Battery Building Competition

[marty]

Does anyone know where to find a specification sheet on the cells in these Makita battery packs?
Copy from:
http://toolhacker.com/2010/01/bosch-dewalt-makita-milwaukee-ryobi-ridgid-hilti-battery-specs/
Cells used in batteries
Bosch Litheon 36v – Sony US18650VT
Bosch 14.v/18v – Samsung INR18650 13Q (1.3 Ah cell / 18 A max)
Bosch 10.8v/12v Samsung INR18650-13P (1.3 Ah / 10 A max)
DeWalt NANO 28v/36V – A123 Systems LiFePO4 M1 cell
Dewalt 18v – A123 APR18650M1
Dewalt 7.2v-24v NiCd Sanyo/Panasonic 1.3 – 2.5 Ah cells
Dewalt 18v NiMH Sanyo 2.6 Ah cells
Hitachi Li-Ion HXP – Sanyo UR18650SAX
Makita LXT slim 1.5 Ah – Sony SE US18650OV
Makita LXT 3Ah – Sony US18650VT
Metabo Lipower – unknown, same as Craftsman’s
Milwaukee V18/V28 series use MoliEnergy IMR18650E/IMR26700A cell
Milwaukee M18 – E-Moli IMR-18650E or Samsung INR18650 13Q
Milwaukee M12 Samsung INR18650 13Q
Ridgid XLI – same as Milwaukee v18/v28
Ridgid 18v – 18650 version Emoli or Samsung
Ridgid 12v – Sanyo UR18650SAX 18650 cells
Ryobi 18v – Samsung INR18650
Sears Craftsman – Samsung INR18650 13Q
____________________________________________________________________________________________________

Here is picture of cells in small 1.5Ah packs. There are 5 cells per pack.
View attachment makita Li-ion 18V 1 of 5 cell.jpg

Here is picture of cells in large 3.0Ah packs. There are 10 cells per pack.
View attachment makita Li-ion 18V 1 of 10 cell.jpg

 

[grindz145]

yeah I guess they just put a 40 fuse in all of their scooters for no good reason at all... haha. 300W would be about 12.5A, and I would be surprised if it actually draws that much. The low voltage control built into the controller is a nice feature and would probably prevent the cells from getting very low. I'd feel alot more confident with a LVC thats designed for the appropriate chemistry and more importantly, a cell for cell LVC, in the event of severely disbalanced cells.

John, If I win I'd definitely be willing to shoot you some of the extra packs, but I really want to hook a friend up who is using lead acid (yuck) on his bike.

 

[grindz145]

View attachment UR18650W.pdf

This should be pretty close if not exact. It's a competing Sanyo cell, but its quite similar.

 

[pwbset]

I ended up getting another bunch of packs from pbwset

Which came from Marty originally.. heh, heh.. :wink:

..and ..I wish I'd never gotten rid of them in retrospect! Doh.

 

[John in CR]

Does anyone know where to find a specification sheet on the cells in these Makita battery packs?

Here's the best data we've come up with on the Sony US18650V and VT cells, and may be the original source of us calling them Konions. These are test results by someone in the RC community.
http://www.elektromodellflug.de/akku-test/LiIonM-1100.htm

What we know about them is that the VT's have a lower energy density, but higher power density, and the V cells can be charged to a slightly higher voltage.

Their most endearing aspect is their ability to self balance, so they don't not require balance charging or individual cell monitoring. This requires matching the cells during pack assembly, otherwise imbalances will occur due to differences primarily in cell capacity and internal resistance.

Marty, you simply cannot leave an EV turned on. Not only is it dangerous, but if left on for extended periods, it will kill your battery pack. I suggest a keyswitch for safety/security AND because it's easier to remember to turn off compared to a normal switch. eg You don't forget to turn your car off do you?, but before the days of ringing bells and auto turn-off, forgetting to turn car lights off was a common occurrence.

John

 

[MitchJi]

Hi,

Also, with such a small pack, cell testing and matching is absolutely critical. With that size pack, if someone just takes seemingly good cells and connects them to form a pack, I can just about guarantee a 20-30% reduction in capacity before cutoff.

Would you please explain the cell matching more completely? I assume you use something like a CBA or a 1010b to determine the capacity of each 2p group of cells? Then if the 2p groups are combined in larger parallel strings do you:
1. Mix and match capacities within each string so that the total capacity of the parallel strings all match each other?
or
2. Match the capacities within each string so that every 2p cell group in each string matches the capacity of every other group within that string?

How do you feel about:
3.) Replacing the controller?
4.) Replacing the gearing?

Lets not change controller and gears. If its not broken, don't fix it.

I think Mike was suggesting replacing the controller to allow higher performance (increased voltage).

Not sure why (or how to do it) he thinks the gears should be replaced.

What is approximately the current going forum price per good cell in used toolpacks for Konion V and VT cells?

How much per cell in new toolpacks?

 

[KTP]

I wish Marty would stumble across some Torqeedo battery packs. They have about 150 Sony LiMn cells in them Not sure if they are the V or VT though.

Man, I would design a hell of a pack if I could get 60 of those...

 

[marty]

x
Marty, you simply cannot leave an EV turned on. Not only is it dangerous, but if left on for extended periods, it will kill your battery pack. I suggest a keyswitch for safety/security AND because it's easier to remember to turn off compared to a normal switch. eg You don't forget to turn your car off do you?, but before the days of ringing bells and auto turn-off, forgetting to turn car lights off was a common occurrence.

John

If a Electric Vehicle can be left on by accident. Electric Vehicle will be left on by accident. Ever hear about the guy who locked his keys in his car and the car was running? It idled for days.

I have issues with buzzers in every gas powered vehicle I have owned for as long as I can remember. First thing I do is remove ALL buzzers. I will leave the key in the ignition if I want to!

I also have issues with trying to remember to turn my headlights on and off. I change the wiring so that the lights come on when I start the car. Lights go off when I turn the car off.

Marty also have issues with the word (I) Should I replace I with Marty?

Did leave my dome light on for a week a few years ago. Car battery was so dead that radio would not play. Lead acid battery had a miracle recovery and worked for about 3 more years.

 

[marty]

x
How much current does your pack need to produce? What voltage?

I don't know how much current battery needs to produce? Motor is rated at 300W.

Voltage with old lead acid batteries was 24V. New battery constructed from cells harvested from defective Makita power tool packs will probably be around 30V.

It's not a monster then. Somewhere around 50A should be the max the motor takes.

grindz145,
Will this estimated 50A max affect your.... Protection Circuit Module For 25.9V Li-ion Battery Pack(15A Limit)




Fechter also says "One test is worth a thousand opinions" Only 999 more opinions to go :lol:

 

[marty]

I recommend the 1010B+, this is the charger I use. No need to send it to me unless you want me the set up the menu on in. Once configured it’s set and forget. Auto shut off and can do up to 10 cells at 40.1volts. The power supply can be any 12volt high current supply up to 25amps. You can find these on ebay or a computer power supply. You can use a lower current power supply, it just takes longer to charge or even your car battery. I use the 1010B+ to test the capacity of the cells as well.
I will be using this charger to cycle the cells and verify the pack for the rated capacity. So you will know you will be getting a fully tested pack.
Link
http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6609&Product_Name=iCharger_1010B+_300W_10s_Balance/Charger

This setup will give you the fastest possible charge time about an hour or less. I recommend using a wattmeter to monitor the batteries, this will also give you a good idea on how much battery capacity you have left so you don't get stranded.
http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=10080&Product_Name=Turnigy_Watt_Meter_and_power_Analyzer

If you want a simpler monitoring system the cell log can be used and it will give you an alarm once the power goes too low. You can use both setups as well.
http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=10952

Hey, I can use those packs on my RC build. Here is my submission. I have built packs with konions on my BMC build and can build a reliable pack. I will use CNC plates of copper for connecting the cells that require it. I recommend staying with the assembled pack as they come from the power tools if possible. The welds are very well done and the separator keeps the packs from shorting out. The konions have a very thin insulation and require extra care to keep them from shorting. The insulation can actually be ripped with a fingernail.

The most you can get with the room you have specified is 8S 6P. This will give you 32.8volts at 9ahrs. As you can see you have room for 9S 6P or 10S 6P if you want to push it. This will give you 36.9 volts, or 40.1volts. The controller might not be reliable at those voltages though. I can build to suit but think 8S is best. I will terminate it with Anderson connectors unless you have something else in mind. I will use 10gauge silicone wires. As you can see I will be providing a CNC cut fiberglass separator. This is needed to keep the batteries from moving around and to keep shorts and fires from happening. I have left a 1/8 inch space so the whole assemble should fit in the space you have specified and not bounce around. I can wrap it in clear heat shrink or glass reinforced tape but think the tape method is best.

My BMC build has a similar setup for the rear rack and it has actually been dropped twice from the bike. Once from the slide lock failing and once from the rack braking. Both falls left the batteries undamaged due to the fiberglass material holding it together. You can see how I built it from this link and what I had to go through to make sure it's reliable. I will use Kapton tape on all edges.
http://www.endless-sphere.com/forums/viewtopic.php?f=6&t=12654

Picture of assembly, duplicate the same group of cells for the back half to get 8S 6P pack at 9ahrs

Kfong,
I like your drawing. How do you plan on charging? According to contest rules Marty pays for the charger, and I imagine that I would have to have the charger shipped to the winner for testing purposes. Remember.... "Marty don't baby sit his batteries while they charging. Marty likes a charger that tells when batteries are charged. LEDs that change color or something like that."

Will take your advise. 8S 6P, 32.8volts at 9ahrs should be fine.

Will read your (Motobecane DS Fantom, BMC 600W torque and Konion build) post tonight.

I had a idea? As explained earlier I hate BUZZERS. Can we use Kfong's Cell-Log Voltage Monitor to trigger a relay to shut down power from battery pack? I see 8,478 relays at newark.com and 28,885 relays at mouser.com
http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=10952

Any other low voltage cut off ideas?

 

[marty]

I just changed the contest rules. I can do that because I am MARTY.
EDIT: 07/22/10 add contest rule number 8. Marty pays for any needed electronic parts in battery assembly.

 

[KTP]

Foot pressure sensor on device wired to 555 timer circuit and set/reset wired relay flipflop. No foot pressure for 5 minutes, relay turns device off. On switch resets the flipflop wired relay. Should also be a simple way to have a LVC wired into same relay.

 

[kfong]

Hi Marty,

I think a better approach is to use mosfets to turn on the battery supply instead of a relay, less power consumption. Use a small processor to monitor the batteries and shutdown when the batteries get past the low voltage setting. The problem is the processor and DC/DC can still drain the batteries. Dewalt A123 packs had this problem and it was a faulty design in there older packs. I have a circuit that I need to test out, but I think it will work. Total shut down and zero current draw. I’ve been working on it for a while, but have been busy with other projects as usual. I might have to get it done since I want these batteries.

The simplicity of this approach is the batteries protect themselves, the user doesn’t have to think about it and if they forget to turn things off, the battery will eventually turn off, waiting to be charged up before use. There wouldn't be any worries if done this way.

 

[MitchJi]

Hi,

I'm with John on this. You can't remember to turn it off when you've completed your ride? How are you going to remember to plug in the charger after a ride and maybe more importantly to unplug it before a ride?

But how hard would it be to integrate a switch into the throttle?

Turn the throttle 1/16 of a turn to switch it on. Release the throttle and the return spring switches it off.

 

[marty]

Hi Marty,

I think a better approach is to use mosfets to turn on the battery supply instead of a relay, less power consumption. Use a small processor to monitor the batteries and shutdown when the batteries get past the low voltage setting. The problem is the processor and DC/DC can still drain the batteries. Dewalt A123 packs had this problem and it was a faulty design in there older packs. I have a circuit that I need to test out, but I think it will work. Total shut down and zero current draw. I’ve been working on it for a while, but have been busy with other projects as usual. I might have to get it done since I want these batteries.

The simplicity of this approach is the batteries protect themselves, the user doesn’t have to think about it and if they forget to turn things off, the battery will eventually turn off, waiting to be charged up before use. There wouldn't be any worries if done this way.

EXCELLENT This is what I want. Can we buy this gismo somewhere?

 

[marty]

What is approximately the current going forum price per good cell in used toolpacks for Konion V and VT cells?

I can't remember what I was selling them for? Topics in [Items for Sale - Used] category delete after a certain amount of time. Doctorbass also sells used power tool packs. He tests them. I don't test.

How much per cell in new toolpacks?

Look for prices on Google, Amazon, EBay, or local tool sellers near you.

 

[grindz145]

x
How much current does your pack need to produce? What voltage?

I don't know how much current battery needs to produce? Motor is rated at 300W.

Voltage with old lead acid batteries was 24V. New battery constructed from cells harvested from defective Makita power tool packs will probably be around 30V.

It's not a monster then. Somewhere around 50A should be the max the motor takes.

grindz145,
Will this estimated 50A max affect your.... Protection Circuit Module For 25.9V Li-ion Battery Pack(15A Limit)




Fechter also says "One test is worth a thousand opinions" Only 999 more opinions to go :lol:

The motor will not take 50A....ugh.

 

[kfong]

Hi Marty,

Not that I know of, too specialized. That's why I've been working on it for a while now. I should have a prototype done by this weekend to show since your contest has put a fire under my ass. I plan to sell them but want to source out cheaper components. The DC/DC part is a bit pricey for what it does; $30 is the cheapest I can find the chip so the final design will be something else I think. If chosen, the board will be a working prototype customized to your application. I will trade it back if you want once I have the final boards done. The final boards will be more generalized for ebikes, ect. and have some extra features.

Hi Marty,

I think a better approach is to use mosfets to turn on the battery supply instead of a relay, less power consumption. Use a small processor to monitor the batteries and shutdown when the batteries get past the low voltage setting. The problem is the processor and DC/DC can still drain the batteries. Dewalt A123 packs had this problem and it was a faulty design in there older packs. I have a circuit that I need to test out, but I think it will work. Total shut down and zero current draw. I’ve been working on it for a while, but have been busy with other projects as usual. I might have to get it done since I want these batteries.

The simplicity of this approach is the batteries protect themselves, the user doesn’t have to think about it and if they forget to turn things off, the battery will eventually turn off, waiting to be charged up before use. There wouldn't be any worries if done this way.

EXCELLENT This is what I want. Can we buy this gismo somewhere?

 

[fechter]

I see two distinct issues here:
1. connecting the cells, both mechanically and electrically to build a pack
2. charge/discharge control, which may or may not require cell-level monitoring.

I'm not that familiar with the recommended voltage set points for that chemistry, but I believe you would want an absolute maximum cell voltage of 4.1v. The low voltage cutoff point I'm not so sure about.

The cells are likely to be damaged if discharged all the way down to near zero. In a large pack, this usually requires cell level monitoring to prevent damage.

From what I can gather, the Mn chemistries are not prone to getting out of balance and can tolerate some overcharge, so a full BMS may not be worth the bother. I'd recommend at least using some kind of HVC/LVC to keep the batteries out of the self-destruct range.

Most commercial (Ping, etc.) chinese packs use direct cutoff (we call active cutoff) where there is a big FET switch in the BMS that disconnects the load or charger in the event of voltage overrange. This makes the connections a bit easier to deal with. The other approach is an indirect cutoff (passive cutoff), where you need to interface to the controller throttle or brake line to stop the discharge if a cell gets too low. This avoids the need for FETs to handle the full discharge current, but is more complex to connect. A third approach is to not have any cutoff, but have an audible/visual alarm that beeps/flashes if a cell gets too low. It's up to the human to stop discharging the battery in this case.

Since your scooter motor has a modest current draw, a direct or active cutoff would be reasonably sized.

Don't those tool packs have some kind of BMS inside? Seems like you may be able to use them somehow.
How many cells are in the tool pack?

According to my math, if you go with a 8S pack, 4.1v per cell, would be 32.8v. A 24v SLA charger would generally be a bit low for that, but most of them have a voltage adjustment that might get you there.

 

[tostino]

Fechter, LiMn is honestly really close to LiCo as far as charge and discharge ranges. They last longer if you charge them to 4.1v/cell, but they are perfectly capable of being charged to 4.2v though. LVC for them is 3.2v/cell. Again, just like any other lithium they like not being fully discharged.

 

[John in CR]

Apparently those with no experience building and using battery packs containing Sony US18650V and VT cells know more than Bosch or Makita who manufacture hundreds of thousands or millions of packs with these cells that are used in a far more stressful manner than on our ebikes or escooters. Anything attached to this pack other than the motor leads, which is already fused, will do nothing more than increase the chance of failure.

If Marty doesn't want to have to turn it off fine, but he can't avoid plugging it into the charger, so he can leave it on full time if Marty likes, and issue solved. The scooter is always ready to go, and the battery never dies if he forgets to turn the switch off. I just hope no children are ever within touching distance of this scooter.

Apparently Marty wants a battery that is more like this bike:
View attachment Marty battery.JPG

Than this pair of 6p20s battery packs containing matched cells, and are built to last the maximum remaining useful life of the cells:
View attachment Marty battery 2.JPG

I'm not having my name associated with any battery that is like that bike, because I know all that glitz will only increase the chance of early demise of the pack, as well as leave Marty carrying or pushing the scooter home with more frequency. The more a Konion pack battery can look like the battery in your car, the better, and just like the battery in your car, if you abuse it, it will die sooner, and all the electronics in the world aren't going to prevent it. Plus the added electronics are quite likely to cause the pack to die. Those kind of extras are needed with other types of cells, not Konions.

Listening to what the pack is telling you and the existing LVC built into the motor are all that's needed to protect the pack.

John

 

[kfong]

I’m not sure I understand your reasoning John. Most modern cars, the electronics on board are on all the time such as the clock and car alarm. If you sit in your car and turn off the ignition and remove the key. You can still turn on the lights, the radio. Roll the window up or down. Once you open your door the system turns itself off. This is all controlled by processors. Not a manual key switch. Some of the really nice cars use proximity sensors that detect the key signature and know when the key is near. You don’t even need to lock your door or put your keys in to turn on the ignition. The complexity is there, just the implementation is well thought out. There is more electronics in today’s car than the original Apollo missions. I’ve worked at GM research for over 20years and I think I know what it takes to build such devices.

 

[texaspyro]

The complexity is there, just the implementation is well thought out.

"Your door is ajar... your door is ajar... your door is ajar..." STFU yammering car voice! BLAM! Ahhh, peace and quiet at last! Been there, done that.

 

[AussieJester]

Just wanted to add my 2 cents worth regarding a switch, definitely should have a cuttoff switch (if not for anything else...safety !)
the less electronic management the better its one more thing to fail, Ductorbass tape man has been using these
for years and IIRC he has no form of BMS the Knonions balance themself out, and if you haven't the ability
to be able to see on the WattsUP or CA gauge when lvc is coming up etc...maybe EVs aren't for you just yet LoL :lol:
Johnny boy is ya man IMO, let him build the pack like he does and i'm sure you will be very happy with the result
he's built a heap of them, they are solidly built carefree packs.

Best of luck in the comp all...

KiM

 

[John in CR]

I’m not sure I understand your reasoning John. Most modern cars, the electronics on board are on all the time such as the clock and car alarm. If you sit in your car and turn off the ignition and remove the key. You can still turn on the lights, the radio. Roll the window up or down. Once you open your door the system turns itself off. This is all controlled by processors. Not a manual key switch. Some of the really nice cars use proximity sensors that detect the key signature and know when the key is near. You don’t even need to lock your door or put your keys in to turn on the ignition. The complexity is there, just the implementation is well thought out. There is more electronics in today’s car than the original Apollo missions.

All that has nothing to do with the battery, and a scooter certainly doesn't need them, so it's just more to go wrong, wires to short, unnecessary weight, etc.

I’ve worked at GM research for over 20years and I think I know what it takes to build such devices.

The how about snagging us some Volt packs, or how about the other packs that got tested rejected in favor of whatever cells they decided to go with in the Volt?

Since you're in GM Research, how about figuring out how to knock off at least 1500lbs? It's got the right fuel, so that's a start. Have you seen anything in the way of smart suspensions that will be required for the far lighter cars that will be the future?

John