Kokam 3200 SHD Lipo
 

I was wondering if anyone has tried the new Kokam 3200 SHD lipo batteries yet. They seem to be very promising, with a 30c discharge rate (64 amps continuous) and should fit reasonably well, too (2s or 3s are a touch shorter than a six cell pack). I have been considering these in my truggy conversion. I can get these from one of my distributors (not cheap) and will likely try them soon. Anyone try them yet? anyone interested?

I'm interested - How much for a 4s pack?

I haven't tried them but was just checking them out the other day (towers site) when I was making a purchase. 20c sounds nice. I would try them if i didn't already have so many batteries already (6 lipos for 1/10th scale and 2 for my rc18t) not to mention the gp packs.

I just checked Tower. I can't match their price. I guess I have to talk to my distributor about a lower price or find another source. The 4s pack will cost me almost $200 shipped (can do better at Tower myself).

Just got two of the 3s 3200 packs. Sorry Mike - I got them from Tower for lower than my 3s 3100 12 C polyquest packs!!!! They had this 30 dollar discount on 199.99 or something so I had to try them. Based on numbers, they're slightly larger than the Polyquest. The Polyquest are at 7.5 oz per pack while the Kokam is at 10 oz per pack (more in comparison to 14.8 volt 3100 polyquest) so energy density is LOWER than polyquest, but discharge rate is higher. Will have to see it in my emaxx with eagle tree to see the voltage drop under discharge...

I'll be using 6s 3200 in my Emaxx... or try that 12000 kv Motor again in my TC4. Last time I used the 1515 5 turn with 11.1 volts, it was pulling over 100 amps and voltage drop was down to 5.0 volts!!!!!

I just picked them up at Tower myself (better deal than I could get through my dealer). I did it the same way you did. I got two of the 2s and just ordered 2 of the 3s packs (were out of stock when I ordered the 2s packs). They are about 1/2 the weight of a regular nimh pack. I haven't tried them yet and would be very interested in your eagletree results. I am thinking of an 18.5 volt setup in the e-maxx and possibly the HB Lightning conversion. Please post your test results here.

i was thinking about trying 18.5volts since i wanted a little more while the novak hv was in the truck (novak actually ran on 16 cells). Since dropping in the 8l i dont really think i will need anymore power then the 14.8 lipos have. Anyways looking forward to seeing how the cells work out since they seem to be a pretty good deal after there coupon codes.

Mike, when I get the batts, what setup do you want me to test? My motors are the Basic 2100, xl1600, Feigao 10L, basic 2700. I'll have to test at 22.2 volts though. In addition, what gear ratio are you looking at? I was thinking of just keeping it at 18/66 (stock ratios) for now.

Young, I was thinking of running the basic 2700 or xl3100 motor. You have the 2700, so lets start there. I ordered 2 2s packs and 2 3s packs, so I have some options. 22.2 volts will over rev the 3100 anyway. I would be interested in the 2700 in first gear with the stock gearing (2nd gear would be too fast for my needs- likely 50+mph even with the voltage drop) as well as a 19 or 20 tooth pinion. I usually gear to reach mid 30s for track racing and would be interested to know what these batteries can take and what kind of draw this speed/gearing yields. The 2100 with 15/66 gearing in second gear is close to what I am looking for as well. What the hell, try them all! I am interested in the 10L for the truggy (although 22.2 volts puts it at or over the rated 50000 rpm limit). I got the 2s packs already and may try them with an xl3100 this weekend (in series). Thanks in advance! I am looking forward to this information!

I think the xl2000 may be the perfect motor for 22.2 volts (or basic 2100). It has enough voltage to keep amp draw in check and enough rpms (mid 40k range) to get some speed without over revving the motors. They say curiousity killed the cat. Well, its a good thing cats have 9 lives! I am very curious!

Actually, I can tell you that the 2700 geared 18/66 with stock tires and 22.2 volts 3100 polyquest gets to about 33 mph in first gear. In first gear, the amp spike is at about 65 amps and voltage drop is about 18 volts - that's for a REAL short time though. In second gear, the voltage spike goes to 15 volts and amp spikes to 90 amps. I would say that any 6s brushless lipo setup with gearing set for low to mid 30's will only draw about 70 amps peak - so getting a slower motor geared taller, or faster motor geared shorter will all yield about 60-80 amp peaks. The Kokam can do 60 amps continuous so I believe with the Kokams, you'll be well under the limits of that battery pack. I'll post a graph soon - the first 4 big peaks are in first gear and the second two big peaks are at second gear.

I wonder how well the voltage holds up on the kokams compared to the 3100 PQ packs you tried. They should hold up a bit better and possibly yield more power. Maybe less amps, too. I am guessing you will get an extra mph or so out of the 20c kokams.

Oh, here's the graph.

The 3200 kokams could likely handle the 90 amp spikes without much trouble, too. What speed did she peak at in second gear? upper 40s would be my guess.

Actually, never got a good shot at measuring - the ONE attempt I had got 46.5 mph in second gear. One thing to keep in mind is that it's very difficult to control. Even in second gear, I have to accelerate slowly and smoothly or else it'll do back flips all day long. The Basic 2700 has GOBS of torque when it's pulling over 1200 watts!

If it wasn't for the amp draw possibly damaging the Lipos, I would have easily geared taller - there was as much acceleration as a 3100XL on 12 cells and geared with like a 12 tooth pinion!!!! The XL3100 on 12 cells and geared 20/66 could hit 45 mph, but no way could it flip backwards in second gear.

Did you get any extended run times with this setup? I bet the little motor works up a sweat putting out that much power. I have experienced the same concept. The little motors put out plenty of power! The problem is when racing, the heat buildup becomes an issue (I fried a basic 3100 in a race - burnt the windings!). The higher voltage should minimize the heat, but that would still be a concern for me.

I did run the Basic 2700 with the 22.2 volts for an extended period of time - but it's COLD here in Chicago and I was running it in first gear the whole time. I was kicking up MAJOR snow rooster tails. The flying snow also kept the motor cool. At the end of 10 minutes, nothing was hot - but the batteries - 110 degrees F.

For racing purposes, I would NOT recommend a small motor. You need surface area and cooling fins and maybe even a fan. In addition, you want to keep the motor in the most efficient RPM range - about 30-40 k rpm. AT 22.2 volts, I think the basic XL1600 or maybe the XL2000 is better suited for long races. BTW, I think I ran for a good 10-15 minutes and I only used 1/2 the capacity!!!

We are on the same page. I run heat sinks and fans during the hot summer months. Racing is pretty hard on things. I haven't raced a basic sized motor in a while for this reason. Even the xl3100 gets pretty hot on 12 cells. I am looking forward to this season with some Lipos and hopefully cooler running with higher voltage. I have been playing with the Lipos, but mostly in my TC, as I had the same packs you did (2000mah, 15c Kokams) and did not want to push them too hard in my e-maxx. I ran them in series with an xl2400 for a good 8 minutes screwing around the house with no ill effects (and only drained 1300mah from the packs), but never raced them. I will race the 3200s, though!:)

I have had great luck with the Feigao "L" cans too. They are big enough to run pretty cool.

When I run high voltage Lipo, the motors definitely stay cooler than with lower volts and NiMH. A basic 5300 with 6 cells get HOT during a 5 minute race. A Basic 2700 with 14.8 cells gets nowhere near as hot, nor does the controller get hot, and to boot, there is MUCH more power too.

When you ran those 15C 2000s, you were probably pulling about 60 amp spikes in first gear if you geared for 35 mph. Probably not damage those, but could if ran hard.

I used to run my 15C 2000s in my TC for 10 minutes at a time geared for 35 mph. I would pull amp spikes of around 40 amps but occasionally would end up swelling a cell here or there. Constantly going over the max rating will harm cells. BTW, for TC, I would rather use the U Force - the parameters can be set for drag brake, etc. First thing I noticed when I went for the 12.97fwe to the U Force 75 was that it was more driveable with a little drag - or maybe it was the car?

Yeah, just got a Feigao 10L which is similar in specs to the XL2400. I got it with 1/8" shaft so I don't have to get special pinions and it holds up just fine for me. Plenty of torque too. But because their max is at 50,000 instead of 65,000, I tend not to use them in speed runs. In speed runs, I max out the motor and batteries. W/O a doubt the BEST value for motors out there. For 80 bucks you get a Neo brushless motor that can peak out around 2HP for brief moments, has no maintenance... Too bad nice controllers cost so much money.

I should have some MGM controllers soon. They are nicely priced and seem to be liked by some others. I hope to test them this week coming. I am getting the 60 amp and 80 amp 12 cell car controllers for now (should work nicely with the 1/10 vehicles and eliminate the rx pack needed in the warrior line). They have some higher cell count car controllers coming soon, too (and higher amp rated), and they are priced quite nicely. Hopefully they will work out.

I have pushed the Feigaos past their rpm limits (I'm sure you have, too!) without any ill effects, but I don't often do speed runs and tend to keep the motors working in the mid 40k rpm range (seems to be where they are happy). The Feigaos are a great motor for the money without question.

Believe it or not, most of my running with Brushless is between 30-40 K. Rarely above 40K. Back to this thread, I got those packs in the mail today and first thing I notice is like the extra 6 inches of wiring - so I'm gonna have to cut open this pack and resolder the wire so it's only 3 inches long. Too bad - I only have clear heat shrink. Funny thing is that this battery looks IDENTICAL to my 15C 2000 mah Kokam packs but just longer. I wonder if those 15C 2000 mah are actually 20C but underrated at the time? Maybe...

They weigh a lot though and considerably larger than Polyquest. Thicker and wider. I guess you have a weight penalty for lower internal resistance. It weighs about the same as a 14.8 volt 3100 Polyquest, but is only 11.1 volts. However, max continuous power is 700 watts (minus voltage drop) vs. 550 watts (minus voltage drop) so oz per oz, it'll pump out more power, but less energy than the Polyquest packs. Good for high power shorter races, bad for 30 minute endurance racing. Good for drag racing too - 700 watts continuous from 10 oz is better than GP3300's. A 5 cell GP3300 cannot give out 700 watts CONTINUOUS. I'm thinking this pack alone will peak out at around 1000 watts - when the weather gets better, tests will show this soon enough.

I've finally got a chance to run those Kokams in my TC4 last night. I've tried all sorts of combinations of motors and gearing. Tried the Twist 4200, C40 12s, basic 2100. Tried different ratios and different voltages. For my track (small indoor carpet track), I find that the ideal setup is C40 12s, geared 10:1 FDR using rubber tires Sorex 20. Funny thing is that 14.8 volts had too much power an dwas uncontrollabe so 11.1 volts was the better setup. Under 11.1, the max speed is only 30 mph, but the stock guys are running about high 20's and that top speed is only reached ONCE on the back straightaway. Motor RPM is almost 40,000. Comparing the Polyquest 3100 11.1 volt pack which weighs only 7 ounces vs. the Kokam 3200 11.1 which is 10 ounces, they were pretty much idential in performance. Actually, the Polyquest being lighter, transitioned better. So, for small indoor carpet tracks gearing a "slow" motor, I don't think you need 20C high discharge packs. The higher discharge packs weigh more for the same energy. I prefer the polyquest in my TC4.

After 20-25 minutes of NONSTOP running, motor temp was at 160 degrees F, controller 130 and batteries were at 105. That's pretty good running temps. I ran a total of 2 3200 packs, 1 3100 pack, and 1 4s3500 pack. I think 4s is better for larger outdoor tracks and 3s better for smaller indoor tracks.

When I get my Emaxx fixed (steering), I'll post actual tests and graphs between the batteries.

Thanks for the info. For a large outdoor track, I find that having some extra weight actually helps at times. I run the 2000mah, 15c discharge LiPos in my tc3 with a basic 4200 motor. I run two packs in parallel, so it weighs about as much as 5.5 nimh cells. I ma geared for mid 40mph and the acceleration is pretty insane. I don't have a data recorder, but I know I run 12-15 minutes and only put about 12-1400 mah back into the packs, so I think the draw is on the safe side. I planned on using the 3200s in my e-maxx and truggy conversion, as they need the amp draw ability. The 2000s will be used in the stampede and tc3. Hurry up and fix your steering! I am anxious to see the graphs for e-maxx duty!

Do you have trouble with your diff on your TC? Mine keeps on getting loose and melting the plastic outdrives. So I got steel ones. Better, but after a few minutes, they slip again - at least it doesn't melt, but I have to almost lock them up between every battery pack! I' m thinking of running a spool in the rear now.

I did try the basic 2100 motor the other day on 11.1 volts geared 28/72 x 2.5. It was okay for speed and acceleration - but when a motor spins too slow, you don't have as much fine motor speed control as you would if the motor was spinning a little faster. It seems like when a motor spins around 40,000 rpm it's easier to drive than a 20,000 rpm motor.

I'll have the emaxx tested by the end of next week. I'll start with the Feigao 10L with 22.2 volts comparing polyquest 3100 vs. Kokam 3200 vs. Kokam 2000. I'll have it geared 18/66 and use only first gear. That should give me a result of about 30mph in first gear. RPM should be right about 50,000 rpm. I'm gonna guess about 65 amp draws during acceleration... We'll see.

I had to go to the steel outdrives also and melted one diff. Once I rebuilt the melted diff and installed the steel outdrives, I haven't had any issues. I also run the front one way, so no diff to worry about there. I agree with your comments regarding rpms. 40000 is a nice number. It seems to be a happy spot for motor in terms of performance and running, and if you have too few rpms, the control becomes less smooth (half as many possible steps, I guess). I am looking forward to the e-maxx test results!

Son of a gun... got the servo today, but more snow too!!! Sigh... BTW, can I order a servo saver for my emaxx for the JR servo? Do you have them in stock?

Yes, Young, I have some heavy duty kimbroughs in stock. I can throw one in with your xl2400 if you want.

Yeah, throw one in - send me the amount and I'll paypal that over to you asap!

You got it. :)

Is there a LiPo Primer out there for me to learn more about it or even batteries in general? I have no idea what you guys are talking about when you say stuff like "30C discharge" or "ordered 2s and 3s". If there were a dunce cap emote, I'd be using it right about now! lol

"2s" means two cells in series. "30c" discharge rate means 30 times the capacity of the cell (so a 3000 MAH/3AH pack that is capable of a 30c dicharge rate can safely discharge at 90 amps). "3p" means 3 cells in parallel. Now, throw away that dunce cap! :)

I'll try to explain in more detail: The lithium packs that we use are called "Lithium Polymer" packs, but they're really "Lithium Ion Polymer".

Each cell is generally rectangular in shape and pretty flat. Also, each cell is 3.7 volts instead of 1.2 volts. Hence the voltages: 3.7, 7.4, 11.1, 14.8, 18.5, 22.2...

Lithium packs originally were not able to deliver the "punch" because of their high internal resistance and small sizes so in order to make a large pack, they would get several small packs and then hook them up in parallel. That's where the xSyP comes into play. The "x" is the number of cells in series (the overall voltage) and the "y" is the number of cells in parallel (to reduce internal resistance by just having a bunch of cells in parallel... also increases capacity). These days, with the larger cells in production, there really is no need to parallel cells anymore. I'm generally just running 3s, 4s, 6s, or 8s in my tc4 and emaxx. So for me, the number is simply the number of cells hooked up in series or "end to end". However, a 6 cell pack of Lithium cells is 22.2 volts vs. 7.2 volts for NiMH.

The "C" that you see all the time is the capacity. When something can be discharged at 10C continuously, that means that a pack can discharge at 10 x the overall capacity. So, a 3000 mah pack can discharge safely at 30,000 milliamps (or 30 amps) continously. You don't want to overdraw a lithium due to their explosive and somewhat fragile nature. These days, the newest generation is safely discharging at 20C rate (so a 3000 mah can discharge continuously at 60 amps). That's continuous - so an occasional peak at 100 amps for a split second shouldn't do too much to hurt it... we'll see about that soon.

The best feature of Lithium packs is their energy density. They are about 2x the energy density of NiMH so given the same weight of batteries, you'll run 2x longer. The newer generation of packs are also higher power density too now. A 20 ounce pack which is roughly equivalent to 10 sub C cells can deliver peaks of over 2000 watts!

I hope this helps. BTW, Mike, I've added just a little bit of slip to the stock slipper and got those cheapo plastic shafts... I'm gonna give it a go this afternoon.

10L, 6s, 18/66 gearing.

Thanks for the detailed explanation of Lipos, Young. And be careful with the stock slipper. Too loose and it will melt! Perhaps some rear cvds are in your future, and a better slipper! I am anxiously awaiting your test results!

Thanks for the detailed explanation -- I think I actually understand it all! :)

I've done my first test run with the Kokam 3200 packs in my emaxx. Once again, 18/66 gearing, 6s and running in first gear, top speed is 35 mph (34.9 and 35.4 two ways). It gets to that speed in a HURRY too - you can't pull on the trigger - too much power. That's about right too - in theory, a 2450 rpm/volt and with 5.75 inch tires and 23.4 volts. will give that speed exactly. Voltage drop is only a couple of volts - approx 3 volts at 60 amp spikes. VERY low voltage drops!

Top speed was in excess of 50 mph, but couldn't get a good clean run. It's only 25 degrees and the tires and the suspension couldn't hook up with the ground.

After about 1000 mah, the motor was at 150 degrees, battereies at 65 degrees and the controller at 90 degrees. Keep in mind that it's 25 degrees outside so this motor is working too hard/and or not really that efficient. It used only 1000 mah after about 8 minutes of run. That should allow me to run about 20 minutes of good running in first gear. Peak amps in second gear was exceeding 100 amps while in first gear it was around 60 amps. Watts were around the 1500-1900 in second gear and 1000-1500 in first gear.


The Kokams at 6s would make an excellent battery setup for racing - however, I think a slower motor would be better and geared a bit taller. I had it going over 57000 rpm in first gear and that's just too fast. I think the 1600 KV motor would be a better racing motor for 6s. But you gotta gear it right - so instead of 18/66, I would need to gear it like 27/66 (if that's even possible) or go to a smaller pinion and lock it in second gear so top speed is around 35 mph. Should make the truck a little more controllable and everything will be a little more efficient and not as hot. Torque is really not an issue. Even geared for over 50 mph, the truck will flip backward instantly in second gear!

What graphs do you want to see? amps? watts? power?

I'm coming to the conclusion that 8s is not necessary. Actually the Kokam 6s is giving out more power than the Polyquest 3100 mah 8s!!!

Then again, it's supposed to. But the polyquest has about 33% more energy density but less power density.

The polyquest 6s was noticeably less "kick", but still, WAY more than enough. 6s Kokam in second gear is not even controllable. I need to extend the chassis like 1 foot and get some super sticky tires etc.