A123 vs. Turnigy (LiPo) vs. Zippy (LiFePo4) vs. you name it

[hillyterrain]

So much good info, again! I was close to deciding between em3ev and ping, but now I'm swinging back to LiPo like a pendulum .. However I read on other posts that the discharge rate for the HobbyKing cells are highly inflated..


etriker, I would love to have more info about your A123 assembly, do you leave those 3cell BMS on, and how do the balancing leads work, what charger do you use and how often do you balance charge?


Are there standard fireproof lipo bags out there or do I just have to build my own?

It's a 48V motor, using two 22.2V hobbyking will give me 44.4V nominal, probably even less in real life (48V packs are usually 50V nominal), will I feel that difference?

How fast will I cycle through the LiPo if I use them every single day?

 

[etriker]

This kinda of shows it.

http://www.rcgroups.com/forums/showthread.php?t=599316

This too.

http://rcflyers.org/rcflyers/page11/assets/A123%20Battery%20Pack%20Assembly.pdf

http://www.youtube.com/watch?v=vkDgoXikI_8

I take them off and the tabs and solder on deans battery bars for the connections using an 80 w soldering iron.

http://www.ebay.com/sch/i.html?_sacat=0&_nkw=weller+80+w+soldering+iron&_frs=1

http://www.ebay.com/sch/i.html?_trksid=p2047675.m570.l1313&_nkw=deans+battery+bars&_sacat=0&_from=R40

Hyperion 1420 rc charger and balance charge them every charge.

 

[oldpiper]

hillyterrain, I don't know where you are, but I moved to Pittsburgh a year ago and it's pretty hilly here. If you want to go the RC-Lipo route (like Turnigy and Zippy), there's a good supplier up the road towards Erie, PA, Spec Point Concepts (www.spcracing.com). He (Tom) has good product and sells it at a good price. HobbyKing may be marginally cheaper (I don't know what their prices are) but you will get quality stuff from him. I don't know anyone (from the RC vehicle side, anyway, I've been a bit disconnected from the EV side since I moved, new job and all that) who has been in the least dissatisfied.

Cameron

 

[hillyterrain]

thanks etriker, amazing resources!

I guess this it the charger: http://www.amazon.com/Hyperion-EOS-1420i-Net3-Charger/dp/B004E7MQ3Y
Do you have a power supply recommendation?

What determines the amps that are being drawn, if my controller can handle 20A at 48 Volt and I have a 48V battery pack, does that mean the controller always pulls 20A? So if I have a 20Ah pack a 1C rating is fine but if I have a 5Ah pack I would need a 5C rating for the pack?

I see posts that say people need 80A spikes, where does the spike come from? Do they have specific throttles to control how much amp does to the motor?

oldpiper, I'm in the bay area, thanks for the tip though!

 

[bowlofsalad]

The throttle sends a signal to the controller, based on that information, the controller sends so much power to the motor. If you are at a dead stop, and you put the throttle to 100%, the controller will draw as much power as it is programmed to. So if it's a 20a controller, it will draw 20a. It doesn't always draw 20a, in fact, that is likely to be rare. The 'spikes' occur when the heaviest amount of acceleration need to occur. But as you accelerate, you draw less power. To further illustrate this and help you understand, it takes less power to maintain a speed, than it does to stop, and then get back up to that speed again. When the throttle isn't engaged, you will consume very little power. The higher the amp the controller is, the faster you can accelerate or the more power you can initially draw or the more torque you have available.

However, you might want to know that the harder you accelerate, the more power you consume. This means to say, a slow or gradual acceleration may take longer to get you to your ideal speed, it will consume much less power than putting the throttle to 100%. This idea is important to understand if range is a concern, I assume it is for pretty much everyone using a battery outside of a race track with multiple batteries on hand.

What determines the amps that are being drawn, The throttle. if my controller can handle 20A at 48 Volt and I have a 48V battery pack, does that mean the controller always pulls 20A? No. So if I have a 20Ah pack a 1C rating is fine but if I have a 5Ah pack I would need a 5C rating for the pack? Maybe, that would really depend. You could ride the entire pack's life and not exceed 5a, but even if you did, it might not be for long, there are many variables here and it may be a little difficult to determine the appropriate minimum pack capacity and capacity rating (c)

I see posts that say people need 80A spikes, where does the spike come from? Do they have specific throttles to control how much amp does to the motor? I think most or if not all motors have a throttle, yours certainly will. The spike is created by hammering the throttle to 100% from a lower 'speed' (or even completely stopped, think of a rc plane taking off), for a few moments, the controller will be drawing a substantially higher amount of power. The amount of power needed will usually slope downward as acceleration picks up.

 

[hillyterrain]

Thanks, that helped a lot!!

I just know from my little e-scooter the throttle is binary, full on or off. I have no idea what kind of throttle / controller the GNG will have, hoping for a gradual one.

I want to replace the e-scooters 10Ah 24V SLA pack with Li of some sort, Razor claims its a 300W motor, so at 24V that would be 12.5 Amps. Since the throttle is binary the controller would always pull 12.5A from a cold start, probably even more? So if I want my Li pack to survive that I either need a 10Ah pack with 1C or 5Ah pack with 2C, ideally even higher C?

Thanks for the amazing help everyone, slowly it's making click and things start to make sense

 

[dogman dan]

For your bike, some least possibly expensive 20c packs would (on paper), be able to provide 100amps. You will have a 20 amps controller. In the real world, most of my 20 amps controllers are actually 22 amps, but for a half second they can pull 30 amps leaving a stop sign. Up hills, you will pull 22 amps all the way if you put the bike in the wrong gear ( and fry the motor btw). In the right gear, I bet you climb those hills at less than 15 amps.

So anyway, if HK c rates are inflated, the standard rule of cut anything they tell you in half would still leave you with 50 amps avaliable from a tiny 5 ah pack of 20c lipo. I'd also recomend spending just a few bucks more for 30c though. My 30c packs definitely outperform the 20c ones by $15 bucks worth. 12s would be 50v fully charged vs 16s lifepo4 at 58v fully charged. But your bike will run fine on 50v lipo, and your lvc will not cut off your discharge too soon.

If you went with cellmans a123 pack, 20 ah pouches is all he has had lately. Again, quite more than adequate for your needs. But you'd be packing about 20 pounds of battery, while with 5 ah lifepo4 you'd be closer to 5 pounds. That's the real reason to go lipo.

If you went with ping or some other 2-3c rate pack, I'd advise you to get 15 ah size to run a 20 amps controller. The idea again being to try to discharge at half, so about 1c.

One nice thing about the lipo route, is you'd have to spend less for a 5 ah pack vs a 15 or 20 ah pack, and it would weigh less. But in addition, your 5 ah 50v pack is also a 10 ah 25v pack. It will run both your EV's.

I'm pretty sure you'd get a year of use out of a 5 ah lipo pack. Not if you discharged them 100% each day, but even up that hill, 1.7 miles is short. I presume you'd have downhill home and use no more than 80% of the charge, insuring a longer lifespan. Most likely you will have enough power to undercharge the lipo to 4.1v, and make them last even longer.

But, if you only got say, 9 months out of them, or get stuck with one dud pack, completely replacing them is dirt cheap for such a small battery.

 

[oldpiper]

hillyterrain, I did not want to imply that SPC only sells locally, they are out there on the internet. My experience is just that they have quality batteries at good prices. BTW, I have no financial interest in this firm, I'm just a satisfied customer.

Cameron

 

[hillyterrain]

Thanks dogman I will give that a shot, what charger and powersupply would you recommend? I'd love to get something that can charge LiPo know but also everything else (LiMn, A123, NCA etc..) in the future ..


oldpiper, I think you mean this supplier: http://spcracing.com/index.php?show_price=yes


Looking over their products I think the voltages of their batteries are to low ..

 

[etriker]

thanks etriker, amazing resources!

I guess this it the charger: http://www.amazon.com/Hyperion-EOS-1420i-Net3-Charger/dp/B004E7MQ3Y
Do you have a power supply recommendation?

What determines the amps that are being drawn, if my controller can handle 20A at 48 Volt and I have a 48V battery pack, does that mean the controller always pulls 20A? So if I have a 20Ah pack a 1C rating is fine but if I have a 5Ah pack I would need a 5C rating for the pack?

I see posts that say people need 80A spikes, where does the spike come from? Do they have specific throttles to control how much amp does to the motor?

oldpiper, I'm in the bay area, thanks for the tip though!

I like used Mean well made in Taiwan supplies.

http://www.ebay.com/sch/i.html?_odkw=mean&LH_ItemCondition=4&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313&_nkw=mean+well+24v&_sacat=0

My controller on the trike can peak at 60amps on start off but has never blown a 40 amp fuse.

It is a 60amp controller.

My 20 amp controller can go to 26 amps peak on startup.

The controllers will limit the peak amps and of course the inline fuse.

It does not use 20amps all the time. Just when you tell it too.

Yes, a 20ah cell rated at 2c can do 40 amps.

A 4ah cell rated at 10c can do 40 amps.

 

[hillyterrain]

5Ah, 30C LiPo packs, Turnigy vs. Zippy vs nanotech, does it matter, do I care?

Turnigy $60
http://www.hobbyking.com/hobbyking/store/__9518__Turnigy_5000mAh_6S_30C_Lipo_Pack.html

Zippy $50 and lighter
http://www.hobbyking.com/hobbyking/store/__8590__ZIPPY_Flightmax_5000mAh_6S1P_30C_.html

Are there quality differences? I see you can get lower C ratings for more money, same brand ..!?!

What's a good future proof charger and which powersupply should I get?

Thanks for helping me putting together a shopping list

 

[etriker]

5Ah, 30C LiPo packs, Turnigy vs. Zippy vs nanotech, does it matter, do I care?

Turnigy $60
http://www.hobbyking.com/hobbyking/store/__9518__Turnigy_5000mAh_6S_30C_Lipo_Pack.html

Zippy $50 and lighter
http://www.hobbyking.com/hobbyking/store/__8590__ZIPPY_Flightmax_5000mAh_6S1P_30C_.html

Are there quality differences? I see you can get lower C ratings for more money, same brand ..!?!

What's a good future proof charger and which powersupply should I get?

Thanks for helping me putting together a shopping list

The HK batteries quality control is very hit or miss. (not that it is any worse than A123s quality control)

It is not uncommon to get new batteries from them that are bad and they are not so good at taking them back.

On the other hand I have bought several Cell log meters and lipo alarms from HK and all were ok.

You can update the firmware on the Hyperion 1420. Kinda of good for the future !

 

[hillyterrain]

I read the hyperion can fry your usb port if you plug it into the computer, did that happen to you?


Will I need a BMS with these cells or will the charger take care of it all ..

 

[etriker]

I read the hyperion can fry your usb port if you plug it into the computer, did that happen to you?


Will I need a BMS with these cells or will the charger take care of it all ..

No, there is a warning about how to hook it up in the instructions and a screen that pops up on the computer explaining how to use it without causing a problem.

The charger will take care of the charging part ok but you have to make sure you don't overdischarge your lipos with lipo alarms.

The lipo cells will not forgive you for that like the A123 m1 cells will.

 

[hillyterrain]

so why is lipo better, or is it simply cheaper?

 

[etriker]

so why is lipo better, or is it simply cheaper?

In the long run it may not be cheaper at all.

I am still running a pack made from A123 m1 cells from 2006.

RC lipo is lightweight and can deliver big amps, made for rc racing and such.

Some people that want to carry alot of power use them because it does not weigh the bike down as much as other battery types do.

HK sells A123 cells and packs.

They are used for RC stuff too.

For a small ebike pack the weight difference between A123 m1 cells and rc lipo cells would not matter so much.

 

[bowlofsalad]

so why is lipo better, or is it simply cheaper?

That is a great question. Lipo, initially is indeed cheaper. In addition, it typically has a higher C rating. However, lipo can explode and light on fire, a123 cannot. The very high C rating is great for situations that require very small packs that can deliver huge amounts of energy, such as a RC car, helicopter, quadrocopter and do on. However, ebikes usually have much larger packs, the need for very high C ratings is lowered in that respect, and also the required output for an ebike is typically significantly lower.

With that in mind, a critical idea to look at concerning ideas like superiority, cost, value and so on is cycle life. a123 has an amazing cycle life, I know of no other chemistry that comes close. Lipo is said to have around 80% capacity after around 500 discharges. Typical or standard lifepo4 can go to 1000 cycles before reaching 80% capacity. a123 can go to 6000 cycles before reaching 80% capacity. There is plenty of variation within all of this idea, but these are the general concepts behind each chemistry. If you reduce the depth of discharge (DoD) or how deeply you drain a pack each time you use it, your pack will last much longer. With standard lifepo4, if you drain a pack only to 70% each time, it would last at least twice as long, but that is likely true for all chemistry.

Lipo is great on weight and size, but everything else it isn't so great. If lipo was as safe as a123, it might be something to consider for myself. a123 has the greatest value, it seems like no contest. In this theory, a123 may last 12 times longer than a lipo pack, and 6 times longer than a standard lifepo4 pack. I am pretty sure a123 isn't going to cost 6 or 12 times more then any chemistry. I think the only situation where a123 is substantially more expensive is used laptop cells, but I suppose that is it's own discussion. There is so much to weigh in these situations, I understand your perspective entirely, it's very overwhelming. To me, long term value is usually what provides the most benefit. Only you can know what will suit you best.

 

[hillyterrain]

Awesome, so where to best buy A123 cells? Is HK a good source, or from other people here on the forum? I here cell_man a lot but people say he only has pouches right now ..

If I use A123 cells for a while and decided to add to the pack / change the configuration, is that a problem?

Also what about A123 vs Samsung INR18650-20R, the one that has a huge thread going, how to make a choice here? I hear the Samsung get custom spot welded into packs which is pretty nice ..

Thanks for helping me sort through this very overwhelming amount of info, it's so appreciated!

 

[bowlofsalad]

Awesome, so where to best buy A123 cells? Is HK a good source, or from other people here on the forum? I here cell_man a lot but people say he only has pouches right now ..

If I use A123 cells for a while and decided to add to the pack / change the configuration, is that a problem?

Also what about A123 vs Samsung INR18650-20R, the one that has a huge thread going, how to make a choice here? I hear the Samsung get custom spot welded into packs which is pretty nice ..

Thanks for helping me sort through this very overwhelming amount of info, it's so appreciated!

I've e-mailed cell_man more than a few times myself. He sells other kinds of packs, it's simply not advertised yet, I guess. Though I don't know exactly what he has available entirely. You might e-mail him and ask him.

Sourcing a123 cells of various kinds seems to be a difficult task. I don't know if you are up to the task of assembling a pack either.

"If I use A123 cells for a while and decided to add to the pack / change the configuration, is that a problem?" Your question likely relates to http://endless-sphere.com/forums/viewtopic.php?f=14&t=48264 something such as this subject. I don't really know the answer myself. What packs are made, they go through a process of matching cells. Some cells have slightly higher capacities than others, this means they will reach various voltages (such as LVC) sooner than other cells, this can cause problems for sure but it really 'depends'. Generally, you might be ok if you aren't ignorant.

For a while I considered purchasing various cells or pouches, there is so many options, so much to consider, and most seem like a gamble. There is a guy that sells cells here, I don't know his reputation, but it doesn't seem bad as far as I know.

Personally, I don't know much about those samsung cells. Hah, but maybe I should.

 

[dogman dan]

Yeah, talk to cellman about what he has at the moment. For some time, he sold some great packs made with 2.3 ah round cells. If he has them, have him make up a 4.6 ah pack and go for that.

What makes lipo attractive in your case is the extremely short ride. 3.4 miles round trip. No need to carry 20 mile range around when a 5 ah pack is all you need. The catch 22 is that only lipo and A123 lifepo4 have adequate discharge rates to climb those steep hills in such a small size.

To me, it's a no brainer in this case to just go for the 12s 5 ah lipo. Cheap, light, easily replaced when it's time, and it can run your other scoot configured as 25v 10 ah. Easy to expand to 10 ah later too, if you decide to ride 10 mile round trips.

I'd recomend a meanwell power supply and a charger good for no less than 150w as a minimum. Cheaper ones that do 6s or 8s will do, but if you have the money get a bigger meanwell and the hyperion. Fast is good, but 150w will still recharge your small pack in less than 2 hours including the balancing. more likely it would take only 1 hour most of the time. It will charge and balance lead, nicad, nimh, lipo, lilo, and lifepo4. Avoid the cheap 50w chargers, and the 4 port chargers that are really just 4 cheap 50w chargers.

On the bike, idealy you want a wattmeter and voltmeter. But you could get by with just low voltage alarms, just a voltmeter, or some such cheaper combination. Get a cellog 8, because it will make checking the voltage of each cell in the packs quick and easy.

Along with your batteries and such, get some bullet connectors the same size as the ones on the packs you buy, and some 12 g silicone wire in both black and red.

I've gotten confused where you live, as I help out many different folks. In the USA a good source for chargers, power supplies, wire, connectors, etc is EP buddy. Nice fast shipping in the US, and if in the US, try to order the battery itself from the HK USA warehouse. Again, just much quicker if they have it in stock. Never order unless in stock, Never order what's low in stock.

 

[hillyterrain]

Thanks dogman, I'm going the 5Ah LiPo route for now, exactly for the reasons you mentioned. I'm trying to find 5.5mm Bullet Connectors that will allow me to run the batteries parallel, I'm having a hard time locating them on EPBuddy or HK, do I have to build those myself?

I'm in the Bay Area

I found a parallel plug for T-Connector, so I go from 5.5mm to T, then parralel plug, then back from T-Connector to 5.5mm ... seems extremely convoluted ... maybe just break out the soldering iron instead.

HK has the LVC alarms on backorder, is there another source for them? Would love to have them on my bike while I ride!!

Here is my complete shopping list, the Hyperion is already ordered, still looking for a good powersupply (why is everyone so into meanwell, will not any 12-24V supply do?!? Just ignorant, please enlighten me..)

I'm I missing anything here?

Turnigy 5000mAh 6S 30C Lipo Pack 2
Turnigy Heat Shrink Tube 30mm Red (1mtr) 1
Turnigy Heat Shrink Tube 30mm Black (1mtr) 1
Turnigy 5mm Heat Shrink Tube - BLACK (1mtr) 1
Turnigy 5mm Heat Shrink Tube - RED (1mtr) 1
5.5mm Bullet Connector to T-Connector Battery Adapter (2pcs/bag) 2
Cell-Log 8M Cell Voltage Monitor 2-8S Lipo 1
T-Connector Harness for 2 Packs in Parallel (1pc) 1

 

[etriker]

I guess it is a no brainer.

I was afraid to solder cells together at one time.

Then I saw the soldering inside a failed HK lipo pack we took apart.

I knew that on my worse soldering day I could do a better job at making a pack than the ones from HK.

It was a pack made with no love.

No kidding. That was why I decided to make my own packs. Packs made with love with the wonderful A123 m1 cells and the wonderful Samsung 18650 cells.

 

[etriker]

And if HK right away sends you a bad battery don't get mad and give up on ES.

We can also help you get some A123 cells for a good price and help you put them together.

It is not as hard as say figuring out kingfish's lipo wiring setup. :?

 

[etriker]

Love pack

http://endless-sphere.com/forums/viewtopic.php?f=14&t=38761&start=600#p709069

No love pack

http://endless-sphere.com/forums/viewtopic.php?f=14&t=48132#p708450

 

[hillyterrain]

I love the Love here at ES, I will definitely not give up on it no matter what HK sends to me

Also I would very much appreciate help sourcing and putting together a nice A123 / Samsung pack. I was thinking of stacking the cells in a pyramid configuration and put them as low as possible in the triangle above the bottom bracket to keep the center of gravity low ... the one draw back is that I read with A123 you show at least have 2p so you don't draw to much current from a single cell (not to degrade it too fast), at 15s thats 30 cells total for 6Ah, just because big and heavy very quickly..