Quote:
Originally Posted by Natalya
So the battery seems to be working fine, but my problem is my driving never allows it to get charged, so I still gotta use clutch switch to keep it from assisting. It's just hanging out at 3 bars because when hypermiling I you know try to not accelerate more than I need to. I'm the slowest car on the road, hanging out in the right lane. FCD right now for current tank says 3.1 l/100km with 145km on the tank. That's like 90 miles at over 70mpg for the Americans in here. I don't ever DFCO + regen because I'll just use EFAS and EoC instead of letting the car regen. I guess for hypermiling not having a battery is better.
|
I went through similar mental logic re. battery use in my Gen 1 Insight, 5-speed standard tranny.
Somewhere, I picked up that the Insight's IMA system is 70% efficient. The item I read had no other qualifying or descriptive information. But if true, that reminds us that while capturing braking energy (or whatever you'd like to call it) is better than wasting it into heat, it's NOT a perfect system. Zooming forward with assist, and then braking with regen, is not going to preserve all the energy lost in the braking process. Even if the 70% figure is not fully accurate, I'm certain the concept is correct. The IMA system can't possibly be 100% efficient.
I noticed that normal driving, with assist and regen enabled, basically runs down the battery until it's low enough that the car decides to put a priority on regen. Then, it charges until it gets up to maybe 2-3 bars from max. Even if you're climbing a hill. That's crazy.
I brought that up on InsightCentral[dot]net, and the response was - that's typical for Insights. It's not optimum but it's typical. I'm convinced it is BAD for the IMA battery.
I made several changes to my driving, over a few months time. In sequence -
I put in a dash-mounted voltmeter to show me the voltage to the battery cooling fan. I theorize that insufficient cooling helps to kill these batteries. Knowledge is power.
I put in a switch to power the IMA cooling fan. Now I ALWAYS have the fan running if it is doing assist or regen.
NOTES on fan wiring: My fan projects connected to the same fan wires that are used in a DIY grid charger, when powering the fan externally. The OEM fan setup has two wires. One has 12V when ignition is on. The other grounds the fan via a relay, when the computer decides to run the fan. It can be grounded via either of two relays, depending if the computer wants high or low speed cooling. IIRC, the blue one is hot and the black goes to ground. But you'd need to cut one of the two, to test conclusively to see which is which. You could pull the wire pair off the connector that's behind the passenger seat and probe there - but it's a tough spot to see into.
Discussions on IC showed my IMA battery was on its way out, and as a 2.25 year old Bumblebee, it was still under warranty. Installed replacement from BBB. Owner there (Eli) let me know that this new battery will run the fan on low speed whenever ignition is on. And it's true.
Granted, having a new battery makes things better and easier, but I'm committed to taking the best possible care of this one.
My fan switch still works - and runs the fan on high speed when I activate the switch. So I have a choice of two speeds, hi and low. "Off" isn't really available any more, if the ignition is on.
I aggressively PREVENT the IMA from being used, by means of my clutch switch. I also have a brake switch that forces regen. Also a kill switch.
I simply refuse to allow assist in most situations. If I need to use 4th or even 3rd to maintain highway speed on an upgrade, so be it. I have many upgrades that are between 1/4 mile and a mile. Sometimes longer. Using assist for a long stretch like that will only drain down the battery, and I'll need to charge it up again soon. Charging is the problem. Stopping for lights and stop signs isn't enough to restore it near full, if charge level has been reduced by hill climbing or by accelerating for traffic.
Now, I mostly keep the battery at one bar below max. Sometimes two. But if it gets to two bars below max, I find or create opportunities for regen. Longish downhills are nice for that. BUT remember, I'm running the fan. A long regen builds heat, just like a long assist does. And, per recommendations from Eli and another person at IC, I avoid long regens at full regen rate. Even with the fan on, that probably creates too much heat.
There's an entire additional discussion to be had on grid charging and deep discharging. I'll avoid huge detail on that now - partially because others know more than I do. But...
Charging should go until you see the pack LOSING voltage slightly but consistently, over maybe a 30 minute period. My pack took 8 hours to get there. I've read it can take 24 hours. I have the same red multitester visible in the photo here - but I don't use it for charging. Make sure you can read hundredths of a volt. If you discharge or deep discharge, it should be done with about a
25 watt bulb. Those high-wattage bulbs you have will only do damage, I fear. They're OK for a short while, till pack voltage comes down to maybe 80V. Then you need to go slower, with a 25W bulb.