I don't even understand why vendors are selling anything less than 18ah SLA's. I got 9 ah sla and I get out about 5 miles and just get to sight seeing and I already have to come back. 90 % of my time on the bike is recreational. Anything less than 18ah SLA or 10/12 AH lithium is just a waste of money if you ask me. Bike frames and racks are pretty cheap but batteries are a real hassle. I'd rather have too much weight and find a way to make it work rather by too small of batteries and be stuck with them. You can always reinforce your bike rack or by a better bike rack but the batteries are a couple hundred bucks. Unless you have a specific use for your bike, like a 2 mile trip to the grocery, I think most people will be disappointed with anything less than 18 ah SLA's or 12 AH lithium.
Lets be honest, anything less than about 18ah SLA's
- Thread starter morph999
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Lock
100 MW
Hey Morph...
I don't think the smaller Ah SLAs were designed necessarily with EVs in mind? In any case, recall that it is Whs that are important...
For the same weight in batts, with smaller Ah units ya have more flexibility w/config'ing packs for Volts rather than Ahs, and more flexibility in how the smaller batts might be mounted eg some here prefer split packs for ease of mounting in two saddlebags.
Just my 2 cents. I would expect that all else equal, the larger Ah batts have higher volumetric energy density w/less wiring and connections.
tks
Lock
I don't think the smaller Ah SLAs were designed necessarily with EVs in mind? In any case, recall that it is Whs that are important...
For the same weight in batts, with smaller Ah units ya have more flexibility w/config'ing packs for Volts rather than Ahs, and more flexibility in how the smaller batts might be mounted eg some here prefer split packs for ease of mounting in two saddlebags.
Just my 2 cents. I would expect that all else equal, the larger Ah batts have higher volumetric energy density w/less wiring and connections.
tks
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vanilla ice
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For getting places I agree the small ones are not good. But not everybody rides to get to places. For having fun or very short hood trips they are good (and if you happen to weigh 40 pounds, they can give loads of range).
IMO 18's would be great, 12's are still decent, 7's and 9's yes you may only get 5 miles there and 5 back before lvc!
IMO 18's would be great, 12's are still decent, 7's and 9's yes you may only get 5 miles there and 5 back before lvc!
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vanilla ice
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Thats the trick with sla, either figure out how to load the bulk/weight properly, or take it easy on the power/range with the little 7 through 12's. Obviously you're not going to get your cake and eat it too for this price! Definitely go lithium if you want that. I know sla is not popular on ES but people out there are making it work.
And the "but you can get it on sale.." argument on other chemistries applies to lead too, don't compare sale lipo prices with full msrp on lead. Another way to look at it, with a (pedal only) tandem you have say 150 pounds of "assist" giving you what, 250w or less? Sla can better that, and (pedal only) tandems work great..
And the "but you can get it on sale.." argument on other chemistries applies to lead too, don't compare sale lipo prices with full msrp on lead. Another way to look at it, with a (pedal only) tandem you have say 150 pounds of "assist" giving you what, 250w or less? Sla can better that, and (pedal only) tandems work great..
icecube57
10 MW
SLA is not fun period. I had 58lbs when I went to 60v on my bike and i had almost 70 when i went to 72v. I would muck around with a shady ebay vendor before i go to sla again.
The jacked up thing is a 22v 5AH turnigy pack has about 110wh and a 18ah sla has about 140. They are the same price. But are you looking at performace weight or range... thats the question.
The jacked up thing is a 22v 5AH turnigy pack has about 110wh and a 18ah sla has about 140. They are the same price. But are you looking at performace weight or range... thats the question.
vanilla ice
1 MW
You must be looking at some expensive sla or not factoring in shipping from HK.. I just got (420wh before peukurt) 210Wh ebay sla at $70 shipped, 3Wh/$. Turnigy is $60 (22.2v) 24v 5ah plus $20 freight.. 120Wh $80 1.5Wh/$
Thats double even with peukurt.. yes yes I know sla is bulky and heavy, and the lipo aint. I'm not arguing those points here, I'm with you on that. Just addressing the Wh$ from the previous post.
Thats double even with peukurt.. yes yes I know sla is bulky and heavy, and the lipo aint. I'm not arguing those points here, I'm with you on that. Just addressing the Wh$ from the previous post.
I've used 3x 12Ah SLAs, and using them as assist-power via my radiator-fan friction drive worked ok, with a pretty decent range of several miles (forgot how many right now but it's probably on my project blog somewhere) to start with, but, being heavily used before I ever got them, they didn't last long before they were down to a mile or less.
I've also use 2x 31Ah SLAs, and those got 22 miles with a rest halfway in there, or about 15 miles continuous. However, that's on a much heavier bike (60+ pounds for the bike alone!), so if I could have ridden the other one with them it probably would've made it at least a third farther, possibly a lot more. Also I'm going a lot faster on this bike than on the first one, several MPH faster, usually.
Now I'm using 3x 17Ah SLAs, on the latter bike, and get around 11-15 miles range at reduced speed or with pedalling too, or perhaps 8-10 miles with just the motor. I have not yet done a ride-till-dead test, so these are guesstimates based on battery level whenever I decided to head home plus current draws under various conditions. Also, my lighting runs off these batteries, where it had a separate 7Ah before.
I do think that a part of the reason the smaller batteries give more range for their size is that there are three of them. As a whole, the weight did not really change, because in getting rid of the small 7Ah battery and changing up to 3 of these smaller ones from the two larger ones, it ends up roughly the same, around 51 pounds. If I used 3x 31Ah though, instead of just two, a more fair comparison could be made, using the same gearing and drivetrain, and those 31Ah's would stand out quite a bit more than they do currently.
That said, if anyone ever donates some LiFePO4 packs, I'll gladly test out the difference with the much lighter bike I'd end up with!
FWIW, due to the weight of the batteries, I'm in the process now of trimming weight from the bike itself (since I can't lessen the battery weight). It's a tough call on some things, like losing the shock fork and going hardnose (already hardtail).
I've also use 2x 31Ah SLAs, and those got 22 miles with a rest halfway in there, or about 15 miles continuous. However, that's on a much heavier bike (60+ pounds for the bike alone!), so if I could have ridden the other one with them it probably would've made it at least a third farther, possibly a lot more. Also I'm going a lot faster on this bike than on the first one, several MPH faster, usually.
Now I'm using 3x 17Ah SLAs, on the latter bike, and get around 11-15 miles range at reduced speed or with pedalling too, or perhaps 8-10 miles with just the motor. I have not yet done a ride-till-dead test, so these are guesstimates based on battery level whenever I decided to head home plus current draws under various conditions. Also, my lighting runs off these batteries, where it had a separate 7Ah before.
I do think that a part of the reason the smaller batteries give more range for their size is that there are three of them. As a whole, the weight did not really change, because in getting rid of the small 7Ah battery and changing up to 3 of these smaller ones from the two larger ones, it ends up roughly the same, around 51 pounds. If I used 3x 31Ah though, instead of just two, a more fair comparison could be made, using the same gearing and drivetrain, and those 31Ah's would stand out quite a bit more than they do currently.
That said, if anyone ever donates some LiFePO4 packs, I'll gladly test out the difference with the much lighter bike I'd end up with!
FWIW, due to the weight of the batteries, I'm in the process now of trimming weight from the bike itself (since I can't lessen the battery weight). It's a tough call on some things, like losing the shock fork and going hardnose (already hardtail).
liveforphysics
100 TW
Lead chemistry simply wasn't designed to cycle. A couple hundred shallow cycles at best? Most won't last for even 10 100% dod cycles.
Lead is the least expensive to get a bike to function, and the most expensive and envriomentally poor to use with a bike that sees duty as a normal transportation device.
Headways are so cheap from EV components, it just seems silly to bother with lead. you get somewhere around 1500-3000 cycles on your pack, and its something like $0.60 per watt hour ( if I remember right). That makes it cost something like 1/6 or less of the price of lead to use.
Lead is the least expensive to get a bike to function, and the most expensive and envriomentally poor to use with a bike that sees duty as a normal transportation device.
Headways are so cheap from EV components, it just seems silly to bother with lead. you get somewhere around 1500-3000 cycles on your pack, and its something like $0.60 per watt hour ( if I remember right). That makes it cost something like 1/6 or less of the price of lead to use.
Absolutely. If I actually had money to spend on anything at all, I'd've been using some variant of those for my whole project life (last couple years). 
As it is, I'm lucky to have the lead, which was donated to me used--I couldn't afford to even buy *these*!
I sort of look at it that at least since I'm using used batteries, I'm contributing to keeping them out of landfills and whatnot (since i know that no matter what the laws are, they get thrown away just as often as fluorescent tubes and CFLs).
As it is, I'm lucky to have the lead, which was donated to me used--I couldn't afford to even buy *these*!
I sort of look at it that at least since I'm using used batteries, I'm contributing to keeping them out of landfills and whatnot (since i know that no matter what the laws are, they get thrown away just as often as fluorescent tubes and CFLs).
If you go on electricrider's website, it says 7 - 9 miles or something for 48v 12 AH SLA. I don't know about you but I like to ride around and think and stuff. I guess maybe I'm just asking too much. I guess we are at the beginning of a long process to get to something much more economical and enjoyable. How can you even enjoy a 9 mile ride? It's a little enjoyable but nothing beats a 2 or 3 hour ride or even a 6 hour ride. I used to go out and ride for 6 hours and come home. Those were some of the best days of my life when I was 16 yrs old.
9 miles ride is not that bad compare to my 10mins ride on 48v 12SLA 12hr on cyclone 1000watts motor. Just outside my house and reach the juction,, Pop out orange led light appear so sooon.. i dare not further my trip and i U - Turn my ebike to Home. I end up scratching my head - how come my new batteries are like that?? that is how i going into lifpo4. SLA batteries need to do a longer charging for 18hr and it is not gurantee that the battery will be fully charged. At times we need just need short range for ebike, sla batteries are best used for below 20km is okay
to mount 18hr sla batteries on a bike isn't simple task too. becasue of the weight itself. to build it it must be strong enough to hold it and the battery holder must be able to take stress on uneven road, bumps, etc. so 12hr is better becasuse of the weight is lighter. the battery weight for a EBIke i think it best not more then 14kg , agree? Most important of all - it must match for balancing & flexiablity, comfortable enough for a long range ride. True??
kentlim
to mount 18hr sla batteries on a bike isn't simple task too. becasue of the weight itself. to build it it must be strong enough to hold it and the battery holder must be able to take stress on uneven road, bumps, etc. so 12hr is better becasuse of the weight is lighter. the battery weight for a EBIke i think it best not more then 14kg , agree? Most important of all - it must match for balancing & flexiablity, comfortable enough for a long range ride. True??
kentlim
AussieJester
1 TW
amberwolf said:As it is, I'm lucky to have the lead, which was donated to me used--I couldn't afford to even buy *these*!
I was in a similar situation amberwolf, i have only been able to afford the heavy SLAs and TBH they have been terrific but ONLY because my longest trip is under 10km. If i wished to ride off the hill onto the flatlands of Perth i wouldn't get back up the hill using the SLAs. Mine are 12v 18ah...I wouldn't have gotten these if the Aussie dollar was what it is now either i give you the tip thankfully its up from its low 60 cents to 86 cents again making the better technology within my reach.320 bucks for my 4 batteries, i can get 22v 5ah Turnigy packs (which i will be doing) now for only few bucks more, they weigh less than ONE of my 12v Slas LoL
Unfortunately Luke not all of us are fortunate enough to be able to drop a few grand on latest new compnents and batteries every second week without batting an eyelid like you do
.. and YES I AM jealous buddy hahahaKiM
dogman dan
1 PW
Sure there are better solutions than sla, but not all of us are able to fork out for the lifepo4. If I lived in the valley, 10 miles from work and no hill, I'd still be running lead today. A good lifepo4 pack treated nice will cost less per mile than lead, but if Safe was still around, he'd chime in how many miles you can get out of a larger sla pack.
I think 18 ah lead, 36v would make a good bike as long as 20 mph or so is ok. One in each pannier, and one on top of a rear rack, and balance the load by having a front hub. You'd get at least 8 miles at full speed without ruining the sla's. At 48v, I'd draw the line with 12 ah batteries to keep the weight down. At full speed, the range would be less, but the better top speed might be worth it.
But the real drawback with lead is that you can ruin em so easy. My first lead pack that came with the WE kit, I hammered it and lost 50% of the capacity in about 30 cycles. Others I bought later and ran on the EV Global bike are still quite good after a lot more cycles. A very conservative LVC would help a lot with a lead powered bike. The WE throttle light simply lets you know you already screwed up.
The key thing when buying lead batteries is to get the right type. The less expensive ones are not for running motors, but for lights and computer power back up. The wheelchair type is what you want, and often they are 18 ah or larger. The B&B EV type is supposed to be one of the best, and 12 ah ones cost nearly as much as lithium.
What really worked great for me was 12 ah sla paralelled with 8 ah nicad. Not quite so heavy, and some pretty tired sla's performed great when teamed with some fresh nicads. Very little voltage sag with that setup.
I think 18 ah lead, 36v would make a good bike as long as 20 mph or so is ok. One in each pannier, and one on top of a rear rack, and balance the load by having a front hub. You'd get at least 8 miles at full speed without ruining the sla's. At 48v, I'd draw the line with 12 ah batteries to keep the weight down. At full speed, the range would be less, but the better top speed might be worth it.
But the real drawback with lead is that you can ruin em so easy. My first lead pack that came with the WE kit, I hammered it and lost 50% of the capacity in about 30 cycles. Others I bought later and ran on the EV Global bike are still quite good after a lot more cycles. A very conservative LVC would help a lot with a lead powered bike. The WE throttle light simply lets you know you already screwed up.
The key thing when buying lead batteries is to get the right type. The less expensive ones are not for running motors, but for lights and computer power back up. The wheelchair type is what you want, and often they are 18 ah or larger. The B&B EV type is supposed to be one of the best, and 12 ah ones cost nearly as much as lithium.
What really worked great for me was 12 ah sla paralelled with 8 ah nicad. Not quite so heavy, and some pretty tired sla's performed great when teamed with some fresh nicads. Very little voltage sag with that setup.
I dunno, I've used the same batteries morph has, and I can squeeze out 20+ miles if I keep the speed around 15 mph and pedal lightly. The main difference is the motor. I used them with a 7x9 9c motor, the forsen hub morph has seems pretty amp hungry.
Lock
100 MW
I am used to getting 6-12 miles (10-20kms) on 240Wh of SLA but the controller cuts out at 80% DOD so only 192Whs... This with a reasonably fresh pack of 2x 12V10Ah SLAs as 24V.
Cold temps and tired pack and showing off and up hills and headwinds and passengers etc = less range. Lucky to get 100 cycles out of these batts at 80% DOD almost EVery discharge. REALLY, 50% DOD would be much better for SLA cycle life. All this on a kick machine that "leans" on the batts more than pedal folks that may employ more meat engine in the mix.
So morph... back to your OP... how many Whs (not Ahs) in your pack?
tks
LloK
Cold temps and tired pack and showing off and up hills and headwinds and passengers etc = less range. Lucky to get 100 cycles out of these batts at 80% DOD almost EVery discharge. REALLY, 50% DOD would be much better for SLA cycle life. All this on a kick machine that "leans" on the batts more than pedal folks that may employ more meat engine in the mix.
So morph... back to your OP... how many Whs (not Ahs) in your pack?
tks
LloK
DahonElectric
100 W
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- Jul 15, 2008
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morph999 said:
I think vendors sell lower capacity SLAs to compete in price. It's pretty normal to see this not only on the ebike circle, but pretty much any electronic gadgets you buy these days. Many of them provide Alkaline batteries that you know won't last for very long on high drain devices like a digital camera. But Alkaline batteries are cheaper than NiMH or Sanyo Enerloop batteries and you don't need to throw in the charger as well.
Besides, not everyone shares the same travel mileage as you and I do. Some people are cool to commute by bike for 20 to 30 miles/day and yet, you see people commuting by ebike using transit to reach the last mile or so. 5 miles is enough to go from the train stop to where you work I suppose. And then, you are expected to charge the battery at work.
But you're right. They would be better served with a 8ah NiCAD or a 10aH Li-Mn or LIFEPO4.
DE.
vanilla ice
1 MW
I've gone 20 miles on 3 12ah's with loads of leg assist. But thats a looong ride for me, and I like to use legs as much as possible. I also do not ride daily so cycle life is not an issue. Your type of riding is going to dictate whether or not sla is a good choice, I do concede there is a fairly narrow range of uses where it works well for ebikes.. For sure if you want hours and hours of tooling around morph, sla is probably not going to work well.
As for the environmental side of sla, I don't know how they stack up vs. other chems. Doesn't the recycling of the lead pretty much mean 100% of it gets reused? What happens to the lithium bats when they die?
As for the environmental side of sla, I don't know how they stack up vs. other chems. Doesn't the recycling of the lead pretty much mean 100% of it gets reused? What happens to the lithium bats when they die?
Lock
100 MW
vanilla ice said:
I have a Lithium, Nickel, etc battery recycling biz close to me:
http://www.rawmaterials.com/index.cfm
Generally speaking, North American folks can find recycling programs and drop-off points from here:
http://www.call2recycle.org/
tks
llOc
Russell
1 MW
nomad85 said:
It's all about speed! I started out with using 36V/9Ah (real world 5.4Ah max) of lead with a Bafang and a 15A controller and could go 24-30+ miles averaging high 15's to low 16's mph and use 6-7 Wh/mi. I soon upgraded to 36V/6Ah of LiMn and with it my average speed increased about 1/2 mph but power consumed only edged up a bit (I was also getting back into cycling shape after the winter). When I added a 12V SLA as a booster to get 48V my average speed took a bigger jump to about 18 mph but with the still small capacity (the SLA died by 4.8Ah) I used the throttle lightly so that power used increased to the 7-8 Wh/mi range. On shorter rides I could goose it to get speeds in the 19's with power consumption increasing to 10-12 Wh/mi. I recently got a 48V/10Ah LiFePO4 battery and with less need to practice conservation It's difficult to use less than 10 Wh/mi to average mid-high 18's. To get 20+ mph I use in the mid to high 13 Wh/mi range. With my 9C/20A combo it's even more difficult to keep power consumption low since the power spikes rapidly on acceleration and up hills...plus it's a blast running up to high 20's or 30 mph (w/pedaling) at will.
I look fondly back to earlier this year when I rode my ebike for the first few times and reveled in the power assist while happily pedaling along at just above a normal pace. In those days of ebike innocence I couldn't understand how people could use so much power from their batteries. While I still don't use the 20 or 25 Wh/mi that many people consume there's no going back now to those early days of using 6 Wh/mi. Heck yesterday on the last stretch home I held full throttle on my Raleigh/9C@48V bike for 1 mile and used roughly 33 Wh/mi. Yikes at that rate my new 'big' battery would only last 12 miles to 80% DOD.
-R
vanilla ice
1 MW
Great quote, I think Russel hit the nail on the head. A lot of it is in how you ride. I hardly ever go over 15mph and I'm ok with that. A five mile trip takes only 20 minutes at 15mph.. but I can see how that speed wouldn't work for some of you guys on longer trips.
Lock, I know the lithium gets recycled, but what I meant to ask was, how does one type of recycling compare with the other? Is one more complete or efficient or earth friendly over the other? An sla is plastic, lead and glass and acid.. what else is there? When it gets recycled I assume all four get recycled.
Lock
100 MW
vanilla ice said:
Good question... Pics of kids in India and China breaking open battery cases do not inspire confidence in the "recycling" process. But from http://www.rawmaterials.com/index.cfm:
...not sure how well SLAs measure up, or if all recycling plants are as conscientious as above
tks
lOCcc
liveforphysics
100 TW
Lets say the lead and lithium are both 100% recycled.
The lead needs to be recycled 6x more... Thats 6x more trips to a drop-off center, to a truck, to a plant, to get ground up and melted down, and purified, and re-cast, and then injection molded to form the case, then transported back to a wholesaler, to a distributer, then to you the customer.
Then, each time the lead is charged, a good deal of that energy is wasted thermally in the batteries, where good lithium takes >95% of the energy it's fed and stores it.
Lead is the most expensive in personal cost, and environmental cost. It's only the cheapest to get a setup up and running initially.
The lead needs to be recycled 6x more... Thats 6x more trips to a drop-off center, to a truck, to a plant, to get ground up and melted down, and purified, and re-cast, and then injection molded to form the case, then transported back to a wholesaler, to a distributer, then to you the customer.
Then, each time the lead is charged, a good deal of that energy is wasted thermally in the batteries, where good lithium takes >95% of the energy it's fed and stores it.
Lead is the most expensive in personal cost, and environmental cost. It's only the cheapest to get a setup up and running initially.
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