Honda Insight Forum banner
81 - 91 of 91 Posts

Registered
Joined
2 Posts
Has anyone removed the duct behind the passenger seat and let the space beteewn the Ima case and panel behind the seat act as a plenum? Seems like this may allow for more airflow.
 

Engine-Off-Coast
Joined
2,114 Posts
When I get mine back I'm going to put an extra 12v fan in there and I'm going to cut a hole in the aluminum IMA compartment case and stick another fan on that hole as well. I might have them in parallel with the stock IMA fan, or I might have them wired up to a thermometer+relay device I got on ebay. After that the only thing I'll need is a decent IMA battery.
 

Registered
Joined
2 Posts
Wow that is a cool set up can you share some details of the components you used and some pics of of what is going on under the dash to get the liquid cooled by the evaporator.
 

Premium Member
Joined
3,415 Posts

Premium Member
Joined
3,415 Posts
Are you really charging your (stock?) pack at around 60 amps, close to 190V? Isn't that bad for the cells?
At sustained levels without supplemental cooling and done on a routine basis, yeah, it's potentially bad, but it's still basically ~11kW limited.

For the purposes of demonstrating the effectiveness of a cooling system, I think it's a worthwhile exercise. It's not like these cells are fragile flowers. In my experience it's accumulated abuse or chronic adverse conditions that take them out.

What I would like to see is the exercise repeated -

charge/discharge/charge.
Pull over and cut the cooling system for 5 minutes.
See what the soak temperature is. :)

That would be a really good indicator of the effectiveness of the cooling system - how much of the temperature is a function of the sensors being on the surface of the cell vs. the core temperature of the cell.

If the battery temp is a pants-s****ing 140掳F after 5 minutes - probably a really bad idea to stress the pack like that and not as effective as the initial data suggests - not because of the ineffectiveness of the cooling system, but the challenges of cooling big, fat cylinders and their s****y, s****y aerodynamics...
 

Registered
Joined
7,844 Posts
On the subject of pack cooling...

In the Insight battery space, would it be better for pack performance and longevity to have cells packed closely so each cell is more likely to be the same temperature, or packed with space for presumably more air flow between cells, better cooling, yet perhaps risk having cells at more varied temps?

I guess the assumptions are that close-packed cells will better transfer heat from one to the other and end up at closer temps; with space between cells, air flow, convection currents or whatever, introduce more opportunities for ... differential heat transfer...
 

Premium Member
Joined
3,415 Posts
On the subject of pack cooling...

In the Insight battery space, would it be better for pack performance and longevity to have cells packed closely so each cell is more likely to be the same temperature, or packed with space for presumably more air flow between cells, better cooling, yet perhaps risk having cells at more varied temps?
We may have our answer in the HCH2. The 06-08 with it's much tighter spaced sticks and offset/nested spacing is the second worst pack ever made with a 1 in 6 failure rate in 5-7 years. The 09-11 increased the spacing slightly. Worst pack ever made with a 1 in 3 failure rate in 3-4 years.

Both have substantially more cooling capability due to an absurdly powerful blower that is literally as effective as a leaf blower and consumes about 100W. I messed my kid's hair up from 10' away when I aimed it at him. "DAD! STOP IT!"

It may be an unfair comparison because I'm pretty sure those are Sanyo and not Panasonic cells (before Panasonic bought Sanyo). They may be less heat tolerant as the Sanyo cells performed wonderfully in the air-conditioned battery of the Ford Escape Hybrid (battery rarely over 100掳F).

From an aerodynamics point of view, more spacing and slower flow is better for laminar airflow around a cylinder's surface for maximum heat transfer. In that regard the puny 120mm fan of the Insight might have more potential benefit than the massive blower on the HCH1. However, in this regard, I would expect the HCH2 packs to have better cooling because the flow is deliberately interrupted and diverted through what amount to serpentine passages vs. complete cylinders.

OH THE HUMANITY! SCREW TRYING TO RECONCILE THEORY WITH REAL-WORLD!!!!!!
 

Registered
Joined
1,071 Posts
OH THE HUMANITY! SCREW TRYING TO RECONCILE THEORY WITH REAL-WORLD!!!!!!
So did you water cool your pack:D

EDIT: Nvm, not sure how missed the second head exchanger. I thought possibly you ran some kind of cooling into the packs.
 
81 - 91 of 91 Posts
Top