HK Lipo Bricks - what do I choose and why?

Getting batteries from HK seems like a marathon. The sheer numbers alone make it daunting trying to a feeling of what to choose from. There are various Names, brands, and even qualities of each brand. Sometimes what sets them apart is apparent other times not so much.

To put thing in context I will be running QS 205 v3 / Adaptto maxi or Sabvoton. I consider running 22s. p depends on cash flow.

So there more then a few 6s 5Ah batteries to choose from. We can see they vary in C - rating. From 20C upwards to peak of 130C.
Will I notice any real life difference between a pack made from flightmax 20 C or flightmax 60 C?
Are the claims of more then 130 C even real?
How high C rating do I really need? For repeated full throttle accelerations until battery is empty?

I would love to hear from people that have used various batteries from HK and that know how to spot the good deals over the hyped ones. As the price per brick varies with close to 100 $ from the most expensive to the cheapest one it is important to know what to choose so one does not throw away good money on something that might just be a paper spec for spec wankers.

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Edited 19th of January 2016.

Today I made my choice of battery chemistry and I owe that to Allex. Here is what he wrote and what convinced me to drop Lipo from HK and go for 18650's.

Allex said:

This is LiPo thread, but ok we can do a comparison.

If we take one of the best 18650 in terms of energi density (Sanyo GA 3,6V 3,5Ah) we get that you can fit:
GA 12.6Wh 18x650mm total: 16.54CC 0,76Wh/cm3
0,76Wh per cubic centimeter

Then we can take the new and popular Multistar High Capacity 4S 8000mAh we get that you can fit:
MS 118,4Wh 142x49x43mm total: 299.194cc 0,4Wh/cm3
0,4Wh per cubic centimeter



How about Wh/kg?
GA:
12,6Wh/45g=0,28wh/g or 280Wh/kg
Multistar Lipo:
118.4Wh/643g=0,184wh/g or 184Wh/Kg

Same thing here, you get 96Wh more or less for each kg
And its is up to you to decide weather it is worth to carry 2kg of 560Wh or 2kg of 368Wh


But lets take those popular hard case packs, they are really horrible in terms of power density and you can almost compare them to Lead acid when taking 18650 into account
http://www.hobbyking.com/hobbyking/store/__26801__Turnigy_5000mAh_4S1P_14_8v_20C_Hardcase_Pack_UK_Warehouse_.html?strSearch=turnigy%20hardcase

These babies have 0,268wh/cm3 or 140Wh/Kg

Click to expand...

Wow that was a compelling argument you made. I don't think I ever have looked at the like this before. Well you just got me hooked Allex. 18650 it is.
Off to learn about spot welding, pack design, strip size and so much more......sigh a little overwhelmed right now, big task ahead for one uneducated old timer new to the world of electric, physics and electrons.

Only HK Lipo I bother buying anymore is 4S 20C 5Ah Turnigy hardcase.

Ykick said:

Only HK Lipo I bother buying anymore is 4S 20C 5Ah Turnigy hardcase.

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Care to elaborate? You buy these because they are the best value for money? Or that one does not need more then 20 C rating?
Or are the Turnigy Hardcase better performing then their other lines? Priced at 23 $ they seems like a good deal, I will do the math and see what it will cost for 100v or 88v hot of charger... How are they holding up for you?

Is it this battery? Turnigy 5000mAh 4S1P 14.8v 20C hardcase pack

In general uses fall into two classes. Commuters, and high power guys.

For commuters, the 20c stuff is fine. It will sag like hell under a 5c load, but if you run them at 2c or less they work great. Very affordable. If you don't mind a bit of sag, then run them at 5c.

But you sound like you might be more in the go fast category, big motor, and I'm assuming you'll run it at 40 amps or more.

For you, I'd recommend upgrading to at least the turnigy 30-40c. Run them at no more than 5c, and sag should be acceptable. Why turnigy? In my experience, slightly better real world capacity from the turnigy than the zippy. Makes sense since they are usually a bit larger physically.

Those are the ones. Using them over a year and very happy. They're a very good deal Wh/$.

Inside the hardcase, pouches are physically smaller than the usual shrinkwrap pouches found in the majority of 5Ah bricks. I do notice slightly less capacity - along the lines of perhaps only 4.7-4.9Ah when using extreme LVC/HVC parameters as opposed to 5-5.1Ah for the 5Ah shrinkwrap bricks.

But, I really like the hardcase for both protection and shape when bundling into larger battery packs. 4S is simple and easy enough to work into 12S, 16S, 20S, 24S voltages.

Having used 6S/5S pouch bricks 3-4 years I'm of the opinion you're better off with bricks and pouches produced in large numbers. Anybody who's paid attention to 4S hardcase over the years know they turnover at a very high rate so you're very likely to get fresh cells. +40qty purchased in the past 12 months I've yet to get a brick with a bad cell. Knock on wood...

I won't even consider anything using Zippy brand anymore. Poor longevity in every version I've tried.

20C labelled rating is plenty for most of our eBike needs, imo.

i have used the 6S 20C lipoly since it is cheapest for the weight. the 4S hardcase packs have a smaller pouch inside that weighs about 10% less and is narrower.

i have also used the 8Ah nanotechs and have a lot of failures on the first pouch in each 6S pack. i would not recommend them for that reason.

but i build batteries different from others because i remove the packs from the shrink wrap and remove the sense wires and then solder the packs together into a series to make the battery. i put hardboard endplates on the assembled battery and then put it in compression with wood clamps and then wrap with tape to keep it in compression.

@ykick
On the one side I kind of like the idea of going for the hardshell 4s battery. It would make big batteries cheap and probably would last for duration I need. Then there is the "go fast" guy, who will feel cheated if I don't go for intimidating high C rating. So with higher C I get more and faster power delivery, correct? So accelerations might be better?

I will have to think about it. I think there was affordable 60 C rater in there. Those 130C well they are just too expensive if risks for getting bad cells are higher then for more popular bricks.

Well, that's what the HK marketing dept wants you to think but my personal experience on 38A controller setting running on 2P or more, there's no measurable loss in performance. In fact, I've had 30-40C "labelled" bricks exhibit much higher IR and greater sag under load than my 4S hardcase bricks.

You requested experienced opinions and that's my story, you're welcome and good luck...

One more thing I am not certain about is the voltage. Been playing around with Ebike calculator from key4design.co.uk

Some say with FOC controllers one does not need to go high 90v and can stop at 7x v, because of the EMF being used for power. Is that correct or an urban myth?

Regarding 98v limit for adaptto I was told to stop charging Lipo at 80-90% for best longevity of the pack. So even 6s wouldn't surpass the 98v limit of Adaptto. So I don't think the 98v limit should be an issue. What do others think, stop at 70v or go 84v (100 v of charger)?

I am kind of drawn to try those hardcase you like so much, problem is I have no referances and no previous experience with e-bikes so most likely I will grin like crazy whatever the performance really is. So maybe it makes more sense to go for that now.

Im running those 4s hard cases with my adaptto kit 84v I broke one 4s batt learning about lipo the hard way works great for me just buy extra batts. Test them before you put on your bike. One cell went bad in my pack and ruined the pack conected to it. Sorry for the bad writing this is from my phone. I will be back from Japan dec. If you need any help pm. Will be posting my build when I get back

dnmun said:

i have used the 6S 20C lipoly since it is cheapest for the weight. the 4S hardcase packs have a smaller pouch inside that weighs about 10% less and is narrower.

i have also used the 8Ah nanotechs and have a lot of failures on the first pouch in each 6S pack. i would not recommend them for that reason.

but i build batteries different from others because i remove the packs from the shrink wrap and remove the sense wires and then solder the packs together into a series to make the battery. i put hardboard endplates on the assembled battery and then put it in compression with wood clamps and then wrap with tape to keep it in compression.

Click to expand...

dnmun,

Do you only build your batteries in 1P configurations?
I have broken apart the 4S Hard Case packs, and reconfigured some for 2S2P. The problem I have is that the aluminum tabs on each cell are a PITA to solder, once you break one apart.
I would love to see some more pics or a video of your pack build process.

these are the newer lipoly packs. the old ones had the little pcb the tabs were soldered onto.

there is a short copper tab welded to the aluminum anode so that it can be soldered on the lipoly.

the nanotech have no copper tabs at all.

when i rebuild the ping packs i have to use the 3P or 4P or even 5P i had to use to match the good cells i was able to conserve from the original batteries when i built the big lifepo4 pack.

but for lipo i can build them as 1P and that is how it should be built. then the individual packs are tied in parallel through the sense wires.

there is no need for large sense wires and in fact you should use paralleling wires that are tiny enuff that they will fuse open if one of the cells in the paralleled packs actually has a short and starts pulling large currents from adjacent cells. like Tesla does.

the other reason for not connecting all of the cells into one node is the need to be able to isolate the defective pouch when you have one channel with high drain down rates. when you find a channel will no longer balance under the balancing current provided by the BMS then you have to find the shorted cell by isolating each battery, 1P, from each other by disconnecting them at the paralleling wires so you can identify the shorted cell by this binary search of isolating the individual batteries from each other. can't do that if the pouches are all soldered to each other.

dogman dan said:

In general uses fall into two classes. Commuters, and high power guys.

For commuters, the 20c stuff is fine. It will sag like hell under a 5c load, but if you run them at 2c or less they work great. Very affordable. If you don't mind a bit of sag, then run them at 5c.

But you sound like you might be more in the go fast category, big motor, and I'm assuming you'll run it at 40 amps or more.

For you, I'd recommend upgrading to at least the turnigy 30-40c. Run them at no more than 5c, and sag should be acceptable. Why turnigy? In my experience, slightly better real world capacity from the turnigy than the zippy. Makes sense since they are usually a bit larger physically.

Click to expand...

But he said he plans a 100 volt, 4P pack...20Ahr, so even 2C would give him 40A and 4kW !
I doubt he would ask for much more !........maybe 4C burst to 8 kW !

macribs said:

....So with higher C I get more and faster power delivery, correct? So accelerations might be better?..

Click to expand...

No , not really. You will have more battery power available, but the question is...could you utilize it ?
You should estimate what your amp draw is likely to be..normal , and max peak load.
In reality , unless you expect to pull 60+ amps continuously, you wont notice the difference between a 20C and a 30C pack.

Bricks are good. Best bang for the buck, and modules of 4 are easy to swap out if you had to. I like the fact they are well protected in the little box that provides the required expansion space that these pouches use. It's just so simple.

Turnigy are rated as 60% longer life than zippy. They are a better product for about the same money. I wouldn't look at zippy.


At 4p the 20c stuff will give 100 amps. I dunno your actual goal though. I'm unfamiliar with the controller.

First of all, you should definitely not exceed 22s or 92.4v with an Adaptto Max-e.

Above 92v the controller reduces current limits, limiting to almost 0 at 98v. Above 92v you will actually go SLOWER as a result. This is for damn good reason, the FET's are 100v rated and under many circumstances the voltage the controller sees can spike higher than battery voltage.
Putting aside the limitations of the controller FET's, there's actually no reason to go beyond 22s. You won't get more power and the historic reason for upping voltage, to increase speed, is not relevant with a controller that can increase the speed of motor 50% higher than normal using OVS/field weakening/timing adjustment. The ideal convenient voltage for Adaptto mini or max-e using lipo bricks is 20s, made up of 4s packs. This makes your BMS wiring literally plug and play, instead of the nest of wire required for 5s or 6s packs.

So - 4s is the voltage

C rating - this is a bit less clear cut... it really depends on your expected usage. If you're going to be a hooligan, pulling 10kw+ on and off the throttle for the duration of your ride, you're definitely going to want high C rated cells. If you're using the bike as more of an commuter, cruising at sane and legal speeds (50-60km/h) then C rating is far less critical... 4KW is enough to maintain 50km/h up some serious hills with a cromotor. I do it every day.

I have a 20s 10ah pack assembled from 4s 5ah turnigy hardcases. Paralleled in pairs (including balance leads) and then connected in series. I have run about 70a draw which results in a total sag of about 4v. If a pack the same size was assembled from 60c rated nanotechs I would expect only ~1v of sag at the same power level.

Capacity also plays an important role in selection of C rating, if you've got a relatively small pack - say 5ah, then pulling 6kw @ 82v results in 73a draw, resulting in a 14.6C load on the battery. Obviously 20c rated stuff isn't going to cut it here, sagging heaps and getting very hot. Rule of thumb for ebike use seems to be hobbyking C rating /4 for continuous. To run with a 5ah pack at 6kw you're going to be needing the 60c rated packs. Increase your pack size to 20ah and the 3.65c is achievable with the cheapest hardcases.

Weigh up those factors alongside volumetric efficiency and price and you'll start to whittle down your lists to something more manageable.

True, if he runs 4p, for 20 ah, even running at 2c rates will give you 80 amps. I just wasn't sure what amps he was talking about.

But I'll still stand by my statement. In my experience, generally running 2s, the 30-40 c turnigy is much nicer to use than the 20c stuff. For me, I got a lot more sag discharging at about 4c from the 20c stuff. Once he goes to 4p, then he'd need a very strong controller to press the cells past 2c.

No big deal at the start of the run, but if you are out having a lot of fun, and push your pack towards 3.5v per cell, then less sag means you don't have to slow and creep home so early in the ride. You know not to go below 3.5v per cell resting, but you can't help but cringe when you see less than 3v under load. So a lot of sag can kill the fun a bit earlier in the ride home.

It's entirely possible to compromise, and run one set of 20-30c stuff, paralleled with weaker packs.

All I'm saying is, if you are riding this bike for the fun of it, it's different from a basic commuter. In the fun budget, a battery that sags less is well worth the cost.

But you'll notice I didn't recommend spending stupid amounts of money for 120c shit. Just go for the 30-40 stuff.

@Ohbse, @dogman dan thx for putting things into context. Now I feel I get a better understanding of this.
I will set up a few different choices of battery packs this weekend and I would be very happy if you could look over that and give me your thoughts and comments.

So looking for 4s bricks there are various mAh available and various C rating. If I my understanding is correct I need to get as high as possible mAh and C rate close to 40-60?


Changing from 20s4p (5,000mAh bricks) to 20s6p seems to make these changes:

Battery Pack Total Amp Hour :
20 Amp Hour
Battery Pack Nominal Total Watt Hour :
1400 Watt Hour
Battery Pack Max Total Watt Hour :
1680.00 Watt Hour

Click to expand...

Battery Pack Total Amp Hour :
30 Amp Hour
Battery Pack Nominal Total Watt Hour :
2100 Watt Hour
Battery Pack Max Total Watt Hour :
2520.00 Watt Hour

Click to expand...

How does the watt Hour relate to range?

20Ah how much range will I get from them for those few longer rides? I mean being conservative with the throttle and speed.
Will the range be much different if I go 30 Ah rather then 20 Ah for batterypack?

AH and wh are both measures of battery capacity. Ah is the level of current you can theoretically sustain for 1 hour before the battery is empty. A 2s 5ah battery and a 10s 5ah battery are rated the same in ah terms, but obviously the pack with 8 more cells is going to contain a lot more energy. Total energy is measured in watt hours.

Watt hours are calculated (approximately) by the nominal pack voltage x ah rating. For majority of lipo cells this nominal voltage is 3.6. 3.6v X number of cells X ah rating of the cells gives you total wh. 1000 watt hours is 1 kilowatt hour or kWh. The real amount of wh will vary according to many factors, heat, current, design of the pack wiring, quality of cells etc.

C rating is measuring how fast you can drain that energy. A load of 1C means that you are draining energy at a rate that will empty the battery in 1 hour. This is effectively the ah rating of the battery. 2C load is double this, e.g the battery will be drained in half an hour. 2C x ah rating is the current. Current divided by ah rating gives C rate. Therefore a 10c battery is capable of being drained in only 6 minutes at a rate of 10x its ah rating. You can see why 130c ratings are getting a bit hard to believe.

Economy in ebike terms is measured in Wh/km or wh/mile. My bike (DH Comp, cromotor, max-e, turnigy pack) consumes 24-30wh/km and has a usable total energy of 650 Wh before cells start to drop off the voltage discharge cliff. My range is therefore limited to 22-27km at that economy level.

My next pack is configured as 20s 10p of 2.5ah 18650 cells. It's total energy is therefore (3.6x20)x(2.5x10) = 1800Wh or 1.8kWh. My new maximum range at 30Wh/km is 60Km. I will draw a peak of 10kw, divide that by the rating of the battery results in 5.5C load, easily within reach of the cells I have chosen.

That battery calculator is flat out wrong and not very helpful, I would avoid making decisions using it.

I doubt you'd see a performance difference from 30c to 60c packs, unless you were to run 5 ah size.

Do choose from 5 ah or larger pouches, you are going to have a monster pile of wires and connectors as it is. Don't make it worse by stringing together small Capacity packs.

When we heard you talking about 4p, we assume you meant 5000mha( 5 ah) pouches in 4p. 20 ah. Packing 20 ah, you might not need to go higher c rates.

You might find 20s 20 ah damn big and cumbersome to carry. It's about 1500 watt hours! So you might find you prefer a 10 ah size battery for many of your rides. You could buy some 30-40c packs for the 10 ah rides, and then add 10 ah more of mere 20c stuff for longer trips. So instead of building one huge pack, build one from 20c packs, the other from something better. 20s 4p will be way too big to carry in one place on the bike anyway. So any way you slice it, you are looking at a split pack, unless you have a custom frame designed to carry a huge battery.

As pointed out before, if you are carrying 20 ah, you won't need it all to be expensive to have a low sag ride.

My advice would be to buy some decent stuff first, 10 ah worth of it. Then see if you even need or want to carry another 10 ah.

Range? My guess is that big ass motor will rarely get less than 50wh/mi. And ridden fun, could easily suck a lot more. Just depends on the speed you cruise at. Figure on 8-10 miles range from a 10 ah pack, more or less.

So even if I choose like one of the cheaper batteries I will get away with 20C rating because I run a 20s4p pack made from 5 Ah bricks?
What is the reason that larger capacity (ah) packs have less sag (voltage) then say a pack with half the Ah? Btw custom frame with large battery box.

So to make a 20s4p package (72v20Ah) it would take 20 individual bricks like this 5,000 mAh?

In rel life I would not notice any difference in performance between a 20s4p pack made with that 20C brick over this pack made from 60-120c brick? Here is 3 different bricks, what yah all think. Are quality or performance noticeable different between these?

Turnigy 5000mAh 4S1P 14.8v 20C, 24,85 $.:







Turnigy 6400mAh 4S 14.8V 60C Hardcase Pack, 49,99 $.




Turnigy Heavy Duty 5000mAh 4S 60C, 63,09 $.







Moneywise the first brick the 20C would cost 460 $ assuming my understanding of 20s4p takes 20 bricks of 5Ah.
Hard Case 60C battery are moer then twice that, 1,000 $. But here the bricks are 6,400 mAh for a total of 25.6 Ah, or save money and have 3p for 19.2 Ah. Then I would only use 15 bricks and price would fall to 750 $.
The heavy duty battery are more expensive and will be a bit over 1,200 $.

I think I am sat on using this for my pack. I think I start out small, with "half a pack" at 20s2p, and then I can add more batteries at later time to better the range. Winter is here so range will not be the most critical now a days. Just get around the city. As spring comes and it gets more enjoyable I will add more bricks so I get a total of 20s4p.

What do you think, does it make sense to use this particular battery? It has 60-120 c and 6,400mAh. Sure it costs more then the 20C 5,000 mAh but for that extra money you get more mAh and higher C rating.

Is this crazy talk or do this make sense? (do remember I have never done battery work before so I have no real life experience)


Turnigy 6400mAh 4S 14.8V 60C Hardcase Pack, 49,99 $.

IMO, you'd notice a difference with the very high c rate packs, if you use only 10 ah of it.

BUT, that difference will only be noted for the first 20 feet of any run from a stop. Once you are moving say, 20 mph, then your motor will not be capable of drawing much more than 40 amps. At cruise, say 40 mph, you won't be really drawing more than 40 amps. This is because after all, it's a fairly light bike.

So 10 ah pack, 40 amps. That is a draw of 4c rate. HK packs of 30-40c ratings won't sag much under load at 4c. 20c packs (10ah of it) will sag under 4c loads.

Why the size matters? Because the bigger the pack, the more packs divide up the load. 40 amps from 20 ah of pack is a 2c discharge rate. Even the cheap stuff can handle 2c. For a 10 ah pack 1c is 10 amps. For a 20 ah pack, 1c is 20 amps.

I'm sticking with my original recommendation. 30-40c for the first 10 ah. After that, you can add more in the cheap 20c stuff.

All this would change if you are racing. If you are in a race, and your opponent has the same motor and controller and weighs the same. The guy who performs best in that first 20 feet may be the winner. So if you are racing, get out the charge card, and buy the hottest shit you can grab. If you are just riding around for fun, I think the 20-30c stuff will be fine. It will sag some in the first two seconds when your controller allows 80 amps, but it will not draw 80 amps for that long a time unless you are really a big dude

If you are big, like 300 pounds, then maybe you do need the higher c rate. Once a bike with rider weighs 400 pounds, the load when just cruising will go up, and the load getting to cruise will be high longer.

The idea is, to have enough c rate to not sag 10v when you are just cruising. 2-4v of sag cruising is fine, but more than that sucks. Every volt of sag will cost you on the maximum speed. You don't want to sag to 60v when just cruising. That would just be slow, after spending all that money.

Mm yes I am heavy rider. 120 kilo + the bike. So I will assume me + bike at least 350 lbs all combined. Might even be more. Steel frame, mc rims and spokes, mc tyres. And a big fat ass rider. Surely not aerodynamic, more like a brick.

Btw was I right about the number of individuals batteries to make a 20s4p batterypack?
4 x 6,00 mAh batteries in parallel to get 25.6 Ah. Then 5 groups of those to make voltage 72? So total of 20 batteries?
It is important that I have this correct before I put in the order, so it would be nice if someone could let me know if I got it right or not.

And I think I will start out with half of this, so for now I will use 12.8 Ah. So starting point will be 20s2p. Then I add more batteries in the spring. And if I start out by using these 60-120 C batteries now, I might be able to go for lower C rating when I double up on capacity, right?

So in the spring the pack will consist of 10 x 60-120C batteries and 1 x 20 C batteries. Think that will work well together?




Another thing that might be nice with this pack I am set on is that the wires are not soldered to the battery. So that should make it easier to do custom length of wires when putting the pack together. I seems all the wiring can easily eat up a lot of space inside a battery box. So I think it will be best to try to keep wires as short as possible and as neat as possible to leave room for BMS, charger and controller also inside the battery box.

macribs said:

Btw was I right about the number of individuals batteries to make a 20s4p batterypack?
4 batteries in parallel to get 20 Ah. Then 5 groups of those to make voltage 72? So total of 20 batteries?

It is important that I have this correct before I put in the order, so it would be nice if someone could let me know if I got it right or not..

Click to expand...

Its important you get that correct,..and FULLY understand the risks involved before you start working with 20 packs of lipo !
This stuff can burn your house down if you make the wrong move with it. It is an incendiary device if abused.
Make yourself fully aware of handling, storage, charging, use, and all safety measures required, before you make that order.

I said it before and will repeat it one more time for the "all Hat and no Cattle" gang, DO NOT overlook volume sales and production. For best results stick with the most common sizes and connection schemes.

For example, those plugs seem "neato" but you're really just adding more potential points of failure into an already cluttered connection environment. Most folks don't really understand what goes into connecting 20S4P battery packs. Gotta get into the game to understand the many nuances involved here...

And do you really want some oddball brick(s) intended for a more "specific buyer" possibly sitting around on shelves for long periods of time? Not me. I'll go with the most plentiful and freshest stuff that's hard to keep in stock long before messing around with "weird sized" potentially older stock.

At the price of under $25 per 20C 5Ah 4S brick you can keep plenty on hand for whatever C rate or problems that WILL arise.