YES or NO on 5 Turnigy Hardcase 5000mAh for MXUS 3000W V2?

[markz]

I'm about to click the buy buttom so here are the spec's (Yes I am a bit ambitious!)
Minimum Capacity: 5000mAh
Configuration: 4S1P / 14.8v / 4Cell
Constant Discharge: 20C
Peak Discharge (20sec): 30C

Cost is $150 shipped.
So I was thinking 5 at 14.8V = 74V @ 5Ah, seems a touch low on the Ah side, but is it a good start??????? maybe make another purchase later for another 74V 5Ah when its summer and I ride regularly.

Power Supply and Charger recommendations?????????

I have an old 2007 300W desktop power supply rated at +5.08V=19A Max, +12V=11A Max that I could use, I personally replaced this one with a new PS on my desktop its reated at 600W with a singular common rail of 25A. So I think I can figure out the wiring, get a voltmeter and get to it.
http://www.hobbyking.com/hobbyking/...IMAX_B8plus_Charger_Discharger_1_8_Cells.html
OR
http://www.hobbyking.com/hobbyking/...O8_150W_7A_8S_Bal_Dis_Cyc_Charger_w_acc_.html

 

[John in CR]

5ah is not "a touch low", it's way too low.

 

[Raged]

You're better off getting fewer large packs rather than alot of small packs. The wiring will give you the shits with respect to balance cables etc.

What controller are you using? Lipo fully charge to 4.2v per cell, so a 20S pack = 84V at full charge (72v at low charge 3.6v/cell) which might trigger your high voltage cutout.

 

[Ykick]

If you plan to draw 3kW, 2-3P minimum.

Fresh 1P handle 15-20A bursts but anything more and sustained they're gonna get hot and thus age quickly.

 

[Hugechainring]

More ah. Double at least. Triple would be better. The performance ratings for these batteries are generally accepted to be overstated. You didn't mention what controller you were using, but I'm guessing it at least 40A for that motor. If you can't afford the batteries now, I would wait until you can afford it. Otherwise, it is entirely possible your current pack will be toast by the summer when you are ready to upgrade. It is really easy to over-discharge a small pack. I don't use RC lipo, but if I did, I would pony up for a power supply that is designed to work with the charger. Other stuff will work, but there are already too many things to keep track of when working with RC lipo. Either that, or contact icecube57 for inexpensive alternates and charging solutions. He really knows that angle.

Did you mean 5S1P? That would be 74V nominal. Think about the math here. A 74V 5ah battery could put out 5 amps for 1 hour, 20A for 15minutes, 30A for 10 minutes, and that is to 100% depth of discharge. You only want to go to 80%. How far are you going to get on that? Have you checked out the Grin e-bike calculator? Do the numbers jive? If the MXUS is not listed, you could probably substitute one of the big Crystalyte motors with the same turn count on the windings to get an approximation.

Hobby King will always be there. Take your time. Also, what Ykick said.

 

[leffex]

Yes I use that it will work. 400-600 cycles no BIG problems, especially 1.5kw= average or 50kmh, maximum distance is about 15km or 7km if you ride fast. I have two full packs. Charging in under an hour. Charged voltage is about 84.5v.

 

[friendly1uk]

Peeps say, used past 5c they cause so much sag even lipo suction cant help.

The voltage will dip below your low voltage fail-safes, causing power failures while considerable capacity still remains.

 

[markz]

Pulled the trigger an hour ago. I knew 5Ah was to low, its that dang low 4s price that I liked. Every other 8s 25C I see is like $80+, figuring it should be closer to $50 with same c rating, but I know nothing to very little. I got an ace up my sleeve, I can solder been trained by Nortel Networks, can even do surface mount soldering, know how to wire, do cct boards.

I will find another set of 5-10Ah batteries, try to stay away from a tangled web of 4s. Will figure something out.

I ended up buying the Geniune IMAX B8plus charger, can do 1-8cells, including A123's (LiFe), 150W, has USB and a Temp port. $40
Batteries came to $21.98 x 5 so $110.
S/H was $50, so all in $200.

What should I get on my next shipment? Was thinking cell log, cell key, cell checker, HK Lipoly audiable LVA

 

[Raged]

If you're running lipo and running close to the edge... get a BMS. All my Lipo fires have happened when I've been doing maintainence on the packs (pulling them apart). A BMS with 1 plug to charge will save you time and heartache later on.

 

[markz]

18 FET Low RDS MOSFET Overclocker Ready LYEN Controller $199 - Which is why I wanted to be around the 72V mark.
John in CR Sorry I was being sarcastic at the touch low statement. Impulse buys, what can I say! I do appreciate the input though!
Raged ya the wiring is going to be a headache, but thats the trade off for cheap batteries and downgraded safety. Where does a guy buy a BMS for Lipo Batteries?

Ykick - "If you plan to draw 3kW, 2-3P minimum" - I meant 4S1P gives me 14.8V, slap 5 in series, gets me 74V. So your saying I slap two or three "5x4S1P series packs" in parallel, gives me 2-3P minimum right, at 74V and 10-15Ah depending on 2 or 3 parallel packs. This idea of mine was in the back of my head when I purchased these batteries. But like it was previously mentioned by Raged, there is going to be a ton of wiring involved now!

Hugechainring what kind of real C rate would a Turnigy pack be which was stated at 25C or 30C, do you just half it, or third it?

 

[Raged]

Any Li-Ion BMS will work as long as high cell voltage cut off is 4.2v and low is 3.3v. You could possibly run without a BMS, however you'd need to set your charger low (20 x 4.1v = 82v just in case they're unbalanced) and keep the cell logs handy or attached for alarms. Cell Logs use some current just being plugged in, so you even lose more power there. For the cost of 3 Cell Log's you might as well get a BMS and avoid the problems in the first place. You still need a balancer for initial setup and testing though. You can charge batteries through the balance cables so you dont need to unplug the main power cables.

Typically speaking, whatever C rate the packaging says, divide by 2. so (25C x 5000mAh)/2 = about 60A continuous. If your controller can pull more than 60A then you need to get another set (20S2P) so you can do continuous Amp draw and not kill the battery. Make sure your BMS is rated higher than the current your Controller will use.

 

[Ykick]

Ykick - "If you plan to draw 3kW, 2-3P minimum" - I meant 4S1P gives me 14.8V, slap 5 in series, gets me 74V. So your saying I slap two or three "5x4S1P series packs" in parallel, gives me 2-3P minimum right, at 74V and 10-15Ah depending on 2 or 3 parallel packs. This idea of mine was in the back of my head when I purchased these batteries. But like it was previously mentioned by Raged, there is going to be a ton of wiring involved now!

Not sure I follow you?

I meant that if you assemble 20S1P you'll sag and heat those cells @ +40A.

I prefer 16S voltages - easy to modify balance connectors for 2qty 8S and then CellLogs can be readily used for spot checking cell voltages. But if you're set on 75V I'd at least wire 20S2P and for that you'll need parallel main power cable and parallel balance connectors. Buddy RC sells those cables in USA. Or, roll your own.

Bestechpower is where some of us buy BMS/PCM circuits. MOQ = 2qty but you'll surely blow one up figuring it out so a spare is handy.

Careful monitoring (alarms?) you could run without BMS and avoid some of the parallel balance connections but that would be more for "educational" purposes, not a daily commuter.

 

[crea2k]

I run 18s5p in mine, the 6s 20c packs work just fine with my cro

 

[made_in_the_alps_legacy]

So I was thinking 5 at 14.8V = 74V @ 5Ah, seems a touch low on the Ah side, but is it a good start???????

74V x 5Ah = 370 Wh
- it's above 0 so it is good to "start"
- 370/3000=.12 : u can even think of enjoying all your 3000W for about 1/10th of an hour, 6min autonomy! it's more than "starting", it's riding time !
- you will be going so fast with 3000W, like 70kph!? wahoo! maybe you can go up to 7kms distance !

 

[crea2k]

This is my ebike battery calculator if you want a play, its good for working out lipo stuff like AH etc >>
http://key4design.co.uk/ebikecalculator.htm

 

[John in CR]

Nothing wrong with using the 4s hardpacks, just order at least another 5 packs if not 10 or 15. Inside are pristine cells not mashed at the corners like shrink wrapped RC packs, so they're nicer for building into permanent packs to avoid the new hobby I call fiddling with RC battery packs with all the plugging and unplugging that some guys love and invariably ends up with learning first hand what a plasma flash is.

 

[Raged]

Nothing wrong with using the 4s hardpacks, just order at least another 5 packs if not 10 or 15. Inside are pristine cells not mashed at the corners like shrink wrapped RC packs, so they're nicer for building into permanent packs to avoid the new hobby I call fiddling with RC battery packs with all the plugging and unplugging that some guys love and invariably ends up with learning first hand what a plasma flash is.

Plasma flashes keep you on your toes.

 

[markz]

Hey crea2k - Is it better to have a higher number of parallels. Likegood to have 18S5P then 18S2P?


This is what I am thinking here for battery setup for my 15 packs of Turnigy 5000mAh 4S1P 14.8v 20C hardcase pack,

4S1P + 4S1P + 4S1P + 4S1P + 4S1P (all in series which equals 14.8x5=74V and 5,000mAh)
above in parallel with same group below
4S1P + 4S1P + 4S1P + 4S1P +4S1P (all in series which now equals 74V and 10,000mAh)
above in parallel with same group below
4S1P + 4S1P + 4S1P + 4S1P +4S1P (all in series which now equals 74V and 15,000mAh)

*****Added voltages in series, then added amperages/Ah in parallel.*****

Cool Calculator btw, thanks!
Ebike Lipo Battery Pack Calculator

Battery Pack Calculations (Please Only Enter Numbers Into The Boxes Below)

Individual Battery Pack Size (e.g 6s)
4s

Individual Battery Pack Nominal Voltage (e.g 22.2)
14.8Volts

Individual Battery Pack Mah (e.g 5000)
5000Mah

Individual Pack C Discharge Rating (e.g 20)
20C

Individual Pack C Max Discharge Rating (e.g 30)
30C

Number of Individual Packs in Paralell In Each Group (e.g 4)
3Packs In Each Group

Number of Pack Groups In Series (e.g 3)
5Group Packs In Series
Battery Pack Layout :
20s3p

Battery Pack Total Nominal Voltage :
70 Volts
Battery Pack Total Max Voltage :
84.00 Volts
Battery Pack Discharged Voltage :
72.00 Volts

Battery Pack Total Amp Hour :
15 Amp Hour
Battery Pack Nominal Total Watt Hour :
1050 Watt Hour
Battery Pack Max Total Watt Hour :
1260.00 Watt Hour

Battery Pack Max Continuous Amp Draw :
100 Amps
Battery Pack Max Burst Amp Draw :
150 Amps

Battery Cell Max Voltage :
4.20 Volts
Battery Cell Discharged Voltage :
3.60 Volts
Battery Cell Critical Voltage :
3.00 Volts

 

[friendly1uk]

All series strung lipo battery packs come with the protection board known as a bms. So far you just have a pile of cells. Not a pack of retail standard.

You can use your pile of cells and modelling charger, but it's not how packs are made and leads to nearly all the fires. Nothing wrong with the cells, it's just not how to use them. Any manufacturer that builds packs for anything will tell you this. Only modellers don't use a bms, but at meetings they are forced to charge outside in flame proof bags.


There are a few peeps here that don't have packs, or have packs so large a suitable bms is hard to source. Your not in that camp though.

 

[ddk]

I run LiCo 5000 hard and soft packs in 3p, 4p and 5p for 30A continuous ...with the only difference being range.
My batteries are paralleled at the cell level, which gives equalization between weak and strong cells.

I tested single-cell packs early on and the results were disappointing.
Further testing derived a 3P connection to be a minimum for cell longevity. My oldest pack is over 3 years old and still has about the same capacity it had after 3 weeks use.
None of my 'standard' LiCo batteries gets unbalanced. I check'em every few charges.
I have nano LiCo cells that always gets unbalanced in "never the same way twice" -go figure, they cost lots more.

i.e- use more packs, if you want your battery chores to be simpler (less balance charging required) and your battery pack to last longer. (lots lots longer)
I used to wire my own packs-deadhead simple; but now I buy my wiring from http://www.buddyrc.com/
because-lazy, can't be bothered, rather watch paint dry than wire a pack up.

hope that helps a little...

notice no one's offered a source for those $20 magic bms units that can source 40-60A yet. (curious, I am)

 

[Raged]

I run 14S (58.8v - two 7S Zippy Compact 5800mAh) on a MAC10T@40A (2.2kw) I can get between 20-25km out of it. Just shy of 30km but it's draining the batteries down to 3.3v (my BMS cut off) which is bad. I had to stack up to 14S2P to do my commutes with heaps to spare (theoretically 45-50km). That said, the MAC10T is a geared up and freewheels like a normal bike downhill.

I picked up my 14S 40A BMS for $50 from em3ev (they seem to have stopped selling them on their website though? I remember he used to have a range of BMS's). The cost calculation is derived as 3 x Cell Logs to monitor and alarm (at $20-25 each = $60-75) vs 1 BMS ($70+? which will allow you to do a 1 plug charge system).

 

[crea2k]

Hey crea2k - Is it better to have a higher number of parallels. Likegood to have 18S5P then 18S2P?


This is what I am thinking here for battery setup for my 15 packs of Turnigy 5000mAh 4S1P 14.8v 20C hardcase pack,

4S1P + 4S1P + 4S1P + 4S1P + 4S1P (all in series which equals 14.8x5=74V and 5,000mAh)
above in parallel with same group below
4S1P + 4S1P + 4S1P + 4S1P +4S1P (all in series which now equals 74V and 10,000mAh)
above in parallel with same group below
4S1P + 4S1P + 4S1P + 4S1P +4S1P (all in series which now equals 74V and 15,000mAh)

*****Added voltages in series, then added amperages/Ah in parallel.*****

Cool Calculator btw, thanks!
Ebike Lipo Battery Pack Calculator

Battery Pack Calculations (Please Only Enter Numbers Into The Boxes Below)

Individual Battery Pack Size (e.g 6s)
4s

Individual Battery Pack Nominal Voltage (e.g 22.2)
14.8Volts

Individual Battery Pack Mah (e.g 5000)
5000Mah

Individual Pack C Discharge Rating (e.g 20)
20C

Individual Pack C Max Discharge Rating (e.g 30)
30C

Number of Individual Packs in Paralell In Each Group (e.g 4)
3Packs In Each Group

Number of Pack Groups In Series (e.g 3)
5Group Packs In Series
Battery Pack Layout :
20s3p

Battery Pack Total Nominal Voltage :
70 Volts
Battery Pack Total Max Voltage :
84.00 Volts
Battery Pack Discharged Voltage :
72.00 Volts

Battery Pack Total Amp Hour :
15 Amp Hour
Battery Pack Nominal Total Watt Hour :
1050 Watt Hour
Battery Pack Max Total Watt Hour :
1260.00 Watt Hour

Battery Pack Max Continuous Amp Draw :
100 Amps
Battery Pack Max Burst Amp Draw :
150 Amps

Battery Cell Max Voltage :
4.20 Volts
Battery Cell Discharged Voltage :
3.60 Volts
Battery Cell Critical Voltage :
3.00 Volts

The more packs you have in parallel the less sag you will get under load, and the higher AH you will have. Iv noticed with the Adaptto controller at least, that you get a slightly higher speed, and the acceleration is better too. I think this is down to most of the lipo pack C ratings being utter crap from what they are stated, so more packs = less current draw per pack, so you are more likely to get a better C rating for the whole of you battery pack, as the current demand on each cell is less for the more packs you have in parallel.

 

[Ykick]

Sorry, I dunno of any BMS for $20. Web search bestechpower and peruse offerings for BMS/PCMs. As mentioned in my earlier post, require 2 x MOQ (minimum order quantity). 35A BMS/PCM wind up costing around $100 for 2qty shipped to USA. I've used the 35A (continuous) D-167, 15A D-140 (not recommended) and more recently 20A D-245 for all my 16S RC Lipo battery packs. Good circuits, not 100% fail safe but an improvement over running naked RC Lipo.

Unless you've worked with battery packs for a while odds are very good you'll blow something up during install and need the 2 MOQ.

 

[dogman dan]

As said above many times, your main issue will be such a small capacity pack.

It will run the bike, but the cells won't like it, and as you near the point you should stop, increasing IR will hammer those poor cells even more.

Do your test runs, but really, you don't have a practical, usable, battery yet. I did nearly exactly the same thing, and none of those first packs lasted more than 6 months. Too much damage in the first month, when it was all I had. Too many too deep discharges at a high (8c) rate.

So again, do your test runs, but try to keep your rides very short, till you get at least 10ah. With the 20c stuff, preferably 15 ah. So save up, and order some more asap.

Re the bms, if you are careful, you can be a great human bms. But it's truly a pain in the ass. Not ideal for a daily rider, but tolerable for less than 7 cycles a week.

 

[friendly1uk]

notice no one's offered a source for those $20 magic bms units that can source 40-60A yet. (curious, I am)

Rated 20-40 but tested to 60 and $25 close enough? bmsb do one, and it's programmable.

For more than 13s, buy two. For more than 60 amps, buy the $20 version and have it control a soft start circuit. You know, one of them contactor replacements. IIRC lebowski designed one for a few quid. Just a few fets and an rc timing circuit. Making a 26s few hundred amp programmable bms about $60 + P&P

I'm not sure how cheap life insurance is, but it's probably no good without a bms anyway, as that is death by misadventure at best. Negligence is more likely.


I'm surprised I have not seen someone here mate two boards yet. I have seen examples using the very bms I'm talking of elsewhere. It's not really a project though. Just making both boards control a single set of output fets and single charge fet. It's just not impressive.