New Battery Advice

[michael.i@me.com]

I was wondering if one of you gurus could take a look at this battery

Cohnis Battery and tell me what you think about it's makeup. I am not yet familiar with all these different cell type and whatnot. I have never heard of 26650 Cylindrical (3.2V 3000mAh) and is it strange that there are 224 of them?

Price seems good. it is big enough that I won't burn it out if the specs are true. and it would take me anywhere that I want to go. (better range) It's 40/80amp (2c) rating also means that I could run WOT without limiting my amperage in my ca and run it like I really want to. I really would like to be able to draw 40+ amps continues without beating up my battery.

price tag of 685US is not completely out of my reach either. Compared to Ping's pricing, I would be getting twice the battery.

I am still using my VPower 48v 20Ah pack (another duct tape pack) daily, and it is working great, however I know I am pushing it a little harder than I should be from time to time and I don't want to destroy it. Also, I am building a second bike, and could use a second battery anyways.

I would love some discussion and input on this before I take the plunge.

Thanks in advance

 

[wesnewell]

16s14p. 16x14=224.
It's a standard 1C battery. If you want to pull large amps, then go to a battery with a higher C rate. RC lipo, A123, Headway, etc. Do you really want to stick a 50 lb battery pack on your bike to ride what, 10 miles. I run 10ah 24s rc lipo. 88.8V nominal, 100.8V charged, 888wh, 200A capable, 5.5x5.5x7 inches, 14 lbs, under $300 shipped, range about 22 miles @30mph, top speed 40+ mph.

 

[michael.i@me.com]

Why is this a 1C battery? is that based on the cell type?

The specs listed say
48V 40AH LiFePO4 Battery Specification:
Battery Model 48V 40AH
Nominal Capacity (AH) 40Ah
Nominal Voltage (V) 51.2
Source Resistance (mΩ）＜40
Cell Combination 16-Series 14-Paralles
Cell Type 26650 Cylindrical (3.2V 3000mAh)
Cell Quantity (series*parallels) 224 pcs
Cell Size Diameter: 26mm Height: 65mm
Battery Size 380×210×140mm 430×200×140mm
Discharge Cutoff Voltage (V) 35.2
Charge Cutoff Voltage (V) 62.4
Rated Discharge Current (A) 40
Instantaneous Maximum Discharge Current (A) 120 (without BMS)
Maximum Continuous Discharge Current (A) 80
Maximum Continuous Charge Current (A) 20
Maximum Standard BMS Limited Current (A) 30
Charge Mode CC-CV
Standard Charge Current (A) 2
Charge Time under Standard Charge Current 24 hours
Fast Charge Current (A) 6
Charge Time under Fast Charge Current 8 hours
Charge Temperature Range 0-45℃
Discharge Temperature Range -10-60℃
Battery Net Weight (include BMS) (kg) 21
Battery Gross Weight (include BMS) (kg) 24
Lasting Distance (48V 1000W Motor) 106km
Charging Cycles >1000 times
Recommend Motor Application 48V 1000W and above

I have read on this forum and several other places online that the c rating is the rate at which amperage can be drawn safely compared to the AH rating of the pack/cell.

so this says 40amps Rated discharge and it is a 40AH pack. but the maximum continuous rated discharge is 80amps. Doesn't this mean that it is a 2c pack?

I am curious why you say it is 1c, can you explain please so I can understand? this is the kind of thing I obviously need to understand, and this is the place where I am going to learn.

I also may have confused the situation a bit by saying I wanted to draw "huge amps" 40amps is really the most I would EVER want to draw using the setups I have now. So even if this pack is in fact only 1c, then this should not be an issue since I would only be discharging at 1c.

You mention 10 miles, but I am not sure where that came from. I am running a 20ah pack now that gives me between 45-55Km (27-34 Miles) range using my current setup. So if I was to go from a 20ah to a 40ah pack, it would stand to reason to me that using simple math I should be able to DOUBLE my range. curious where the 10miles came from.

the lipo setup you are reffering to is way higher voltage than I need. I mean one day I might want to try some crazy higher voltage, but I am really happy at 48v.

Lastly, you mention a 50lb pack. 53 lbs is a lot of weight I agree, but it is not like I am lifting it, it would be on the bike so I don't think that it would bother me.

I like the idea of having a second pack that I can choose to use for longer range rides. like more for when I go off road down to the lake or something.

I appreciate your input, I really just want to understand what it is you are saying.

Thanks in advance, Michael

PS, My setup is basically a 48v 1000W rear hub motor that draws at max 40Amps, which if I do my math again is basically 2kw tops.

Hope to hear more on this.

 

[wesnewell]

It's 1C based on this;
Rated Discharge Current (A)40
And that's what they base cycle life on. It's rated 1C, but can do 2C. Take the BMS off and you could probably suck 5C out of it. No telling how long it would last though. But if you are only using a 40A controller, you won't be exceeding the C rate anyway.
I don't know how much range you require. I was justing pointing out the extreme weight of the battery and it wouldn't make much sense if you only needed a 10 mile range.
I could change my lipo pack to 44.4V 20ah in a matter of seconds. That's one reason I use it. Others are cost, size, and weight. 40ah 51.8V rc lipo pack would be a lot smaller and only weight ~30 lbs. But I could use a 5ah RC lipo pack and draw 40A out of it without it breaking a sweat.

 

[dogman dan]

It's crap, and I wouldn't touch it with a ten foot pole.

Why? Mostly because it's too likely to have the all too familiar cheezy spot welds. They leave the factory ok, but after the thing drops off the conveyor a few times in the sorting center, it arrives at your door with at least a few disconnected cells. One of those hundreds of cells disconnected, and bingo, the whole pack is 3ah less capacity.

Find something with pouch cells.

Sounds like where you are heading, you should be looking at A123 pouch cells that can power a large controller anyway.

 

[michael.i@me.com]

Find something with pouch cells.

Sounds like where you are heading, you should be looking at A123 pouch cells that can power a large controller anyway.

Can you make a recommendation ?

 

[wesnewell]

Can you make a recommendation ?

What's your objective, range or power? The smallest, lightest, most powerful pack will be using rc lipo. 14s lipo can be configured to about any size you want at about 3.5 lbs per 5ah. It can also be balance charged all at once with a Hyperion 1420i charger, Cost will be about $105 per 5ah.

 

[dogman dan]

If you just want 1000w for 40 ah of range then a 2c pack is fine. For a better chance of getting it's full lifespan, plan for discharging it at 1c for the most part. As cells age, or if you just get a few weak ones, the extra amp capacity prevents the weak parts of the battery going to 3c discharge, which would kill it quickly. Once you lose some capacity, the c rate starts climbing compared to when it was new.

I just advise the pouch type packs because really big round cell packs tend to have a bad cell or a bad connection lurking in there. Often as not, a really big one suffers damage in shipping, and never puts out the full capacity.

I was assuming that like many of us, your interest tends to be toward the next bike having more watts than the last one. Emissions free is one source of a123 pouch packs, and lately there are others. I don't have the info on the tip of my tounge where else though. There are threads that talk about sources though, in battery, and for sale sections.

RC lipo (lico) is the other source of high c rates. If you can afford it, 50c is out there, and more! But 20c RC lipo is fairly cheap. Less cycles so only cheap up front. It's the way to go for high power with light weight, such as racing and dirt riding where handling is far more important than anything else including cost.

A 40 amp controlller (2000w?) has a lot of potential to ruin your current battery. When you do actually pull 30 amps, you are getting really close to the limit. But very likely, when you cruise at full throttle on flat ground, you pull closer to 15 amps, and actually discharge at .75c 90% of the time. But if you have long hills, you could be pulling 30 amps for some time.

I would REALLY discourage you from buying a 45 pound battery that is in one piece. You better strap 45 pounds on your bike and ride it before you decide it's OK. My commuter can carry 50 pounds, but the handling gets worse and worse as you load it up. Two batteries that carry low in panniers will help, but you will still need a good quality bike with lots of side to side stiffness. A cheap alloy frame bike loaded with 50 pounds will display an amazing flexibility from side to side. They call it death wobble, or tank slapper. The way a bike is designed, it really wants the weight to be located on the seat or the pedals. 50 pounds elsewhere bends the crap out of weak frames. Carry as much battery as possible in the frame triangle, which locates the weight in the middle, rather than one end of the bike.

 

[michael.i@me.com]

If I want to build say a 10 - 20 ah 60v pack out if these rc lipo packs, how would I do it?

Can you offer me some guidance here?

Also if you have any links to good sites that would be helpful.

Ps has anyone ever made scalable packs? Like modular do they can customize the bike for different riding styles of the day?

What I mean is some days I just need to go to my girlfriends house and I only use 4ah @ 48v. Other days I ride for like 50km and use 19ah@48v. Also, I am sure I probably don't even need 48v to go to her house. It is an easy ride and not a joy ride. (well it is once I get there, but thats a story for a different time. Lol) :wink:

So can this be done easily?

 

[mark5]

If I want to build say a 10 - 20 ah 60v pack out if these rc lipo packs, how would I do it?

Can you offer me some guidance here?

Also if you have any links to good sites that would be helpful.

Ps has anyone ever made scalable packs? Like modular do they can customize the bike for different riding styles of the day?

Buy a Lipo wiring harness from icecube57 here or make your own. Here's a couple previous posts by others. One is a diagram for connecting 4 packs and the other is a review of an icecube57 4 pack harness with nice pictures that you should look at closely. It's not a 60V 20AH pack but could be made to be with some harness changes and more packs. I miswrote the preceeding sentence and wesnewell below is of course right--you won't be making a strictly 60V pack but more with 15S.

LegendLength 12S2P diagram
Re: How set up your first LiPo batteys
http://endless-sphere.com/forums/viewtopic.php?f=2&t=27522&start=15#p398801

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

This could be a "visit the girlfriend TMI" pack minimal harness configuration but you'd use 1 less pack for 12S.
jkbrigman 18S Series Harness
http://endless-sphere.com/forums/viewtopic.php?f=14&t=36097&start=30#p540966

Some basics articles that have been mentioned by others here.

RC E-Bike Drivetrain tutorial
http://www.recumbents.com/wisil/e-bent/rc_drive/tutorial.htm

Understanding RC LiPo Batteries
http://www.rchelicopterfun.com/rc-lipo-batteries.html

Parallel LiPo Charging – The Faster & Safer Way To Charge?
http://www.rchelicopterfun.com/parallel-lipo-charging.html

 

[wesnewell]

You wouldn't build a 60V lipo pack. It's not practical or even possible. It has a nominal voltage of 3.7v and a full charge voltage of 4.2v per cell. And using the same size packs in series makes charging easier. You can parallel charge all at once. So 3 5s packs in series is 55.5V, 3 6s packs in series is 66.6V, etc.,etc,, etc. the combination is almost limitless if you want to mix pack sizes. Perosonally I use a 24s2p pack at 10ah using 12 4s packs because it's cheaper that way. Could do the same thing using 8 6s packs. That's 88.8V nominal and 100.8V charged. RC lipo comes with power and balance leads. To make a pack, just plug them in series til you get the voltage you want. It's pretty much that simple and the same as you'd do with any other battery.

 

[michael.i@me.com]

Ok. Help me figure this out. I went to HK and found a this one battery. Is this a good one? I have never used rc lipo packs before so I am asking many questions here before I buy anything.

So here is what I want to do. I would like to make a 72v 5ah battery but three of them. Then I can use one while another is balancing and such. Switch them around so they can cool between uses, and lastly I would like to be able to parallel them together to make a 5/10/15 ah configuration. This way I can choose how much "fuel" I have in the tank. This way I would be able to choose just how far can go and know how much I have left and just allow me the versatility to do what I want.

So if you could help me out and maybe supply me some links and also what kind of charger I would need for both bulk and balance charging that'll be awesome.

And one more thing money really isn't an issue i mean I'm not rich but I don't mind paying for quality and paying more for things are going Last longer and give me better performance so help me out the best you can like I said i woukd like it in five amp hour increments would be beautiful and I appreciate the help in advance thank you very much.

Cheers, Michael.

PS I live in Canada so if there's a Canadian supplier it's better than Hobby King or if you have any other ideas for Canadian that would be great thank you

 

[mark5]

That battery you found is fine. Unless you want to read more about basics and do the wiring yourself you should get a harness from icecube57.

If you do want to do the wiring yourself a quick answer for a discharge harness, at least to imagine one way to do the wiring involved if not to actually do it that way, would be to take that jkbrigman 18S Series Harness posting and use it, or 2-3 such setups in parallel.

Here's a Ypedal article about his Meanwells charging but I don't use a bulk charger and don't know much about it.
http://ypedal.com/Lipo/Lipo.htm

 

[wesnewell]

Good battery choice, but you can't make a 72V pack using 3 of them. You can make a 66.6V pack that will charge to 75.6V. Typically, a *72V* rc lipo pack is 20s (74V). That would take 4 5s packs or 5 4s packs to make. Of course you could mix them with any combination of packs to get 20s, but you really don't want to do that if it can be avoided. And it can be avoided. However, if you are using a 60V ping now, then using 18s would make a lot of sense if you are happy with the performance you get with the 60V pack. You'll get the same or a little better with 18s lipo. And yes, you can make 3 packs and use them any way you want. Just make a simple 1 to 3 plug for both your positive and negative connectors to your controller and use 1, 2, or all 3 at a time as you like. That's really all you need. You use the wires coming from the packs to put them in series. red to black, etc.

 

[michael.i@me.com]

I am not using 60v right now. I am using 48v 20ah

 

[Confab]

Can the RC lipo packs be realistically used to replace an ebike battery? It seems like they're cheaper for the same amount of power. Can they be wired up so that two 3v 5Ah packs can give out 6v10Ah, for example?

 

[michael.i@me.com]

Apparently lots of people are using RC Lipo batteries for Ebikes.

To answer your second question know when you put them in series you double their voltage and when you put them in parallel you doubled their amperage.

What I'm trying to do is figure out how to economically build a second battery pack with more range and more power.

I'm trying to get some answers in this form but so far it is sort of information overload.

 

[mark5]

What I'm trying to do is figure out how to economically build a second battery pack with more range and more power.

I'm trying to get some answers in this form but so far it is sort of information overload.

The diagram that wesnewell attached for you showed how you can wire an 18S 5, 10, or 15AH pack. The 1-to-3 wire 3-legged black and red wires on the left and right sides would go to the controller on one end and could have 4mm plugs on the other battery-side ends. You connect a set of 3 series-connected packs to 1, 2, or all 3 of these plugs on each side depending on the AH you want. Bottom layer of 3 series-connected packs only for 5AH, add middle layer for 10, add top layer for 15. You can vary voltage by using 2 or 4 series-connected 6S packs instead of 3 in the layers. Sorry if I'm telling you something that's already understood.

 

[michael.i@me.com]

Don't apologize for stating the obvious. Even though I already knew this I'm sure my other friend there doesn't so by all means please give me even the complicated and the simple you can never have too much information.

 

[Ykick]

You can always start small with the goal of a reserve pack and gradually learn and expand what you will need for a complete large replacement pack down the road. Many of us got started with RC Lipo this way. 2 or 3 bricks, RC Charger, connectors, wire, power meter, cell logs = best tution money ever spent!

It's awful hard to get it all worked out without some hands on experience. A small reserve pack gives you this experience without breaking the bank or risking a larger pack fireball.

 

[wesnewell]

I am not using 60v right now. I am using 48v 20ah

I had this mixed up with another post running 60V ping. Most 48V controllers have 63V caps, so if this the case of yours, you wouldn't want more than 15s, 3 5s packs wired the same as above for each 5ah. It's the same principle for all though. Your controller will be what limits the voltage you can use.

 

[michael.i@me.com]

I am not using 60v right now. I am using 48v 20ah

I had this mixed up with another post running 60V ping. Most 48V controllers have 63V caps, so if this the case of yours, you wouldn't want more than 15s, 3 5s packs wired the same as above for each 5ah. It's the same principle for all though. Your controller will be what limits the voltage you can use.

In your signature you list the prices for all the parts you've used on your bike except for your battery pack I'm wondering if you would be kind enough to break down the costs of what you bought as well as your charger and harnesses etc.

I am really curious about what it actually costs to build a 24 series pack like yours

Thanks in advance Michael

 

[Confab]

One thing I'm curious about, how would you go about charging a pack of reserve LiPos? One by one or would you need a special charger?

 

[icecube57]

Im not boasting my products or anything but you need to go to my Harness For Sale Thread. Im doing a newb series that explains alot of things about lipo and how to use the charger. Im adding videos almost daily covering specific topics. If you have time to listen and learn you will be more education in venturing into lipo battery territory.

http://www.youtube.com/icecube578

 

[wesnewell]

In your signature you list the prices for all the parts you've used on your bike except for your battery pack I'm wondering if you would be kind enough to break down the costs of what you bought as well as your charger and harnesses etc.

I am really curious about what it actually costs to build a 24 series pack like yours

Thanks in advance Michael

I already had a Hyperion 1420i charger and 600W power supply. I think I paid close to $200 for both about 18 months ago. I only charge once a week, so I could get by with a cheap $30 6s charger. Battery pack is 12 4s hardcase packs at ~$22 each. But they're out of stock again on them. There isn't a harness per se. I just soldered wires together I had to make it. It's just 2 Y cables with connectors. With extra paid for priority mail shipping I think the batteries were about $290, but don't remember for sure. I bought 6 2x 4s parallel cables for about $20, but those aren't really needed. If you want to build 24s packs, just find the cost of the lipo at Hobbyking. That's really the only cost except balance charger and power supply if you don't already have a charger. Throw in $20-$30 for misc. stuff.