new eZip motor

[latecurtis]

Ok I got that. I realize all SLA batteries are shit. I got that. I am looking for batteries for dual AmpFlow motors. I also just posted on skakabalas misfire post. Please check it out if you can.I am looking to move on to bigger and better things. Post some affordable 72V 200Ah batteries please if they exist. Under $3.000 is what I mean by affordable as I know they wont be cheap. Thanks.

LC. out.

 

[latecurtis]

I already have a reliable bike in the Schwinn and the front end kit you sent and the LIPO packs Dan sent me. It is just kind of big for my stairs. The 20" Diamond back is my play bike. When I really have something important to do like go to my heart doc I break out the Schwinn. Library is closing. I will talk to you guys Monday.

Once I get the new 24 to 60V controller I can run the LIPOs or the four new SLAs on the 20" bike and it will be both fun and reliable. Thanks.

LC. out.

 

[DrkAngel]

SLA batteries are not "shit"!
You are tasking them in a shit manner!

You willing to get real?

Rig your 4 10A batteries as 24V 20A! = possible years of proper use.
*("15mph = 20 miles range - 100 cycles = 2000 miles" = 400 x 5 mile trips)
You can always swap to 48V 10A when you want to destroy them! = possible months, maybe only weeks, of overtaxed use!
*("30mph = 2 miles range - 5 cycles = 10 miles")

* "48V 10ah battery - SLA 480wh
... to 80% of rated capacity ... based on typical SLA "

 

[slowhands]

Acid is the way to go. Lead Acid. I got you covered.

 

[Sunder]

Ok I got that. I realize all SLA batteries are shit. I got that.

Are you not getting it? Or are you just being childish? Because both DA and I made it very clear that there's nothing wrong with SLAs - when used for the right context. They're great for starting cars and storing backup power. They are still the world's most used battery chemistry.

But do you see Tesla using them? Are they driving the world's best selling hybrid? Surely Stealth Electric Bikes, who make no compromise eBikes are using them in their flagship "Bomber"? No? Why not?

You've gotten this far by sheer stubbornness and leveraging other people's expertise to build for you. You call this "Experience", but I think you're mistaken. This time, I think you're on a path of danger and money wasting, because you think you know what you're doing, but you don't.

A mate of mine used to work in personal injury insurance. He said one of the hardest things about his job was when people got paid out for their disabilities, they'd blow it all on a holiday, or a car, or a hobby, then when their disability flared up again, they'd go back for more money - and rage at how unfair the system was when they don't get it. Don't be that guy. I can imagine you getting your SSI payout and blowing it all in bad moves on your eBike and then coming on here to complain how unfair the system is, and someone needs a knuckle sandwich.

A bike that is too big to use isn't "working". Get your daily bike working first, then worry about your Dr Nitschke special.

 

[DAND214]

Keep on dreaming LC.
You must have no idea what a 200AH 72v LiFePo4 battery will weigh.
More than you weigh and again.
All you need is a few 120c LiPo and your on your way. Even 50c would be enough. It's AH x C rating is what you need to figure out.
A 72v 20AH LiPo pack of high C rating would power it for the big race with Luke But 72mph on a BMX bike? Yes, you are nuts.
We know you are just dreaming and funning us.

Dan

 

[slowhands]

Ok I got that. I realize all SLA batteries are shit. I got that. I am looking for batteries for dual AmpFlow motors. I also just posted on skakabalas misfire post. Please check it out if you can.I am looking to move on to bigger and better things. Post some affordable 72V 200Ah batteries please if they exist. Under $3.000 is what I mean by affordable as I know they wont be cheap. Thanks.

LC. out.

The Stealth Bomber bike, probably the most powerful commercial bike, uses a 72v 20Ah lithium phosphate battery. A replacement battery costs about $2300. It is not likely that one ten times larger would be physically practical, not to mention it would cost more than many cars.

 

[Sunder]

The Stealth Bomber bike, probably the most powerful commercial bike, uses a 72v 20Ah lithium phosphate battery. A replacement battery costs about $2300. It is not likely that one ten times larger would be physically practical, not to mention it would cost more than many cars.

72v @ 200Ah is 14.4kw. To give you an idea, I have a 12kw battery. This is what it looks like:

To give you a sense of scale:

This is what I'm talking about, LC. You think you are experienced in building eBikes, and yet you have no idea that you specified a battery the size of a child's mattress, and weighing several hundred kilos. You have all these "great" ideas, but none of them come with any knowledge or experience to implement them.

I'm not saying give up. I'm saying LEARN! Stop being stubborn and ignoring advice. Stop paying other people to do simple work. You can and should ask all the questions you want on here, but stop ignoring the advice that comes back.

 

[DrkAngel]

SLA Murderer ...

 

[Sunder]

Hey check these out:

http://www.aliexpress.com/item/High-capacity-30Ah-3-2V-Lithium-ion-rechargeable-lifepo4-cell-IFR117163202PA/32314051473.html?spm=2114.01020208.3.1.vSbTZ4&ws_ab_test=searchweb201556_1_79_78_77_91_80,searchweb201644_5,searchweb201560_9

You could build a 60v, 30AH battery for under $500 shipped. Alternatively, you could negotiate another 4 packs and get a 72v battery for under $600.

If the Aussie Dollar wasn't so low, I'd be getting these for a battery pack for my dad's farm. We need to baby those things so badly because they're Flooded Lead Acid. Needs ventilation, needs top up of water, occasional desulphation. For almost the same price as I paid for the Flooded Lead Acid, I'd have about 85% of the capacity, which in practical terms would actually be nearly double usable capacity.

Dammit. Wish they were this cheap 2 years ago.

 

[DrkAngel]

LC ... don't buy any Lithium batteries!

Well, not until you learn how to treat batteries.

Lithium are damaged-destroyed, similarly to SLA, by too small a battery size or excessive discharge rates.
So, 'twould be wasteful to destroy expensive Lithium when you can destroy cheap SLA and learn the same lesson from your mistakes.

If you can learn to listen and recognize your mistakes ... then learn from them?

 

[DrkAngel]

Lithium cells suffer a similar deterioration from excessive discharge rates.

Even though rated at 20A discharge the INR18650-25 suffers a horrific capacity loss. 10% at ~45 cycles.
Compared to a 2.5A discharge, the same 10% capacity loss after 400+ cycles!

See - Samsung INR18650-25R cycle test.

 

[latecurtis]

View attachment 18

 

[latecurtis]

As the Hub Motor Turns and the Lipo Fire Burns. Special post. 2 years of e bike madness!

11/15

I don’t exactly know when I started posting on ES or when I joined ES but am calling this post my two year post as it has to be close either way and I am glad I am alive and still posting over 90 pages now. I have learned a thing or two as they say and have quite a few bikes and parts and ideas.

I ran into an old friend Bill. I told him to check out my posts if you want to know what I have been doing for two years. Building e bikes. I went to college for electrical technology. I got him a job there back in 06 as a tutor for networking because I am a natural with hardware but struggle with software. I was his friend already and knew he had the knowledge. I think I got a B in it. I was into audio and computers back then.

Today I have found my calling as they say. I posted these pictures also for Sunder and Dan as they are my friends too and so is DA. Skalabala and LiveForPhysics as well as a few others on my friends list. I have always dreamed about my future. I used to dream about e bikes long before I knew they existed. I rode them but did not know what they were.

I never learned how to ride a motorcycle. I have never done it. I don’t know how to drive a standard car either. Also I never liked motorcycles. I always thought about them tipping over on me. A big heavy red hot motor on top of me don’t sound like a good time! Also they are too loud and difficult as well as expensive to fix. I dreamed about a bike with a motor that did not have a clutch or make a loud noise.

The original Currie made a really cool noise and went 26mph@36V. It did not sound the same with the MY1020 motor@36V. The Diamond Back with the heavy duty chain however makes a wicked cool sound when accelerating. It is not as loud as the Currie but sounds awesome.

Sunder did not post for a while and missed many pages. This will cover some of what he missed. Also a question came up about a work bike. Since I can’t work according to five doctors including a heart doctor and mental health professional it is my reliable bike. A bike I use sparingly. see pic 6. It is a Clear Creek Schwinn. Up until then I did not care for Schwinn but this one is special. I am a sucker for a curve in the top bar of the frame. It also has a shock under the seat. pics 0 and 1 show the four LIPO packs Dan sent. They are inside a LIPO bag. see pic 00.

The bag is inside the sentry cash box. I have to keep it covered as I am afraid someone might call the bomb squad when I lock it up and go inside places. It would be an easy mistake to make. I am also making a sign to put over it stating LIPO batteries inside for electric bike. Please do not touch. That way if someone does mess with it hopefully they won’t call the police.

Packs 1 &2 are combined and go to the terminals on the right and packs 3&4 to the two terminals on the left side. A simple wire with two gater clips completes the series connection. I have a pre hook up wire with two 10 ohm resisters taped in series I use prior to making any connections. see pic 11. The wires from the controller end with clips also with red tape on the positive one.

For safety I store it in a dryer with a washer the same size behind it which are used for a stand for a 60 gallon Bala shark tank.pic 12. I charge it in the window behind the tank with the wires coming out of the holes facing out the window. The set up is going on about 8 or 9 months I think and survived a major bike accident a couple of months ago when I flipped the bike. Without that level of protection a pack could have been punctured making the mishap much worse.

Charging is done with the Sky charger. I LILO balance charge them each time and hook the balancer to check cells and voltage before and after each use. Pics 2 thru 5 show normal voltage when storing. They get charged about 24 hours before running. It looks like my multimeter is reading a little high. I appreciate the front kit and LIPOs that were sent to me and wanted to prove I have been taking proper care of them.

The Diamond back (pic8) was built to do what both the Currie see pic 7 and the Schwinn do, only smaller and more compact so it will go up the stairs easier. I have posted many pictures and even a video showing how narrow and difficult the stairs are for a 26" bike. The Currie had a very large rear basket for hauling things. I have a normal size front basket on the Diamond Back but with a large back pack I can haul as much as I did with the Currie.

Pic 9 show the Magna which is my pedal bike, however I want to put a small very light hub motor on the front that can be powered by a single 20.0 - 6s LIPO pack inside of a small steel compartment with a locking lid just large enough for the brick to slide in which will be bolted to the frame somewhere. 15 to 18mph is all I expect for top speed on that. It will be a pedal assist bike and not for speed.

Pic 10 shows the Roadmaster I mentioned. Dual 280W unite motors out of toy scooters will go on the back hooked to the single 80 tooth #25 sprocket which came off the Currie. pic 14,15 and 16. I will have a lot of pedal gears if doug gets it going. Total wattage will be 410. 210W each. and rpms will be 2100. The calculations are easy 280/4 = 70. 280 - 70 = 210. Since rpm at 24V = 2800 simply add a zero to 210 and that is the rpm. The 80 tooth is perfect as the sprocket calculator on page 71 gives 17mph as the top speed.

What will make the build special and important is, it is a perfect low budget build for NOOBs as you call them. I am no longer one as I already had both those motors running on the front of the Diamond Back for over 7 miles at about 10 to 15mph with a single motor sprocket. People throw away a lot of toy scooters because the batteries won’t charge anymore. Rich people don’t bother replacing batteries, they just buy a whole new scooter. Also I think those motors are only about $30 new. They could be run at 48V in series especially if they were new but they would require a larger sprocket at 2800rpm making it unpractical.

The 20" rear wheel with a cassette has about 10 gears I think so the 80 tooth will get holes drilled and I will be modifying it to be a spoke mount on the opposite side the pedal gears are on. If it don’t work I may need a #25 - 80 tooth spoke sprocket if there is one. Please let me know if there is.The front will get a pair of 20" forks and brakes. Replacing the little motors with dual 7 pound 3300W AmpFlow motors is still in the dream stage. I can drive 55 will be the name of that post if it ever happens.

When I finally get money and move to a first floor place then the Currie will get the original 1,000W MY1020 motor upgrade restored exactly like the beginning of this post. The large basket will go back on the back but it will be 48V instead of 36. That is the only thing I am changing.

11/16
Pic 000 shows the pot......... which broke off when moving the bikes around. An important change needed to be made anyway. The danger before was the kill switch being too far to the left of the pot. When squeezing the right brake lever my right thumb should be able to easily flick the switch down to shut off the motor. I don’t use brake sensors so it became an issue. I managed to solder it and made the improvements See pic 17. However it came with a cost. FRONT BRAKES!!

I failed miserably hooking them back up. I will try again tomorrow. Doug said something about new springs. I want a brake upgrade anyway but had them working well in that video. They will be better with the right size cables and better springs. Doug is really good with brakes. I am amazed I managed to solder that. It was not easy as my tip is broke and only a few millimeters to work with. It was a miracle as my skill level soldering is very poor too. I surprised myself with that and the motor sprocket I JB welded. I got about 25mph out of it and am going for 30 when I get the new controller.

My plan for breaking in the new SLAs is the CVS pharmacy as it is about two miles round trip and all flat. I will take it very easy under 10mph with a lot of pedal assist. I will recharge and then go to Wall Mart which is 2.6 miles round trip with a little less pedal assist for the second cycle. Then McDonalds on the third charge cycle which is a three mile round trip with no pedal assist but under 15mph. I won’t go faster until after the break in period.

My greatest concern at this time is the throttle that comes with the new controller. I am not sure if it is three or four wires. four wires may be impossible to work for the pot. I have a feeling I am going to really like the pot now that the kill switch is in the right spot. pic 13. I don’t want a twist throttle at all. I plan on hitting radio shack and getting a couple more pots. I may not even use the new controller if it won’t work for the pot. Thanks.

Sincerely LC. out.

 

[latecurtis]

http://lunacycle.com/batteries/packs/52v-samsung-18650-20-8-ah/

I read your posts and still think SLAs are total crap. This is a real battery. Thanks Dan for posting the link on the last page. As soon as I get the money I am ordering that for the Dimond Back and the 1.000W 48V unite motor.

After that the SLAs will be used mostly for testing new builds and for very short trips. Thanks. Library is closing.

LC. out.

 

[DrkAngel]

Yeah, you need at least a 20Ah battery!
The 10Ah Lipo are taking some heavy abuse.
And your new 48V 10Ah SLA look to die a very quick death ...

 

[DrkAngel]

Your old controller uses a Hall throttle but might be Magura compatible (0-5k pot) also ... not common.
Typically, potentiometers will not work properly with Hall controllers.
But, you'll find out.

Added:
Running a pot in series with a Hall throttle can limit throttle function effectively.

 

[DrkAngel]

http://lunacycle.com/batteries/packs/52v-samsung-18650-20-8-ah/

I read your posts and still think SLAs are total crap. This is a real battery. Thanks Dan for posting the link on the last page. As soon as I get the money I am ordering that for the Dimond Back and the 1.000W 48V unite motor.

After that the SLAs will be used mostly for testing new builds and for very short trips. Thanks. Library is closing.

LC. out.

52V 20.8Ah battery ...
Uses Samsung ICR 18650-26f which are fairly common LiCo cells with a 2C maximum continuous output.
Should be about perfect with a <40A controller.
Should provide 27mph capability with a 20mile range and a possible 400 cycles (8000 miles) ... cycling down towards 15 mile range.
At 1C, deterioration is reasonable.
Same cells in 10.4Ah pack ...
Might provide 27mph capability with a 8mile range and a possible 200 cycles (1600 miles) ... cycling down towards 5 mile range.
At 2C, deterioration greatly accelerated!

Size of battery ... moving cells into optimal operating range is essential for satisfactory performance!

Warning! - Adequate cooling necessary to avoid rapid and severe damage to cells!

 

[DrkAngel]

As a good way to break in your new 4 x 10Ah SLA ... !
Rig as 24V 20Ah!
This will give you a much safer, more gentle break in and hopefully ... a good example of reasonable performance with excellent durability and lifespan.

 

[DrkAngel]

 

[DAND214]

LC, it's easy to see when you started.
Just look to the right of your post, it's right there.
If that's not it, then it's in your profile.

Posts: 1531
Joined: Sat Jan 18, 2014
1:53 pm
Location: upstate NY. Albany area

Dan

 

[latecurtis]

View attachment 8View attachment 6View attachment 4

 

[latecurtis]

As the Hub Motor Turns and the LIPO Fire Burns. 24V is doable, 36V is better.

I read DAs posts and looked at the graphs and it is starting to make sense to me. I admit that DA is right and I am stubborn and mule headed. I see how SLAs can be damaged by discharging them at too high a rate by going 25 to 30mph. That is why I am considering getting two more. 30mph = 1000W / 48V = 20.8A / 4 = 5.2 amp discharge for each 10Ah SLA. 25mph = 750W / 36V = 20.8A / 6 = 3.47 amp discharge which is less damaging to the SLAs.

However for maximum life I should not exceed 2A discharge and 1A charge rate or run them until they slow down. I got that now. 450W / 36V = 12.5A / 6 = 2.08 amps for each SLA. 450W = approx. 15mph. 420W / 36V = 11.6A / 6 = 1.93A for each SLA when I build the Road master with the two little motors which would be perfect for about 12mph without pedal assist but good for 20mph easily with pedal assist and would only require light pedal on hills because of a cassette and at least 10 pedal gears.

That is why I am ordering two more 10Ah SLAs as I can finally get full usage from them on any of my bikes as long as I keep it under 15mph. I know it took a while to understand the concept. The graphs and tables are difficult but simple ohms law makes perfect sense to me. Watts / Voltage = current or amps. / # of batteries. The larger the Ah rating is the faster you can go without damaging batteries. If I were to hook up a meter with clips to the terminals would it give me an Amp reading? 36V * 12A = 432W. 12A/6 = 2A from each SLA so keeping it under 12A with an amp meter in front of me would be very cool for the batteries.

How is it my motor is 1,000W but my batteries are for a motor 450W or less? The original Currie motor was 450W and came stock 24V @10Ah SLAs. at 450W and 15mph I get 450W / 24V = 18.75 / 2 = 9.375 amp discharge rate. If 300W = 10mph then 300/24 = 12.5 / 2 = 6.25A. Why did the Currie SLAs last as long as they did being discharged over 5A during normal usage? They lasted at least six months I think. They should have been dead in about three or less according to DAs chart. Please explain.

The fact is eventually they will have to give me my SSI disability check and I can afford a real battery. In my opinion SLAs are shit for e biking. They are good for electric wheel chairs that go from 3 to 5mph. The 52V pack can take the full output of the unite motor without any damage to it. The race against Doug will take place then and the Diamond Back will be a serious machine humming down the road at about 35mph.

I posted the dual motor set up when it was hooked to the Diamond Back. That is before I got the new 48V 1,000W Unite motor. I doubt I will ever run anything at 24V again unless I get a geared hub motor that will go up hills.

I have a very bad right knee and cant pedal much without compromising it further. That is the main purpose for running e bikes. If the bike won’t go up hills without pedaling or with light pedal assist then it is useless to me. When I get my SSI, after I order the 52V battery I might order a single 20.0 6s LIPO pack and a 24V geared hub motor kit for the Magna if it is capable of going up hills and is very light. Does a geared hub motor mean you can switch gears for climbing hills?

The new controller will be here soon hopefully. I will try once again to do a you tube video and post a link showing 30mph with the LIPO packs on the Diamond Back. A follow up video will show the Schwinn and the LIPO packs at about 27mph. I will only maintain top speed a couple of seconds though to conserve battery life. Next month I will check both bikes at 44.4V with a speedo to see how close I am guessing. After that I won’t run them over 15mph until they need replacing.

If I start going easy on the LIPOs (under 15mph) I figure I can get another six months out of them if I run them about once a week like I have been. I will replace the four of them with two 6s -20.0 Ah packs but use the same set up with the LIPO bag in the cash box for safety and protection as I have proven it to work regardless of how ridiculous other ES members may think the setup is. It works very well and is easy to hook up and charge. I could also run them all in parallel for 22.2V if I wanted to by simply using wires and alligator clips.

Pic 1 shows the terminals more clearly and how I combined them on the LIPO set up. Pic 2 shows that the mustimeter don’t need recalibration as I thought and pic 3 shows the standing voltage of the old SLAs I abused. If they are that severely damaged why do they still hold a charge of 13.26V not only in parallel but I tested them separately also several hours after charging?

Maybe it is because I have exceeded the number of useful recharging cycles they are capable of. Heavy abuse and severe damage should have caused a bad or defective cell and voltage would be much lower at about 11V or under I would think. Constantly desulfating them has kept the voltage high but is not going to save them anymore.

I have never heard one time on this forum that I did anything right! It is always what I should or should not do, or what I am doing wrong. I got to have some credit coming for something I did. The eels are on my side on this one. Pic 4, 5 and 6. They get their worms most of the time because of my e bikes.
11/17

Since I will be getting two more SLAs and running 36V I will be breaking in three that I have now and when I get two more I can break in the other three. Wall-Mart is 1.3 miles from here and a 2.6 mile round trip. For the first break in cycle I will bring the three old SLAs and three new SLAs and split the difference. I will take the new SLAs there and use the old ones to return home. 10mph with light pedal assist will work for the entire trip

I ended up running them about 1 -1/2 miles instead of 1.3 but about 7mph with a little pedal and never over 10mph. I went to advanced auto for clips but they were out and I had to go back to Wall -Mart to get them and paid almost double. Over six bucks. I switched to the old SLAs then for the trip home. They did not quite make it. It may be the last time I run them as they are not even good for a mile now at 7mph.

I did something right as the voltage after charging them raised from 13.07 when initally charged to 13.21V about 6 hours after charging. The next break in cycle will be the same speed. Electric wheel chair speed 5 to 7mph with light pedal assist for 8 to 10mph sometimes but for the full 2.6 miles. I won’t need to go the extra 1/4 mile to Advanced auto. The third cycle will be downtown and back on Friday also 2.6 miles but at 10mph and no pedal assist.

There is a decent size hill about 1/4 mile. The Schwinn with the LIPOs go up it about 5 to 7 mph full throttle. With the pot I can get going about 10mph before the hill and try to make it up pedaling without turning up the pot much. Heavy pedal should work to keep the SLAs from being damaged. If my leg hurts I will hit the kill switch and walk up the hill. I will get my money’s worth out of the SLAs this time around. I will end up paying $111 for 20Ah at 36V when I get two more.

With the pot it is very easy to maintain slow speeds such as 1 to 3mph for operation on sidewalks and with my thumb on the kill switch also safe. When approaching an intersection I hit the kill switch. I keep my thumb on it when I am riding so I can kill the motor quick and It is something I use a lot so I should replace it often and use quality switches.

I can match speed with an electric wheelchair easilly.The pot rules! An easy pedal assist and good for batteries. How slow should I go for optimum life? Will 3 to 5mph save the batteries even more? When I get a speedo I can basically dial in the desired speed I want on flat land and maintain a much more even speed than with a throttle. How slow should I go?

Pic 9 and 10 are how I plan to run and charge them. 14.7V * 6A = 88.2W. But since current drops to 0A when fully charged the average power consumption is probably like running a 60W light bulb. I have zero tolerance for dumb people who are worried about me charging my batteries. My Dell power supply is all dirty now. With 36V and 20Ah I won’t have to worry about recharging when going downtown.

pic8 and 11 shows the cover I am in the process of fabricating out of another milk crate. I want to put a thick piece of black plastic over the top to keep water out and the batteries mostly hidden and figure out a way to lock it with a small chain and padlock so nobody steals the batteries or calls the bomb squad when I am running the LIPO set up.

LFP may or may not find me an FX - 75-5 motor but since he told me about them I will never rest until I have one. Doug also told me about Haro and I already knew about Cannondale but not the Jackal. He said it is a very rare and special bike. That is my dream bike and build. 70 foot pounds of torque and 90mph. It is rated for 85mph on a motorcycle so should do 90mph easily on a Jackal. Like I said before; Will the rider have the guts to do 90mph?

There will be lots of big questions if I succeed in building it someday. Will LC go out like Jax Teller did in the final episode of Sons of Anarchy? We all know he is crazy! What will become of his poor eels if something happens to LC? Hopefully someone on ES will take pity on them and take them in. Please let me know if anyone wants to be God parents to five Swamp eels. Thanks. Please post when you can.
LC. out.

2.5A * 6 slas = 15A * 36V = 540W = 18 to 20mph. Perfect. I am going to power / speed graph to check it. approx. 23mph according to graph on page 66.

 

[DrkAngel]

As the Hub Motor Turns and the LIPO Fire Burns. 24V is doable, 36V is better.

I read DAs posts and looked at the graphs and it is starting to make sense to me. I admit that DA is right and I am stubborn and mule headed. I see how SLAs can be damaged by discharging them at too high a rate by going 25 to 30mph. That is why I am considering getting two more. 30mph = 1000W / 48V = 20.8A (/ 4?) = 5.2 amp discharge for each 10Ah SLA. 25mph = 750W / 36V = 20.8A / 6 = 3.47 amp discharge which is less damaging to the SLAs.

Ouch and damn!
30mph = 1000W / 48V = 20.8A ("/ 4"?) = 20.8 amp discharge for each 10Ah SLA.
1000w motor output requires ~1333 battery input at optimal cruise (~75% efficiency), so:
30mph = 1333W / 48V = 27.8A / 4 = 27.8 amp discharge for each 10Ah SLA.

 

[latecurtis]

27.8A / 4 = 6.95A each SLA. still too high. Your chart states 1C = 2.5A. I can go 23mph with 6 SLAs in parallel series without damage.

2.5A * 6 slas = 15A * 36V = 540W

540 * .75 = 404W = 15 mph. Was right first time. I did not factor in .75%

battery input at optimal cruise (~75% efficiency),

A discharge of 1C draws a current equal to the rated capacity. For example, a battery rated at 1000mAh provides 1000mA for one hour if discharged at 1C rate. The same battery discharged at 0.5C provides 500mA for two hours. At 2C, the same battery delivers 2000mA for 30 minutes.

That is why I go by ohms law. !C is confusing as it changes according to the AH of the battery. My formulas still stand true. I just don't know how much more I am willing to spend on SLAs. I might just order two more and live with 15mph until I can afford the 52V battery pack. I am not sure.