Calpod IMA disable... impact on battery life?

[RobertSmalls]

I'm using Calpod's clutch switch method of disabling the IMA. IMA assist and regen are disabled when the toggle switch on my dashboard is closed. I pretty much leave the toggle switch closed except when I have an opportunity for regenerative braking, and I very rarely use assist. Note that I'm disabling the three bars of "background charging" as well. After a week of mostly expressway commuting, my SOC is down from 3/4 to 1/2.

Should I stay the course and wait for forced charge to kick in at three bars SOC, or should I let it do background charging on the way to work tomorrow?

Will this usage profile prolong or shorten the life of my IMA battery? Any recommendations?

My battery is out of warranty (salvage vehicle) and isn't in great health (sat for ~9mo without being used). It does occasional forced recal, and I believe its rate of self-discharge is high. I'm planning on rebuilding it, eventually.

[Cobb]

Are you near Staten Island? That is where the hybrid battery rebuild battery guy lives. Maybe he can give you a deal or something?

In general, I cant see keeping em charged causing any problems.

Wondering whats your mpg without ima?

[3-Wheeler]

Originally Posted by RobertSmalls

Should I stay the course and wait for forced charge to kick in at three bars SOC, or should I let it do background charging on the way to work tomorrow?

Hi Robert,

I have been using the IMA disable since about the fourth week of owning the car that was purchased in March of 09.

I typically drive with the IMA disabled for about 90% of my driving, but put the battery into use when slowing and accelerating. A typical slow-down/start-up would be as follows:

1) Approaching stop sign from about 1/2 mile away
2) Flip on IMA enable
3) With car in fifth and off the gas, allow regen into battery
4) At close to 30 mph, slowly shift from fifth to third and regen some more. This usually requires a tap on the accelerator to initiate the regen.
5) When regen quits at about 20mph or so, do not push in clutch, but simply allow engine to spin. This keeps the fuel injectors off longer. About the same as a FAS. The car typically FAS's below about 14mph on mine.
6) Pop in the clutch and brake
7) Check road conditions and pull out in first with IMA disabled
Shift to second and enable IMA
9) Shift to remaining gears and keep IMA disabled

If this sequence is done correctly, then I typically maintain the SOC about 75% at all times, and rarely get below this, unless by intention. So I typically do not have to back ground charge the battery.

So far, there are no issues with the battery.

Hope this helps, Jim.

[RobertSmalls]

~60mpg without much IMA. I've had the car on the road for two weeks now, and I'm sure that number will improve with modifications to the car and driver.

I'm 300 miles from NYC. I may end up contacting Hybrid-Battery-Repair eventually, but I was hoping to repair the battery myself.

When I see a light that will be red when I arrive, sometimes I don't bother with Regen at all: I'll shift to N well in advance, and try to coast down to about 15mph before hitting the friction brakes. This should be done with the engine off, but I haven't built a FAS button yet.

Other times, especially in traffic and on the expressway, I'll hold my speed as long as I can, then enable the IMA and hit the brake lights. That causes regen until I'm going 30mph, at which point I shift to N, hit the friction brakes, wait for the auto stop (20mph), then throw the IMA disable switch. If I had extra SOC, I'd probably use some Assist in second gear, but I don't often find myself in that situation.

I'll have to add #5 to my driving style until I have a FAS switch; I had overlooked that one.

But here's a specific question: With what SOC is it best to park the Insight, for best battery life?

[3-Wheeler]

Hi Robert,

First off, welcome to the site!

Originally Posted by RobertSmalls

Other times, especially in traffic and on the expressway, I'll hold my speed as long as I can, then enable the IMA and hit the brake lights.

Do you mean to hit the brake pedal at the last minute, and REGEN at a high level?

From following the site for several years now, it seems best to REGEN at a conservative level for battery longevity.

Originally Posted by RobertSmalls

If I had extra SOC, I'd probably use some Assist in second gear, but I don't often find myself in that situation.

Take a look at:

How To Trickle Charge the HV Battery

It sounds like your battery could use some balancing by building yourself a nice trickle charger and topping off the individual cells.

Originally Posted by RobertSmalls

But here's a specific question: With what SOC is it best to park the Insight, for best battery life?

According to Ron the Hybrid Battery Repair man, the only requirement is to top off the battery pack *before* driving the car after sitting for a long period of time. My car sat for some three months this summer while working on a belly pan, and Ron insisted that I fully charge the battery before driving as a preventative measure.

Hope this helps, Jim.

[RobertSmalls]

Thanks, Jim. I've added a HV trickle charger to my to-do wish list, along with a full bellypan and 12V trickle charger and DC-DC converter toggle switch. If I'm going to hook the car to the grid, I may as well do it right. Does that make mine a PHEV? :-P