Hi there! I brought up this topic (actually it happened accidentally) on the facebook group for esk8 users…
One user ‘‘complained’’… that instead of 12miles he usually got for his evolve gen2 AT board… he now got only about 6miles… in -10 cold weather… (14F)
I rode almost yesterday at weather which was -5 till -7C cold (23F till 19F)
I did not witness such harsh capacity drop for my ‘‘high discharge’’ NMC Li-ion cells…
–
In comparison, it seems his evolve Gen 2 is having lipo’s… plus, he also admitted that he has bought his board second hand (used)… so the battery might be a bit worse
It does hurt efficiency and for something like AT wheels, maybe he needs to pull huge amps so it’s hurting him worse.
Just a small circuit to warm them up and a cozy graphene blanket is all we need The challenge is individually, you will still want cells isolated from each other, and needs individual temp monitoring/alert. I’m working on something right now! Should have a prototype right around the time weather gets warmer LOL
Cell heating Tesla style (taking heat from the motor and directing at batteries via heatpipes.
@FredSaberhagen anyways fitting temp meter to the batteries I think is a good idea in the winter… at least to see at what temp they more or less get to operate…
The crazy thing is… it looks like there is something like 5-15% extra capacity… if you heat your cells while in use… there was this example that is a cell type that needs really high temp, something like +70C (158F) to even be able to operate! They operate in a very high temp range… and underperform or does not work at all at lower temps… This brings this ‘‘Battery Technology’’ topic even further…
today was+3 c and my benchwheel seemed a bit less powered than normal going up hill ,maybe it is due to the cold .
i will add more details once the warmer temps come back /
how ever i have had this board for 5 months and i have noticed it has a deffo reduction in power out put
yes, below 0C degrees it starts to get bad… non the less, I found a thread on another forum about ebike users… and how they ‘‘survive’’ the winter…
Some of them just ‘‘pre-heated’’ the battery and were fine (by keeping their ebikes in warm room etc)
One guy put these ‘‘hand warmer mats’’ in his enclosure (though, not so practical for elongboard users with closed enclosures)…
Then there were ideas about heating mats powered from another power source, which would keep the ambient temperature for the batt pack
–
Basically, the best suggestion was to insulate the batteries with some sort of heat/cold reflecting material… so that they dont lose their temperature as fast when subjected to cold weather
It looks like simple plastic enclosure and just ‘‘heatshrink’’ wrapping are not the best insulators against the cold…
Main complains about ‘‘cold batteries’’ were:
Massive voltage sag…
Power not available at start…
Decreased capacity (possibly because of voltage sag / higher internal resistance of batteries)
The challenge is individually, you will still want cells isolated from each other, and needs individual temp monitoring/alert. I’m working on something right now! Should have a prototype right around the time weather gets warmer LOL
