BMC motor version Question

.5 miles would be about right, from a 12s 5 ah pack charged to 3.5v per cell.

This is old stuff right? I think you are just having your charger stop when the ruined cell reaches 4.2v.

Spring for some new packs. 3 new 4s, and a 2s. Or two 6s and a 2s. Bet you get better than 20 mph out of new 12s.

The good news is it now appears the only real problem you have is your RC batteries are done in. This mish mash of partial info in multiple threads confused the hell out of me.

Get a cellog 8 to keep an eye on voltages, cell by cell. Reasonably accurate.
Or at least one of the cheapie low voltage beepers, that are not very accurate but they will chirp when you have a cell too low to keep running. Adjustable, so make it beep at 3.5v or so. It will then beep under load when you are at about 3.7v. When it beeps, back off the throttle till it stops and keep riding. When it won't stop, you stop.

http://www.hobbyking.com/hobbyking/store/__18588__HobbyKing_8482_Cell_Checker_with_Low_Voltage_Alarm_2S_8S_.html
 
Thanks for all the info guys. I appreciate the insight and help. I do have one battery that has two unbalanced cells. 3.78 and 3.69 when the other two cells are reading 4.08. I'll have to remove that pack as the balance charge doesn't want to bring the pack back up to 4.1+. Looking at the other three packs I only see 4.16 to 4.18 when the alarm goes off(full charge). I don't see any other alarms set. My max capacity cut off is set to 6000mah.

On some other batteries like a 3S 2200 that I use to fly my electric planes I do get 4.20 4.20 4.20 on that pack but not on these 4S 5000 Nanotechs. I'm getting 4.16-4.18. I also double check the battery with a cell checker on the balance plug. The cell checker individual readings are always different from the readings on the balance charger. (You get what you pay for).

What it sounds like your saying is that on my charger I should be able to set charge the pack to 4.20 per cell as opposed to setting the mah of the pack. I don't know where that setting is. Nor have I ever seen this functionality on the A6.
 
Old packs will sit there warming them selves forever, it could take 10 ah flowing down the wires to charge his packs to 5 ah full.

I was wondering why his charger stopped so soon, now I get it. Looking at the display on the charger, 4.15v. Unplug, 3.5v.
 
Thanks I looked at those videos. And that's exactly how I charge my packs. I'm pretty sure there isn't a way to set the voltage per sey to 4.20. There is a lipo setting that says 3.7 but you cant change that. It's fixed. I also noticed that typically these chargers are very conservative in the charge. If I do get a full charge and they measure 4.20 on the charger there not really 4.20. I have a couple of different cellcheckers and they always measure lower than the stated 4.20. You get what you pay for. Some folks have recommend the Experion or iCharger 1010b.

mark5 said:
I don't see a way to explicitly set a voltage like 4.20 or 4.15. Only to set it in 3.7V nominal volts increments. So, as amberwolf suggested, I'd just turn the Capacity Cutoff off.

PDF manual:
http://www.hobbyking.com/hobbyking/store/uploads/ACCUCEL_manual(2).pdf

voltage setting at 1:24
https://www.youtube.com/watch?v=BYFHQHQ1aD8

voltage setting at 6:08
https://www.youtube.com/watch?v=kvr-25yGeVk

voltage setting at 3:50
https://www.youtube.com/watch?v=zm7ZKVGYAiE
Click to expand...
 
I went ahead and bought 4 6S 5000mah 30c packs. I'll have to make one more series connection. I already have two parallel connectors. Or I can just rig them in series with out the connectors as others have previously mentioned. The packs I had were fairly new my buddy gave them to me after he discharged them way to low and was never able to charge them back. I was able to revive one of the packs. But the second pack is damanged. So I think I'm in a good spot now. I still have one good 4S 5000 plus the 4 on order.
 
It's probably a good thing to get new packs, given the slowly-revealed pre-damaged pack condition you're telling us about. FWIW, if you told us about the pack condition to start with, we could have helped you better a lot sooner with a lot less frustration on all sides. ;)


As for how to use your charger to fix an unbalanced pack, or to a specific typical per-cell end voltage, it's easy.

Set the per-cell voltage to 4.2 by setting it to LiPo mode.

Set it to 4.1 v/cell by setting it to LiIo mode.

(no, you can't directly set the voltage, but using those modes will result in those final voltages for balanced packs).


For undamaged packs, get a full charge with balancing by disabling the mAh counter limiter and the timer limiter, if those are stopping the charge/balance before it's done.


But the limiters on the Accucel6 (the one I have, at any rate) goes up to 50Ah, and 12 hours, so if you set them high enough even a fairly out of balance pack may still eventually balance. And if it isn't done the first round, just start it over again.


Buuuut: Don't *use* the packs if they aren't charging up the cells....it's just asking for a fire if you overdischarge the cell(s) and then recharge them, especially if you do this repeatedly. :/ You have to get the low cells charged up *somehow* before you can use the packs they are part of.




I can't say if the Accucel6 is any good or not, relative to other RC chargers...but I've used it numerous times to balance the 20Ah 4s EIG NMC lighting pack just fine, in LiIo mode for 4.1v/cell (as the NMC max is 4.15v/cell), after having used the 3s tap on the pack for my air compressor long enough to unbalance it.

It's not all that out of balance, usually, but I've gotten it far enough a couple of times to take days to balance it with the tiny amount of high-cell-bleeding the Accucel6 can do per cell. Without turning off the timer limit, it wouldn't have been able to do that. (I also had the Ah limit off, at the time).

(of course, it would have been been better if I had individually charged up the 3s to match the last cell that didnt' get anything used from it, or if I'd charged just the 3s section, but that wasnt' teh point of the example. ;) I did in fact start doing that later)


If you have a damaged pack, as in the case of your original ones, all bets are off, though. :/
 
Ok I got 4 6S 5000mah 25C Zippy packs in the mail this morning. I want to make 1 12S 10ah pack. How do I wire these up.

I checked each pack each individual cell reads 3.86 or 3.85. I had one 3.87 and one 3.84 so not too bad. I had my fingers crossed. Any advice on first charge? I'm kind of limited as to how I can charge these. I'm using the HK Accucell -6 cheapie china charger.

NEXT QUESTION: How do I assemble the pack for 12S 10ah pack?
Do I put the 2 packs in parallel first then split the two packs in series??

Purpose / intent:
Not looking for speed but some help in getting to the top.
BMC V2 Torque Kit, 36A controller(don't know what kind)
Mountain biking off-road primarily used for hill climbing. Trails are typically 3-5 miles. I've got a Wattmeter I can hook up and use.
 

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I’d go with series connecting the stock main power leads and parallel that termination into whatever controller connection used.

Then (if I don’t feel like making my own) I’d probably go with 2qty these - http://www.buddyrc.com/jst-xh-6s-parallel-blance-cable-x2.html this will parallel connect the individual cells.

Gotta connect in the correct order, maintain polarities, etc.

Some people swear you gotta parallel main power 1st but that’s an awful lot of large parallel wire and connectors.

When balance wires are paralleled in the correct series string order that will keep the cells in parallel until there’s a cell short in which case the small wire will most likely let you know.
 
Look at the 12s2p drawing here.
http://endless-sphere.com/forums/viewtopic.php?f=14&t=39666
Basically split the the pack connectors in half, then plug the red into the black of the second. That's now one 12spack. Do it for each 2 6s packs you have. I'd then parallel the 2 12s packs using two of these.
http://www.hobbyking.com/hobbyking/store/__43873__JST_XH_Parallel_Balance_Lead_6S_250mm_2xJST_XH_USA_warehouse_.html?strSearch=6s%20250
Now make a Y cable for the positive and negative ends of the pack to take to your controller. Or buy a 4mm charge cable and adapt it.
 
geosped said:
NEXT QUESTION: How do I assemble the pack for 12S 10ah pack?
Do I put the 2 packs in parallel first then split the two packs in series??
Click to expand...
Make two series groups. Then make or buy a couple of Y-connectors, like shown below, to connect the two series groups to the controller.
file.php

file.php

file.php


That was connecting in series then parallel. It would take more work, wire, and connectors but you could connect in parallel first before series instead (the second of the two):
file.php

which allows you to use Anderson connector blocks for easy connection for charging and discharging like shown in these links:

Icecube 57's Lipo battery harness review. 4 battery set. by Dogman Dan
http://endless-sphere.com/forums/viewtopic.php?f=4&t=32096

Parallel Charging Wire Harness w/Pics
http://www.modifiedelectricscooters.com/forum/topic.asp?TOPIC_ID=947
 
Thanks for all the info. I went with this, " connect in parallel first before series instead (the second of the two):" I had the connectors already. Its a simple plug and play. Now besides the extra wire, is there any drawback to the way I did mine. And did I do it correctly?

I put two 6S packs in parallel first to make two 6S 10mah batteries. Then I joined them together to make 1 12S 10mah pack. Is that right?

Regarding the balance plugs. My charger is a cheapie china Accucell -6 it only charges up to 6S and goes as high as 5ah. I cant charge it by voltage. Meaning there is no selection where I can charge 4.20 by cell count. So I have to wind up doing a balance charge on each 6S pack. Unless you guys know something I don't which I'm sure is the case.
 

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I don't see in your charger's manual a way to set pack capacity. Try balance charging one parallel group. You'll need a cable like below to connect the two brick's balance cables in parallel to connect to the charger.

To connect both bricks in a group for balance charging or while riding(this is optional) you'll need one of these cables for each group.
JST-XH 6S Parallel Balance Cable X2
http://www.buddyrc.com/jst-xh-6s-parallel-blance-cable-x2.html
or/and
JST-XH 6S Parallel Balance Cable X6
http://www.buddyrc.com/jst-xh-6s-parallel-blance-cable-x6.html

You'll need to make or buy a parallel charge cable if you want to charge both groups at the same time. With a better power supply and charger.
Parallel Charge Cable - 4mm Bullet Connector X6
http://www.buddyrc.com/parallel-charge-cable-4mm-bullet-connector-x6.html
or
Parallel Charge Cable - 4mm Bullet Connector X2
http://www.buddyrc.com/parallel-charge-cable-4mm-bullet-connector-x2.html
 
geosped said:
Thanks for all the info. I went with this, " connect in parallel first before series instead (the second of the two):" I had the connectors already. Its a simple plug and play. Now besides the extra wire, is there any drawback to the way I did mine. And did I do it correctly?

I put two 6S packs in parallel first to make two 6S 10mah batteries. Then I joined them together to make 1 12S 10mah pack. Is that right?

Regarding the balance plugs. My charger is a cheapie china Accucell -6 it only charges up to 6S and goes as high as 5ah. I can charge it by voltage. Meaning there is no selection where I can charge 4.20 by cell count. So I have to wind up doing a balance charge on each 6S pack. Unless you guys know something I don't which I'm sure is the case.
Click to expand...
You need a better charger, this one;
http://www.hobbypartz.com/75p-1220-charger.html
It allows you to charge the whole pack without breaking any connection.
If you keep splitting your pack to charge, eventually you will have an accident.
Rather than splice the balance wires and use the paraboard on the Thunder, I just use 4 of these. Easier and more fool proof.
http://www.hobbyking.com/hobbyking/store/__10328__HobbyKing_8482_Battery_Medic_System_2S_6S_.html
 
motomech said:
geosped said:
Thanks for all the info. I went with this, " connect in parallel first before series instead (the second of the two):" I had the connectors already. Its a simple plug and play. Now besides the extra wire, is there any drawback to the way I did mine. And did I do it correctly?

I put two 6S packs in parallel first to make two 6S 10mah batteries. Then I joined them together to make 1 12S 10mah pack. Is that right?

Regarding the balance plugs. My charger is a cheapie china Accucell -6 it only charges up to 6S and goes as high as 5ah. I can charge it by voltage. Meaning there is no selection where I can charge 4.20 by cell count. So I have to wind up doing a balance charge on each 6S pack. Unless you guys know something I don't which I'm sure is the case.
Click to expand...
You need a better charger, this one;
http://www.hobbypartz.com/75p-1220-charger.html
It allows you to charge the whole pack without breaking any connection.
If you keep splitting your pack to charge, eventually you will have an accident.
Rather than splice the balance wires and use the paraboard on the Thunder, I just use 4 of these. Easier and more fool proof.
http://www.hobbyking.com/hobbyking/store/__10328__HobbyKing_8482_Battery_Medic_System_2S_6S_.html
Click to expand...

I agree I need to do something about a charger. This is a real pain in the ass having to charge 4 individual batteries. Unfortunately the Thunder 1220 charger isn't sold anymore. Nobody seems to have one. Also it doesn't look like it comes with a power supply bummer. Another cost. But your right that seems to be the perfect charger. So do you use the LiPo Medic to balance your cells during charging? Not sure I get how that's used.

Looks like I'll have to get a couple of those JST-XH 6S Parallel Balance Cable X2
http://www.buddyrc.com/jst-xh-6s-parallel-blance-cable-x2.html Thanks Mark!

Thanks everyone. Man this is becoming a money pit lol.
 
I didn't notice it was out of stock.
That happens every several months and takes a couple of months to get back in stock, There is always rumors that it will no longer be produced, but it always returns.
One of the neat things about the 1220, is that you run it with a super inexspensive Internet server power supply. I got mine for $15 on Ebay a few years ago.
Icecube57 used to have some too.
They are non-insulated, but since a single one will do the job(400 to 500 Watts), all that needs to be done is to wrap it insultation(I used foam and duct tape)and make a jumper wire to turn it on.

One of the things I don't like with the 1220, is the quality of the paraboards and balance leads. It all works, but they aRE stiff and hard to connect and dis-connect.
When the cells agv. 4.0V, the Thunder gives a beep and I usually check the pack then, brick by brick. 90%, they are fine nad I just top charge and I'm done. The other sm. percentage of the time, one or two of the bricks have a cell that is high/low and I will leave a BM on in balance mode during the final top charge..
On rare occassion, there are enough cells off, that once they are charged(around 4.12V) i'll leave the Medics on in discharge mode to take them all down to 4.1V That usually takes 10 to 15 min.s.
When I have hit my controllers LVC of 42 Volts, they cells are around 3.65V and just starting to stray, I'll clip on all 4 Medics to monitor them as I bring them back up, and they always have so far.
This technique works great for packs up to 12S/2P, but 3P requires a BMS, I.M.O.
SAM_1016.JPG
P.S. Go ahead and fill out your profile.
 
You don't have to balance-charge all the time. If you want to "get by" with the charger you got you could do this:

- ditch bullet connectors for Andersons
- bundle the 4 Anderson pairs from your 6s cells into a pack
- make a 4 into 1 connector that makes it a 6s4p
- bulk charge that via your charger
- make a 4 into 1 connector that makes it 12s2p, connect that to your controller when riding the bike
- balance charge each 6s pack with the same charger if cells get out of balance (not that often)


So what you'll end up with is a 4x2 bundle of Andersons coming from your 4 packs, then two different "jump connectors" for if you're connecting to a bike or to a charger (12s2p or 6s4p). You could keep one of them on your charger and one of them on the bike, so you only have to connect the other side that's just 2 wires. Once in a while check cells for balance and if they're getting unruly go to the trouble of charging each of the 4 packs individually.
 
You could also probably just frigging get 4 6s chargers and jam them all in every time into each 6s pack and be done with it. Might come out cheaper too, some of them 6s chargers are dirt cheap.
 
I would BMS and bulk charge. Quit messing around plugging/unplugging configurations and streamline wires/connectors to minimum. Nothing good ever comes from a big wad of connectors/wires or trying to reconfigure every charge cycle.

Avoid deep discharges and need to balance is practically eliminated.

RC Chargers still have their place but at much reduced importance to the riding routine.
 
I agree. if you don't already have a 12s charger then get a bms and bulk charger. These com to mind.
https://bmsbattery.com/bmspcm/330-smart-bms-513-cells-in-series-bms-pcm.html#/discharge_current-20_40a
https://bmsbattery.com/ebike-charger-ev-charger/711-s240-charger-built-in-active-pfc-charger.html
 
Can anyone that has a BMC setup post what kind of results they get on a 12S 10mah pack in terms of watt's and how many Amps there drawing. I put a new 12S 10mah pack together this weekend. 4x 6S 5mah 25c. LiPo and was getting 50v and peak watts reached 1361 and I want to say about 26A under WOT on the watt meter. I got up to 23mph. I think it's governed though. Is everyone else getting about the same results? I'm upgrading the controller to 30A and wondering if these motors can handle a little more power. I'm not sure I'm happy with the 12S Setup. Wondering If I can bump it up a bit with out frying the motor. I think I should be ok on 14S max but wanted to see what others out there are pushing their BMC setups too.

I noticed on a fresh charged pack 10S 5ah pack I was drawing about 21-22A continuous on the controller under WOT peak power was 1030watts. On a 12S I was drawing about 25-26A WOT. Max watt's went up to 1361w. If I add another 2S to the pack and make it around 28A? I think this would put the motor / controller in it's upper limits. Curious about durability. Do my numbers match others out there with a similar setup? And or what are you getting?
 
geosped said:
Can anyone that has a BMC setup post what kind of results they get on a 12S 10mah pack in terms of watt's and how many Amps there drawing. I put a new 12S 10mah pack together this weekend. 4x 6S 5mah 25c. LiPo and was getting 50v and peak watts reached 1361 and I want to say about 26A under WOT on the watt meter. I got up to 23mph. I think it's governed though. Is everyone else getting about the same results? I'm upgrading the controller to 30A and wondering if these motors can handle a little more power. I'm not sure I'm happy with the 12S Setup. Wondering If I can bump it up a bit with out frying the motor. I think I should be ok on 14S max but wanted to see what others out there are pushing their BMC setups too.
Click to expand...
You can read old threads like Ilia Brouk's BMC for sale thread for that. For instance, Sacman's posts (1, 2). Or old posts by knoxie (example) and others who had builds using BMC. BMC users from those days are still around but maybe haven't read your threads or, for whatever reason, don't respond. Doesn't matter. Search instead to find what you want to know.
 
QUESTION:
Lets say I have a 2 6S 5ah batteries and 2 4S 5ah batteries. Can I connect one 6S and 4S in then connect the two parallel sets into series to have 1 10S 10ah pack?

I had 4 6S 5ah and connected it similar but the 12S pack is too jerky on my Lyen controller so I wanted to tone it down to a 10S which makes it a bit smoother on the throttle.
 
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