999zip999 said:Zesty 240vdc 400amps to my folding bikes for a 15 min charge.how long do you think it takes you to run into circle k and get a coffee and donut ?
Can you say floating plasma ball. Small mushroom cloud and a flying folder.
I am eyeing NMC 14s6p 7.5ah cells which will be about 13.5kg (each cell is 159 grams but it's a Chinese taobao seller so might be lighter/heavier due to misunderstanding on my side)999zip999 said:I have a 24s A123 20ah pouch cells charge as 2 12s with mean well 24v turned to 28.8v and a 12.6v HP 550 power supply times two. This is the limit for my garage outlet. Any more juice it will trip breaker. I think 42.3v @ 14mps each in 50 min. For 6.5 years 1,480 cycles 24,00 miles still going strong. No BMS just bulk charge and check. Looking for new battery now 72v so need help too.
. This bike is just too heavy.
I messaged jimbob01 who sells them.amberwolf said:just some stuff to run by you, as food for thought:
if those are like most of the nmc cells i've seen / used, they'll only have a 0.5c charging rate, meaning it will take about 30 minutes to charge to mostly full, with the appropriate charger. probably about 45-50 minutes for "really full", assuming all cells are well-matched and balanced (potentially much longer if they get unbalanced easily). the cells you link to may well handle faster charging rates, as technology is always improving...but i don't knwo those cells, and tend to distrust the quality control and cell-matching ability of any of these.
the 10c discharge rate is just a peak, for a few seconds, and 5c or less is the continuous rating. meaning, a 22ah pack would handle momentary peaks of up to 220a, with 110a continous possible. i doubt you'll need more than 1c (22a), so even if they're crappy cells they'll probably handle that.
however...since you're in the uk, then if you have the space for a "block" battery about the size and shape of a classic .50 caliber ammocan, and don't need a custom shape, you can use the cells that jimbob01 is selling over here
https://endless-sphere.com/forums/viewtopic.php?f=31&t=102908
that are also nmc, and which are easy to bolt together and make packs from, not requiring any special machines (spotwelder, etc) to assemble. just need either busbars or lugged wires to connect them. tehy're what i use on my bike and trike, and are good quality cells that stay balanced, and i've been using mine for years now. (and all of mine came to me used already). they're not miracle cells or anything...but they're almost certainly significantly better than whatever random chinese stuff you may find.
a 14s1p pack is 20ah and capable of 100a continous and 200a peak discharge, and easily 10a charge rates, so about 30 minutes to charge. they can handle twice that charge rate, so they can actually charge in about 15 minutes if you used a 10a charger (though the faster you charge them, the shorter their lifespan, similar to discharging them harder). they're more likely to stay balanced, based on my experience, than the generic stuff is, so unlikely to take extra time to balance and finish charging. (i actually don't use a bms on mine, and just let the controller lvc and/or the cycle analyst lvc protect them from overdischarge, and mine stay within a couple of hundredths of a volt of each other in either 1p or 2p configurations).
Sorry this is so off topic of the original post, but I can't help but answer a question asked.john61ct said:Gravel roads, scrub, desert and forestry tracks, badly surfaced roads, to me means 20" will be too small, so 24-26" outside diameter? Thinking fatties, at least 2.5" tires?John in CR said:What motor to use really depends on how small a diameter tire you can live with.
> You also have to look at the top cruising speed and range you want.
The cargo and hill climbing capabilities is 99.9% of my drivetrain design focus right now. If energy efficiency were optimized for cruising at under 15mph, that'd be fine and top speed is truly irrelevant; a 20-25 max would be fine.
A modular swappable battery pack system will give me the necessary range. Hauling supplies, propane, drums of water so an extra pack or two's NBD. On flat terrain hoping for 400-500lbs, will reduce as needed for hilly country....
______
....Outstanding:
Would it be better to have the front & back hub motors match each other? ....
yeah, sorry, i'm still exhausted from nightmares (from peanutbutters' death three weeks ago), so math is not my friend right now (actually, it never is, but especially now).nickceouk said:Had to recheck on the 30 min charge - 20ah cells charged at 10a(0.5c as per spec) would actually take 2 hours right?
i don't know how they would handle that. their spec is only 1c max, meaning 1 hour charge time. you'd have to test if this is feasible (monitoring cell temperatures, etc).I would need to charge at 40a to get 30min full charge from empty.
amberwolf said:yeah, sorry, i'm still exhausted from nightmares (from peanutbutters' death three weeks ago), so math is not my friend right now (actually, it never is, but especially now).nickceouk said:Had to recheck on the 30 min charge - 20ah cells charged at 10a(0.5c as per spec) would actually take 2 hours right?
i don't know how they would handle that. their spec is only 1c max, meaning 1 hour charge time. you'd have to test if this is feasible (monitoring cell temperatures, etc).I would need to charge at 40a to get 30min full charge from empty.
i usually charge mine at about 1/4c, 12a for a 14s2p pack (40ah) with the meanwell hlg-600h-54a mounted under the trike. just plug in an ac extension cord from the trike to the wall and walk away; come back in a few hours and it's done. if i really think i'll need faster charging on some long trip (rare) i can carry a pair of those wired in parallel for 0.5c charging. if *really* needed 1c charging, i have four of them that can be wired in parallel for that (including the one already on the trike), but have never had to do that.
realistically, if i only needed one recharge on a trip like that, i'd just carry a second 40ah pack, as it wouldn't weigh much more (35-40lbs) than the four chargers (about 30lbs), and i wouldn't have to stop at all. just wire the two in parallel, and off i go. 40lbs isn't even a tenth of the gross weight of the trike and me, so not that noticeable, though it certainly would be on a folding bike. (even the less-than-20lbs ofa 14s1p pack in the wrong place on a small folder would be a huge handling change).
if i were going to put one of these packs on a typical 20" folder (don't know what yours is like) i'd put it right over the front wheel on a frame extension from the top/downtube, like some of the small-front-wheel cargo bikes do. it wouldn't be on the fork or bars, whcih can make for undesirable handling changes in steering.
then you also still have your whole rear rack/panniers/etc for other stuff, hopefully not as heavy.
those kinds of things would work, too, and give you even more cargo space. but i was thinking of stuff like these that have racks as "part of the frame":nickceouk said:
With rear rack
or even this one on a suitable folding bike(with rear rack + panniers for gear
i wish taht was the case, but losing dogs has never been easy for me, and his death has been much harder than most for whatever reason. its not as bad now as it was at first, but it's not very good yet either.Hope you don't get caught on peanut butter again
:wink:
thanks--i appreciate it. most of these go to help feed the monsters (i still have three st bernards, yogi, kirin, and jelly, and they eat about 15 cups or so a day, depending on the particular dog food, so even the biggest bag only lasts a couple of weeks or so). sometimes i can use a bit here and there for ebike projects and the like.A small gesture to you via the link in your signature from me
999zip999 said:AW is right you live in the UK I would buy those eig cells in a heartbeat. They look easy to bolt together
Punx0r said:nickceouk said:Ride a folding bike long distance? Nope!
...
and Street AC/DC recharging in 40mins
...
As to 25kg+ battery it's not a deal breaker on its own ...
25kg (by the time it's built into a sturdy pack you're looking at ~30kg) on a bike frame is a lot. Before commiting to something like that I really would strap a bag of sand or bricks to your frame or on the rear rack, take a ride and see how the bike handles at speed to ensure you're not going to find the thing flexing all over the place/wheelie-ing/death-wobbling.
40mins charge time = much more doable with readily available, relatively energy-dense li-ion cells
Punx0r said:nickceouk said:Ride a folding bike long distance? Nope!
...
and Street AC/DC recharging in 40mins
...
As to 25kg+ battery it's not a deal breaker on its own ...
25kg (by the time it's built into a sturdy pack you're looking at ~30kg) on a bike frame is a lot. Before commiting to something like that I really would strap a bag of sand or bricks to your frame or on the rear rack, take a ride and see how the bike handles at speed to ensure you're not going to find the thing flexing all over the place/wheelie-ing/death-wobbling.
40mins charge time = much more doable with readily available, relatively energy-dense li-ion cells