Between hours spent on uni work ive been sneaking in an hours ride or two most days this past week. Today however was a tad warmer than it has been the last week. I was riding at about 25deg and a hot sun as opposed to overcast, windy and about 15deg. The temp probes in my bats read a peak of about 28deg, when they normally run at closer to 20. And what a difference it made!!!
I thought that the CA must need recalibrating or something, because it was showing me a pack V of 76, with 6.5ah having been used, normally by this time ive only used about 5.5 ah or less! I knew that lipo liked being used in warmer temps but I didnt know it was this sensitive! makes me wonder if something like this...
- i'd found a battery pack warmer on hk, but cant find it now...
is worth it for the colder winter days. better yet, a heat exchange that takes heat form the motor and puts it on the batts! hehe. Might be a tad bit of overkill i think...
Bikes been going great. Got the rear tube upgraded to a heavy duty DH piece, hopefully that means less punctures in the future. Getting the tire off and on again was a pain in the ass too, Im thinking I might have to switch to a traditional slot dropout with a pinch bolt. Should be just as strong if I make it out of SS or similar too.
top speed so far has been 64km'h, confirmed via a gps. it was on about a -3% grade or so though. Fastest on flat has been about 55. Makes me reconsider the switch to 24s, as I really dont need more speed for what I use it for. Still, Ive gone and bought the batts now so may as well give it a go. It'll make reconfiguring the pack for balance charging much easyer too, given that ill be using 4s packs and I have an 8s charger. Ill make each 4s pack into 'effectively' a 8s 3p sub pack, before hooking these subs up to be a single 24s 3p pack for discharge. Im hoping the extra voltage will give a bit more mid rpm push too, witch couldn't hurt.
Range has been great for a smallish 700wh pack. 24km friday, 26km today, both on about 6.5-7ah each time. Works out to an average of around 17wh/km, and given how ive been raging around the local hills to find little dirt trails Im pretty damn happy with that. I do however still pedal like a maniac, I feel guilty letting the motor do all the work, particularly up hills. makes you feel like superman too to be going up a 6 or 7% grade at 35km'h. and Ive started trying to hold wheelys and being a bit more agressive on the trails since upping the support inside the battery cases, to stop em moving as much. The throttle in those conditions takes some getting used too, best ive managed so far is a pretty abismal 20m or so.
Keep giving it to much and falling off the back. Moving the battery case down lower should help with the balance.
Speaking of witch, with the mid semester break coming up I will hopefully have the time to do a bit more work making a neater batt case and clean up the hornets nest of wires I have at the moment.
Damit, how the hell do i keep making these long ass posts?