splitfire said:
hey stealth user. I just want to know what are the differences between the new bomber and the old bomber. MK1 vs MK2 vs B52.....
The differences between the MK1 and MK2 is the MK2 has the newer and slightly smaller battery compartment in the frame. The MK1 was designed for Lifepo4 Headway cells if I recall correctly and the MK2 was modded for pouch cells allowing for a smaller battery with the same capacity. With the exception of the very first series of MK1s, early 2008 and older if I remember correctly. Initially power was rated at 3kw, I don't remember when Stealth increased the output to 4.5kw, but imagine it was about the time that Stealth transitioned from the 53XX to the 54xx hubmotor. The majority production of the MK1, and the entire model life span of Mk2 stayed at 4.5kw (4500wh) output for the duration of the series. Early last year, Stealth increased the KW out put to 5.2KW, and introduced the DC1 compute and other software and programing upgrades hence the name, B52. The same with the Fighter, output increased from 3kw to 3.7kw hence the name, F37. The DC1 is like a really advanced CA and much more precise at reading DC input and monitoring data then the CA it replaced. As battery, motor, and controller technology improves, and if Stealth stays with their current model identifiers, I imagine in the future, we will see a B75 Bomber to and F50 Fighter reflecting 7500wh and 5000wh output respectively. I am just speculating here, I don't know anything for certain about future models.
[quotequoteMy stock Stealth LiFeP04 pack however looses 20-40% capacity when the temperature drops below ~10C]
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You know CD, I am starting to rethink my impression of cold weather performance as relates to batteries with lithium in the chemistry. My Bomber, I mean dad's Bomber. is still running the original Pouch Lifepo4 battery in the Bomber. CA is turned down to 50amps and here is what he's getting. During the summer, if he takes it easy and keeps speeds less than 20mph and rides on pavement, he can expect 55 miles and 1362wh consumed. Winter, he can nurse almost 1000wh when riding below freezing temps. Of course if he turns his amps up to 70 and twists the throttle wide open, he will BMS shutdown instantly summer or winter with that much wh consumed. That being said, my custom 14s LiIon pack isn't effected very much at all. There is more volt sag sooner in cold weather, but I aint loosing no 30%, maybe 10%. On the geared hubby home built running 12s 24ah zippy lipos, whether riding in hot weather or below freezing weather, we are getting 1000wh usable and not hitting the LVC which is set at 42 volts. So my experience, like yours suggests that Lipos aren't nearly effected by the cold as lifepo4 and LiIon is closer to Lipo in terms of cold weather performance than lifepo4.
