HobbyKing Lipo Battery Pack

Batteries, Chargers, and Battery Management Systems.
markz   100 GW

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HobbyKing Lipo Battery Pack

Post by markz » Jan 13 2015 3:42am

*I changed the title*

I am building me a 74V 10Ah pack with five 4S1P (14.8V 5Ah) Turnigy batteries in series = 74V 5Ah, then putting exact setup in parallel to make 74V 10Ah, maybe 15Ah.
Image

Controller will be lyen 18fet 72V nomial 65A current rating. LVC 62.5

I assume Anderson Connectors are the professional/safer way to go, better then the bullet connectors that come on the Turnigy Batteries.
Those bullet connectors seem to be able to pull apart easily.

Where can I buy Anderson Connectors for cheap, that wont cost a lot to ship, to Canada?
I found these guys http://www.powerwerx.com/anderson-power ... -contacts/ Shipping is around $20

Here is my wiring diagram I came up with, are the wire guages correct?
Series - Image https://www.flickr.com/photos/128734122 ... 647507954/
Parallel - Image https://www.flickr.com/photos/128734122 ... otostream/

Who sells BMS's?
BMSBattery has some, but thats BMSBattery.
Here is one 10S/13S/30A/50A Lipo Battery BMS System $18, who knows what shipping will be.
https://bmsbattery.com/search?search_qu ... arch=&n=87

I can figure out how to hook up the alarms and such if I choose not to got BMS route.

How do I charge this pack?
Genuine IMAX B8plus Charger/Discharger 1-8 Cells (Max 150W, 1-8Series, 7A Charge)
What are the smaller wires coming out of the battery pack? (Used only for charging? and/or BMS?)
Last edited by markz on Feb 08 2015 1:22am, edited 2 times in total.

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by dogman dan » Jan 13 2015 7:00am

I started out using andersons on all my HK stuff. It was quite a pain to replace all those connectors.

Now I just make up adapters that connect to the 4mm bullets, and those convert only the final (to the controller) plug to andersons. Still like andersons on the controller, the CA, the charger. Those can be replaced or temporarily fixed in the field if you need to, without soldering. So all packs retain the original connector, or get a y connection that terminates a pair of packs in one bullet connector.

Initial testing of new stuff is done by running 5s at a time, for a few cycles.

Tape up any connection you want to stay plugged in, Anderson or bullet. Powerwerks is a good source for andersons.

Diagrams look fine to me. 10g should be fine for 65 amps IMO. Nothing wrong with going to 8 if you want to. 45 amps Anderson too small, but big ones will work, larger bullets, or two sets of 45's in parallel.

Re warning buzzers. Get to know your packs. One pack in there is bound to have slightly less capacity than the others. If you have the packs pretty balanced, then ONE warning buzzer on that pack can do the trick. That one pack will always have the cell with the least capacity.

Use a CA or other monitor for watching the entire packs voltage, and wh or ah used. Stop long before you have any of your cells below 3.5v. If you stop around 3.6v per cell resting, likely you never get close to setting off a warning buzzer set to 3.3 or so.

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by izeman » Jan 13 2015 11:39am

i prefer xt60 over anderson. they are idiot proof. too easy to make a connection combination of andersons if you don't take care enough and do some thinking before soldering/crimping.

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by friendly1uk » Jan 13 2015 2:51pm

The banana connectors won't pull apart if your not hanging things from them. With very little thought, they are a perfectly good connector.

Your using 20 cells in series, that is 20s. You will need a bms that is 20s. The bestech one's can be easily under-populated, so a board for 20s or more would do.

You would then buy a charger like your phones, but bigger. Look at any on any ev site. They don't resemble the modelling chargers your looking at.

If you tried to use the b6, you might be up all night. No fun at all using a complicated 150w charger with such a large pack. Maybe 5 of them would be bearable, but it's modelling stuff, not the much safer easier and often cheaper ev stuff. As a competent person I'm legally bound, and can't recommend this relatively dangerous RC charging gear. Nor would I. The sphere has found nearly every fire involves an RC charger somewhere in the story. This is why RC packs are charged outdoors in flame proof bags. The act of charging RC style, involves to many variables.

Have a look at this: http://bestechpower.com/74v20spcmbmspcb ... -D131.html
Before you get a price, think how much time it will save you every charge. Then multiply that by how many charge's you expect to get from the pack. You may find a bms saves a week of wire swapping. Time is money. A bms will save expendature. Paying for itself many times over. Ultimately it could save your life.


Many with a 'I know best' attitude will ignore the industry and use RC stuff like the cheap ass b6. Often they just kill the entire pack through deeply discharging it. They also set their houses on fire. Most commonly they just waste weeks of there lives, and quite a few connectors. There are no winners. Keep on at the bms idea, it's the only thing excepted by the ev industry. Or just about any other product where these batteries are strung together. I can't think of an exception except modeling.

Obviously we have a lot of modelers here. Many are all to willing to share how modellers charge their packs. Just decide now, are you building a model to nurse or an ev to ride. Then buy whatever you feel best. I just like to know you had a fair chance.
bmsbattery sent me broken and incorrect stuff, and won't even talk to me about it.

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by markz » Jan 13 2015 4:37pm

I am definately sold on the BMS idea, hopefully its not too pricey in comparison.
I will swap out my 10AWG in parallel wiring harness to 8AWG.
Is it wiser to use 10AWG instead of 12AWG in the Series wiring harness?

So the 20S 80A BMS is what I want, the one you linked too. I buy three of them if I have 3 parallel banks of 20S?
Bestech is reliable source for products?
Do I just email them that I need a price, or do I find someone that they supply?

The only thing I dont know what to do is when I look at my Turnigy 4S pack, obviously theres the big red and black wires.
What am I going to do/buy and how am I going to hook up the other little 5 wire connector on each battery?
I connect each battery connector up to the BMS for each series bank? So I see the 20S BMS has the white connectors on it where I hook my battery connectors up to. However I am counting the pins on this picture below. I count 5 pins on my batteries times 5 batteries = 25 pins. Pic has 30 pins total, each white connector has 10 pins each, times 3 white connectors on the BMS. Looks like each white connector on the BMS holds 10 pins each.
http://www.bestechpower.com/74v20spcmbm ... -D131.html
So one 20S bank = one 20Sbms...I get that.
I leave the BMS installed all the time, or just when charging?

So I install one BMS for each series bank, connecting up the red/black as mentioned in my diagram to the controller. Are those 3 BMS's for each series bank them connected up to a single over-all bms, or a Cycle Analyst or is there another device I buy.

Oh I get it now, it connects up to the Controller, batteries go off spec, shuts down.
Also hooks up to charger, ideally I would want 20S if they sell them.

What charger should I buy?
iCharger 1010Bplus 300W 10s Balance/Charger for $120?
iCharger 208B 350W 8s Balance/Charger $126
iCharger 206B 300W 8s Balance/Charger $112

https://www.flickr.com/photos/128734122 ... 274534362/

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by dogman dan » Jan 14 2015 6:45am

If you are going to use a bms, then the whole wiring is different. Paralell then series. Obviously you also have to parallel the balance wires too.

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by TheBeastie » Jan 14 2015 7:22am

markz wrote:I am building me a 74V 10Ah pack with five 4S1P (14.8V 5Ah) Turnigy batteries in series = 74V 5Ah, then putting exact setup in parallel to make 74V 10Ah, maybe 15Ah.
Image

Controller will be lyen 18fet 72V nomial 65A current rating. LVC 62.5

I assume Anderson Connectors are the professional/safer way to go, better then the bullet connectors that come on the Turnigy Batteries.
Those bullet connectors seem to be able to pull apart easily.

Where can I buy Anderson Connectors for cheap, that wont cost a lot to ship, to Canada?
I found these guys http://www.powerwerx.com/anderson-power ... -contacts/ Shipping is around $20
Anderson connectors are expensive.
I don't like Anderson connectors but I have never tried the super chunky ones I see some guys use on serious power builds.
Here is my mini tutor on getting bullets going without needing to solder like Andersons..
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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by hardym » Jan 14 2015 8:40am

I agree with dogman dan, the way you are proposing connecting the batteries, you'll need a BMS for each string, resulting in a separate monitoring for each cell. The BMS costs for your proposed configuration will be far more than the connectors. If you paralleled the cells first, then applied a BMS you can save significant $$ in bms costs.

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by dnmun » Jan 14 2015 10:48am

not true. the way he was asking is the way everyone should build the battery up. connect all the cells in series first for each of the HK packs, then tie the cells together in parallel through the sense wires. or JST connectors in this case.

i know from my experience with the ping pouches that the shrink wrap damages the lipo pouches inside those plastic shrink wrap sleeves so take the pouch packs apart and build a regular battery with them instead of trying to make all those wires work


if you only need 35A for your controller then you should consider the D167 20S lipo BMS. we got them for $44 with shipping in the last order from Bestechpower.

you can see how the individual serial packs are connected in parallel through the sense wires sin these pictures.

those connectors on the HK packs are more than adequate and you do not need 10AWG or 8AWG for 35A of current. i use 12AWG solid copper wire for the current collectors on my packs.
Attachments
DSC01825.JPG
21S 24Ah of 8Ah nanotech with D131 BMS
DSC01825.JPG (151.75 KiB) Viewed 5234 times
DSC01829.JPG
3 individual 21S 8Ah pouch packs tied together in parallel through small 26AWG wires to make one 24Ah 21S pack
DSC01829.JPG (138.23 KiB) Viewed 5234 times

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by markz » Jan 17 2015 3:47pm

To parallel first then series wire it is beneficial over series first then parallel.

I can see the benefits by having 4S3P 15Ah @ 14.8V in series with same pack again, then repeat for 74V.
I disconnect it after that 2nd pack in series, and charge it. Same goes for the 3rd parllel pack in series 4th parallel pack, after that 4th parallel pack I disconnect it, charge it. Leaving me leftover with a single parallel pack (4S1P in parallel 3x for 15Ah)
Ideally for charging purposes, I should really have 88.8V total pack voltage, which just adds another series to the last group 4S3P.
Which correlates to more ebike speed.

I have an 8S rc charger, I kinda fluked out on that purchase. So ideally I should have boughten a 12S charger.
But I think I can find a way to put that last pack of parallel batteries that is in series, I can put that pack in parallel somehow.

Now I dont think I can have a 5Ah single parallel pack, in series with a 10Ah paralleld pack (two 5Ah packs in parallel) can I?
So best to put all three of my paralleled packs originally in series, put them in parallel when charging?

Then one Bestech Power 20S BMS, is on the output of the entire pack.

For a series first then parallel, there is a lot more disconnecting and reconnecting of wires.

As for connecting the balance leads, that website makes a lot of sense now.
http://scriptasylum.com/rc_speed/lipo.html
I just parallel each 4S3P pack
201211422736929.jpg
So if this is my Bestech Power 20S BMS, plug each of my 5 connectors in.

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by markz » Jan 19 2015 2:31am

Yes? No?
NEW balance and power wiring.jpg

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by izeman » Jan 19 2015 3:00am

basic wiring looks ok. but two questions:
1) what are those caps in the balancing leads for?
2) the setup misses the power wiring through the bms. if you wire it like that you only get HVC and can charge through the bms. it will NOT cut the power at low voltage.

and you won't need your 8s charger. the bms is what it says: a BATTERY MANAGEMENT SYSTEM/SOLUTION. it's here to check all cells and act based on their SOC. if one/more cells are too low it will cut the power to the controller. if during charge one cell gets above high voltage cutoff it cuts the power to the charger (basically).
so you will connect all together and BULK CHARGE with a power source that is the same voltage as your top charged pack. connect it, and the rest will be done taken care of by the bms. of course you will need to to some bench testing charging and discharging the battery while checking cells with a DMM to ensure the bms was setup correctly by the factory before you want to trust it :)

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by markz » Jan 19 2015 5:46pm

I was thinking through my process thats why theres a "----||-----" symbol there at the output of the balance leads at each row.
That was going to be my other question; about power cables to BMS. I just didnt see any on the picture of the 20S BMS.

Updated.jpg

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by markz » Jan 21 2015 4:34pm

Bought the Lyen 18 FET Low RDS Controller last night.
Exchange rate is pretty bad these days.

What does RDS stand for?

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by markw » Jan 23 2015 8:45am

Subscribed! I swapped from series to parallel every day to charge with my "smart" charger. 20+ plugs every day ... I'll be stalking this thread for knowledge. I want to build precisely the same battery and have never dealt with BMS before. I'm excited to learn along side you. It's difficult question - from reading a lot I feel the trend, technology, and products available now have been changing pretty quickly. It's nice that you have a bunch of pros in this thread already. Keep posting your diagrams and work markz, I wanna steal your work :)

RDS (resistance drain to source) is linked to power efficiency due to heat loss due to resistance in the MOSFETS. I'm not sure how the application works in high amp controllers specifically, but in motherboards it is related to the quality of manufacture and the number of "legs" or connections soldered to the board. Generally the more, the better.

Do you have a bike project thread up I can stalk too?
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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by wesnewell » Jan 23 2015 11:04am

If you plan on running the battery down to LVC, then 62.5V is way too low for 20s imo. That's 3.125V per cell. It will also be too low to allow regen to work above ~78V. Have LVC adjusted to 68-70V for a 20s pack.
Stick with the 4mm bullets, they will handle 65A easily, while you will need sme big PP connectors to handle that much current.
There's no need to parallel your packs anywhere but at the ends of the strings if you parallel the balance leads at cell level.
http://endless-sphere.com/forums/viewto ... 14&t=39666
For charging a 20s pack made up of 4s packs, the easiest method would be to use a bms and 84V charger. Just make sure the bms you get supports a high enough discharge rate for the max amps of the controller you use. That's one reason I went to 24s, using 4s packs, so I could split it in two and charge the whole thing as a 12s pack using an rc 14s balance charger which I already had. Otherwise I'd have probably went the bms route to charge it and just bypass the bms output and do a direct hookup to the controller if the bms didn't have a high enough output rating. There's all kinds of safe ways to charge a pack. Just depends on what you want to do.
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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by markz » Jan 24 2015 2:07am

Thanks wesnewell, I was just reading the wiki and other threads last night and doing the calculations.
3V is absolute minimum whereas 3.5V-3.6V is a preferable dishcarge level. 70V divided by 20S = 3.5V
The LVC is changable on the Lyen 18fet RDS, I wont be doing regen, at first anyway. Maybe later. Have enough to learn as it is.

I am trying to choose the correct BMS now. More confusion for me. Bestech Power is it, which one, will figure out sooner or later.
I was stuck on this one, 20S unit, HCX-D131 until I saw 80A continous rating (seems like waaay to much).
I am thinking now a 40A continous rating at 74V nominal puts me at 3000W continous or 84Vcharging voltage x 40A = 3300W, which is good for the mxus 3000W v2 motor. HCX-D166 has 40A continous rating. Of course website doesnt state max Amps. Just 84V charging voltage, which puts it at 4.2V = 84V divided by 20S.
HCX-D166 - http://www.bestechpower.com/74v20spcmbm ... -D166.html

The series first then parallel was my first choice, seems logical to me.
So paralleling the balance leads at the cell level. I did buy parallel balance leads.

3x #015000046/27073 JST-XH Parallel Balance Lead 4S 250mm (6xJST-XH) = $4.65
2x #015000051/27078 JST-XH Parallel Balance Lead 4S 250mm (2xJST-XH) = $1.48
2x #258000066/32032 JST-XH Parallel Balance Lead 4S 250mm (6xJST-XH) = $4.90
2x #258000071/32037 JST-XH Parallel Balance Lead 4S 250mm (2xJST-XH) = $2.24

I do not know what the difference is between the 2 different SKU's.

Do I parallel the Balance Leads in each of my 3 series row?
Parallel Balance to BMS.jpg
Thats an interesting idea, 24S, splits into two nice 12S packs. Bad part is I got a 8S charger, but 24S splits into three nice 8S packs. Uping it from 74V to 88V, inching up to the 100V mark, which makes me nervous. I did however think of that before I bought my 15 4S batteries.

I know how to, and can do the red/black power cables easily.
With those parallel balance leads, I believe it makes life much easier.

What do you mean by "the easiest method would be to use a bms and 84V charger"

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by dnmun » Jan 24 2015 2:40am

if you wanna have the pouches last a long time you have to put them in orthogonal compression and get them out of the shrink wrap and then remove all the JST plugs and 10AWG wires and solder the packs together in series to make your 20S and then connect them in parallel with a small 26AWG wire which you then terminate your sense wires on.

as i told you the D167 goes to 20S and handles up to 70A surge and 35A continuous. how many amp hours is your battery and how long will it produce 35A? $36. plus shipping.

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by wesnewell » Jan 24 2015 11:57am

You don't want a bms that has less continuous output than the max amp draw of your controller. At least not more than 10% less or it will cut out on you when you don't want it to, like trying to cross an intersection fast or climbing a steep hill. To be safe i would get a bms rated for no less than the max amp draw of the controller. It doesn't hurt anything to do so and it might save your life.
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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by arkmundi » Jan 24 2015 12:28pm

markz wrote: 72V nomial 65A current rating. LVC 62.5
I assume Anderson Connectors are the professional/safer way to go, better then the bullet connectors that come on the Turnigy Batteries. Where can I buy Anderson Connectors for cheap, that wont cost a lot to ship, to Canada?
Where I get mine: http://www.powerwerx.com/digital-meters ... poles.html. Lot's of places to obtain - try THIS search.
Here is my wiring diagram I came up with, are the wire gauges correct?
Image
Image
Powerpoles Explained - connectors
For R/C modeling purposes there are 3 ratings/sizes which are 15, 30 & 45 amp contacts that all use the same housing. Therefore, they all plug into each other. The only difference between the 15, 30 & 45 amp contacts is the size of the receiving barrel that holds the wire and the 45 amp is a beefier contact. The 45 amp contact is perfect for 10 Ga. wire. I am a little puzzled why Power Poles are rates them way the way they do because you can put many more amps through them than their rating suggest. I have friends that are consistently putting over 100 Amps through these connectors with no problems and while I have not gone as high as 100 amps, I do regularly exceed the Amp rating suggested by Anderson. Why is this possible? According to an Anderson Engineer in the article Using Power Poles “The actual rating for a 30-amp Powerpole is for a 30° Celsius (54° Fahrenheit) temperature rise at 30 amps (and 110 volts) using 12-gauge wire” and “that 30-amp connectors would not fail in sustained use until over 200 amps.”
In conclusion: for eBike purposes, I use Anderson Powerpoles and exclusively the red/black housing and 45 amp connectors, which I keep stocked. I also keep stocked 10, 12 and 14 gauge wire in red & black and use an amperage appropriate gauge for the application.

You're wiring diagram I believe works.
Who sells BMS's? I can figure out how to hook up the alarms and such if I choose not to got BMS route.
I don't use a BMS on my batteries. The caveat is active monitoring, especially on charging. Over-charging is the main culprit and secondarily discharging to zero, which will ruin a battery. I use celllogs on my batteries to monitor. I stay within a safe 80%<SOC<20% so really never have to worry. My packs stay balanced. But, I use high quality, high-C-rate, robust A123 cells. You should consider not going the BMS route, but if you do, do so in a manner that will preserve battery longevity. How do I know 80%<SOC? I use a Smart Charger from...
How do I charge this pack?
Consider this: http://www.batteryspace.com/Smart-Charg ... -Pack.aspx... they have compatible chargers for other chemistries.
dnmun wrote:if you wanna have the pouches last a long time you have to put them in orthogonal compression and get them out of the shrink wrap and then remove all the JST plugs and 10AWG wires and solder the packs together in series to make your 20S and then connect them in parallel with a small 26AWG wire which you then terminate your sense wires on.
1++, yes, ditto that.

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by markz » Jan 26 2015 1:02am

Well I will be using the MXUS 3000W V2 motor, so whats the continuous amperage on that? 3000W/74V = 40A

I think the 167 or 166 bms is good for continous, do not know when I top out at 80A though on the hills.

I am game if you do a groupbuy, the MOQ is 2 for Bestech Power.

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by dnmun » Jan 26 2015 1:36am

he thinks he uses 55% of the battery capacity. i use 95% of the battery capacity when i have to. he thinks that leaving it undercharged extends the life.

i do not, i think cycle life depends on how long the cell is kept charged up to high voltage, maybe even the 4.1V they use is too much if they leave it charged to that voltage 24/7/365.

i leave the lipo partially charged at 3.8V and then charge to 4.2V when i use it and i think it will last longer that way.

sent you a pm and if you can see how to build a battery out of the lipo, then you wil understand why, in getting them into orthogonal compression and protecting them with a BMS so you can bulk charge at 15-50A on this BMS.

i have no idea how these people would figure out how to charge my 21S 44Ah lipo pack with the little RC chargers.

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by wesnewell » Jan 26 2015 1:39am

The motor you use has absolutely nothing to do with choosing a proper battery pack for your system. The motor doesn't draw any current from the battery pack, the controller does, and that's what you need to match your battery pack to. If you don't understand this, you may find yourself with a dead battery pack sooner than later and out a lot of money. If you are going to use a 65A controller, I'd higher recommend your battery pack be capable of putting out 65A continuous. That includes both the battery pack itself, and the BMS if you use one.
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Mongoose 26" Ledge 2.1 mtb bike $99, yescomusa.com 48V 1000W rear hub kit $200, Hua Tong 72V 40A controller $35, 10ah 24s lipo $217=~43mph, range=45 miles @ 20mph. 25K miles and still going strong.
Huffy Fortress 3.0 with MXUS 3000 4T motor, 24s lipo, 96V 60A controller. Total cost with extras <$700. Top speed ~50mph
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999zip999   100 GW

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by 999zip999 » Jan 26 2015 2:40am

Please make yourself a list of all the costs to see if going A123 may not be so costly after all. Safer longer cycle life. Heavier. If nice to know before buying everything. I wish batteries were easier.

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arkmundi   1 GW

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Re: DIY Battery Pack Question - Connectors, BMS or Alarms

Post by arkmundi » Jan 26 2015 2:05pm

wesnewell wrote:The motor you use has absolutely nothing to do with choosing a proper battery pack for your system. The motor doesn't draw any current from the battery pack, the controller does, and that's what you need to match your battery pack to. If you don't understand this, you may find yourself with a dead battery pack sooner than later and out a lot of money. If you are going to use a 65A controller, I'd higher recommend your battery pack be capable of putting out 65A continuous. That includes both the battery pack itself, and the BMS if you use one.
Hmm. Well, not exactly, but what do I know. Yes, the controller sits between, but the motor is the load and the current draw. The mosfets are just little capacitors and have no ability to store a charge for long, just little equalizers. But the principal should be noted, that battery, controller and motor be well matched to one another for the watts delivered. These are investments that should last a long time and there is nothing more annoying than to be on a journey and have one or another of these components fail.

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