new eZip motor

[DrkAngel]

Should be simple math for someone with electrical technician training.

30mph = 1333W / 48V = 27.8A [strike]/ 4[/strike] = 27.8 amp discharge for each 10Ah SLA.. = Actual

+12V x 27.8A = 333.6w
+12V x 27.8A = 333.6w
+12V x 27.8A = 333.6w
+12V x 27.8A = 333.6w
48V x 27.8A = 1334.4w

vs

30mph = 1000W / 48V = 20.8A / 4 = 5.2 amp discharge for each 10Ah SLA. = wishful thinking?

+12V x "5.2A" = 62.4w
+12V x "5.2A" = 62.4w
+12V x "5.2A" = 62.4w
+12V x" 5.2A" = 62.4w
48V x 20.8A = 249.6w = LC math

 

[DrkAngel]

"1C" from a 10Ah battery is 10A.
You are looking to draw 27.8A from each 10Ah battery for a 2.78C, nearly 3C!

 

[latecurtis]

The graph you posted states 1C as 2.5A and 8C as 20A on the bottom left hand corner.
It was on the last page

page 91 towards the top.

I am good at math and everything adds up. I just found out about the 75% though.

 

[latecurtis]

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.

1C discharge changes its value according to the AH of the batteries. that's why I stick with ohms law. Watts / voltage = amps / number of batteries gives discharge current for each battery.

 

[DrkAngel]

Graph was to demonstrate LiPo being as susceptible to damage as SLA.

Lithium cells suffer a similar deterioration from excessive discharge rates.

High output Samsung INR18650-25R Lithium cells
2500mAh cells at 2.5A discharge = 1C discharge rate
2500mAh cells at 20A discharge = 8C discharge rate

 

[latecurtis]

Ok but my math is correct and basically the more SLAs I get the faster I can go without damaging them However it would be much more simple just ordering this

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

I am wondering what type of batteries the zero motorcycle uses.

http://www.zeromotorcycles.com/shop/index.php?main_page=product_info&products_id=190

$2,500 to go 90mph.

 

[DrkAngel]

1C discharge changes its value according to the AH of the batteries. that's why I stick with ohms law. Watts / voltage = amps / number of batteries gives discharge current for each battery.

Watts / voltage = amps gives you the amps for every one of the 48 volts of your 48V battery.
You don't go dividing it by 4!

You already divided it by 12V and the 4 batteries = 48 ... remember?

 

[DrkAngel]

In series:
1 12V 10Ah battery = 12V 10Ah
2 12V 10Ah battery = 24V 10Ah
3 12V 10Ah battery = 36V 10Ah
4 12V 10Ah battery = 48V 10Ah

or ...

In Parallel:
1 12V 10Ah battery = 12V 10Ah
2 12V 10Ah battery = 12V 20Ah
3 12V 10Ah battery = 12V 30Ah
4 12V 10Ah battery = 12V 40Ah

You can add one way or the other not both at the same time!

48V 40Ah would require 16 12V 10Ah batteries.

 

[latecurtis]

library is closing. If I run 36V@20Ah how fast can I go without damage to the SLAs. For now running 36V@10Ah I plan on keeping under 10mph. I would like to get 15mph when I run 6 in parallel series. and 20mph if I go 48V@20Ah. thanks. Please let me know. I will be back Friday.

LC. out.

 

[DrkAngel]

library is closing. If I run 36V@20Ah how fast can I go without damage to the SLAs. For now running 36V@10Ah I plan on keeping under 10mph. I would like to get 15mph when I run 6 in parallel series. and 20mph if I go 48V@20Ah. thanks. Please let me know. I will be back Friday.

LC. out.

Based on info I half-heartedly absorbed ... your gearing was too high at 36V.
24V 20A might give near 20mph capability

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 "

36V will not run efficiently at 15mph ... geared too high. (Incapable of throttle restraint?)

 

[Sunder]

Ok but my math is correct and basically the more SLAs I get the faster I can go without damaging them However it would be much more simple just ordering this

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

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18631

$15! You lucky bastards. For $45 + shipping, you could have a 12S, 5Ah pack. For a Benjamin Franklin, you can have a battery with twice the effective usable range as the battery you have now.

If it was that cheap in my region, I'd be building a monster pack for my new electric car.

Don't want to waste your existing investment? Buy a step down buck converter which is current limited, and charge on the go. The controller draws from the LiPo. Following the "divide C-rate by 5" rule for LiPo packs, you could probably get 50A safely out of those.

You then get like a 2A buck converter to convert the energy from the SLAs into something useable for the LiPos. At 2A with such a close change in voltage, 85-90% efficiency wouldn't be out of the question. 2A will be 0.2C, and so the Peukert effect will be minimal, giving you more of the 10A usable.

Stop throwing good money after bad. Stop the loss now, get some value out of the SLAs, and get a much better outcome! You won't regret it.

 

[DrkAngel]

Ok but my math is correct and basically the more SLAs I get the faster I can go without damaging them

I figured necessary motor output
Actual battery output notably higher, but for comparison purposes only.

1s x 12V 10Ah = 12V 10Ah = 10mph = 68w = 5.66A = .566C - excellent range and life
2s x 12V 10Ah = 24V 10Ah = 20mph = 333w = 13.875A = 1.3875C - OEM eZip comparable fair range and life
3s x 12V 10Ah = 36V 10Ah = 30mph = 993w = 25.91A = 2.59C - rapid deterioration-death
4s x 12V 10Ah = 48V 10Ah = 40mph = 2247w = 46.81A = 4.681C - severe damage
5s x 12V 10Ah = 60V 10Ah = 50mph = 4280w = 71.33A = 7.133C - severe, nearly immediate irreparable damage dangerous!
6s x 12V 10Ah = 72V 10Ah = 60mph = ~7500w = 104.16A = 10.4C - unreasonable-unsustainable dangerous!
potential speeds roughly estimated for demonstration purposes only.
Severely limiting throttle and speed will reduce damage and increase life!

1s2p x 12V 10Ah = 12V 20Ah = 10mph = 68w = 5.66A = .283C - >excellent range and life
2s2p x 12V 10Ah = 24V 20Ah = 20mph = 333w = 13.875A = .693C - very good-excellent range and life
3s2p x 12V 10Ah = 36V 20Ah = 30mph = 993w = 25.91A = 1.3C - Marginal range and life

*5mph = 22w
10mph = 68w
15mph = 163w
20mph = 333w
25mph = 601w
30mph = 993w
35mph = 1532w
40mph = 2247w
45mph = 3147w
50mph = 4280w

After you find your chosen discharge rate, find your optimal discharge depth.
EG - At 1C discharge rate >11V looks optimal.

 

[Sunder]

Don't forget those numbers are motor output numbers, not battery output numbers. I'd be adding in at least another 25% to get the battery output number.

 

[DAND214]

Sunder Don't bother, he's petrified of LiPos. Only if he could just listen to the good advice he has gotten here. He's a stubborn individual. I sent him 9AH 44.4v and it took him months to even get them wired so he could use them. All he had to do was connect it to the controller. Just change TWO connectors on the controller, a positive and the negative and it was ready. No he had to change the bullets and Sermos one to gator clips. I just don't understand why he doesn't listen to all of the good info he has received here. You sent him a motor setup and I supplied the power, batteries wiring and a charger with a power supply.

I have tried to help and now I don't KNOW any more. DA has gone over and over what to NOT do and what TO do and he still questions him. I don't want to piss him off or chase him away but he needs to LISTEN. No one here has given him the wrong info to mess him up and anyone that has helped were concerned for his safety. BRAKES, do you know when your gonna need them? I'm never too sure and have great brakes just because.

LC don't take this rant the wrong way. I like trying to help here and you need all the help you can get, since you don't listen/read what has been posted. I think you read it your way and ask the same question again or question the answer you got. Do you think DA does all these graphs and posts all the info he does to mess with you? NFW, he is putting so much time trying to get you to listen/read what has been posted and take it as fact. In the 91 pages here I don't remember reading any corrections to his basic info he has given. You keep asking the same thing hoping that you get the answer you want to hear. Like the newest thing is SLAs. If I wasn't tapped out now I would send you a couple speedos and batteries just to shut you up about 35mph on a 20" death trap. I have a few bikes that do that and then some. They are solid FS mountain bikes with good tires and GOOD BRAKES. They climb the local sled hill accelerating! But I don't ride them as fast as they can go. I have the controllers programed slow 18 med 25 and fast 30+. I'm not bragging since my rides are nothing compared to others here, In most cases I ride around 20mph. I find that I can go farther and see more at 20 or less than I will at 30. By keeping the speed down under 18mph I rode 35miles on 14AH of MultiStars.

As for you wanting to hear you have done things right. I suppose you have but you need to listen and run with the info and use it. DA has said repeatedly, about over gearing to get more speed and how it ruins batteries as well as motors. SLAs are not too bad if you take it slow and be sure to not run them too far down,

Dan

 

[Sunder]

Sunder Don't bother, he's petrified of LiPos.

Err, does he realise that the Luna pack he wanted to buy is a LiCoO2 pack? Same as a LiPo battery?

 

[DrkAngel]

Many, including myself at times, believe I am wasting my time.
It seems I have to repeat myself over and over in several different ways before things start to soak in.
But ... I have learned so much ... about an increasingly obsolete technology (SLA), while trying to explain it ... better.
To the point of considering its use in slow eTrike builds.

Surprisingly, while I have excellent patience with inanimate objects (computer tech), stubborn humans have often frustrated and occasionally infuriated me ... to the point of being struck dumb, turning around and walking away.
I work with and from a system view, as opposed to component view ... gathering info, adding research and then forming-growing knowledge = open minded. As opposed to the component method of learning that forms bricks of knowledge, hardening them into certainties, and building walls of opinions ... developing a form of ... mental constipation = close minded! Trying to modify any of the bricks of certainty endangers the solid wall of opinion and evokes a defensive response ... often with hostility!

Consolidating knowledge and formatting into a simplistic understandable pattern is a good exercise for me.
I try to view this as therapy for dealing with the sugared up grandkids (ADHDHs) that get dropped off occasionally.

Also developed a simple ~$100 eBike - eTrike motor kit!

Built several graphic representations and charts, lists etc. to clarify various eBike principles and capabilities.

Gathered info and charts to produce several esWiki pages.

Also, difficult to walk away when you see the inevitable trainwreck approaching?

 

[DAND214]

At least you guys read it. We'll see.

Dan

 

[latecurtis]

View attachment TM1_x264.mp4View attachment 2View attachment TM3_x264.mp4

 

[latecurtis]

As the Hub motor Turns and the Lipo Fire Burns. Discharge rates. / 30 to 50mph.

11/19
It has been raining all day and I could not ride my e bike however I got worms last night and am working with the eels to attempt to teach them proper table manners. TM1, 2, and 3. The clips have good sound if you turn up your speakers. It has been a very difficult task as you can see but there is actually some improvement. TM3. I am attempting to help these poor creatures to evolve However I can’t afford a full scientific laboratory yet but am doing all that I can.

I am surprised that each 12V 10Ah SLA needs to discharge at 10A for a 1C discharge rate. I finally figured that out. I made a mistake on my math yesterday but figured it out today. Now I get why DA informed me that 24V was good. 500 / 24 = 20.8A. A perfect match for 24V @ 20AH. 500W is also about 20mph and the legal speed limit. The thing is I did not buy a 500W motor. I bought a 1,000W motor to go 30mph.

Math is something I struggle at and not even very good at. Kind of like the card game Bridge. I love playing it but I suck at it but want to do it anyway. I really want to get better at it and I won’t give up on it. I did the second break in run last night and went 2.6 miles at 7 mph and about 10mph with pedal assist. Friday I will go down town and will need to climb the hill to come home with pedal assist. The Schwinn did it with no pedal assist and the Currie also many times at 36V without a problem.

Currently after the break in cycle I will be keeping track of how many cycles I run them and distance. 15mph will be top speed at 36V @ 10Ah. When I run the other three I can get them to about the same state as the three I am breaking in now.

My plan then is to order two more for 8 total. They will be broke in at 24V @ 10Ah. This will take place over the winter months as I will be running the LIPOs also. In the spring time I will combine all 8 SLAs for 48V @ 20Ah. (see discharge rate 52.8V) . If I get my SSI settlement soon however instead of ordering more SLAs I will have a choice of ordering the 52V 20.8 Ah pack from Luna Cycles for $500 + shipping

If the 20.0 LIPO packs are capable of a 2C discharge rate then a 1500W 48V brushless motor would be the logical upgrade from the Unite motor. I am not sure about the discharge rating on the LIPOs but will find out as Skalabala posted a 1500W motor awhile back which he said would run up to 3 kilowatts. 2214W should be good for at least 40mph.

As far as the 3300W Amp Flow motor, the only thing I can think of off the top of my head is the build your own battery kit Sunder posted a page or two ago. 20 pieces for $500 I think and $600 for a 72V pack. Yea. I do pay attention a little. Not much time online though. Thanks for those links.
If a 72V pack can be built for $600 then a 36V pack with double the AH rating could be built also for the 3300W Amp Flow motor. DA would you be interested in helping me out with that? If I get my SSI settlement I could accomplish it if I knew how. Could you show me how to build it. I am a NOOB and want to go 50mph on an e bike.
12/20

The library closes at 5pm on Friday and Saturday. I never got the front brakes hooked up on the Diamond Back so I took the Schwinn. The LIPO packs were not charged and at 3.8V per cell so I did not want to run them so I took the three new SLAs. I took it easy at about 10mph top speed and slower most of the time. It was downhill a lot on the way to City Hall however it did not make it back. I thought it was a loose wire but it was not. I thought it was the controller but it was not that either.

I was climbing a small hill and was pedaling also and was at approx. 1/4 throttle maybe going 5mph and I lost all power. The red light on the throttle was dim. I had to walk and pedal to get it home and almost fell down the stairs trying to get the bike up. The first thing I did was test the new SLAs with the meter. All three read 12.66V exactly. I then hooked the LIPOs up and got a bright red light and full power.

Now I am here on the computer and calculator says 38.1V. 12.7V * 3 = 38.1V. The controller that came with the front kit has a 38V cutoff. I ran the three 12AH SLAs quite a few times before with the front kit and went at least three miles and had it over 20mph also and never went below 38V. I get these new 10Ah SLAs that never came close to three miles on a trip and have not gone over 10mph and they still failed me. It may be because I am still breaking them in.

I will not even go 15mph with them. 10mph is good until I get three more for 36V @ 20Ah. I will still keep it under the federal speed limit of 20mph then to conserve battery life. Once I get 48V @ 20Ah I will be able to go as fast as I want and still be around 1C discharge. However the farther you travel the lower the voltage so the only time I can exceed 25mph without going above a 1C discharge is the first mile or mile and 1/2. That is when voltage is around 52V. Once voltage drops down to around 50V or lower than the 1C discharge rate will have to be exceeded to achieve speeds greater than 25mph. see discharge rate 52.8V.

I guess I will try to hook front brakes up to the Diamond Back. The calipers are there, it is just the levers and cable that is giving me a hard time. I will be posting this at the Library up here tomorrow. Please post when you can. Thanks.
LC. out.

 

[latecurtis]

Specs:
Minimum Capacity: 20000mAh
Configuration: 6S1P / 22.2V / 6Cell
Constant Discharge: 10C
Peak Discharge (10sec): 20C
Pack Weight: 2405g
Pack Size: 200 x 90 x 60mm
Charge Plug: JST-XH
Discharge Plug: XT90

4.1 * 6 = 24.6V * 200A = 4920W.

Each brick is good for almost 5killowatts. That seems very high. What is the discharge for long life. 3C.



http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=18631

Spec.
Minimum Capacity: 5000mAh
Configuration: 4S1P / 14.8v / 4Cell
Constant Discharge: 20C
Peak Discharge (20sec): 30C
Max Charge Rate: 5c
Pack Weight: 528g
Pack Size: 139 x 45 x 44mm
Charge Plug: JST-XH
Discharge plug: 4mm Bullet-connector

4.1 * 12 = 49.2V * 100A = 4920W * .75 = 3690W = 50mph with the 3300W AmpFlow motor. @ 5C discharge.

However I should run 9 or 12 bricks in parallel series so I don't drain them and run them low. 50mph would only be possible for a few seconds at 49.2V and 10 or 15 AH however $200 should get me about 20AH @ 49.2V. That would be minimum requirement for 50mph for 5 minutes I believe. 30 or 40Ah would be better and since the price is right it is doable.

$50 * 6 = $300 = 18 bricks in parallel series and 49.2V @ 30Ah. 1.6lbs * 18 = 28.8lbs. I will need to build something for that. Also charging all those will be a challenge.

Thanks for the link on those. It makes 50mph more affordable for me. On that note I have to go to Doug's house and get the brakes working on the Diamond Back. I still did not get the controller. That's what I get for free shipping from China. It was my fault. I should have not ordered it. I am not running 48V anyway and will be running 36V @ 20Ah next month. It may be awhile before running 48V @ 20Ah. Thanks for the posts and the links.

LC. out.

 

[latecurtis]

At dougs brakes fixed new phone needs activation when I get money good for hot spots galaxy ace

 

[latecurtis]

Any ideas on what will hold 18 4s SlAs

 

[Sunder]

Each brick is good for almost 5killowatts. That seems very high. What is the discharge for long life. 3C.

Recommendation is keep it under 1/4 of the rated continuous C rating. I find that works well for me. I suspect it's just as much that you don't see the early sag, as much as it reduces wear on the battery, but whatever works, right?

However I should run 9 or 12 bricks in parallel series so I don't drain them and run them low. 50mph would only be possible for a few seconds at 49.2V and 10 or 15 AH however $200 should get me about 20AH @ 49.2V. That would be minimum requirement for 50mph for 5 minutes I believe. 30 or 40Ah would be better and since the price is right it is doable.

You may have to run me through the maths that led you to those numbers for a reasonable answer to your question. 30Ah would be 6 bricks in parallel. 40Ah would obviously be 8. How did you come to 9 or 12?

50mph @ 49.2v is going to have to have an insanely fast wound motor. You'd be better off using them in a 16s (60v) or 20s (74v) arrangement, and a more moderately wound/geared motor.

That also saves you money on the current handling capabilities of the controller, and allow you to run smaller wires and connectors without having to worry about resistance and melting.

 

[DrkAngel]

You are geared too high for optimal speed or torque @ 36V.
(Motor output watts for desired speed must be attained at the proper wheel rpms to be effective )
Especially when you climb hills ... your torque will be poor and efficiency bad. like driving uphill stuck in high gear, using a lot of energy to sputter along and producing excess damaging heat.
48V is even worse!

On the other hand 24V 20A or 24V 30A, if you insist, looks optimal with a 20mph capability. (guesstimated, based on your comments about desired, required and present gear ratios)

Full throttle at optimal rpm = ~80% efficient
Full throttle at low rpm might be <50% efficient

 

[DrkAngel]

3 SLA failed at 38V LVC on Schwinn build.

SLA 1C discharge shows almost immediate voltage sag to 11.75V x 3 = 35.25V ... yeah, should have cut off!

Only time, that I remember, you using 12Ah SLA on Schwinn was when throttle problems prompted you to put 48V SLA on Schwinn. ... ? - IIRC