Max volts for this controler

Hi I'm brand new on here. I have a ebike kit coming soon from ebay. It's the cheep $250 rear hub with tire and rack and thumb throttle. This is the link. http://www.ebay.com/itm/281199914680?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649
I think I have found the china website where the motor and controller come from. This is the controller I think.
http://conhismotor.com/ProductShow.asp?id=111
On this site it sais the controller has a max 60v and 30a. Which sounds right. Does anybody know for sure if this controller can handle a little more volts? like 61.5 for a short period of time until the cells settle into nominal voltage 54-55.5v. Or if this is even the right controller for this kit? My problem is I plan on building my own lithium Ion battery pack from old laptop batteries (18650's). I planned on it being two 48v 20ah batteries in parallel making 48v and 40ah. This seemed all fine and dandy until I realized that this battery to be 48v would most ideally be 13 cells in series. This is a problem for me cause I'm cheep and I already bought an Imax B6 balance charger. This charger can only balance charge 6 cells in series, with a max charge output of 5A or 22.2V. Well I got a parallel balance charging board coming for the Imax (also with 6s, 4s, and now 5s leads and some dean connectors) and I don't want to have to charge two or three batteries at once (either 6s or 4s) just to turn around and charge a single cell after. Do you get my point? So now I have decided to either make a 12s or a 15s battery? So I can balance charge the whole battery at once. The problem with the 12s battery is that the nominal voltage is only 43.v! Now I'm not trying to be a speed demon, but from what I've read a 48v system will get you 27mph on the flats and about 20 on a hill. I live in Minnesota so it is legal to drive a ebike everywhere a normal bike can go as long as is doesn't go over 20mph with out peddling, and it doesn't have over a 1000w motor. I was just going to limit my speed on the flats. My concern with the 12s battery is that I'll be running around most of the time at 44v I might not be able to go up them hills at 20mph and the lower voltage will be using more of my precious amperage and will make my motor run a little hotter and not to mention the laptop batteries probably will only have a 1-1.5c rating. I don't know I haven't got them yet, but I figured a 40ah battery even at 1c could keep up with the demand on a 48v 20a 1000w system. So should I just make it a 15s battery? The max voltage will be 61.5 (15X4.1), and a nominal voltage of 54! (15x3.6). I'd really be cruisin then! Probably go around 35mph! I'm also not apposed to having that power available, but can the controller handle that much voltage? (I know the motor can). Is it bad for the cells to only charge them up to 4v each time I recharge the batteries? (15x4=60v) If the controller can really handle 60v this may be the best solution. As far as I know you just don't want to over charge or over drain Lithium Ion cells. If it's really bad to never charge over 4v a cell I can always charge to 4.1 and then turn lights on or something to drain a little initial excess voltage.

Well, that's not the controller, but all 48V controllers will have minimum 63V caps and 68-75V fets, so 63V max rated. That's 15s lco max fully charged. If you're not looking for more than ~28 mph, then go with a 12s lipo pack. It's perfect for the LVC the controller will have (42V). And it's also easier to maintain than 15s. That little imax B6 is a 50W charger , so it's going to take 14 hours to charge 6 5000mah 6s batteries in parallel from empty to full charge. A decent 12s charger that can charge at 300W would be easier and take about 2.5 hours and without breaking the pack down to charge it.
http://www.hobbypartz.com/75p-1220-charger.html?gclid=CNa3z9_N57ICFayPPAod10MAPw
If you're going to build your pack from old 18650 cell, you'll need to make them in 6s blocks so you can split them to charge if you use a 6s charger. I hope you know what you're doing.

Is this your first battery build ? Because it sounds like you need some more reading. Or buy a plug and play battery so you can get on the road. Building a battery is lots of hidden work to get it right and not as cheap as you may think.
Would look at Drk angles homemade build thread in the battery section.

Yah if I'm going to do 12s I will break them down to 4s and 5s if it's going to be a 15s. because then I can charge to 4.1. Do you recommend charging to 4.2?

63v is pushing it hard if you have a controller with 63v capacitors inside.

But if you do 15s, charging to 4.1v vs 4.2v per cell, you have 61.5v. So 15s and slight undercharge should work fine, and hopefully make the pack last a bit longer too.

dogman said:

But if you do 15s, charging to 4.1v vs 4.2v per cell, you have 61.5v. So 15s and slight undercharge should work fine, and hopefully make the pack last a bit longer too.

Click to expand...

this is exactly what I do when I run into the 48v controllers, all my packs are 5s config so 10 15 or 20 is easiest for my testing.

In lieu of direct experience with over-volting this controller I would take the quoted specification as a warning:

"Max. Cut-off Voltage: 60V"

This suggest that the controller may cut off if it sees more than 60V. My goldenmotor controller did this when I tried it at 60.5V.

I have the same kit, I charge to 4.19v, thats 20.97v per pack. The stock controller has 63v caps.





Shunt mod and beefed up traces

My Conhismotor controllers are a few years old but have survived running 15S RC Lipo for a ton of miles. I did the 4.15V/cell thing = 62.25V hot off the charger.

LVC will likely be iffy on 15S. 12S LVC often works well as long as all cells remain reasonably balanced into the lower regions of discharge curve.

Sounds like HVC is not a problem on this controller

thanks for all the replies! it's nice to know I can go 15s. but after more thought I really don't need to be going more than ~28mph...cops...and where am I going to put all those cells! and in doing a lot more reading I bet out of the 336 cells I got coming...even though I only need 300 (15s 20p) to make a 60v 40ah battery.... I will prob only get half good ones if im lucky. we'll see... I do think your right about the charger. I do need a way of bulk charging a gang of cells. But I think I will be doing the light bulb trick to capacity test a gang of them at once. But I will be using a watt meter also because I will need one anyway when im actually riding to make sure I don't over use the capacity. Although I will only have to go 45 miles max and a 48v 40ah should be more than enough! all the more if I make it 60v and try to limit my speed to 20mph. Any cool tricks for limiting speeds/cruise control? O and any good cheep bulk chargers with 250+whts in a 4-60v range? :wink:

Personally, I prefer old space heaters, clothes irons, toaster ovens, etc, for static load current testing. I just never seem to have enough lightbulbs around to draw enough current for any meaningful testing.

Limiting speed - cruise control? Get a Cycle Analyst - hands down the most useful metering device you can apply to this discipline. Although, many controllers have the ability to perform these tasks with some programming and/or certain wiring connections.

Bulk chargers? Can be ordered from BMS Battery, E3M or convert practically any switching power supply(s) to perform the task. Hell, many of us have series wired several together to reach desired voltage range.

However you go about bulk charge, caveats abound regarding current limiting, charge termination, etc.

Why not post your general location - it's kinda rude IMO to be seeking technical help when we have to guess what continent you'll be sourcing/using this setup? Oh, and a paragraph break or two would make reading your posts much easier....

diggler said:

thanks for all the replies! it's nice to know I can go 15s. but after more thought I really don't need to be going more than ~28mph...cops...and where am I going to put all those cells! and in doing a lot more reading I bet out of the 336 cells I got coming...even though I only need 300 (15s 20p) to make a 60v 40ah battery.... I will prob only get half good ones if im lucky. we'll see... I do think your right about the charger. I do need a way of bulk charging a gang of cells. But I think I will be doing the light bulb trick to capacity test a gang of them at once. But I will be using a watt meter also because I will need one anyway when im actually riding to make sure I don't over use the capacity. Although I will only have to go 45 miles max and a 48v 40ah should be more than enough! all the more if I make it 60v and try to limit my speed to 20mph. Any cool tricks for limiting speeds/cruise control? O and any good cheep bulk chargers with 250+whts in a 4-60v range? :wink:

Click to expand...

S-350-48 MeanWell can be easily modded for 60V ... See - MeanWell Mods - S-350-48

4V? Your iMax 1s (~5A), charging a bunch of cells in parallel.
Parallel only cells of similar starting voltage!
MeanWell S-150-5 (30A) - if you want to go pro.

"Light bulb trick" involves discharging 28s-30s cells (~120V) through 2x60w (120w) light bulbs = 1000mAh capacity for each 1 hour of discharge. See - Bulk Capacity Testing

Thanks Ykick

I'm in Minnesota by the way, upper Midwest USA. Interesting tid bit. Minnesota is the only state I have found that legally allows a 1000w motor. Other states mostly allow 750w or lower or not at all without a license. 20mph non peddle assist still applies though.

I will look into heating elements. My only initial concern is consistent current draw particularly the iron. But a space heater or the like I assume would be real consistent.

Yes the Cycle Analyst. A lot of people seem to rave about them. I've only briefly looked at them and saw they were $100. But they must be worth it! I'll look into it more.

Thanks for all the suggestions on chargers. I haven't got a chance to price the MeanWell. I have glanced at the mods. Also glanced at using laptop chargers in series. This is tempting because some lot's of laptop batteries come with a lot of chargers for free! Need to spend time understanding that though. Right now this suggestion looks the best for me. http://www.hobbypartz.com/75p-1220-charger.html?gclid=CNa3z9_N57ICFayPPAod10MAPw Simple and powerful. For now the B6 will do fine for charging cells in parallel.

DrkAngle

Thanks for the reminder about charging only like voltages in parallel. Just got my first pack of 80 cells today. Hp packs. 4s2p. All but 1 pack 2010 the other 2011. 1 pink, 1 blue, 1 gray (2011), and the rest purple. All 14.4v... 8-4910mAh, 1-5100mAh, and 1-4400mAh. I'm glad there all at least over 2Ah cells.

14 pairs 3.7-3.78v. (ppl, blu, pnk, Smoked one of those getting them apart. The pink. Were wired a little different then the rest. Too bad this was my best pack, all were at least 3.7v! prob won't be using that one. It got pretty hot!)
3 pairs 3.4v. (gray)
2 pairs 3.0v. (ppl)
3 pair 2.7-2.8v. (ppl)
3 pair 2.4-2.6v. (ppl)
That leaves 17 pairs .0-.1v (15 ppl, 1 gray, 1 blu) junk but I will play with them.

Charged one 3.7 pair at first while I was working on getting the rest apart. It took 1500mAh before the 2 hr timer chimed in. I think it took another 1Ah after that, but it reads only 4.01 on the volt meter. So that one will be going back on till I get it to 4.1v. I think these are the 3.6 cells not the 3.7 cells you were talking about in your thread, because the package said 14.4v. 14.4/4 =3.6v. So I will be charging them to 4.05v for the <30 mile days, 4.1v on the ~45 mile days. But 4.2v for the testing.

I've been charging one of the 3.4v pairs just for fun, while I was soldering pairs in parallel. Managed to get 5-3.7v pairs done before I ran outta solder. (My soldering iron sucks balls! Will be getting a new one.) The 3.4v pair has now past the 4Ah mark! That's a good sign. Even though these cells are suppose to be closer to 2.4Ah. I consider them for building purposes to be 2Ah, because there used. We'll see how they test...

Next I will be charging the 10p string as fast as the B6 will do... See how long that takes.

I will be following your method as close as possible. (Prob only bleed test for a week, or until latest possible date. Due to waiting on more cells, or what not.)
I read the last half of the thread. From page 16 up I think. Will be reading the hole thing over again.


Questions:
When your doing your capacity test with the light bulbs, and you see one cell dropping below 3.6 (or 3.5 as you put it), do you just quickly unsolder them out?
Have you thought about using cell holders for this process? Seems like a lot of soldering and unsoldering. Or do you just use a bunch of alligator clips or something?
And doesn't this make it harder on the other cells left in the test?... I guess your only discharging at a ~.2c rate so that's probably not a concern. But at what point is it? Probably when 20% get removed from test, or 30%?

Also do you even bother with the IR test anymore? It seems to me that the IR would still be nice to know. Just another way to balance packs better at the very least.

Bulk Discharge - Capacity Test
Moved to Bulk Capacity Testing under Battery Technology Section

well gotta meanwell S-150-5 commin. $30
100 alligator clips with rubber protector $7
soldering iron, solder
braided tinned copper
and check this out. With the $3.00 1-8s low voltage alarm you get two other different ones for free now. the last one 2-4s QD-0345 will measure to 300v/100A!
this will work great to adjust the pot on the meanwell when setting amp output! http://www.ebay.com/itm/310559391965?var=610171363102&ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

Okay so apparently I didn't notice the voltage alarms are you pick one and the last one 2-4s is out of stock.

And I must have not finalized that soldering iron, so I got a second chance to think about getting a 100w one. http://www.ebay.com/itm/New-5pc-100W-Soldering-Gun-Kit-w-Case-Iron-Solder-Professional-Style-Sodering-/190832475742?pt=LH_DefaultDomain_0&hash=item2c6e807e5e

Or is a 60w recommended for soldering cells?

My last one was a30w. drove me nuts. :x

I recommend a ~40w soldering iron (pencil type) with adjustable heat, rather than a soldering gun.

Soldering gun (100w or higher) is handy for soldering heavy gauge power rails, terminals etc.
However, for soldering a large number of lighter connections, a pencil type iron is much preferable.
And ... higher temperature is not always better!

Practicing a bit on bad cells is nice for tuning your own procedure.
Once you get the hang of it, soldering can be a breeze.

Speaking of breeze ... a gentle fan keeping flux and solder fumes out of your eyes and lungs is a very good idea!

I updated the ES Wiki Soldering and Soldering Irons subject a bit, might be good to look at.

Hi everybody.

Been sitting here just reading cause I made the mistake of clipping all the cells into pairs before I realized I could have just left them 3s2p and had a bunch more charged right now. It's okay cause I'm going to bulk charge them all again once my meanwell gets in, in a couple days. Found a way to charge them all to a perfect 4.1v on the Imax b6 though. I figured 4.1 was best because that is what the manual suggest. Anyway I charge them with the fast ion setting first at the 5 amp setting. (got the timer all the way up on the settings) After this it's usually bouncing from 4.08 to 4.09 on the volt meter. Then a charge on the charge ion setting, not the fast charge, at .05. After this they are usually bouncing from 4.09 to 4.10. Then I switch to lipo mode at .5 amp and pump another 10ma into them. After this they usually settle right into 4.1 exactly. (With some suborn exceptions.)


Anyway so I've been reading a lot and came across this link. http://batteryuniversity.com/learn/article/charging_lithium_ion_batteries

Very interesting stuff! Really got me thinking about charging to maximize battery cycles. So they mention that the saturation charge is stressful to the cell. They said that once the battery voltage catches up with the charging voltage then it go's into stage 2 "saturation charge". This stage takes 2/3 of the charge time and only accounts for 15% more capacity at 4.2v! 10% at 4.1v. This got me thinking does the same thing apply when your only charging to 4.1 instead of the max 4.2 of a cell? Of course there is still a saturation charge but does it put stress on the battery like charging to 4.2 does. I asked them this. We'll see if I get a reply. I also asked them if they had a graph for figure 3 charging to 4.1 instead of the standard 4.2. I presume it is pretty close to the same thing.
http://batteryuniversity.com/_img/content/ion1.jpgCharge stages of lithium-ion
So if someone wanted to stop charging right as stage 2 started or 10-20 min. after it started. How would they go about doing that?? Would you just have to sit there with your volt meter on the battery and watch it till bat. voltage got close to charging voltage??? Or is there such a charger on the market that will do this for you automatically??? Do the programmable chargers that plug into your pc allow you to control this sort of thing? Or is there such a thing as a high voltage alarm that you can set like the low voltage alarm?? You could wire this alarm right to the battery, set it to a voltage a little lower than charging voltage, like .2v under, or more or less, idk. Then you could charge for another 10-20 min. and get a lot more cycles out of your batteries only sacrificing 5-7% of the capacity you would have gained!!!
And save about a hour and a half of the charge time!!!!


Any thoughts, Ideas, Comment's, Answers....
Don't hesitate to reply.
thanks
Diggler out

the only ones I found so far were these ohttp://www.ebay.com/itm/NNB-C-D-RATELCO-CIRCUIT-BOARD-mbc-4650-12-high-voltage-alarm-/181362183930?pt=BI_Control_Systems_PLCs&hash=item2a3a074efanly

don't know about them. How bout one you can set to 4.08v or what ever you want? like lets say 4.03 if you were to charge to 4.05v instead?

If you're using an imax B6, just set them to lilo mode and it will charge them to 4.1V iirc. You can charge as many as you want at the same time. With paralleled balance leads I've charged as many as 12 4s packs at once.

Haha right now I'm stuck on house arrest till the forth. So I'm just working with what I got.

Once I have everything I ordered and able to go to the store for odds n ends I will be able to really ramp up testing.

I plan on using my MeanWell S-150-5 to charge 60 cells at once to 4.15v.

Questions:

Could I just wire diodes into the output battery positive wire instead of the mods on here?

If I did so would it be with a diode like this wired 3 in parallel?
http://www.ebay.com/itm/20PCS-10AMP-Bypass-Blocking-Schottky-Diode-for-DIY-Solar-Cells-Panel-10SQ045-01C-/201062862553?pt=LH_DefaultDomain_0&hash=item2ed047ced9

Also, do these diode have a voltage drop of .55v?

So to get 4.15v I could wire the diodes 3p2s and set the MeanWell to 5.25v?

Then I wouldn't have to worry about frying the MeanWell and I wouldn't have to solder on it.

Wow... So I found some diodes that were 1v drop instead wired three in parallel and it worked good for two days but they got really hot on batteries that were already charged to ~4.05-4.1v.

Today I charged some to ~3.65v on the IMax B6. Then hooked it up to the meanwell, cranked up the voltage on the s-150-5. Volts on the ends of the charge wires was only like 3.9v and 5.5v on the meanwell terminals. Then after about ten min. POP! go's a diode! I was thinking three ten amp diodes in parallel would handle 30 amps. I guess they are made to rectify switching AC current so the 10A continuous rating was for AC not DC. Because of the AC pulses they probably get little brakes. I got 7 more... now i'm thinking at least four.

These diodes are tricky though... When more current is going through them they drop more voltage. By the end of the charge I got the meanwell turned all the way down ~4.42v and I get a perfect 4.15v...This is what I'm shooting for.

Why screw around with diodes?

diggler said:

Wow... So I found some diodes that were 1v drop instead wired three in parallel and it worked good for two days but got hot on batteries that were already charged to 4.1v.

Today I charged some to ~3.65v plugged it in cranked up the voltage on the s-150-5. Volts on the ends of the charge wires was only like 3.9. Then after about ten min. POP! go's a diode! I was thinking three ten amp diodes in parallel would handle 30 amps. I got 7 more... now i'm thinking at least four.

These diodes are tricky though... When more current is going through them they drop more voltage. By the end of the charge I got the meanwell turned all the way down and I get a perfect 4.15v...This is what I'm shooting for.

Click to expand...

Typically, running Diodes in parallel produces "unreliable" results.
Interesting that you got things working.

Likely, small gauge wire is responsible for your noticed voltage sag.
MeanWell S-150-5 at 5V 30A would want 10AWG-ga-gauge copper wire to maintain 30 amp throughput ... without noticeable voltage sag.

Remember though ...
Without modding, MeanWell S-150-5 is current limited at ~40A, (at 4.15V x 40A = 166w), will allow entire unit to overheat, ... so setting for final voltage and using lighter gauge charging leads ... might be a good thing?

But, don't be afraid to mod the MeanWell!

ES Wiki article - MeanWell S-150-5 mods

Swapping voltage pot from 1k to 2k will allow voltage adjustment from ~3.75V to 5.4V.
Or the R25 mods ... upping R25 value 1k would change oem voltage adjustment to a more accurate 3.75V - 4.5V.
Sorry, I have not figured the values for the current mods yet. - Had to rig a <5V 50A digital meter