Hi, I've been lurking around for some time now and there is just a ton of info here. It helped me decide to purchase the BMC kit. I haven't decided on batteries yet, all I know is I woun't be using sla. I'm leaning toward a 36v nimh triangular pack from ebikes.ca, any suggestions I would appreciate, the 37v 8 ah Lipo pack from batteryspace looks so tempting- so light! I just have to wonder if it can really hold up .
New member, just purchased hub kit from EVTech
- Thread starter Tony
- Start date
xyster
10 MW
Hi Tony. What's your battery budget? Is 36 volts 8ah enough voltage and capacity for your needs? How important is weight vs. price? Any desire to DIY a pack from bare cells?
Hi, I'm only really using the bike for around the neighborhood fun no more than 6 miles per trip. I'd like to keep the cost to no more than about $350. Don't think I'm capable of making a custom pack myself athough I am pretty handy. Would the 37v 8ah lithium ion pack be a good fit? I'm going to be running the stock 15a controller on a 26" wheeel. Somthing tells me the 36v 8ah nexcell pack with 5c rating on ebikes.ca would be a better choice.
xyster
10 MW
There's plenty of choices in that price range...
OK. That removes a cheap lithium hack like mine, or stringing together quality lithium powertool battery packs.
On paper, yes. I assume you're referring to that batteryspace pack? The member here who tried it, Reid, had problems with the pack. There are a few other lithium polymer options between 8 and 15ah, but they are either about double the price, or require a good, working knowledge of lithium systems in order to install protective circuitry. Unless you're comfortable learning alot about lithium, to stay safe I'd stick with nickel (nicad or NiMH)
I think that's your best option too. Since you're only running 15 amps, the 36V 8ah 3C nicad pack at ebikes for $170 would also work great, and probably last longer, but it's a little heavier. Nicads are generally a little tougher than NiMH, but also a little heavier, and the Cadmium presents environmental concerns upon disposal that NiMH doesn't.
I bought my hubmotor from ebikes.ca. Justin there is a good guy, very knowledgeable, helpful, and says he tests all his battery packs before sale.
Reid Welch
1 MW
Hi, yes, Justin is really good.
The BatterySpace pack is so new that it still has a few bugs.
Mine worked great--but some flaw showed up on the second charge cycle;
a bad cell or a damaged PCM.
But I will say, that it can't be beat for light weight and small size.
And it would be ideal for your 15A controller--it -should- live a long life.
But, ah, they don't or can't stand behind the product for long: only 30 days warranty.
After that--it'd be best to pay them to fix it if the pack goes bad in some way
(unlikely, if it lasts a month, it'll last for many cycles)
Mine failed due to infant mortality syndrome---both that it has a kink yet to be fixed (maybe they've fixed that problem already), and the luck of the draw: sometimes things go wrong.
I won't badmouth the pack. I really regretted sending it back.
Yet, now that it's gone---I think I don't want to be their beta tester
on a thirty day warranty. It's too risky.
Risk.... I may be jumping from a fry pan to a fire---I may buy a lipo pack long-distance from China.
Someday Justin will offer Lipo packs again---when he feels they are ready.
That's his common sense and pro-consumer stance.
cheers,
Reid (in manual pedal mode for the foreseeable future)
The BatterySpace pack is so new that it still has a few bugs.
Mine worked great--but some flaw showed up on the second charge cycle;
a bad cell or a damaged PCM.
But I will say, that it can't be beat for light weight and small size.
And it would be ideal for your 15A controller--it -should- live a long life.
But, ah, they don't or can't stand behind the product for long: only 30 days warranty.
After that--it'd be best to pay them to fix it if the pack goes bad in some way
(unlikely, if it lasts a month, it'll last for many cycles)
Mine failed due to infant mortality syndrome---both that it has a kink yet to be fixed (maybe they've fixed that problem already), and the luck of the draw: sometimes things go wrong.
I won't badmouth the pack. I really regretted sending it back.
Yet, now that it's gone---I think I don't want to be their beta tester
on a thirty day warranty. It's too risky.
Risk.... I may be jumping from a fry pan to a fire---I may buy a lipo pack long-distance from China.
Someday Justin will offer Lipo packs again---when he feels they are ready.
That's his common sense and pro-consumer stance.
cheers,
Reid (in manual pedal mode for the foreseeable future)
Matt Gruber
1 MW
i can appreciate what u guys are up against, with flimsey lightweight bikes. my new scoot is 22# and i'm worried about sla weight. LOL
i'm willing to see how fast it falls apart LOL
But my mx500 is a TANK! will likely last 20-50 years!
Conclusion:
BUY A STRONG BIKE(strong like a motorcycle) AND DONT WORRY ABOUT WEIGHT!
i'm willing to see how fast it falls apart LOL
But my mx500 is a TANK! will likely last 20-50 years!
Conclusion:
BUY A STRONG BIKE(strong like a motorcycle) AND DONT WORRY ABOUT WEIGHT!
That may be so, but motorcycles and bicycles are different beasts. If you rode one, you'd come to understand how badly weight hurts a bicycle. As in: When you get tired you feel every last ounce going uphill. In this case, 36v15A assuming 75% eff, ~400w to the road. Gonna feel every pound or so.
But one thing is very clear: More weight does not mean a better bike. Heavy means cheap & flimsy, eg Huffy, Pacific, modern Schwinns & sundry department store grade bikes. They do weigh a ton but that's because they're made of super cheap straight gauge steel. They'll get worn out really fast if you actually ride them, but the average one gets ridden 150 miles, so it's not like they actually have to last. They're so poorly made it's usually not possible to adjust the derailleur, or the brakes. Some are so bad they actually have stickers that warn "not for off road use". I sure as hell wouldn't take one down a flight of stairs or more then a couple of inches off the ground. Feeling lucky?
Now go in an actual bike shop and you won't find anything new below 300$, at first glance it'll look a lot like the 50$ pieces of trash from wall-mart, but if you look closer you'll see actual parts on them. Even the untrained eye can see a marked difference in quality, and the parts are actually adjustable and a pleasure to work on. When they do wear out, they're even repairable, you know? They'll outlast any department store bike, and are a lot lighter from better construction. Bikes only get fragile again when you go in the multi K$ range, but even at that level they can take air and be ridden down flights of stairs all day. (exception made of things like track bikes, but they almost only sell trendy MTB-like devices at department stores, so it's a fair comparison)
But one thing is very clear: More weight does not mean a better bike. Heavy means cheap & flimsy, eg Huffy, Pacific, modern Schwinns & sundry department store grade bikes. They do weigh a ton but that's because they're made of super cheap straight gauge steel. They'll get worn out really fast if you actually ride them, but the average one gets ridden 150 miles, so it's not like they actually have to last. They're so poorly made it's usually not possible to adjust the derailleur, or the brakes. Some are so bad they actually have stickers that warn "not for off road use". I sure as hell wouldn't take one down a flight of stairs or more then a couple of inches off the ground. Feeling lucky?
Now go in an actual bike shop and you won't find anything new below 300$, at first glance it'll look a lot like the 50$ pieces of trash from wall-mart, but if you look closer you'll see actual parts on them. Even the untrained eye can see a marked difference in quality, and the parts are actually adjustable and a pleasure to work on. When they do wear out, they're even repairable, you know? They'll outlast any department store bike, and are a lot lighter from better construction. Bikes only get fragile again when you go in the multi K$ range, but even at that level they can take air and be ridden down flights of stairs all day. (exception made of things like track bikes, but they almost only sell trendy MTB-like devices at department stores, so it's a fair comparison)
xyster
10 MW
I totally agree with your scientifically exacting assessment, Mathurin
While working on the lithium pack, I tried riding my bike with the 4, 10ah, 9lb SLAs I usually in my scooter. Handling was horrible. The extra weight in the back exaggerates a tail-wagging-the-dog death-wobble syndrome of dangerous handling. 30 lbs of lithium split between the rear rack and the midframe handles great. 27 lbs of lead on the back and 9 on the midframe made the same bike a completely blowfull ride. Another member aptly described the fourth SLA as the "straw that broke the camels back" so far as acceptable ebike handling. Since the weight is low to the ground and all midframe, my scooter handles great with those four SLAs. IMO, for an ebike, any more than 30 lbs of battery weight split at least 50/50 front and rear radically degrades handling.
Matt Gruber
1 MW
u guys missed the point
STRONG LIKE A MOTORCYCLE
upgraded kids toys are just quality toys.
.
and of course i ride a bicycle,
i wouldn't think of turning it into an ev because IT CAN'T TAKE THE SPEED, OR THE WEIGHT(i agree with u guys, U REQUIRE LIGHT STUFF)
.
A 25# HUB MOTOR puts NO static weight on the frame!(i surmise this is why many hub motors work well, but only at low to moderate speeds) a 10# frame mounted motor is more static frame stress(i'm not missing that little torque arm problem your toys have, which gets dangerous at high speed & power) When do u see a motorcycle twist up the fork?(huge disc brakes) could they know something? LOL
STRONG LIKE A MOTORCYCLE
upgraded kids toys are just quality toys.
.
and of course i ride a bicycle,
i wouldn't think of turning it into an ev because IT CAN'T TAKE THE SPEED, OR THE WEIGHT(i agree with u guys, U REQUIRE LIGHT STUFF)
.
A 25# HUB MOTOR puts NO static weight on the frame!(i surmise this is why many hub motors work well, but only at low to moderate speeds) a 10# frame mounted motor is more static frame stress(i'm not missing that little torque arm problem your toys have, which gets dangerous at high speed & power) When do u see a motorcycle twist up the fork?(huge disc brakes) could they know something? LOL
esr750
1 mW
My personal experience is that nickel (either one) chemistry isn't worth the cost and trouble. For practical e-bikes it's either lightweight or low AH using good old cheap SLA.
Nickel stuff drains by itself just sitting, damages easily when recharged hot or overcharged/discharged, saves little weight compared to SLA and IMO is simply not worth the trouble or money for e-bike applications.
High power lightweight lithium is the future chemistry but for now it's expensive and/or complicated DIY project.
6 miles? Keep bike speed under 15 MPH and with a little pedaling you should be able to do that on 4-5 AH using 15A controller. My Panasonic (very efficient) regularly covers 8-10 miles level @ 15mph pedal assisting 230lb rider on barely 3AH battery capacity.
At least with SLA it's easy to charge and a person can more easily keep hot batteries ready to go at home and at work, in the car or points inbetween. So cheap by AH comparison too. just keep 'em small packs or it will suck to ride and overload the chassis...
Nickel stuff drains by itself just sitting, damages easily when recharged hot or overcharged/discharged, saves little weight compared to SLA and IMO is simply not worth the trouble or money for e-bike applications.
High power lightweight lithium is the future chemistry but for now it's expensive and/or complicated DIY project.
6 miles? Keep bike speed under 15 MPH and with a little pedaling you should be able to do that on 4-5 AH using 15A controller. My Panasonic (very efficient) regularly covers 8-10 miles level @ 15mph pedal assisting 230lb rider on barely 3AH battery capacity.
At least with SLA it's easy to charge and a person can more easily keep hot batteries ready to go at home and at work, in the car or points inbetween. So cheap by AH comparison too. just keep 'em small packs or it will suck to ride and overload the chassis...
esr750 said:
What, no middle ground? SLA is aweful due to peukert effects, not to mention only 15-16Wh/lb. Even at only 1C drain, NiMH will have 3x the capacity per weight of lead. Good NiMH chargers incorporate temperature sensing so the charger won't cycle hot.
I run a lithium booster pack, but to outfit the whole bike with lithium (TP extreme cells) would cost over $4k. For that cash I'd rather drive my car, which has about 595 more horsepower than my ebike.
If your NiMH packs have the chance to self discharge any significant amount, you're not riding enough! I put over 400km on my bike in 6 days, as my round trip commute to work is just under 70km.
When the auto makers switch from NiMH to lithium, that's when it will be ready for mainstream use in large packs.
Nimbuzz
1 kW
Lowell, I'm glad you straightened out the advantages of Nickel but then you state $4K for Lithium. Where did that figure come from? What about the proven EV Tech pack, 36v 15ah, 10lbs for $750?
http://www.texaselectricbikes.com/
I've been comuting over a mountain with one for a year now. Whatdya think?
Al
http://www.texaselectricbikes.com/
I've been comuting over a mountain with one for a year now. Whatdya think?
Al
knightmb
100 kW
I've had a much difference experience with my NiMH pack. Over 3 years old and close to 500 charge cycles, still going strong. Light weight, no worries for recharge since I have two smart chargers for each pack. Low heat from both since I use large guage wire to try and minimize resistance. The last time I did a full 1C test on them, they still out perform brand new SLA of the same capacity, which surprised me.esr750 said:
Not sure which pack you were using, but I've had mine sit up for over a month sometimes (winter mainly) and they are still strong when the weather finally warms up and I take them for a test drive.
I agree, but let's not throw away chemistry that is well proven and cheaper than the current lithium out there. We at least they use to be cheaper, seems prices for the NiMH are going way up lately
Yeah, 6 miles, some cheap SLA will be no problem. It's when you try to break the 20 mile 20 mph barrier it starts to get heavy and expensive.
I'll have to disagree from personal experience. I have bikes that use both chemistry and SLA die quickly in the heat (brand new SLA mind you), unlike my NiMH (3 years old) counterparts. I've also found that mixing SLA with NiMH in the series results in the battery power not lasting as long. I figure it's because the SLA resistance increases quicker than the NiMH, they don't make a good combination.
As far as charging, both can take opportunity charges without any problems from my personal experience. Both can be charged while hot, the only difference is that a NiMH gets hot when approaching a full charge state. My SLA pick up some heat from a deep discharge state as well when going straight to full charge. Our sense of hot varies from person to person, I have to use a thermometer to set me straight. Often what feels like a NiMH pack that is burning is really only 110 degrees F or so. It's helped me to understand better what "hot" really is. I don't worry so much about my NiMH packs going nuclear. I figure it's already been 3 years and I would swear sometimes those packs were hot enough to fry an egg on, but they keep going strong. Mind you, they sit in the back of a bike pack with no ventilation what so ever. Great for the cool weather, murder in the hot weather. Which is why I suspect my SLA don't last long in the hot weather. The NiMH don't seem to care
Well anyway, what I was trying to say is I'm a big fan of NiMH because it's been good to me for many years without any problems. I've used SLA (AGM) much longer and they are what they are. Cheap and useful, but they do have their limits and I just don't want to haul around 50+ lbs of batteries for my bike. :wink:
But for the record, my NiMH packs are going on 19,000 miles right now. Well worth the $500 investment I made years ago.
esr750
1 mW
Lowell said:
With all due respect, I know each chemistry 1st hand. How much they weigh, how they charge, how they discharge, how much they cost and with that in mind - simply don't find middle ground with nickel-anything.
Ride enough, haha - yep, at my home in So Ca that ain't too hard but try that during winter in the NE where I work. Hell, my 13AH F cell NiMh packs seem "soft" after charging and sitting less than a day. If weather breaks after 3-4 days forget about getting full range from that pack. Sit for much longer than that and they'll need excersize to get back to full output. When you charge and they're not cool enough, good luck getting much current back into them as well. They're dense metal and seem to hold-in their heat for a long time too.
My lithium packs can sit after a charge for a whole month and still seem pretty hot when placed back into service. I have a conservative cut-off voltage for those cells but even when mildly warm, they cool down to optimium charge temperature much quicker than the NiMh chemistry.
Now compare weight savings - that 13AH NiMh pack is not even 1/2 the weight of 14AH SLA. On the other hand, my lithium pack is about 1/8 weight of same AH rating in SLA.
Of course, it could easily take about $800-$1,000 to reach 14AH @ 24Vdc in high power lithium chemistry compared to $300 or so for the medium power nickel variety.
All I'm saying is that in my case it's better bypassing that middle step and save for the lithium stuff because based only on weight savings, nickel is not $300 improvement over SLA for an e-bike. Factor in all the other sucky things I discovered during my road testing with nickel chemistry and it's a no-brainer. That's just my opinion, take it for what it cost...
OMT - before people start weighing their batteries and calling me stoopid and "off" on my weight/price estimates, they're just ESTIMATES. It was almost a year ago when I was deep into my sourcing and testing between NiMh & SLA. I once had exact weight/price numbers at my fingertips but it's not an exact science and I'm too busy right now to dig through volumes of data just to be exact for purposes of a hobby conversation.
Nimbuzz
1 kW
knightmb wrote "my NiMH packs are going on 19,000 miles right now. Well worth the $500 investment I made years ago."
WOOOOWWW -- you can't beat that!!
WOOOOWWW -- you can't beat that!!
Nimbuzz
1 kW
In my opinion, there are different qualities of Nimh cells and I would never charge warm cells, especially Nickel as we RC racers see the degradation that ensues.
I think good Nimh cells are more robust than claimed above but agree that saving for Lithium is wisest.
EV Tech 36v 15ah 10lb pack $750 has been proven for over a year on a number of ebikes. The US military bought 50 of them after severe testing.
http://www.texaselectricbikes.com/catalog/battery-chargers-c-36.html
I think good Nimh cells are more robust than claimed above but agree that saving for Lithium is wisest.
EV Tech 36v 15ah 10lb pack $750 has been proven for over a year on a number of ebikes. The US military bought 50 of them after severe testing.
http://www.texaselectricbikes.com/catalog/battery-chargers-c-36.html
Nimbuzz said:
Eight TP9000-6S2PX will cost $4k and give 88.8v and 18Ah of proven power. That's on the top of the price range though, but if I was going to spend the money, I'd get something that will give punch like my e-helis. Several times I've been dissapointed with the climb out performance of other lesser batteries.
Three of the EVtech packs for $2250 sounds ok, but I don't know much about them. Can they handle 50-60 amps continuous and 80 amp bursts?
My controller has a stall current drain of 90 amps (only for an instant like when starting a wheelie or burn out) and will sustain 80 amps for a few seconds at lower speeds.
Nimbuzz
1 kW
It seems that lowell is describing a very different bike than what we ride and are discussing.
It sounds very interesting!! Is it a Bonneville racer, a farm tractor or what?!!?
Can you give me a pic and description -- I love to see this monster!
It sounds very interesting!! Is it a Bonneville racer, a farm tractor or what?!!?
Can you give me a pic and description -- I love to see this monster!
Nimbuzz said:
The bike is a vintage Rocky Mountain Experience w/ Manitou fork. After much research and emails with Justin @ Ebikes.ca, I purchased a Crystalyte 503 hub, 72v 35 amp controller and 84v x 18Ah of Nexcell NiMH batteries. This was a good starting point, but it was underpowered so I tweaked the controller up to 45 amps and promptly blew up the stock FETs. In went the IRFB4110 MOSFETs (3.7 milli ohms resistance vs 15 for the stockers) with much beefed up wiring and a final controller current setting of 80 amps.
In the search for more power, I added a 2s12p lipo booster pack made from RC heli cells I had collecting dust, and due to some road debris that killed the stock rear rim, I installed a 37mm wide Arrow Racing wheel with DT spokes and spoke washers. Lighting is a Nitehawk K2 dual emmiter system which is bright enough that I've been highbeamed twice by oncoming traffic even though the lights are pointed straight ahead and down to illuminate the road.
http://endless-sphere.com/forums/viewtopic.php?t=612
That's the newest pic I have... minus the tank fairing as that's back where it belongs on the real bike :lol:
I'll have some new pics once the reconfigured battery pack shapes are done, and hopefully it will be an honest 50+ mph commuter bike.
Hello
Id like to add that I have had no problems at all with my NIMH packs, both the chargers use neg delta t charging with temp termination on 2 x 10k thermistors.
The performance of the packs dropped a little in the really cold weather but they are now back up to top form, I have 48V 13AH F Cells, I can pull 40A from them peak and have been for a year with no problems and can take the full 13AH out of them.
I monitor each cell periodically to check for reversal and have had no problems. I used lead acid for 3 years they were awful, I had to put new batteries in every 3 months or so it was ridiculous, they are ok for the first 5 mins then they are no good.
Also decent Lead acid batteries cost almost as much as NIMH here in the UK, Lead is ok for 6 mile range as this guy wants but I have to disagree about Lead, NIMH is a fantastic upgrade to lead, you obviously didnt get good cells or a good pack, this is important as there are some very poor NIMH packs around, as there are Lead acid batteries.
I have high capacity Lipo packs around but it still use my NIMH packs daily thats how good they are, I often mix lipo and NIMH in series which works well.
Its a shame the price of nickel is rising, this will come down I am sure, lipo is great but its not for everyone, there is no reason not to choose NIMH, those batteryspace blue and white packs do seem to be very good, Devin who posts here and did all the San Fran vids has been running 4 of these packs now daily for 18 months or so and they are as strong as new.
Lead is ok for low power very short range stuff, but if you are serious about your biking you would only use lead acid batteries to hold the door open.
Cheers
Knoxie
Id like to add that I have had no problems at all with my NIMH packs, both the chargers use neg delta t charging with temp termination on 2 x 10k thermistors.
The performance of the packs dropped a little in the really cold weather but they are now back up to top form, I have 48V 13AH F Cells, I can pull 40A from them peak and have been for a year with no problems and can take the full 13AH out of them.
I monitor each cell periodically to check for reversal and have had no problems. I used lead acid for 3 years they were awful, I had to put new batteries in every 3 months or so it was ridiculous, they are ok for the first 5 mins then they are no good.
Also decent Lead acid batteries cost almost as much as NIMH here in the UK, Lead is ok for 6 mile range as this guy wants but I have to disagree about Lead, NIMH is a fantastic upgrade to lead, you obviously didnt get good cells or a good pack, this is important as there are some very poor NIMH packs around, as there are Lead acid batteries.
I have high capacity Lipo packs around but it still use my NIMH packs daily thats how good they are, I often mix lipo and NIMH in series which works well.
Its a shame the price of nickel is rising, this will come down I am sure, lipo is great but its not for everyone, there is no reason not to choose NIMH, those batteryspace blue and white packs do seem to be very good, Devin who posts here and did all the San Fran vids has been running 4 of these packs now daily for 18 months or so and they are as strong as new.
Lead is ok for low power very short range stuff, but if you are serious about your biking you would only use lead acid batteries to hold the door open.
Cheers
Knoxie
esr750
1 mW
I guess there's people using Nickel chemistry and enjoying it? I don't get it - my F cell packs are from batteryspace. I monitor the cells and there's nothing wrong with them except that they're nickel which for my stuff behaves like I already stated.
40amps? Ain't that cute, did they put the 14ga wire leads on it too?
With an ESR750 you can expect at least 100-200 amp demand from the controller on startup. Lead or A123 lithium are the only cells I've found that can provide that.
I'll repeat one more time - In my experience, nickel packs didn't save enough weight compared to SLA to make them worth my time/money. Especially, when they behave the way they do for even short periods of storage time, recharge difficulties, etc. Knowing what I know now, I would have never bought them in the 1st place...
40amps? Ain't that cute, did they put the 14ga wire leads on it too?
With an ESR750 you can expect at least 100-200 amp demand from the controller on startup. Lead or A123 lithium are the only cells I've found that can provide that.
I'll repeat one more time - In my experience, nickel packs didn't save enough weight compared to SLA to make them worth my time/money. Especially, when they behave the way they do for even short periods of storage time, recharge difficulties, etc. Knowing what I know now, I would have never bought them in the 1st place...
Reid Welch
1 MW
Nimbuzz said:
Hi Al, how can I hear from actual users of their pack?
This must be the lithium pack---I would like to hear independent reports,
and wonder too what was the "severe testing" and such, that the US military then bought fifty packs from them for use in what application? needing 36V? That Halliburton wouldn't get the contract for, for a million bucks instead (eh!)
You know--I am getting hard of credibility after my recent unfortunate abortive BatterySpace pack purchase.
I sort of want to know what's inside any black box I might buy.
I can ask EV tech--and will.
Better first I hear from actual users.
There must be some reviews somewhere.
Can I draw 15Ah from their pack?
If, for instance, the BMS cuts it off at 10 or 11Ah, then, hey:
to my mind, that's a 10 or 11Ah pack, and should be sold as such.
Thanks for bearing with me---thanks for your recommendation.
I think they must be really good folks there at EV tech.
I think the same way about the BS people---I think they all mean well.
tiredly,
r.
esr750 said:
Your ESR750 puts out over 10hp? (200A, 48v?) Now that's my kind of thinking
Post some more info on your ride please.
Drawing those kind of amps out of any lead battery would decrease your capacity to only a fraction of it's normal rating. The 10C NiMH cells that RC racers use would happily deliver that current in a 3 or 4 parallel pack.
Lead batteries are great for stopping those pesky car covers from blowing around in the wind...
This is a great thread. I love the real-world give and take of the entire thing. I don't believe there's any perfect battery solution either, otherwise it still wouldn't be a hot topic of debate. Perhaps halve SLA's weight and suddenly it's back in favor. To be continued....
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