Ideas for better cooling the IMA battery in 2003 Honda civic hybrid.

[Matt04]

I love in a hot climate and I believe that is the reason my IMA battery fails every 2 years. To help with cooling the battery I installed 2 computer fans on the intake vent on top of the back seats. This didn't seem to help much.

Does anyone know of a better way to cool the battery in the hot summer months?

[gone-ot]

It'll kill you gas milage numbers, but keeping the A/C operating will DEFINITELY help.

Nevada isn't hotter than Arizona that I'm aware of...

[Matt04]

Originally Posted by Old Tele man

It'll kill you gas milage numbers, but keeping the A/C operating will DEFINITELY help.

Nevada isn't hotter than Arizona that I'm aware of...

I have tried that, but blasting the A/C makes the car use the battery more, thus shortening the battery life.

I believe where you love is hotter. However, I just put in new Bee max sticks 2 years ago and 9 already went bad. All the sticks in the center of the pack went bad. I believe it is because they get hotter then the sticks on the edges.

[ThermionicScott]

Originally Posted by Matt04

I believe where you love is hotter.

Sure is for me!

[vskid3]

If the battery is dying so often, you might be better off disabling the IMA and taking a slight hit on your mileage.

[Mr. Pancake]

Matt04: is the car an automatic or manual? I ask because it is possible to wire in a switch on a manual that will allow you to temporarily disable assist which would use much less of the battery = less heat build up.

[Matt04]

It's has an CVT transmission.

Also, I did try to disable the IMA system but when I did that it wouldn't charge the 12v battery at stops. After a day or two the 12v battery dies as well as the car...

I was wondering if there was a way to make the IMA battery fan turn on more frequently. Or maybe if there was a better fan that I could install.

[Daox]

I'm sure there is a way to kick the speed up on the IMA fan. There are probably several ways of doing this depending on how knowledgeable you are and how fancy you want to get.

You could fake the pack temperature sensor(s) to show that the temperature is higher than it actually is. This might double mod in that it may hopefully assist less. I'm not sure of the IMA BMS programming.

You could put a manual switch on the fan to bypass the speed controller and turn it on at full speed.

You could create your own fan controller based off of temperature readings.

You could add additional fan(s). I would highly recommend using a squirrel cage design, not an axial fan (like the computer fans). Axial fans move lots of at at low pressure differentials, but stink as soon as they come up against any pressure. Squirrel cage fans aren't quite as efficient, but they will push the air even if it gets pressurized. This is what you need and it is also what Honda uses to cool the pack most likely.

How fancy do you want to get?

[Matt04]

Thanks for all the ideas. I know basic rewiring but not too much. I would want to put in a manual switch for the current fan, but I'm unsure which wires I would need to mess with. I also have a grid charger harness and wouldn't want to mess that up. If you know how I could put in a manual switch that would be great.

I'll also look into finding a squire cage fan that will fit onto the intake vent. If I find one that fits I'll post the pics.

[fusion210]

Do you park in the sun? Tint and the custom solar cabin venting would be my #1 and #2. You may want to refocus on lowering cabin temps.

Tint is obvious, the second is not. It involves rigging fans to trunk vents so you can draw air from the cowl (or custom perhaps, like a vent in the floor you can make?) The struggle is the cost of solar panels and keeping them in sunlight which would be hampered by tint. Even factory stuff.

Even a car cover might help a lot.