Re:Tesla Model 3 Ramp Up Aims to Compete with BMW 3 and Merc...
by falcolas on Tuesday March 28, 2017 @12:31PM
(#13978044)
> It's true that the charging rate of a supercharger gets pretty slow once you pass 90%, but it doesn't stop.
That's what I meant: the supercharging stops at some less-than-advertised capacity, and becomes normal charging (and normal charging rates also slow down above the 80% mark).
> thanks to the active cooling system in the battery pack.
That makes some sense, as the damage does come from heat buildup in the cells. However, since battery packs are typically remarkably dense to achieve a good W/h : size ratio, that would have to be quite the cooling mechanism; I don't believe that simply cooling the air around the battery cells (such as with a peltier and a fan) would suffice.
I base this supposition on the completely unscientific method of recharging batteries in my garage in the winter; they still get remarkably warm with an ambient air temperature of around 40°F and normal charging (around 1c - their mAH rating). Perhaps they simply set artificially lower capacities per cell than the battery pack's real capacity in order to prolong their advertised lifespan.
That's what I meant: the supercharging stops at some less-than-advertised capacity, and becomes normal charging (and normal charging rates also slow down above the 80% mark).
> thanks to the active cooling system in the battery pack.
That makes some sense, as the damage does come from heat buildup in the cells. However, since battery packs are typically remarkably dense to achieve a good W/h : size ratio, that would have to be quite the cooling mechanism; I don't believe that simply cooling the air around the battery cells (such as with a peltier and a fan) would suffice.
I base this supposition on the completely unscientific method of recharging batteries in my garage in the winter; they still get remarkably warm with an ambient air temperature of around 40°F and normal charging (around 1c - their mAH rating). Perhaps they simply set artificially lower capacities per cell than the battery pack's real capacity in order to prolong their advertised lifespan.