bottom end crud is either β-NiOOH in large crystals, or γ-NiOOH. The top end crud is either β-Ni(OH)2 in large crystals, or amorphous Ni(OH)2. Small crystalline stuff is good stuff: it has large surface area. This is a very important point because chemical reactions during charge and discharge occur exclusively on the surface of the crystals. In order for chemical reaction to proceed to the inner layers of a crystal, the outer layers must have reacted first.

Due to their large surface area, small crystals support high rates of chemical reactions, which translates into the possibility of high charge and discharge currents. Large crystals undergo exactly the same chemical reactions, but because their surface area is small, they can only support low currents, and at such low currents, long periods of time are needed to dissolve these large crystals...

Now how the crud is formed. Ever watched crystallization of common salt? If saturated solution of NaCl is poured into a jar and water is allowed to slowly evaporate, crystallization begins, and if the jar is left undisturbed, large cubic crystals are formed. "Undisturbed" is key to obtaining large crystals. Crystallization can be done fast, for example, by quickly pouring an equal volume of alcohol into the saturated solution. In this case, the crystals formed will be small.

In a battery, "undisturbed" is "not being cycled". If the NiOOH or Ni(OH)2 crystals were all of exactly the same size, all the crystals would be uniformly used during partial charges and discharges, and there would be no problem of crud. However, in reality some crystals are inevitably larger than others, and these larger crystals become the ones that act as crystallization centers which nucleate growth during the course of shallow charge-discharge cycles. If shallow cycling continues, it is a matter of time when these crystals grow to the point of becoming crud."


Here's a link to about where this passage is in that thread: Tinkering with a "non-working" IMA battery
 

·
Registered
Joined
·
36 Posts
Discussion Starter #50
That is really fascinating eq1, thanks for folding in the science to this discussion. I've been driving up to Pahoa daily, an approximate 7 mile one way drive, the first 5 up hill from 300 ft to 1000. Today I drove up aggressively, and I must say this car really can generate some power when pushed. Started at my driveway with about 65% Soc according to the OBDIIC&C. At the top I was reading about 40%. Driving into Pahoa is a slight downhill 2 miles 1000 to 800, so I got a bit of regen, SoC up to around 45%. In town the pack was reading less than 140V and I became a bit concerned. On the way back I used a bit more SoC, but going down the long hill I used the brake and the OBDIIC&C joystick regen as well and ended up back at my driveway ad 78% SoC Bv of 160. Pretty neat!
 

·
Registered
Joined
·
7,193 Posts
...In town the pack was reading less than 140V and I became a bit concerned.
Is that an assist-loaded voltage or 'resting' voltage? At first I thought you were implying resting, but now not sure. If resting, that shouldn't be possible - without causing an IMA light - so if it is resting, something might be off with whatever OBDIIC&C parameter you're looking at... Actually, your last 160V value at 78% SoC seems too low, too. It should be more like 165-168V. Different BCMs can have different voltages. One of my BCMs reports voltage low by about 2-3V...
 

·
Registered
Joined
·
36 Posts
Discussion Starter #52
That was an assist loaded voltage, and it came back when resting, I'm not sure to what level. I'm going to try to be more exact with these observations, and as you reminded me, whether assist loaded or resting. I did observe that the voltage seemed to bounce back when I parked.
 
41 - 52 of 52 Posts
Top