litespeed wrote:My next super high powered pack I want to build another VTC pack. Right now I'm using the VTC3's I got from Dr Base and it performs well pushing 200 amps on a 20s15p but I get voltage sag pretty good. I want to go 30 amp hour on the next pack for more range less cell stress, I get over 50 miles now and 25% hot ridding and 75% bicycle speeds mostly peddling. So my choices on the new pack are a 20s15 of VTC4's, 20s12p of VTC5 or 5A or 20s10p of VTC6 cells.
Pricing is not drasticly different since the amount of cells drops and the cost goes up. Weight goes down as prices go up!
All prices in euro, (to lazy to convert!)
VTC4 20s15p 450 amp peak 627 +70 to ship
VTC5 20s12p 360 amp peak. 672 +60 to ship
VTC5A 20s12p 420 amp peak. 768 +60 to ship
VTC6 20s10p 300 amp peak. 750 +50 to ship
My bike has a Q205 3.5T and loves to suck amps (peaks at just about 200 amps) so I'm leaning toward the 5 or 5A to lower the weight some and still have 160 to 220 extra peak amps that I won't even be touching for future requirements......
VTC4 best bang for the bucks. VTC5A if you can afford price per cell. VTC6 if you want high capacity but don't mind slightly more voltage sag.
Got my VTC4 from Doctorbass, slightly used (less than 100 cycles)... Mine are between 1.6 and 3.8 years old ; 2.5 years old average (from date of manufacture printed on cells).
In some makita BL1840 though, some cells were Sony VT4 rather than Sony VTC4 (same capacity, but DCIR is more around 28 mOhms DC rather than 21 mOhms DC). I actually notice the difference because of a systematically (and reproducible) difference in DCIR values. Code tag is also different (label says VT4 rather than VTC4). Out of 290 cells I got, 230 were VTC4, and 60 were VT4. 286 cells were as good as new. Even 3.8 years old cells have the as-new DCIR values (Doctorbass stores them in a cool and dry environnement and at around 50% SOC, with reduces effects of Calendar life dramatically).
Here's my erxtensive data on Doctorbass's cells : https://endless-sphere.com/forums/viewt ... 5#p1299346
20S15P (300 cells) from him would be 450$ (canadian dollars, that's 303 Euros)... But i did it the local pickup way since I'm in the same city.
Curious... How much voltage sag you getting on the old VTC3 ? Are they that old ?
How many volts drops per amps drawn ?