My first e-bike project log named: "P.O.S."

[def215]

ok. so earlier last week was my spring break from school, so ive decided to go riding around the city. long story short, i ended up wiping out on my bike. no real damage to my bike, just some broken pedals. but now im second guessing things. i think i *expletived* something up when i went down because my LVC on my controller seems to keep kicking in under full throttle, and it has never done that before, and thats hot off the charger. now im thinking to myself, is it possible to destroy SLA's from the shock of a crash?

i carry my batteries in a backpack and i dont remember really if i fell on them, but they have no signs of ruptures or damage anhd they still take a charge. i really dont know whats going on right now. if possible, can someone give me some insight to what is goin on? because im baffled by this(waiting for the answer to go lifepo...lol)

[amberwolf]

Theoretically it could be possible to damage them, but most likely only if the case is cracked open for them to leak gel.

I've had (at least twice) 17Ah AGM SLAs leap off my CrazyBike2 during systems testing and hit the pavement; once at almost 20MPH it bounced a few times before skidding another dozen or more feet and stopping. Still didn't have a problem with it, even though that's a lot of impact energy, given that the first two impacts left corner impressions in the asphalt, and scarred the outside of the case (but didn't dent or crack it).

It did teach me never to use just zipties to hold them in place, though. (Hose clamps, yes)

I'd be more likely to suspect a connection. A poor connection, or damaged solder joint or crimp will be higher resistance and thus more of a voltage drop, preventing as much voltage from reaching the controller, potentially triggering the LVC.

[def215]

im highly impressed at the durability of these SLA cells. after my crash, and what you said happened to your SLA when you crashed amberwolf. im really surprised they can take a beating.

so i did solve my problem with the so called problem with my batteries and LVC. it was actually my controller. earlier on when i was still experimenting with stuff before my motor rewind, i did the shunt mod for more current so i can have more "punch" off the line. little did i know that that mod would come back to bite me in the ass after i rewound my motor. so me thinking the LVC was kicking in was actually my 30 amp breaker kicking in and tripping. i feel like a total tool now that i think of it. after i unsoldered the shunt back to normal, the symptoms of the yellow light coming on at full throttle at a dead stop isnt happening anymore. i also think i can get more range out of my bike now(im guessing) i was real close to breaking my bike down or chucking it into a river because this problem was really frustrating me.

now i can have that EV grin again

my controller is limited to 29 amps. would the motor only be given the maximum amps the the controller can handle and no more(theoretically?), which is 29 amps? im just really curious to this because my 30 amp breaker kept tripping.

[amberwolf]

I didn't crash, just that at least a couple of times an SLA leaped off when riding, due to zip ties breaking during vibration/etc.


If a 30A breaker pops, it's getting at least 30A pulled thru it for a sustained amount of time. Exactly how long it takes to pop it at it's rating depends on the breaker's specs, but I have had little 15A and 20A breakers (out of the back of a UPS) I experimented with take over 30 seconds to pop at higher currents than they were rated for.

There will be more current pulled at the motor end than the battery end (when not at zero acceleration), and I think most motor controller current limits are probably on the battery side. So the 29A limit should keep it below the 30A breaker limit, but only at the battery side. Motor side could be many times that.

Just remember that if you're using 12Ah SLAs, they were meant to have 0.6A (600mA) pulled out over a total of 20 hours (as opposed to 12A in one hour), so if you are pulling upwards of 30A out of them for any length of time they will only give you (at a guess) 10 or 15 minutes runtime max, running them into the ground. I killed my set of 12Ah by abusing them in discharge and charge on my original DayGlo Avenger MkIb friction drive, running two 12V motors in parallel at 36V (fairly high current, dont' remember exactly how much).

[def215]

I didn't crash, just that at least a couple of times an SLA leaped off when riding, due to zip ties breaking during vibration/etc.

whoops. i misread that one. a 17ah battery is still a pretty hefty battery to be hitting pavement like that.

well that blows my mind. i thought the 29 amp limit was for the motor to regulate current from the batteries. guess i was wrong. i just didnt want to see that yellow light flickering when it comes hot off the charger and im trying to get it moving at full throttle anymore.

[amberwolf]

whoops. i misread that one. a 17ah battery is still a pretty hefty battery to be hitting pavement like that.

Yeah--I wouldn't've wanted it to be my foot it landed on. It left dents in the asphalt! Little ones, but still!

well that blows my mind. i thought the 29 amp limit was for the motor to regulate current from the batteries. guess i was wrong. i just didnt want to see that yellow light flickering when it comes hot off the charger and im trying to get it moving at full throttle anymore.

The amp limit usually would be to regulate current from the batteries. Probably is in yours, too.

The problem is that the smaller the battery capacity, the smaller the surge current from it before you see voltage drop. Sometimes you can get more effective acceleration by *not* flooring it / going WOT at startup, but rather by holding back on that to some degree until it starts to get going. Otherwise you wind up using up a lot of Wh just getting the very first bit of startup accomplished. Often having the bike in a nice low gear (for those with shifters) for the cranks, and pedalling just a bit at the very first part of getting going from a stop, will save enough power to let it not sag for the rest of the acceleration.

Depends on the motor, controller, and batteries, but I know it works that way with the DayGlo Avenger MkII's Fusin hubmotor and NiMH pack, which is only 36V 9Ah. The controller tends to limit peaks to around 16A, but that's a lot for a 9Ah NiMH pack. If I help it by cranking during startup, too, in a nice low gear, I can save a lot of power--probably at least a couple of Wh per mile. Problem is, that's tough on my knees, so I let the motor do almost all the work, and live with the Wh loss.

[dequinox]

Hey def,

Hows that bike treating you? Everything working out alright since the little battery incident you had? Amberwolf is right about the SLAs...you don't want to use them at 30amps for very long. They tend to crap out quickly. I've been keeping my draw at 20& below and getting about 5 miles before the performance noticeably drops off from my 12v12ah pack. The day shall come soon when I invest in lithium!

[def215]

Hey def,

Hows that bike treating you? Everything working out alright since the little battery incident you had? Amberwolf is right about the SLAs...you don't want to use them at 30amps for very long. They tend to crap out quickly. I've been keeping my draw at 20& below and getting about 5 miles before the performance noticeably drops off from my 12v12ah pack. The day shall come soon when I invest in lithium!

so far i think its at a point that its truly commutable with. i seem to have found all of its flaws and breaking points and fixed them, so i think the weather it getting better and better and i think im going to take it to school soon to see what it can truly do.

Depends on the motor, controller, and batteries, but I know it works that way with the DayGlo Avenger MkII's Fusin hubmotor and NiMH pack, which is only 36V 9Ah. The controller tends to limit peaks to around 16A, but that's a lot for a 9Ah NiMH pack. If I help it by cranking during startup, too, in a nice low gear, I can save a lot of power--probably at least a couple of Wh per mile. Problem is, that's tough on my knees, so I let the motor do almost all the work, and live with the Wh loss.

yeah. im at that point that im really learning to ride it more for efficiency and not for speed. speed runs are if im in my own neighborhood...lol.

im just curious to how the performance of the NI-MH's are like on your Dayglow Avenger MkII amberwolf. how are they treating you? id like to try and get a pack for my bike because im not ready to go lithium yet, for financial reasons and for the fact i tend to be neglectful(i forgot i left a soldering iron in the wall overnight the other day. imagine if that was a lithium battery, that situation couldve turned out bad ) ive ran across a thread knuckles made about building a NI-MH pack out of 10000mah tenergy and powerizer cells and said he had good results out of them. id like to try and do that but everyone doesnt even look at them and say just to go lithium.

[amberwolf]

im just curious to how the performance of the NI-MH's are like on your Dayglow Avenger MkII amberwolf. how are they treating you?

It's ok; better than SLA for sure. Only catch is charging them requires either:
--A NiMH specific charger that is capable of monitoring it's temperature/voltage/whatever, so it doesn't overcharge and damage it, especially to prevent it overheating.
--You paying close attention to it while charging so you don't overcharge/overheat it
--Always only charging at very low currents (like 100mA or so) for a long time
--Using a thermal cutoff like Knuckles, preferably several of them in series, scattered throughout the pack. (there's always a sensor in the middle or so for chargers that monitor that, but if it breaks or comes loose it doesn't help!)

Or some combination of the above.

So...it works for me so far, but I am always a little worried about it when I have to charge it faster (at about 900mA, fastest I can with the Sorensons) due to needing it quicker than just overnight. Usually I use much less power, and can let it charge about 150mA or less, and it'll be about perfect by the time I have to leave the next day, if I do. (if i don't, I just unplug it).

As an example of use, today I ended up making two back-to-back 6-mile trips, and was about 13-14MPH anytime I could stay at one speed, with lots of traffic control stops (a few dozen). One trip was loaded up heavy, about 40+ pounds of stuff for the 3 miles back. The outbound was empty (just me and bike) as was the second trip both ways. Took about 3.4Ah out of the pack to do the whole 12 miles (bringing it up to 120 miles total on the motor/pack since I got them). Forgot to write down the Wh.

The only big problem I have with it is the sag--it was already used when I got the pack, so it's not as healthy as a new one, but the sag is pretty bad (a few volts) during draws of 2C, about 16A, which is what it takes during heavy acceleration on the "low" setting of the Fusin. It still accelerates well enough, since it's a geared hub, but using it on a non-geared would probably not be as forgiving due to higher current draw likely needed.

NiCd is similar in properties to NiMH, and probably easier to get a pack (ebikes.ca has them). Never used them myself.

But if you want a lightweight pack that can take high current draws, Lithium of one flavor or another is the only good option I'm aware of. Just expensive. Still working on getting mine built up.

SLA will take the high draws with little sag, depending on the size of battery vs draw, but they're really heavy and suffer horribly from Peukert.

id like to try and get a pack for my bike because im not ready to go lithium yet, for financial reasons and for the fact i tend to be neglectful(i forgot i left a soldering iron in the wall overnight the other day. imagine if that was a lithium battery, that situation couldve turned out bad )

Well, Nickel isn't a forgiving chemistry either. If you have a good BMS and a good charger, Lithium wouldn't be a problem, but then the same is true of Nickel. The real problem is that most of the chargers are really cheap, and don't have proper safety features or they are made so poorly that the features can't work or just plain break.

If you really want a chemistry you can just leave charging, Lead is probably the only one that doesn't just die from it, simply because once the charger reaches the max voltage, the charging current is very low, if any. (same could be true of Lithium, but I think most chargers are setup expecting a BMS to shunt for a while to balance, and that will still eventually overcharge the pack).

ive ran across a thread knuckles made about building a NI-MH pack out of 10000mah tenergy and powerizer cells and said he had good results out of them. id like to try and do that but everyone doesnt even look at them and say just to go lithium.

I personally don't think Tenergy is worth the powder to blow them up based on all the overhyping I've read of them over the years, vs what their cells will actually do. Sanforce supposedly is pretty good from what I have read around; I have one of their 24V 13Ah packs, which before it was accidentally overcharged/overheated by it's previous owner due to a thermistor failure, was apparently a very good pack. Now it has bad sag at only 7A or so, but that could happen to any NiMH that's been overheated.

I forget what Giant used to use in their packs; but that's what is on the bike right now--a Giant D-type 36V 9Ah pack.

[def215]

i was just about to make a purchase on the tenergy cells then i ran into lithiums for sale.

so thanks DoctorBass for the makita packs. im enjoying the lithium power...lol

so now im running lithiums and they are way better than the SLA's by a long shot. also these konions are really putting out the power i want. no voltage sag that i can fell is very nice when i go full throttle.

i made it official so everyone knows...lol


so the pack i put together in 7S6P for my 24v system and 9ah. heres a pic of my cells getting put together:

all the cells that will be going in my bike

some of the cell i was putting together

so far, the furthest trip i took with it was 3.5-4 miles, which is up to school. so im not sure what the range of the batteries are. i want a cell log 8 and a wattmeter before i do any testing for my range. until then, im stuck using the voltmeter

also at the moment, ive been using my original SLA charger that came with my electronics, but i closely monitor voltages when i do that. it charges up to around 28.2 volts at green light and all of the cells are around 4.1 volts. if anything is out of balance, i just top them up individually with a single cell lithium charger, but im surprised with the fact that they always like to be closely balanced i still want to get a hobby charger for my cells though, i can always use one also because i play with rc stuff too. but im enjoying them to the fullest extent right now and now i see why everyone on this forum says to go lithium

on another note, i dont think its a good idea for me to open up my backpack at school because the konions and speed contoller looks highly suspicious...lol



also, i found something to do with the loose cells...lol

[dequinox]

Nice! I'm about to go up to 36v myself, can't wait to try out the higher voltage. Unfortunately I'm still stuck with lead for now... but I'm looking at the Foxx Power cells from ebay...and purchasing one of their packs. I figure sure I could save about $100 by assembling it myself...but it looks like they do a good job so I'm going to differ to their pack-building skills. Knowing me I'd melt a wrench!

[def215]

Nice! I'm about to go up to 36v myself, can't wait to try out the higher voltage. Unfortunately I'm still stuck with lead for now... but I'm looking at the Foxx Power cells from ebay...and purchasing one of their packs. I figure sure I could save about $100 by assembling it myself...but it looks like they do a good job so I'm going to differ to their pack-building skills. Knowing me I'd melt a wrench!

man, higher voltages are tempting to me now. i did my pack in 8s configuration(about 32 volts) for one ride and i hit 22.5 mph(i know, not ground-breaking, but its the fastest ive ever been on my bmx unassisted). my top speed with my pack at 7s(28 volts) is just about 20 mph, its more than enough for me to just cruise around with. the foxx power cells remind me of thunder skys...lol. i think they would fit perfectly on your bike. if i try to do that with my bike, i can forgetaboutit . my frame is way too small for anything and i could barely get my motor in...lol. i have to keep wearing my bag when i ride.

ive had only some knowledge to pack building from doing r/c. putting the cells together was not so bad, but i would occasionally see sparks fly from time to time due to my error

[dequinox]

Ha ha ha ha I know how that feels... I've fried a charger, a controller and at least 3 or 4 connectors that way. Its pretty darn scary when you hook up 48 volts in a closed series loop! Curious, when did you pick up those konion cells from doc? Is he selling more or are they gone?

[def215]

haha. yeah. you live and learn. now i know to be more careful now...lol.

i got them from doc at the end of march. ive been watching the items for sale very closely for that whole month because i was in the market for new batteries. the last time i checked i think he sold all of the makita packs with konions. i just saw him post up that he has dewalts with a123's.

[def215]

well ill update this since its been a while.

so i havent ridden this thing in a while and most of the time its been sitting around, but ive recently got a wattmeter for it which is pretty essential. i got the HK one, its no cycle analyst or turnigy watt meter but it does the essentials that i really want to know like aH's used and my pack voltage.

if i want the other numbers, i know someone with a dynamometer that i can use to get my wattage, amp and power reading so i dont kill myself trying to read the wattmeter and ride with one hand.

ive been busy at work so i havent ridden in a long time. i get to take it out once in a while only and all i can say is that the EV grin is still there when i fly down the streets at 25 mph with nothing but silence(well some chain noise to be exact)
as for now the bike is down, so i have to hold out on riding it for another week until replacement parts come in.

p.s.- dont mind the electrical wire spring connectors. theyre only there for testing until everything get ironed out and working correctly. i want things to be correct before i make them final.

[def215]

my motor is fried.

i let a friend borrow it to go somewhere, which was around 4 miles away from where i was. the bike did its job, which was be a source of transportation. but when i got it back, it had 1 out of 8 of the series strings were dead at 0 volts. also, im guessing the motor was really hot(it was a summer day with the temperature in the 90's) also the rider outweighed me by about 80 lbs(im about 130 lbs.) so it was loaded way more than it was used to. because of that, one of the magnet wires came loose on the armature and shorted out against the motor magnets. it totally sucks but im not really mad, its a homebrew project and i expect this type of thing to happen. so the things on my list right now to do is a rewind on the motor and it should be it tip top shape again.

heres a pic to show you guys the extent of the damage:

fried to a crisp! :banana:

on a lighter note, i was able to revive the dead bank of batteries by breaking down that 6p bank, but it in 6s, and charging them with my sla chrager. when i did that, they sprung back up to 3.1 volts, and after that i put them on a lithium 1s charger and they charged them up back to life

so no EV grin for me in the meantime, only ICE machines for now:

[amberwolf]

I don't suppose said friend offered to help with repairs? One reason not to loan out stuff.

[def215]

yeah, the friend did offer to pay for repairs so that was cool. its just a simple rewind and it will be back running like a top

im not really mad that this happened, i really was just expecting something like this to happen everytime i took it out for a ride. but the one time i dont take it out and let someone else ride it, it happens

[amberwolf]

Well, that's good (the offer); I've had stuff broken (or lost) that I loaned out, with no offer to do anything about it. When I've broken stuff I offer to repair/replace it, most often they turn me down, having loaned me the old worn-out tool in the first place.

I guess it's different if it is something you *expect* to break anyway, like a lot of stuff on CrazyBike2 I figured would fall off every time I started riding, but didn't. Also didn't break whenever I had other people ride it. (though most are afraid to get on it because it doesn't look/ride like a normal saddle-bike, and some because it looks like a pile of junk. )

[dequinox]

Sorry to hear about the motor man... I've been lucky with my currie brushed one so far...I've dumped upwards of 140 amps through a motor that's only supposed to take 40...and it's survived incredibly well. Good luck getting her running again!

[def215]

Well, that's good (the offer); I've had stuff broken (or lost) that I loaned out, with no offer to do anything about it. When I've broken stuff I offer to repair/replace it, most often they turn me down, having loaned me the old worn-out tool in the first place.

I guess it's different if it is something you *expect* to break anyway, like a lot of stuff on CrazyBike2 I figured would fall off every time I started riding, but didn't. Also didn't break whenever I had other people ride it. (though most are afraid to get on it because it doesn't look/ride like a normal saddle-bike, and some because it looks like a pile of junk. )

haha. yeah i expect things to just fall apart while riding, but the only things that will really do that is my tensioner, sprockets, or motor. the tensioners have fell apart on it before so i always keep an eye on them...lol

Sorry to hear about the motor man... I've been lucky with my currie brushed one so far...I've dumped upwards of 140 amps through a motor that's only supposed to take 40...and it's survived incredibly well. Good luck getting her running again!

thanks dequinox. ill have it running again in no time... the highest wattage ive put into my motor so far was about 20 amps, so my wattmeter claims...lol. yeah, it just sucks that a wire came loose inside of the motor from the heat and caused this. well, its time to build it better, faster and stronger than it was...lol

[def215]

so a rewind is underway, i started but i soon ran out of magnet wire. so that is on hold until i get it, which is tomorrow or the end of the week. heres what ive done so far:

another note to myself is that i should epoxy my windings back together so this cant happen again. i know theres super corona dope as enoob mentioned to me once in another thread, but is there something else i can use to stabilize my windings, epoxy maybe? this time im gonna wind it only 35 times opposed to the 37 i did the last time i did the rewind.
right now i took the drivechain off and been riding it around with pedal power, not at fun. but it just doesnt seem as fun as it was before.
it just seem so empty on the left-hand side

i might do a remagnetization too. im not sure on that one yet. i have broken a ceramic magnet and glued it back in there so only time will tell if i really should

it seems empty in there.

[def215]

so i got my magnet wire the other day and i finished rewinding the motor. it took me most of the day and looks good.

i just finished it. its 35 turn with 22 gauge wire.

i epoxied it so i left it in the window in the sun to dry and cure.

i got it done and put the motor together and it just doesnt feel the same. im not sure what it is but i only hit like 18 mph and im like running on 32 volts(8s konions). usually it will top out around 22 mph and this was on 37 turns. i tried everything to get it to get that speed again, like advancing my timing, cleaning the excess epoxy off the motor, cleaning the commutator, made sure the wires to the commutator was good, but it still only topped only 18 mph. thats what i dont understand, i ran it unloaded and it will go 30mph unloaded. right now at this point, im just fed up with this project and ready to throw it in the delaware river.

right now, ive lost all hope for this ebike, im just about to call it quits and call this project a loss. so it might be a possibility that this thing will be ICE-powered soon

[dequinox]

Hey don't give up on it yet! I've burnt a charger, a controller, a couple lights, my skin, and a few other things on my project and I'm still in there! don't worry I'm just kiddin around, I know they can get frustrating believe me...

I've been wondering, is this a brushless or a brushed motor? It seems to me you have a brushed one...and if thats the case I would recommend just swapping it for a more powerful motor if you want to go faster. I'm blown away that you bothered to rewind the thing in the first place...that is some serious dedication to take that project on.

TNC scooters has some good parts at reasonable prices, I've ordered one part from them and I seem to recall they ship within a decent time frame. This is the 350watt motor: http://tncscooters.com/product.php?sku=106128

You can find these motors really easily on ebay too. I got mine for 50 and it's taken a beating over the year I've had it... I've went and pushed 140 amps at 36v through it before. These little motors are not to be overlooked as an inexpensive solution to non-hub builds.

[def215]

ive done a few things like that, like burn my contoller and my voltmeter, but right now, im just frustrated with this thing. maybe i need to step back from it for a little bit and clear my senses and start again with a clear mind.

i am using a brushed 250 watt motor which this will be the second time ive rewinded it. maybe i need to touch the leads of my 8s konion pack and blast some sense back into me to get this running again, because im really unhappy with these results im getting after my rewind.

i do have a lithium pack which is rather new, should i just go ahead and invest in newer technology and say i get a brushless rc motor for it now?

but then again, ive been thinking, can ceramic magnets loose their magnetism from extreme heat? im sort of suspecting this as a case, but when i put the guts of this motor back in, the magnets do pull everything in pretty strongly. so im not sure what is going on with this P.O.S. i own.