Reprogram ecm drive battery parameters??

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two20142lts

Member
Joined
Dec 1, 2017
Messages
18
Since both my sparks are out of warrantee and only charge to 67 on the GOM these days I was wondering if it is possible to change the programing to allow full use of battery capacity? Is there any software out there?
Would GM do it at my risk?
 
two20142lts said:
Since both my sparks are out of warrantee and only charge to 67 on the GOM these days I was wondering if it is possible to change the programing to allow full use of battery capacity? Is there any software out there?
Would GM do it at my risk?
.
The warranty for the Spark EV battery pack and charging system is 8 years or 100,000 miles. Are you sure that you are out of warranty?
 
My observations of the battery cell voltage when the car is charged to 100% SOC shows that the battery is using about 98% of it's capacity so I don't think there is anything to unlock on our cars.
 
two20142lts said:
Since both my sparks are out of warrantee and only charge to 67 on the GOM these days I was wondering if it is possible to change the programing to allow full use of battery capacity? Is there any software out there?
Would GM do it at my risk?
You would have to rewrite the code for at least one module, to allow for charging to a higher voltage (available capacity corresponds to the voltage the cells are charged to.... the Spark EV already charges cells to near the ceiling of what is safe) and/or discharging to a lower voltage. That modified software very likely doesn't already exist presently. I give a snowballs chance in hell odds, at getting GM to entertain this.

Speaking of snowballs, that's how I would describe the effect of degradation in certain battery products, the Spark being a prime example. The more the battery is FULLY UTILIZED, the more wear it receives. Well maybe we can utilize our batteries less? I don't know about you, but I have places I need to go, and I often need as much range as the Spark offers to ensure I get there.... which is a recipe for the accelerated degradation we're seeing.

The tragedy with small battery electric cars, like the Spark, is that unless a manufacturer holds back on useable capacity, the cells are going to wear out significantly faster than packs larger packs, due to a number of factors: 1) Pack utilization (ie keeping the cells at voltages that reduce wear); 2) Reduced C Rates for charging and discharging of cells, which lessens wear/damage. You can look at the Chevy Volt as a real world example in principle, which had a very conservative ~40% capacity withheld in the first generation, due to both it's hybrid nature, and unknown long term effects of battery wear. The batteries in these Volts have generally suffered extremely minimal degradation. Battery chemistry and anode/cathode materials, also play a role in battery life/degradation.
 
TheLondonBroiler said:
The tragedy with small battery electric cars, like the Spark, is that unless a manufacturer holds back on useable capacity, the cells are going to wear out significantly faster than packs larger packs, due to a number of factors: 1) Pack utilization (ie keeping the cells at voltages that reduce wear); 2) Reduced C Rates for charging and discharging of cells, which lessens wear/damage. You can look at the Chevy Volt as a real world example in principle, which had a very conservative ~40% capacity withheld in the first generation, due to both it's hybrid nature, and unknown long term effects of battery wear. The batteries in these Volts have generally suffered extremely minimal degradation. Battery chemistry and anode/cathode materials, also play a role in battery life/degradation.

Oh my! Another battery geek! I thought I was one of the few....

I met a guy at the fast charge station last week, and rambled on about battery statistics and charge rate (1C vs. 3C, why I was using the 20 kW charger and not the 60 kW charger) and chemistry and SoC as it relates to battery life, blah , blah. His eyes glazed over after about 5 minutes. :D

Up until about 3 months ago, I had been considering buying a 2012 LEAF with a crap battery pack, dropping the pack and rebuilding it with modern (much higher energy density) Lithium cells. I'd have to buy (or rent or borrow) a Li cell charger to get all the cells to with .005 volts of each other before combining the individual cells, but I figured that I would be able to build a pack with twice the capacity of the 2012 cells, and have a car with 150+ miles range for a fraction of the cost. But now that Bolts are selling for under $15k, it just isn't worth it (although still a "neat project", it would drive my wife up the wall, so definitely not worth it)
 
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