Newbie needs help with battery - sla vs hobby king?

[auraslip]

I've finally settled on a nine continent kit from ebikekits.com from user drasp for $250. Quite a deal!

I've tried to read as much as I could before I posted so I wouldn't ask something that has been answered, but digging through all these posts is getting tedious.

I initially was going to get 4 12volt 14 ah SLAs for $25 each, but after thinking about my situation decided I would kill them by discharging them fully and not having a chance to charge them. Am I correct in expecting a 15 mile range at low speeds in a hill less area from that setup?

So the real question is what are my options?

The $300 dollar ping 36v 10ah kit is just barely in my budget, but it says "for kits up to 400W".

http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=9177 6 of these could be wired to 36v and 10ah, and would be easy to add more as I needed. However I've read about bms and chargers and I'm confused as of what I would need! Ideally I'd like to be able to pack the charger and batteries in my topeak bag and rack, so I could charge at work, my girlfriends, or the bar.

Do I need BMS?

Could I get away with having only one charger?

 

[morph999]

I don't think this is one of those forums that says "use the search" everytime. We like to talk about electric bikes here. It's fun.

6 of those Lipo would be 44v10AH, not 36v. Right? It'd be about $180. Those are much more dangerous than lifepo4. I'd personally never buy lipo. I'd buy lifepo4 or SLA.

You never considered Thundersky lifepo4? 95 % of users on here would advocate using a BMS. I would say that if you are going to get a 36v10AH lipo or lifepo4 then yeah, you'd need a BMS. If you were going to get a bigger pack, like a 36v20AH then I'd say, it's not as necessary and you can manually balance your pack and get away without using a BMS as long as you are willing to put in some time in learning how to use lifepo4 and also the time in manually balancing them. If you want something to just plug in and forget about it, then you'll need a BMS.

As far as SLA, my SLA's lasted 7 months. If you find that you are using your SLA, and they are pretty hot after each use, you can expect them to not last long. If I were to buy SLA again, I'd buy the B&B EB20-12's which are a 12v20AH battery but you'd need either an axiom or topeak bike rack to support that kind of weight because they are heavy. The reason I'd buy those is that they are specially made for e-bike use and some guys on here who use these have been using them for almost 5 years. That's if you baby them. When you buy SLA, the capacity that it says and what you get are two different thing so if it says 20AH capacity, you're probably only going to get about 50 % of that.

I'd buy the Thundersky lifepo4 at elitepowersolutions.com if I were you. That's the pack that I'm using. They are kind of bulky but I think they are a steal for $104 per 12v20AH pack. Not everyone likes that kind of prismatic cell, though.

 

[auraslip]

I'd like to get SLAs because they're cheap, but I know I'd get drunk one night and crash at a friends house and not charge them. If I do that a bunch of times they'd die pretty quick!

How much does a BMS system run for the thundersky systems? That sounds pretty cheap. 36v20ah for $312!

 

[MitchJi]

Hi,

I'd like to get SLAs because they're cheap, but I know I'd get drunk one night and crash at a friends house and not charge them. If I do that a bunch of times they'd die pretty quick!

If you do that with Lipo they will explode pretty quick.

 

[dogman dan]

You are just like I was at the beginning of my Ebiking. You think you'll go further than you actually will on your new motor. And you don't have a lot of money to put into the project. It's a problem.

You might want to stay away from lipo unless you have some experience with them. Noob mistakes get expensive. They aren't as likely to explode nowdays as they uses to be, but the whole deal of putting a pack together series connected to ride at one voltage and then charging at a different voltage is a bit much to deal with on your first ebike. But they do have a huge advantage in weight, ability to carry on the bike without being a huge weight on the back, and you can easily buy more packs to expand the size. So the lipo advantages will be very tempting.

Sla's to go 15 hilly miles is not realistic at all though. You just won't have the capacity to go that far on hills. If the hills are steep, you might get so heavy carrying more lead that you go less far than before. That actually happened to me, trying to carry enough sla's to go 15 miles uphill home to my house. I ran out with 4 miles to go. Adding more batteries, I ran out 6 miles from home because the batteries were so heavy to lift up the hill. The cure was a 36v 20 ah pingbattery. Also the deal with having to charge sla's right away is way too inconvenient at times. A freind who rides to work on a 48v scooter and waits till she gets home to charge kills her batteries faster than she would with another chemistry.

A pingbattery or similar bms regulated lifepo4 would be the best thing for you, but the cost is a bear. You are correct that a 48v 10 ah would be a bit on the small side. It would be ok for a shorter ride on flatter terrain, but for a bunch of hills, and 15 miles, a 15 ah battery would be the minimum size, or a 36v 20 ah if you ran 36v. You need the extra for the day when your uphills are into the wind, and you need to discharge less than 100% to maximize the battery lifespan, and you need to discharge at less than 100% of the avaliable continuous amps to max out the lifespan. It just makes too much sense with all chemistires to have 20-30% extra , because the battery really will last a lot longer.

So it's hard for us to suggest a solution to the problem with no solution, no money. As Morph did in the beginning, it might be worthwhile for you to simply start with what you can afford, some sla's. Use them to gain experience riding the bike shorter distances, and save up, work extra, or whatever it takes to get your lithium in the future. The same approach could be used with lipo, buying two 5ah 18v packs to make a small 36v battery for the bike. Consider the first two packs expendable, since you will be likely to ride em to death faster than usual, just like you consider a first sla pack expendable as a learning process. Either way, you won't be riding 15 miles though.

Good luck, hopefully it will work for you the way it did for me. Even the shorter rides were saving me money, and pretty soon I was able to get the lifepo4 and save even more on the longer trips.

 

[auraslip]

frocking hell this is the second time I'm writing this. Apparently if focus isn't in the text box and you hit backspace the browser goes back.....

So it's hard for us to suggest a solution to the problem with no solution, no money.

This forum isn't my personal EV genie? Damn..

A friend who rides to work on a 48v scooter and waits till she gets home to charge kills her batteries faster than she would with another chemistry.

This is what I'm afraid of. I think you misread me though. I live in hillless flat north texas. I know 3 12v14ah SLAs would have the range to get me to work and home. But I don't think they'd get me to work, and then class, and then to the coffee shop, and then to the bar, and then to home. Although with everywhere having power plugs for laptops, if I had a portable charging system it could be doable!

The same approach could be used with lipo, buying two 5ah 18v packs to make a small 36v battery for the bike.

If you do that with Lipo they will explode pretty quick.

Lipo is SOooo tempting at this point for weight and cost reasons. However I know nothing about BMS. Why do I need it? How do I implement it on lipo packs? How much does it cost? Where do I buy it? etc etc et...

I appreciate your response dogman, I've read a bunch of your post and found them all very helpful! I wish we could condense all the knowledge on this forum into a wiki or something more accessible to people that don't have all the prerequisite know-how to understand most of the posts!

 

[auraslip]

If I were to buy SLA again, I'd buy the B&B EB20-12's which are a 12v20AH battery but you'd need either an axiom or topeak bike rack to support that kind of weight because they are heavy.

Got the topeak bag and rack, and I love it to death!

Are the B&B really that much better than, say, power sonics? I found 12v14ah power sonics for $30 online.

 

[Lock]

Lipo is SOooo tempting at this point for weight and cost reasons. However I know nothing about BMS. Why do I need it? How do I implement it on lipo packs? How much does it cost? Where do I buy it? etc etc et...

You mentioned ping packs... LiFePO4 is a lithium compromise w/less energy and power density than other Li formulations but the tradeoff is safety and knowledge. Ping etc LiFePO4 packs come w/BMS included. It's a printed circuit board w/tiny wires to each cell in the pack to monitor each cell and typically slipped inside of the packaging for the cells. Just save your pennies for a bigger LiFePO4 pack than you think you need, and with care over the lifecycle of the Li cells they should work out cheaper per mile than lead, a lighter vehicle, plus you can design to remove the lighter weight pack to charge indoors at work or maybe class. Plug in no diff than a laptop computer...

Cheers
Lock

 

[evblazer]

Wait Hillless North Texas? I'm in North Texas I know it sure ain't no mountain range but there are hills and a few on my commute and tons on my 200k+ rides When I drive my "normal" car I wouldn't notice them since they are so gradual but riding my bike and even more so driving my electric car I sold you really can feel em.

The cheapest way up front way is to use SLA and even cheaper is to use used SLA from say the school when they change all the UPS batteries if you can smooze the right person. 36v sla chargers are pretty cheap. If you are careful and make sure you check your cells once in a while and the controller has a low voltage cutoff the Thunderskies are a good option from a price perspectice and seem to be holding up well in my 24v mower using the built in charger. Small lipo's need lots of care by your or by electronics (BMS) and you. Pings are a nice solution that is plug and play and from what I read here most are without problems as long as you don't leave them sitting for months without charging them.
Problem with SLA's are poor performance and short life when deeply discharged or pushed too hard like in the 105 degree heat and such. Then they need frequent replacement and people hate electrics or end up spending alot more $$$. Course I jumped into thunderskies for my electric bike and if they aren't enough I'm out more $$ then I would have been with some SLA's.

I'm personally kinda scared of charging not in home base in case something happens. Lipo's can have violent burn through steel plate events if handled poorly or overcharged. Even with SLA's though or with a BMS in "safer" lithium chemestries I'd hate for something to let go of it's magic smoke or pop at work but then this company is on the hunt to get rid of anyone and everyone and make their life miserable and then kick them to the curb. That and I'm in an enclosed room with no windows and the two other people definately would not appreciate the smoke or sparks and certainly not when they found out what it was from. I'm overly cautious though and respectful of EV's and have always charged my EV away from my house because a few of my friend had their cars or garage/workshops turn into piles of ashes. One of the ev's I got was dirt cheap because the previous owner had a charge wire across the battery box that worked fine for decades but one day it finally wore through and shorted two terminals and caught fire melting the batteries and lots of damage to the car. So between that and the flooded lead acid batteries I used gassed a bit when balancing so you don't want that in an enclosed space for smell and the urban legend(?) of hydrogen buildup and the charger igniting it I don't like charging anything bigger than a laptop inside unattended.

 

[vanilla ice]

How fast do you want to go? From what you've said your use would be.. I think sla would work assuming you're more a cruiser than speed demon.

 

[auraslip]

How fast do you want to go? From what you've said your use would be.. I think sla would work assuming you're more a cruiser than speed demon.

Speeds not really important. I'd like to ride at a speed that gives me maximum distance. 15mph?

pushed too hard like in the 105 degree heat and such.

Yup. 105 degree texas heat. Batteries in a nylon black bag. Talk about stress.

I'm overly cautious though and respectful of EV's and have always charged my EV away from my house because a few of my friend had their cars or garage/workshops turn into piles of ashes.

Now your just scaring me I used to install batteries for AAA mobile service, and I met two people who had batteries explode on them. One of them lost his vision for 6 months from it, so I am always nervous with big batteries. Especially automotive ones.

That's cool that ping has built in BMS. They are starting to look more and more like a great investment.

What part of North Texas are you from:?

 

[vanilla ice]

You are new to all this ebike stuff, and only needing 15 miles of range at 15mph.. If you can deal with the weight of lugging four 12ah sla bricks around I think that's the way to go for you. After you burn them out (hopefully after years of good use) you'll be ready for the touchy lipo.

 

[dogman dan]

Duhh, I did misread about the hills. A really good set of 4 12 ah sla's might do it for you then, but if you can go for a 10 ah lifepo4. Personally, I could only get about 10 miles out of 3 12 ah sla's on flat ground at 15 mph. The rub with the sla's is the peukerts effect that makes them really have only about 6 ah in them that's usable. So there is more range in a 10 ah lifepo4 or lipo than in 12 ah sla's. At 15 mph you should be able to get just about 15 miles out of a 10 ah 36v pingbattery. At 15 mph, you will be using less wattage, so it should be ok. 48v is nice, but I'd rather have the 36v lithium than all the weight of sla's.

 

[evblazer]

Now your just scaring me I used to install batteries for AAA mobile service, and I met two people who had batteries explode on them. One of them lost his vision for 6 months from it, so I am always nervous with big batteries. Especially automotive ones.

What part of North Texas are you from:?

I'm in the Flower Mound area south of Denton. Yeah big batteries are big and have alot of energy but these little batteries are more densly packed balls of energy
I shorted a pack of flooded nicad starter batteries wow did that insulation burn off before I even noticed I shorted them. Then there was that 18650 that went off on a long bikeride when I dented it against something. Just need to be careful and respect them and care for them. I think I'm bad luck everytime I start thinkings pings are great a post comes along like so Ping Disaster! http://www.endless-sphere.com/forums/viewtopic.php?f=14&t=16796 Course if that is the worst disaster that can happen it's pretty good but not something for a library That thread about putting some LIPO packs in a backpack

*shudder*

 

[auraslip]

Crazy small world. I went to FMHS, and i'm going down there for my step dads birthday tomorrow night

Carrying all this energy is a lot like driving a fuel truck. The only difference is the danger isn't as apparent.

I just spent 4 hours looking for cheaper lipo and lifepe04 and ping is the cheapest anywhere, but still tantalizingly out of my budget for this project. What can I say? I promised my mom I'd get a bike helmet if I got an ebike

I think I've decided on these SLA's http://cgi.ebay.com/ws/eBayISAPI.dl...akeTrack=true&ssPageName=VIP:watchlink:top:en That's only $80 for four of em'! I know I could get 3 power sonic 12v14ah for $100, and maybe I should but as everyone else has said maybe my first pack should be disposable?

 

[moostrodamus]

I rode for 2 seasons with SLA's before i got my Ping, 4X12v 14 ah about 44 lbs. How do you plan to carry your batteries on the bike? I have a few broken rear racks, some bent rims with broken spokes that will attest to troubles carrying on a rear rack. Maybe i'd try to mount them in the frame if I was going to do it again with SLA's...

Having said that, The batteries lasted the 6-7 months i rode each season, and it was what i could afford, and got me where i needed to go. You might want to invest in a spoke wrench if you end up breaking a spoke and the rim goes all whacky...you can adjust the opposite spokes so the rim wont rub enough to get you home. ...

Moo

 

[auraslip]

I have the topeak rack and bag that slides into place and locks to the rack. It comes with the crystalite kits.

You might want to invest in a spoke wrench if you end up breaking a spoke and the rim goes all whacky...you can adjust the opposite spokes so the rim wont rub enough to get you home. ...

Wow that's hardcore. I'm aware my wheels now are single wall. I guess I'm gonna have to beef it up! I'm already pretty good at truing wheels from my ex-girlfriends vintage sears road bike. The city I live in has lots of pot holes. It should make riding a bike with 50lbs of gear fun

 

[moostrodamus]

Eventually i broke enough stuff that I bought a ping battery which weighs about 21lbs, which is the outer limits for a rear rack IMHO. I rode like a maniac though, about 28mph so maybe you will be ok if your just doing 15mph. Just be aware that if you hit a big pothole, its good to have a spare tube/tire and spoke wrench for on the road, and have a few spokes handy at home to fix the rim. I am sure there is lots of advice available for a SLA setup....Anyone?

Moo

 

[moostrodamus]

I found a few pics of my old bike with the SLA setup. I bought the plastic box after getting caught in the rain a few times and ending up with a soggy bag full of batteries. Also, I would gloop a big wad of Clear silicon (tub) over all the contacts as I had power cut out a few times because of corrosion. The clear silicone just peels off pretty easy if you have to take anything apart.


Here is a 60volt pack I built while waiting for a new charger for my Ping. 5 AGM 12v 12ah batteries. Have to remember to poke holes in the tape where the battery vent holes are.
View attachment 1
Lastly, my "safety Bungee"...my rack broke twice where it connected to the bike. I eventually had the guys at work weld a solid aluminum plate where the flimsy stock bolt -on area was. I tied the bungee to the rack and the seat post as the first time it happened, the whole rack just flopped over the back wheel onto the ground spraying batteries all over the road...uncool.

Hope some of this remotley helpful!

Moo

 

[Pablo_1985]

Hey, i have a 48volt 1000w hubmotor, and i have 8 used(i don´t know the exactly capacity) sla batteries ( http://www.yuasa.com.tw/english/vrlafile/NPW45-12.htm) do 15 miles range, with soft and large hills, there is a lot of everything.... look at one of my ways, notice is a round trip, google street view is available.

http://maps.google.es/maps?f=d&source=s_d&saddr=Calle+Pintura,+63,+28224+Pozuelo+de+Alarc%C3%B3n&daddr=40.446261,-3.812685+to:Av+de+Pablo+VI+to:Ctra+de+Carabanchel%2FM-502+to:Ctra+de+Carabanchel%2FM-502+to:Calle+Tramontana+to:Ctra+de+Carabanchel%2FM-502+to:Calle+de+Picasso,+4,+28223+Pozuelo+de+Alarc%C3%B3n,+Madrid,+Comunidad+de+Madrid+to:Calle+Pintura,+63,+28224+Pozuelo+de+Alarc%C3%B3n&geocode=FelEaQIdt9PF_yktiL7kiIZBDTE470VgdlSw_w%3B%3BFWz7aAId1ODF_w%3BFVrFaAIdGwDG_w%3BFcqKaAIdZEPG_w%3BFeKMaAIdBh7G_w%3BFTqYaAIdYjvG_w%3BFb2caAId3j_G_ylZDOrjf4hBDTH2ACdcNo_GvA%3BFelEaQIdt9PF_yktiL7kiIZBDTE470VgdlSw_w&hl=es&mra=dpe&mrcr=0&mrsp=1&sz=15&via=1,2,3,4,6&sll=40.442211,-3.808951&sspn=0.025672,0.038581&ie=UTF8&ll=40.424343,-3.788738&spn=0.102714,0.154324&t=h&z=13

After this trip my batteries still have some charge...

I put my throtle to 80% ... before i had two bags each one at each side of the rack (also topeak! controller is on the bottom of the rack) and when i changed it to just one bag on the top of the rack i notice a higher speed and better range! man aerodinamics are pretty important, don´t forget!! even in a soft downhill without motor and without pedalling if you put your body ok you can reach 55km/h (37mph)(that´s the only advantage of all this weight!...make the most of it!) all my way is a good road with just a little of stop and go (sla and regenerative mode... bad), with high presure in my tires, and road tires of course, i weight 68kg and i pedal...ok i am good at pedalling, but i don´t try it so hard...my average speed is above 30km/h (19mph). Now i´m waiting to arrive this watt meter http://endless-sphere.com/forums/viewtopic.php?f=3&t=13607&hilit=watt+meter wich allow me to see how much i could push my batteries....anyway, there is something bad here, the range is too high and as they told you it is not good for the batteries to make a deep cycle. I think if you do somethiong like me and go slower could make it, but if you are going to make this way normally... maybe is too much for the batteries. Furthermore, ride a bike with so much weight is something tricky and more when it is so high... anyway with time you learn to move it...

Actual:

I hope my experience help you in your decission

PS: yeah, i don´t have rear brake and i´m not happy about it.... don´t try this at home XD, let´s say it´s just a beta! actually i´m looking for a frame because this one also is heavy and have a rear shock wich don´t work (hopefully for the topeak rack XD)

 

[morph999]

The cheapest lithium on the market is these: http://elitepowersolutions.com/products/product_info.php?cPath=16&products_id=74

If you live in the USA, shipping is only about $25 so a 36v pack would be about $335.

Get a $40 ..12v SLA charger and a $13 3.2v lifepo4 charger from all-battery.com and you are set. Just don't use more than about 50 - 60 % of the pack. If you are good with electrical wiring, you could buy two 8s Celllog monitors from hobbyking for $39 each for a BMS. Even if you buy a separate BMS, it's still probably cheaper than the ping. The ping are smaller, though. If you already have an 12v or 36v SLA charger (or whatever capacity you are using), then it'd be even cheaper.

 

[FeralDog]

SLA versus Lipo/LiFePo04 ???

IMHO if you don't have the money right now, SLA's are a proven cheaper, relatively safe, lower tech, easy maintenance solution to getting on an e-bike NOW. But they are heavier and may not produce the expected energy you want over time. They will do the job for for months , and maybe a few years.

 

[auraslip]

Hey moo I like your set up! Looks secure, and It'd be nice to have to worry about it being locked up!

Pablo you live in a beautiful country! You have an awesome looking ride everyday! I'm curious if you still have your controller mounted on the bottom of the rack? I want to mount mine there but I'm worried about rain! I have a nice fender to protect it, but still!

You should get a rear brake. They aren't expensive. I think the new ones I got were....$30 for the complete set? Don't want you to take to much advantage of the weight coming down a hill one day

morph that is indeed a good deal for a 36v20ah li pack. I'm just worried about not having BMS. That's a big investment to fry in the 105 degree texas summer heat. I thought BMS was an absolute necessity for those types of batteries?

Here is my advice ---- Get the SLA's to fit your budget, ride with them and their "limitations" , then when your friends say they also want an e-bike too (but they can't afford the Lithiumstyle batteries) , then get you a new LifePo4 and sell/give your old the SLA's for your buddies use on their new e-kit.
American Special Forces call that tactic a "force multiplier".
You will both get what you want, when you both need it. And the joy will spread at a rate you can afford ....

That is actually the best reason I've heard for getting SLA's yet. That may be the deal breaker.
It's funny how we get in the gasoline mind set. We think of batteries as cheap disposable fuel. It's hard to spend $300 on batts when you are of the mindset that they aren't really part of the system. The more I learn though...the more I realize that they more or less make or break the system.

 

[Pablo_1985]

I live in Madrid, Spain, but in a small town (80.000 population) called Pozuelo de Alarcón (http://en.wikipedia.org/wiki/Pozuelo_de_Alarc%C3%B3n), i am lucky because it is a good town full of parks, anyway thanks

I still have my controller there, and i have just protected the part where the wires come out of the controller... i usually don´t ride with rain, but i have use it with snow and some water and no problem, in fact for me it seem to be very protected and more if you have a fender!

I love riding, it is something i do allways since i was a little boy, and i have more than one bike... when i decided to make an electric bike i just use one bike that i have ...not a good one, and with the topeak rack i can´t use disk brake (not in this frame), and also i can´t put a v-brake because the frame don´t support it hahaha, so... i will get a frame. The front brake is a mechanical disc brake, and surprisly works very good...BUT yeah i have to fix this.

Feraldog had a good idea, all my friends want an electric bike, the problem is that i´m not going to sell them something wich cost me 0€...but maybe your friends want to do less miles and you can sell to 2 friends, pretty good idea...

By the way today i get the turnigy, and my bike is 1048w!(shit, now that i know this i want to improve it...... NOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO) hehe, do you know how much money did i spent in this bike? believe it or not, 305$ :O the entire bike!

Do you want a simply plug and play bike? then get a BMS...(by the way, is not necesary a BMS for SLA pack? isn´t it?). I´m using SLA batteries because a friend who work with UPS get me batteries wich his company would throw it to trash, but my friend check them and say they were allright, if i have to buy something i would buy a LIFEPO4, if you make numbers you would see it´s woth it.

 

[Lock]

SLA's are a proven cheaper, relatively safe, lower tech, easy maintenance solution to getting on an e-bike NOW. But they are heavier and may not produce the expected energy you want over time. They will do the job for new guys (like me!) for months , and maybe a few years.

Dream on my friend... There's a saying in the EV community that old batteries don't die, they are murdered. VERY few folks get many years out of lead chemistry unless they are EXTREMELY responsible w/commissioning and maintaining their packs... or just don't use them.

Also, not a lot of discussion here from folks converting from Lithium to Lead.
Tks
Lock