So you wanna buy a battery pack but you’re not sure which one to get and you are a dirty rotten cheapskate to boot. There are so many new choices on the market of batteries that completely blow away the batteries of yesteryear that before you plunk down your hardly earned dough you should have a pretty good idea of what you’re buying.
So many choices, do not get stuck with analysis paralysis
In the old days (being just a year or so ago) you were stuck with only a few realistic choices for 18650 ebike batteries. So many of the battery choices that dominated 2014 & 2015 are now pretty much old news. There are some very exciting batteries that are coming on the market that have much higher capacity, much higher discharge rates and some even now have both. This article will help you understand your options and what is the best type of battery pack to buy or build yourself.
How to calculate the discharge capacity of your batteries
When you buy a pack there are two different discharge capacities to pay attention to. One is the discharge capacity of the BMS, the other is the discharge capacity of the cells. Let’s say you buy a 52v 14S5P triangle pack made of 25R cells. You take the discharge capacity of each individual CELL (20 amps) and multiply it by the number before the P (in this case 5). That gives you a nominal discharge capacity of 100Amps (20 x 5). If this pack is hooked up to a BMS that only has a 50Amp nominal capacity then you will not be able to draw more than 50 amps continuously. Consequently, if you have a BMS which is more powerful than what the cells can put out if you run it too hard the cells will start to overheat and may trigger the temporary thermal cutoff on the BMS (if it is so equipped). Smaller packs tend to get hotter quicker than bigger packs because the load on the batteries per cell grouping is higher the fewer cells there are in a pack. Both batteries and BMS have a burst rate that they can put out for about 10 seconds or so without damaging anything. The burst rate is usually quite a bit more than the continuous rate.
Good capacity or good discharge rates but not both
The rule of thumb for the olden days was you had to pick a battery that had good capacity (the amount of energy it can store) or a great discharge rate (the amount of energy it can provide continuously without overheating) but you really couldn’t have both. The only two cells that are still relevant from the olden days are the 25R and the 29E cells. The 25R is one of the most insane 18650 cells ever made with the ability to put out 20 amps sustained for extended periods without overheating. This cell has been tested with a maximum burst rate of over 100Amps. The 25R still stands alone as a cell that has a discharge rate that nothing else can touch. The downside of course, is the capacity which is 2500Mah tested with a 2Amp continuous drain. All manufacturer rate their batteries with a 2Amp drain, so you better believe when you hook it up to your ebike and pull 20 Amps continuously out of it for an hour you’re NOT going to get that full rated capacity out of the battery. If you pull more power than 2Amps then the capacity will drop, some cells this happens more than other. I can still recommend the 25R cell for packs bought today because nothing comes close to it for the price\performance and it still is an excellent high discharge rate cell for ebike packs.
The 29E is an older high capacity cell that still has a decent discharge rate and it used to be a favorite for large high capacity packs. Samsung rates the 29E cells at 2.75A continuous and 8.25A burst, but if you want the cells to last for any period of time you should not run them at much more than the 2.75A for any real length of time. That means on a 5P pack that the continuous discharge is going to be around 13.75 Amps which is painfully low for a real ebike. I do not recommend this cell, but I’m just using it to show how far we’ve come in the last year.
Brand new cells I’m really, really excited about
There are over a dozen cells that have hit the market this year but there are 4 cells that I have experience with that I’m really excited about that I’m going to write about. Each of these cells has benefits and drawbacks, but each of them fills a price\performance niche that has not been filled by the older style cells.
Panasonic NCRb, a very high capacity, relatively inexpensive, lower discharge cell
The NCRb is a pretty amazing cell in that it puts out 3400Mah with a 6.8Amp peak output. This cell gets pretty hot when you draw more than 6 Amps continuously out of it. I got a 4P shark pack from Lunacycle.com which I reviewed here as ‘the best pack I’ve ever owned’. The pack has insane range and works well with the 25Amp BBS02, although it gets too hot when paired with a 30Amp BBSHD. When you want to use a smaller pack with a high power draw application you are better off going with the PF or GA cells which cost a little more. The NCRb is being used in some Teslas and if you don’t abuse it, this battery should give you many, many years of power.
Panasonic PF, a decent capacity, inexpensive, high discharge cell
The Panasonic PF is somewhere between the NCRb and the GA cell both in terms of cost, capacity and discharge rates. With a 2900Mah capacity and a 10Amp continuous discharge the PF cell sets a new bar for high power cells. The best part is that the PF cells are not that expensive. With a 4P frame pack you can get 40Amps of continuous power with the pack barely getting warm, with a 5P pack you can get 50Amps continuous which is enough to satisfy the appetite of almost every ebike builder out there.
This tiny, lightweight 30Q 7P pack could put out over 100Amps continuous with the right BMS.
The Samsung 30q, Similar to the PF although with a much higher discharge rate and more expensive
The 30Q has a 3000Mah capacity and a whopping 15Amp continuous discharge rate. This cell has been tested by several reputable vape sites and it actually does very well up to about 20Amps. Above 20Amps discharge per cell you’re better off going with a 25R. I have a 30q pack (reviewed here) that I really love for higher power applications, at 40 Amps of continuous draw with a 7P pack these cells don’t even get warm (although that same power draw really heat up my large 20Ah 26F pack). This 7P pack theoretically would perform very well at 105 Amps of continuous discharge which is way more than the 50 Amp continuous BMS is going to allow. The 30Q cells are amazing both in their capacity and their discharge rate, but performance like that comes at a cost, a higher price than the above-mentioned cells.
The holy grail of ebike cells, the Little Red Riding GA cell.
The Panasonic-Sanyo GA cell, Finally a high capacity, high discharge cell for the masses
I’m saving the best for last and the joint venture between Panasonic and Sanyo has created a real monster : The NCR18650GA cell. This cell does not even get warm at it’s rated 10Amp discharge rate and stores an insane 3500Mah per cell. There is some speculation that this could actually be an 11 or 12 Amp continuous discharge cell that is conservatively underrated. Eric from Lunacycle went crazy with this cell and bought way more than he should have so he is selling these cells wholesale right now at a mere $6 a cell (basically at cost) in quantities of 50 right here. I bought 2 boxes which is enough cells to put together a 7P pack which will have 24.5Ah or power and will not even get warm pulling 70Amps and will weigh in at a svelte 12lbs. If you’re too lazy to build this pack yourself from scratch you can buy a triangle pack here for $729, but do it fast because they will certainly sell out. To give you some idea of how much battery technology has advanced my old 25Ah 52v LifePo4 Prismatic cell battery that was top of the line last year weighs in at 25lbs and can only put out a mere 30 Amps continuous. I predict that within a year the GA cell will become the new 25R cell completely dominating the high power ebike battery scene. For the full specs on the Panasonic GA cell click nhere.
From the outside it can be nearly impossible to tell the difference between the real cells and the fake ones. You can’t tell by the price or the feedback rating, the only way to tell is to buy them and test them.
Counterfeit cells
There are a LOT of counterfeit 18650 cells on ebay and alibaba\aliexpress (almost all of them actually). If you’re trying to buy a few individual cells then I strongly recommend buying from a reputable vaping or flashlight company (I use wakandvape.com because it’s owned by Eric and I’d trust him with your life, but probably not mine). There are also a few places to buy cells at wholesale, check the bare cells listing under Lunacycle if you can afford to get them 50 at a time. If you buy a 100 then you can build a 14S 7P pack with only 2 cells left over, you can find a variety of 14S BMSes right here. My advice is to buy from a reputable cell dealer, if you’re not sure then post a question on endless-sphere before you pull the trigger and give anyone your credit card number.
Other new cells I didn’t mention because I’ve never used them
There are a lot of 18650 cells on the market that I didn’t mention in this article. I only wanted to talk about the cells that I had personal experiences with. For a more in-depth article with lots of information on new cells check out this article on our evil twin sister blog electricbike.com written by the all-knowing-ebike god spinning magnets. The article is about 8 months old but the information is still quite relevant today.
So what ebike cell should you buy? I recommend figuring out first if you’re going to go with a 48v (13S) or 52v (14S) pack. I almost always recommend going with a 52v pack unless your controller can’t take the power (most 48v controllers can). Once you figure that out you need to figure out how much continuous power you need to provide and purchase the battery pack according to your power requirement. Lets say you have a BBSHD and want to be able to run at 30Amps all day long. If you go with a 4P pack like a shark pack you will want to avoid the NCRb cells because they will get to hot at those power levels. The PF and GA cells are both good choices but a 4P 30Q or 25R pack is a total overkill and you should save your money. If you had a 25 Amp BBS02 and wanted to go with a 4P pack or larger then I would say that only the NCRb packs make any sense as if you get anything else you are paying more than you have to for capacity that you’re not going to use. The 25R cells are a good choice if you want a tiny pack with a short range for a higher power ebike. A tiny 28 cell 2P 25R pack will give you only 5Ah of range but will give you 40Amps of continuous power (200Amps burst). If you are in doubt about what is the best pack to use for your application then you should ask the ebike battery dealer and they can always point you in the right direction.
In short, with the exception of the 25R cell I would avoid the cells of yesterday and focus on the packs of tomorrow. Buy an ebike battery pack that will not only provide for your current continuous power needs, but will also be able to provide power for your future, slightly more powerful builds. If on the other hand, you know you’re going to be happy for several years with the ebike you currently have then don’t buy a cell that costs more and has a much greater capacity than what you need.
No matter what you chose in 2 or 3 years your pack is going to be obsolete anyway, so might just as well suck it up. You gotta pay to play.
Ride On.
ElectricBike-Blog.com 
Loved learning more about batteries!!!! Thanks Bro!
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Karl – Excellent article. Spot on and informative. I’m also very excited about the GA cell. Such a huge improvement. I’ve been reading your articles for a couple months now and you’ve convinced me I need a to electrify my Spez Fatboy Trail. Just ordered a BBSHD and a 52V 25Ah GA triangle pack from Luna this past weekend. Can’t wait! Thank you for your dedication!
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Yes that GA triangle pack is the bomb and at that price Eric is basically giving it away. It’s shameful how little he is making on packs like that. Shame on you Eric!
Karl
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Thanks for article. The LG MJ1 lasted a little longer than the GA at 5a and 10a discharge based on individual cell testing with an icharger 206b. So for me that cell is the holy grail right now.. Disclaimer is I sell them and they are very hard to get!
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Yes I have heard good things about them, but have not had my paws on them yet.
It’s an exciting time for 18650 cells. It seems like all the manufacturers are clamoring over each other for the next big thing.
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My Sanyo GA are on the way allready. Karl, do you think its ok to stick them together with hot glue? Wont get too hot? Does have the tiny space between cells in battery holder any meaning when it is enclosed in pack where is no air flow? I gonna use 14S3P and 30A BBSHD.
Thanks
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Glue should be no issue with a 3P pack running 30 amps.
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Please consider more than 3p for this pack. 4p is an absolute minimum for the HD and cell spacers will stop the cells getting too hot.
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Need to put there just 3P as dont have more space in fancy battery case. Will have another pack for longer range, lets say 4P or 5P.Will be monitoring temperature of pack. Just have a thought isnt there a small termo sensor with BT to put one in battery and maybe glue second on motor.
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We tried a 3p pack and GA cells with the HD it got really really hot and if glued will be worse. Very range compromised. It may work but will definitely not have a good range / cell lifecycle. Would you consider a backpack 4p pack?
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possible, could you take a quick look at my configuration and let me your professional opinion, where it could be improved and/or modified for optimum performance?
My plan is to will convert my Motobecane all aluminum hardtail which is about 10 pounds into an ebike. It has XTR derailers, cassette, brakes, carbon fiber cranks (which I hope to integrate) along with carbon fiber seat post and handle bars. I plan to upgrade to XTR hydraulic disc brakes, as I currently do not have them and as everyone knows, stopping is a priority!!!!
I would like to purchase as much as I can from LunaCycle, starting with the BBSHD 1000W middrive motor along with the gear sensor for derailers, befang hydraulic E-brake sensor, and a Luna Eclipse 42T chain ring.
I will order 2 boxes of the Panasonic/Sanyo GA battery and build my own. I was looking at the NCRb but your article has shifted my attention. thank you for this! Near the bottom I explain why I cannot just purchase any of the pre-made ones.
For the battery, I would like to build something similar to yours. A 14S7P, which would be 98 batteries at about 12 pounds and run 52V/24.5Ah, correct?
What BMS do you use? what do you recommend? What about the charger?
Being that I will be buying and building the battery myself, I need a quality spot welder, solder gun, pure nickel strips, glue gun/glue (as well as the BMS/charger) Could I ask you to PLEASE point me in the right direction on where and what models to buy for this setup. Thank you!
Finally, is there anything else that you see that I may need? is there anything missing? Thank you in advance for reading this and for your professional advice.
FYI – I live in Rio de Janeiro Brazil and will use the bike for my daily commute. The ride is about 15 miles, mostly flat but with a big hill on arrival. On the weekends, it will see its fair share of hill climbing and trail riding.
MY PLAN ON HOW TO GET THESE BATTERIES TO BRAZIL: I viewed the airlines Lithium battery restrictions as well as the FAA’s and this is what I found. You must make sure they are all individually wrapped and protected and carry them on as instructed by the FAA. They have no limit on quantities of spare batteries but have maximum 100 watt hours (wh) per battery. Here is a cut and paste from their website and also a link if you would like to see the whole article
“Size limits: Lithium ion (rechargeable) batteries are limited to a rating of 100 watt hours (Wh) per battery. These limits allow for nearly all types of lithium batteries used by the average person in their electronic devices. With airline approval, passengers may also carry up to two spare larger lithium ion batteries (101-160 watt hours). This size covers the larger after-market extended-life laptop computer batteries and some larger batteries used in professional audio/visual equipment.
Quantity limits: None for most batteries – but batteries must be for use by the passenger. Batteries carried for further sale or distribution (vendor samples, etc.) are prohibited. There is a limit of two spare batteries per person for the larger lithium ion batteries described above (101-160 watt hours per battery). Batteries must be protected from damage.”
Based on this, individual cells, that are protected, would be allowed in carry on baggage, here is the link to the entire article. https://www.faa.gov/about/initiatives/hazmat_safety/more_info/?hazmat=7
I would like to thank you, once again, in advance for your assistance (as well as your great article)!!!!!!!!!!
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I would just buy a cheap spotwelder from ebay, that’s what I did. The nickel strips can be bought from Alibaba, but beware there are some fakes. As for the 14S BMS you might be able to score one from Paul at em3ev, he ships anywhere, but be aware that he does not support the BMS. Eric sells 14S BMSes on the website but does not ship out of the US.
You’re still better off just buying a prebuilt triangle pack from Paul and having it shipped. Building your own pack is a pretty hefty undertaking and there is no guarentee that it is going to work properly. I would be skeptical about the airlines letting you get on a plane with 98 individual 18650 cells, although I know that Justin has gotten away with it. The airline security guys make up the rules as they go along.
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I agree, its up to airline security but I am confident I can get it done. In regard to the items, I will have them all shipped to my house in San Diego and pick them up in mid May when I am back. Then I will pack it all up in suitcases and fly back with it. Nothing will need to be shipped internationally, so the BMS only needs to go to California.
In regard to shipping to Brazil, this is possible if you want to pay DOUBLE with regard to the import tax. The post office grabs up your package when it arrives, determines what it is and the cost you probably paid (estimating high) then send you a note that you need to come in and pay 100% import tax to get the package out of jail! It has happened to me before so it is just easier to bring stuff in via suitcases.
My plan of building one myself is to go real slow and do much more homework before I start. I am very mechanically inclined so after I do all my homework I believe I will be fine. But without a doubt, I understand that safety is a big issue when building batteries and I plan to use the utmost in care. Who knows, I may hit you up with another question or two down the road.
In regard to a spot welder, how many rows deep can you go with one that is mounted directly on the box, 2 and then flip it for 2 more for a total of 4? Would this be enough as I want to build a triangle shape. Or do I need the slightly more expensive hand held spot welder?
thanks again for the assistance!
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Yes 4 deep. Most builders who build big packs just glue and weld as they go. Check out Damian Rene’s Youtube page, it has lots great direction for home pack builders.
If it’s going to the US then order the BMS and the batteries from Luna. I suggest the GA cells, they are awesome. There is 100 of them on my porch right now.
There is also an article I did on pack repair which you should read.
https://electricbike-blog.com/2016/02/24/repairing-damaged-or-dead-cells-in-a-18650-pack-without-blowing-yourself-up/
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I liked your repair artcle, something I never want to get into but it does show the potential dangers for sure. So I got a response from another ebike site and have a few additional questions.
Eric from Electricbike.com wrote, “panasonic GA cells are overkill for a 7p pack and a bbshd….its twice the available amperage that you need. You could go with a more affordable cell like the PF or even the NCRB in that large of a pack.”
My questions in reply to this would be, do you agree? can too much be bad for the BBSHD or the accompanying components? the cost does not concern me when looking at lunacycles prices. How can (if possible) the extra amperage help? range? power? speed?
please, can you give me a bit more info on this. thanks again.
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Extra amperage is good when u need go on full throtle. You can get more amps when batteri are almost empty. And the pack wont get so hot. You wont get better range.
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Karl,
Do you have any data on # of cycles for the different batteries?
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They are all around 500 unless you charge them to 80 or 90% then its about double that. If someone quotes a number like 2000 or 3000 cycles they are lying.
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I’ll get more excited about cells when the usability and safety gets to be like AA cells, reduced waste and longer alternative domestic use of B-grade or aging cells along with genuine legitimate recycling.
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Hi. I’m just getting round to building my first ebike conversion.
Whilst it’s overbuilt got my needs, I’m going to go with the Bafang BBSHD.
After reading this article, I’m really looking the look of the GA’s.
You briefly mention LiFePO4.
How would a pack of 14s4p (3.6v14AH) Sanyo 18650GA compare to a pack of 16s1p (3.2v 15AH) Headway 40152S LifePO4?
Obviously in that example the LiFePO4 has both a slightly higher overall voltage and capacity.
But they are also heavier and more expensive (I think).
Do LiFePO4 really have twice the charging life cycles over the other 18650’s
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I have lifepo4 cells that claim to be able to go through 3,000 charging Cycles. I am extremely skeptical of these claims. It’s more likely that they can probably get around 1,500 charging Cycles. As for the lithium 18 650 cells it depends on how much you charge them how long they’re going to last if you charge them 100% they will probably only get 500 full Cycles out of them. But if you charge them to 80% there is some speculation that you could get as much as a thousand full charge cycles out of them.
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Thank you for the quick response.
I’ve read the same about charging to 80, discharging to 20.
Does that not apply to LiFePO4? Because that would suggest more of their capacity is usable.
I have seen the 48v(51.2v) pack I listed above with Ecipse in the UK for £478 GBP, that’s ~$690 USD
http://eclipsebikes.com/eclipse-commute-15ah-headway-lifepo4-battery-p-1065.html
Over at Luna I can get 48v(52v) 20AH packs for the same or less (but with 80/20 charging they are really only 12AH.
http://lunacycle.com/52v/?sort=pricedesc
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Lifepo4 is the same.
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So using an 80/20 cycle extends the LiFePO4 as well?
What’s the C rating on these?
I’m also thinking that the number of charge cycles is actually irrelevant…
I suppose it depends on how heavy a user/how large the pack is.
At 500 charges, your looking at 18 months life with a daily charge – but nearly 10 years with a weekly charge.
So the higher charge cycle life is less important if the charging frequency is low?
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Hi there,
I’m building up a Santa Cruz Nomad with a BBSHD, primarily for singletrack freeride purposes. Being from Whistler and the North Shore in BC Canada, we generally have different requirements of our bikes due to the unique types of trails here – rooty, loamy, steep, and often wet. This bike is an older aluminum frameset with carbon wheels, but a great bike nonetheless. I plan on running the battery in a backpack to retain as much of the original ride quality (by keeping weight down) as possible, thus the weight of the battery pack isn’t a huge deal, but I intend on keeping it narrower for ease of storage in a hydration pack.
My question for those experienced is what 52V battery I should use – the GA batteries sound great, but the price point gets up there. That said, I’d rather make the right choice up front, which is hard not knowing how much power will be necessary to navigate the woods here as of yet.
In the end, if I have two of the smaller GA 7Ah cube batteries, it might almost be better as I can build up some two additional cruiser/fat bikes and have two batteries available so that my wife and I can go out together. If that is the case, is the Panasonic GA better for my uses or the Samsung 30q.
Or do I just stick with a Panasonic bottle battery. But now I read about the 48V 21Ah battery and I’m totally out to lunch.
I’d love to hear your opinions, and I will definitely share my build and experiences once I make a decision.
Thanks,
J
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I would avoid the 48v packs.
If it were me I would get a 52v GA shark pack and a 52v 30Q mighty mini cube. Although both batteries are very expensive they will not get too hot even when riding hard with 30 amps cont. The shark pack will give you 1.5 hrs of hard riding or 2 hours of PAS and the mini cube will give you 30 minutes of hard riding or 50 minutes of PAS.
Karl
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Thanks Karl – those stats help make the decision. Certainly 50 mins of PAS is helpful, but the shark pack sounds like the solution if that is the case, as most rides here average about 1.5 hours. I will report back once I’ve got everything from Luna and get her built up.
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Hi Karl, I have been reading your articles for a little over a month now and they have helped a ton with deciding on a bbshd from lunacycles. I plan on building a 14s4p GA pack from a bolt on case, battery tab welding isnt an issue, i also plan on running a 45A BMS from alieexpress. My few questions are A) Who should i get the case from, i would go for a dophlin or shark, aluminum bottle is cool too but seems finicky B) Is there a reputable place to pick up BMS boards C) Know of any good trails in The Black Hills or The Badlands of South Dakota?
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A) I would buy a prebuilt pack, you can get one for about $500 or so
B) Not that I know of right now
C) Nope, sorry
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What 80-90% 14 series would you reccomend? Hopefully under 100 USD
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