[Wifey'sInsight]

Honda lists our battery as a 60 Cell Lithium Ion pack. Nominal Voltage for Lithium Ion Batteries is 3.6v. (Most battery manufactures use 3.7v). Fully charged a Li-Ion cell is 4.2V, soft cell cut-off is 3.2V. What does this mean:

Fully charged pack 60x4.2V= 252V
Nominal (50%) = 60x3.7V (conservative number)= 222V
Discharged (Safe) 60x 3.2V= 192V.

The reason for my nerd-ing out was to try and figure out at what voltage were our Electric Motors operating at. I'd be willing to guess that our Insights EV propulsion system is rated at somewhere around 180V.

What I find totally confusing is that the NFPA Service Manual provided by Honda states our HV system is around 270V.

I got this bug in my head when reading about battery mods done to the second Gen insight (roughly 150V system).

Basing this information on our 10-unit battery gauge, each bar represents roughly a 6V change, operating range of 252-192V. If Honda used the 3.6V nominal calculation, then soft cell cut-off = 180V, each bar represents ~7.2V.

I'm sure that I'll expand on this when I get more information.

 

[hasarad]

Found this in the emergency response guide:

"High-Voltage Lithium-Ion Battery
In addition to a 12-volt battery, the Honda Insight Hybrid has a high-voltage lithium-ion battery located in a well protected area below the rear seat. This means that the lithium-ion battery body is normally hidden from view. The battery pack is made up of 60 cells, totaling approximately 270 volts."

So, that would put the full charge at 4.5v. Maybe they are "magic cells?"

As for the the battery gauge, there could be a ton of wiggle room put in by Honda. A bottomed-out gauge would not necessarily mean soft cut-off was hit. I'd bet they'd put a small margin in.

 

[Wifey'sInsight]

Found this in the emergency response guide:

"High-Voltage Lithium-Ion Battery
In addition to a 12-volt battery, the Honda Insight Hybrid has a high-voltage lithium-ion battery located in a well protected area below the rear seat. This means that the lithium-ion battery body is normally hidden from view. The battery pack is made up of 60 cells, totaling approximately 270 volts."

So, that would put the full charge at 4.5v. Maybe they are "magic cells?"

As for the the battery gauge, there could be a ton of wiggle room put in by Honda. A bottomed-out gauge would not necessarily mean soft cut-off was hit. I'd bet they'd put a small margin in.

Correct, all of this is speculation, reinforced with my knowledge of lithium cells. And yes, the only reason I felt safe that a bottomed out gauge could be soft cell cut off is the fact that the car essentially cuts off at ~20% remaining.

I wonder if they specified 270v for first responders due to the ppe requirements of 277v vs 220v. 277v is a whole different animal than 220v.

 

[insightfully]

So, that would put the full charge at 4.5v. [270 volts divided by 60 cells.] Maybe they are "magic cells?"

It's possible that they are indeed magic (high capacity) cells:

"Li-ion with traditional cathode materials of cobalt, nickel, manganese and aluminum typically charge to 4.20V/cell. [...] high capacity Li-ion may go to 4.30V/cell and higher." (Source = https://batteryuniversity.com/learn/article/charging_lithium_ion_batteries)​

Many of the review articles also mention the 2019 Insight is rated at 1.1-1.2 kWh (versus the Clarity PHEV at 17 kWh and Clarity Electric at 25.5 kWh capacity). Is it better to think of the energy measure in power (volts) rather than energy (kWh)... or are both needed for the full picture?

 

[Wifey'sInsight]

I'm used to working with single li-ion cells (I'm sure this answer would differ for someone more electrically engineering inclined), and we always work with them in terms of state of charge, (Voltage). So short answer, it's the unit I'm most comfortable with.

Long Answer:
kWh is a tricky thing because it's a good number for comparison, but in all reality tells you very little about what's going on behind the scenes.

kWh= 1000 watts running for 1 hour.
kW= 1000 watts
watts= amperage x voltage.


Trying to decipher how much energy used by our car for one hour of use, would require quite a bit of math with unknowns to account for, for example how many amps of current does our system use under what percentage load.

I don't know the Current of our system, so the unit that makes most sense to dissect for me at this time is Power (voltage). I could figure out more if I used the horsepower conversion, to find out the wattage, leaving the variable of current. Most lithium Ion cells are rated from anywhere from 5 amps of discharge up to 30 amps continuous discharge.

 

[pasei]

Here's what the progression of battery specs look like for the Insight. The Gen3 is the first Lithium Ion HV battery:

Gen 1 (ZE1) = 1999 - 2006 = NiMH | 144v output (120 cells @ 1.2v) | 6.5 Ah capacity​

Gen 2a (ZE2) = 2009 - 2011 = NiMH | 100.8v output | 5.75 Ah capacity​

Gen 2b (ZE3) = 2011 - 2014 = NiMH | 100.8v output | 5.75 Ah capacity​

Gen 3 (ZE4) = 2019 - TBA = Li-Ion | 270v output (60 cells) | 1.1-1.2 kWh capacity​

And the current Clarity (2016 to present) for comparison. Different design intent than Insight hybrid:

Clarity PHEV = Li-Ion | 17 kWh capacity (~14 kWh usable)​

Clarity Electric = Li-Ion | 120 kW output | 25.5 kWh capacity​

Clarity Fuel Cell = Li-Ion | 346v output | 103 kW capacity​

Here are a few threads with comments on the Insight's HV battery size so far:

HV Battery too Small - HV Battery too small​

Reserve/Capacitor Idea - Almost Perfect​

Insight vs Clarity Battery - Honda President & CEO: 2-motor hybrid system coming...​

I have a question about the battery... I have back computed multiple times the HV capacity using my OBDII reader, while idling.

Example:

1% lost in 90sec @ 0.7A @ 220V ---> Capacity = 0.7*220*90*100/3600 = 0.385 kWh.

I'm often in the 0.4-0.5kWh range, which is less than half of the rated capacity. Is that normal?

 

[pasei]

I have a question about the battery... I have back computed multiple times the HV capacity using my OBDII reader, while idling.

Example:

1% lost in 90sec @ 0.7A @ 220V ---> Capacity = 0.7*220*90*100/3600 = 0.385 kWh.

I'm often in the 0.4-0.5kWh range, which is less than half of the rated capacity. Is that normal?

According to this website, the usable range of the Honda's hybrid batteries is 80%-20%. Our battery pack cannot go under 20% already based on my OBD reader, but can reach 100%, meaning there is just 20% unaccounted for. That still doesn't explain why the capacity I computed is less than half the rated capacity.

 

[yecam]

According to this website, the usable range of the Honda's hybrid batteries is 80%-20%. Our battery pack cannot go under 20% already based on my OBD reader, but can reach 100%, meaning there is just 20% unaccounted for. That still doesn't explain why the capacity I computed is less than half the rated capacity.

I noticed that the web site referenced is talking about NiMh batteries, not Lithium. (See the quote below) They are a different animal so the numbers mentioned there (20% to 80%) probably do not apply. The older Insights dating back 10 years or so used these older battery types that did not have nearly the same capacity as today's varieties of Lithium based batteries.

Eventually all batteries will fail. Hybrid Electric Vehicle (HEV) NiMh batteries have a life cycle

 

[Min Pin]

Hasarad said "As for the battery gauge, there could be a ton of wiggle room put in by Honda. A bottomed-out gauge would not necessarily mean soft cut-off was hit. I'd bet they'd put a small margin in. "
I agree, I don't think you want to discharge batteries to the cut-off voltage.

I have an E-Unicycle with a 15 cell, 820WH battery system. It uses a 76.2-volt power supply to charge its Lipo system.
So 60 cells are 4 times my E-unicycle,, 4 x 76.2 v = 268.8 V.. So, is Honda stating the maximum voltage that may appear in one of those orange-harnesses?

 

[insightfully]

Hasarad said "As for the battery gauge, there could be a ton of wiggle room put in by Honda. A bottomed-out gauge would not necessarily mean soft cut-off was hit. I'd bet they'd put a small margin in. "
I agree, I don't think you want to discharge batteries to the cut-off voltage.

I agree as well. It'd be like the 'HV battery' equivalent of the gas tank having 1.59 gallons remaining when the 0 gas bar / 0 range / refuel light appears.

 

[Min Pin]

Sorry my mistake on power supply voltage, 67.2 volt instead of 76.2 volt
67.2 volts x 4 = 268.8 volts

 

[Mobilcams]

I also believe from watching Weber Auto, most inverters raise the voltage going to the motors from the batteries especially at higher speeds - so the battery voltage is not as significant as the current the batteries are able to supply.