Check out the new Civic with lithium ion batteries!

[jonnyvtec]

Originally Posted by Cobb

Opps, my bad. Wonder how the extra "stick" helps with performance, fuel economy and longivity?

It lets the IMA motor produce 15kW rather than 10kW as 158v allows an appropriate current for the battery technology to supply.

[MN Driver]

Originally Posted by Cobb

Opps, my bad. Wonder how the extra "stick" helps with performance, fuel economy and longivity?

Performance - 15kw instead of 10kw, big difference there, but needed for public acceptance in a vehicle that weighs what a Civic does.

Fuel economy - With 15kw if someone uses that power, its more charge that has to be replaced back into the battery, so it is possibly worse, depends on the driver, but in most cases it would be worse for those who would use more than 10kw regularly.

Longevity - Reduced, 120 cells is already a whole bunch of cells, add 12 more and that is 132 points of failure. Considering the results when it comes to the way these batteries fail, it is better to have less since capacity, self-discharge, and internal resistance don't all degrade consistently from cell to cell, the more you have the more issues are involved.

Lithium doesn't have the varying self-discharge problem and for the same power, a third the amount of cells(or even less) could be used and they are easier to work with in terms of charging and discharging because their voltage response is more predictable. Historically lithium wouldn't last a long time before it losses capacity and with a certain number of cycles and calendar life the whole pack would be shot at about the same time. Newer lithium promises so much more and in the smaller cycles of a hybrid, it is possible that todays lithium could last far longer than any NiMh to where a 10 year 150k mile warranty would likely never be touched. Time will tell, for what its worth, Chevy Volt is aiming for EAT-PZEV for either their next model year or the year after so if they want to sell it in CARB states, they will have a 10 year 150k mile warranty. They said they will do it. If they last that long and I'm not reading of failures, confidence in electric cars and lithium hybrids will be much better. Most people who ask me questions about my 2000 Insight that is closer to 11 years old than 10 are asking questions about the battery, with lithium I think those questions would have a more confident answer. Instead I tell people how much it costs to refurbish them and that my battery is doing great.

[Cobb]

1 "stick" is 5 kilowatts? :confused

[joecvt]

Originally Posted by Cobb

1 "stick" is 5 kilowatts? :confused

It is really 2 additional "sticks"......Just the 2 sticks alone does not make up the 5 kilowatts additional.....It just makes the whole pack be able to cope with the 15 kilowatt usage a bit better. It doesn't drain the pack so quickly compared to if the Civic had the same pack as the Gen1 Insight.

Probably the same thing could be said in the opposite direction of the Gen1 vs Gen2 Insight with a reduced number of cells in the Gen2, the pack either drains more quickly and / or does not provide assist as long of time compared to the Gen1 Insight.

JoeCVT = Just your average CVT owner

[jonnyvtec]

Hybrid batterys are sized for power output not energy.

So if you move from a battery that is happy to discharge at 15C (15x capacity of 6.5A) to provide the design intention 10kW assist to a better spec that can achieve 20C and still give 10kW yet take up less space, easier to manage and lighter whilst reducing the pack cost thats what you do... infact thats what Honda did.

[02insight]

saw on honda website for the new civic hybrid specs, its using 144 volt system. I wonder what options for hacking/modifying this opens up for gen 1 insight.

[Hybrid-Battery-Repair]

Originally Posted by Cobb

Opps, my bad. Wonder how the extra "stick" helps with performance, fuel economy and longivity?

It helps with the heavier car, electric AC and electric only mode. It also makes it more susceptible to a battery imbalance.

[Hybrid-Battery-Repair]

Originally Posted by MN Driver

Lithium doesn't have the varying self-discharge problem and for the same power,

Yes it does. In fact, it's worse because you can't overcharge lithium to balance it.

What lithium packs DO have is a BMS which controls the balance of each and every cell independently.