harrisonpatm
Member
- Joined
- Jan 5, 2022
- Messages
- 401
My motorcycle uses 32650 LiFePO4s from BatteryHookup, 6000mAh rated. They are rated for a continuous charge current of 1C. At 12p24s, that means continuous charge current of 72 amps. Continuous being the key word to my inquiry here.
I'm setting up regenerative braking. I want a decent amount to extend range. I realized that I should keep an eye on the max amperage that's coming in (my ammeter for driving is analog, so I can see amps leaving, but the needle stops at 0 and I can't accurately read amps going in), so I pulled out my phone to read current while braking off my bms's bluetooth. At 30mph, regen engages and I saw around 70 amps max, did it a few times. Charge current decreases as you slow, obviously.
So here's my question. If I was going faster, 60mph, and engaged regen, I am likely to see a pulse charge of around 150-ish amps, which will immediately decrease as I start to slow. It will last only seconds, especially the faster I am going, because if I'm going 60mph, I will also be using my good ol analog brakes in addition to regen, slowing myself faster than regen alone would. This will exceed the recommended "continuous" charge current, but only for a few seconds. Is this a bad idea in the long run? Is it likely to decrease my battery's lifespan? If more info helps, they are rated for 3C discharge continuous, 10C discharge pulsed 10 seconds (216amps and 720 amps, respectively).
Edit: https://iopscience.iop.org/article/10.1149/2.0801713jes
After wading through the internet for awhile , finally found something resembling research. Seems to suggest that short pulses of high C charging during regen don't strongly contribute to lithium plating, as long as they're short. One takeaway from the paper is that they suggest it even increases the battery's lifespan.
I'm setting up regenerative braking. I want a decent amount to extend range. I realized that I should keep an eye on the max amperage that's coming in (my ammeter for driving is analog, so I can see amps leaving, but the needle stops at 0 and I can't accurately read amps going in), so I pulled out my phone to read current while braking off my bms's bluetooth. At 30mph, regen engages and I saw around 70 amps max, did it a few times. Charge current decreases as you slow, obviously.
So here's my question. If I was going faster, 60mph, and engaged regen, I am likely to see a pulse charge of around 150-ish amps, which will immediately decrease as I start to slow. It will last only seconds, especially the faster I am going, because if I'm going 60mph, I will also be using my good ol analog brakes in addition to regen, slowing myself faster than regen alone would. This will exceed the recommended "continuous" charge current, but only for a few seconds. Is this a bad idea in the long run? Is it likely to decrease my battery's lifespan? If more info helps, they are rated for 3C discharge continuous, 10C discharge pulsed 10 seconds (216amps and 720 amps, respectively).
Edit: https://iopscience.iop.org/article/10.1149/2.0801713jes
After wading through the internet for awhile , finally found something resembling research. Seems to suggest that short pulses of high C charging during regen don't strongly contribute to lithium plating, as long as they're short. One takeaway from the paper is that they suggest it even increases the battery's lifespan.
Last edited: