Longer life by skipping regen?

[user 1485]

Okay, this may be a dumb question...I know our batteries degrade over time, whatever that percentage is. If we didn’t use the regeneration options, would that help extend the life at all? My thought is that perhaps by not having that constant charge trickling in, maybe it slows down on the battery wear? Not based in any science, just curious what everyone thinks.

 

[f1geek]

If you are talking about the drive train, it's science, of course. In the e-Golf, if you apply the brakes so that the power needle stays in the green portion of the dial, the motor charge the battery (regen). If you stomp on the pedal, the needle will be pinned, and the friction brakes will engage, but I suspect there is still max regen occurring. Yes, you can drive in "D" and coast when not pushing the accelerator pedal, but if plan on stopping using the brake pedal, the car will engage regen.

Regen charges the battery, so all caveats that apply to charging apply to regen. You read alot about charging on this blog and elsewhere.

 

[RonDawg]

If constant regen were a big cause of premature EV battery degradation, you would have heard about it from the Prius crowd by now.

 

[Verkehr]

If we can agree that heat is the enemy of battery life, I suspect sustained driving at high speeds will cause more heat in the battery than heavy regen ever could, since there is no road on earth that will allow full regen for more than a few minutes, if that.

 

[f1geek]

I beg to differ about the roads providing regen for more than a few minutes: I've driven down a mountain road (~3500 feet) that provided regen for around 30 minutes. I plan to drive up to 5500 feet this summer and I suspect I'll be getting regen for 45+ minutes on the way back down since there are a ton of switchbacks with idiot motorcyclists flying up the mountain and crossing the double yellow line (I see these idiots every summer), and I'd like time to be able to get out of the way or at least slow down and give the idiot time to get back into his lane. Additionally, as was mentioned, since I'm going to have gentle regen, the pack won't heat up as much as if I flew down the mountain in "B" mode with the power needle near the max regen.

 

[Turbinator]

Take this as it is, just a single data point.

I had a 2015 Leaf that I constantly drive in "B" mode (regen) for the 3 years I had it on lease. I charged whenever I wanted, I regen'ed all the time, and during the 3 years I had the car, the battery health meter never degraded at all. I was still getting as full of a charge on the 36th month of the lease as I was during the 1st month of the lease.

If this is at all indicative of what to expect out of the e-Golf's batteries, I'd be completely comfortable driving the e-Golf with the most aggressive regen turned on, all the time. And that's precisely what I'm doing on a daily basis now, anyway.

 

[f1geek]

The 2015 Leaf "battery health" gauge is not the best way to evaluate battery health. I believe the first bar is worth around 15% of the battery health, so until you lose that much capacity, it will show all bars. Did you use LeafSpy to get the true data on battery health? If you don't need to charge to 100% SOC daily, I would recommend you only charge up to 70 or 80% if you want to extend the life of the battery.

 

[Verkehr]

I beg to differ about the roads providing regen for more than a few minutes: I've driven down a mountain road (~3500 feet) that provided regen for around 30 minutes. I plan to drive up to 5500 feet this summer and I suspect I'll be getting regen for 45+ minutes on the way back down...

You may have missed the part about "full regen" which would be with the energy needle all the way to the left and similar charge rate to DCFC. Of course, no highways are steep enough to keep the needle pinned to the left but I don't know of any roads, either.

If your car and driver weighs 3500 lbs and descends 3500 feet, that's 4.6 kWh in potential energy. If you're do that whole descent in a vacuum with no rolling resistance in 30 minutes, that's still only an average charge rate of 9.2 kW into the power electrics (before losses) which is not a whole lot more than the 7.2 kW e-golfs charge at.

 

[Turbinator]

The 2015 Leaf "battery health" gauge is not the best way to evaluate battery health. I believe the first bar is worth around 15% of the battery health, so until you lose that much capacity, it will show all bars. Did you use LeafSpy to get the true data on battery health? If you don't need to charge to 100% SOC daily, I would recommend you only charge up to 70 or 80% if you want to extend the life of the battery.

No, I did not use any software or special methodology to gauge battery health. Anecdotally, I knew of two drivers who have Leafs that reached the 3 year mark, and had degraded battery health as indicated on the dashboard meter. Mine did not at the 3 year mark.

I never charged only to 70% / 80%. I charged fully whenever I wanted. For the 3 years I had the vehicle, this practice didn't seem to have any observable effect.

I have no problem admitting this is non-scientific with zero tangible data to back it up.. I was essentially a dumb consumer and used the car pretty much as a dumb consumer would use it.

 

[NurStrom]

Okay, this may be a dumb question...I know our batteries degrade over time, whatever that percentage is. If we didn’t use the regeneration options, would that help extend the life at all? My thought is that perhaps by not having that constant charge trickling in, maybe it slows down on the battery wear? Not based in any science, just curious what everyone thinks.

where are the moderators ... J/T where are you?