I prefer lipo only because it's cheaper

I was hesitating between purchasing lipo and I was wondering what would worth the most the money. I tried to compare with similar battery capacity (around 360Wh).

Choice 1: 4 zippy flymax 18.5V5AH:

Wh: 370
weight: 2.9 kg
Price: $146.68
Lifecycle: 400
http://www.hobbyking.com/hobbyking/store/__8581__ZIPPY_Flightmax_5000mAh_5S1P_20C_.html


Choice 2: Ping battery 36V10AH:

Wh: 360
Weight: 3.7 kh
Price: $289
Lifecycle: 1000
http://www.pingbattery.com/servlet/the-8/lifepo4-lithium-phosphate-iron/Detail


Finally, when I compare the 2 batteries together:
Weight: 27.5% heavier
Price: 2 times more expensive
Lifecycle: But last 2 times longer

Finally, lifepo4 is only 27.5% heavier than lipo. Not that much. But it's 2 times more expensive. It has maybe much lower number of lifecycles, but by the time I reach lipo lifecycle limit, I could just buy another new pack for half the price.

If lipo and lifepo have the same price mark, I would certainly prefer lifepo because it's only 27% heavier. But lipo is so much cheaper that it's actually the best value for money battery for ebike.

You didn't factor in a few things on LiPo...

1.) Power source for charging = $$
2.) Balancing charger = $$
3.) BMS of some type for discharge?
(not needed if you have a watt meter or cell monitors and watch your cells closely - cell monitors = $)
4.) Connectors for connecting the zippy packs = $
(JSTs and wiring harnesses)

Unless you already have those things, then it's a moot point..
The other thing is tho, if you have those things already, you can easily upgrade by paralleling more zippy's.

Just to throw a wrench in there as well..
Shipping charges on each? Is there a difference?

ALSO, you CAN (don't know if you WANT to) get a different 36v 10Ah basic duct tape lifepo4 pack for only $230 on eBay.
(Shipping included)
Or for about the same price as a ping, a 36v 15Ah (540wh) shipped to your door. ($299)

P.S. The other thing is, if LiPo lasts half the cycles as the ping and is half the price, it's (technically) the same price!
(But if battery prices start to drop within the 400 cycles of LiPo, you can get more energy density for less than now)

LiPo has lower volume per Wh, so you can fit more capacity in a given space than Ping. And did we mention it's cheaper?

Of the two choices, Ping is much safer, and doesn't require balance charging. If I was a newb, or lived in an apartment, I would probably go with the Ping.

For our distance bike we made our own packs with A123 M1's, Konions, and LiPo. I like Konions, because in my experience they don't need a BMS or balance charging... in a well constructed pack. They also don't catch on fire

I dunno if you're calculating the wh based on the real nominal voltage or not.. ( 3.8v/cell ), but that needs to be considered.

Also, are you going to run a 2C load ( 20A ) only? if so, then the ping will be fine. However, the lipo will do 5-10C ( 50A-100A ) all day long and give you minimal sag..

So you need to figure in all the factors.

sangesf, I haven't check, but I'm pretty sure lifepo shipping charge will be higher than lipo because it's heavier.
Over time, Lifepo looses gradually its capacity but from what I've read on lipo, over 470 lifecycles, the battery capacity drop suddently. If I had to use my battery extensively lifepo may worth it. But for general use (I do about 100 km / week), I believe lipo is better for what it is.
It's true that there are additional cost to it (balancer, charger, etc). But once purchased, it's an investment over additional batteries I may purchase.

By the way, I think paralleling additional lipo to already used lipo pack is not a good idea. If the initial pack has already a certain number of lifecycles, its voltage would be different to the new one during discharge. Connecting new and old lipo in parallel may damage both of them.

Also, I was wondering about the value of cheap batteries from ebay, and on many forum feedbacks, it seems that "you get what you pay for". Cheap lipo lead to poor performance (winforce, leaderhobby...). The best value for money seems to be Zippy or Turnigy batteries. I believe the same rule applies for lifepo4 and I wouldn't buy them cheap on ebay.. Unless they are proved reliable.


ElectroSurf3r, are the A123 or Konions better value than Zippy Lipo? I'm not really informed about these batteries but I believe they are either the same price as lipo or slightly more expensive :lol:

neptronix said:

I dunno if you're calculating the wh based on the real nominal voltage or not.. ( 3.8v/cell ), but that needs to be considered.

Also, are you going to run a 2C load ( 20A ) only? if so, then the ping will be fine. However, the lipo will do 5-10C ( 50A-100A ) all day long and give you minimal sag..

So you need to figure in all the factors.

Click to expand...

Isn't lipo nominal voltage at 3.7V/cell? That's the value I find everywhere (wikipedia and other places). On hobbyking site, it's written:
Voltage: 5S1P / 5 Cell / 18.5v

So 5 series gives 18.5V. And 18.5 / 5 = 3.7V nominal voltage.

Do I miss something here?


And yes, I'm considering a "normal" amperage usage. At 100A a 10AH battery would be depleted in 6 mn. Not sure it would be really useful even if the battery can handle that easily.

I've been lucky with all my duct-tape eBay batts.. So I'm a bad example..


BUT, I had received a 36v 20Ah duct tape shipped to my door ($389) in about a week and it gave me 21Ah out of it using it a 1C.
(Until my bike got stolen and I never recovered the battery )

So for $389 shipped I got a 756wh battery.. NOT BAD.
YMMV

cwah said:

And yes, I'm considering a "normal" amperage usage. At 100A a 10AH battery would be depleted in 6 mn. Not sure it would be really useful even if the battery can handle that easily.

Click to expand...

What Neptronix means is, 10C does not hurt LiPo at all, run most of LiFePO at max C rate and you will never see specified cycle life. You do not run 100A all the time, but it is certainly great + to have this capability in some situations.

5.55 Wh per Konion V cell (3.7 V nominal, 1.5 Ah)

67.3 Konions to match your LiPo pack, call it 70 cells for an even 5s14p. 21 Ah, @ 3.7 V nom, One extra Ah :lol:

Our Konions cost about $2.50 per cell (hard to find, maybe ask DocBass). I just found $3.6 per cell brand-new Makita packs on ebay.

70 Konions = $175

370 Wh LiPo for your total of $146.

+ $30 decent RC Charger = $176

Konions win by 1.

Time NOT spent balance charging, or worrying about your home burning down... priceless


This does not take into account shipping, harnesses, tape, etc... but neither did the OP.

sangesf said:

I've been lucky with all my duct-tape eBay batts.. So I'm a bad example..


BUT, I had received a 36v 20Ah duct tape shipped to my door ($389) in about a week and it gave me 21Ah out of it using it a 1C.
(Until my bike got stolen and I never recovered the battery )

So for $389 shipped I got a 756wh battery.. NOT BAD.
YMMV

Click to expand...

You can say you had a good battery... Initially. But that doesn't mean your battery will still perform as well after 50 cycles. That's another important aspect to consider with battery. Do you have a link to this seller? Therevis maybe online feedback about him.


Parabellum, I agree with you with the C rate, it's useful for some situation. I still think that below 30 mph we don't need to draw more than 30-50A

sangesf- your pack's equivalenty $194.50, plus it's a duct tape EBAY batt...
Next time make your own duct tape pack! Much more rewarding, and it's cheaper.

ElectroSurf3r said:

(hard to find, maybe ask DocBass)

Click to expand...

Doc is just out of Konions till sometime in January, maybe SlyCayer still has some.

cwah said:

Isn't lipo nominal voltage at 3.7V/cell? That's the value I find everywhere (wikipedia and other places). On hobbyking site, it's written:
Voltage: 5S1P / 5 Cell / 18.5v

So 5 series gives 18.5V. And 18.5 / 5 = 3.7V nominal voltage.

Do I miss something here?


And yes, I'm considering a "normal" amperage usage. At 100A a 10AH battery would be depleted in 6 mn. Not sure it would be really useful even if the battery can handle that easily.

Click to expand...

Depends entirely on the lipo. I'm referring to hobbyking's turnigy/zippy series ( including nanotech ).

All my tests indicate that it's somewhere between 3.8 and 3.5v nominal in reality.
I'm not sure why hobbyking labels them as such. Probably because RC users often run them at close to their maximum C rate, and get a lot of sag as such. That's why there is crazy shit like 90C lipo out there.

http://neptronix.org/forumpics/lipotutorial/24_dischargingmechanics.gif

Here's a 5AH 20C lipo being discharged. Now tell me that the above battery is 3.7V nominal when 3.7v is just right before the battery hits the cliff and dives for 0v.

BTW i didn't even charge these batts up to 4.2v before the test.. so the nominal voltage *is* higher than reported here.

cwah said:

sangesf said:

I've been lucky with all my duct-tape eBay batts.. So I'm a bad example..


BUT, I had received a 36v 20Ah duct tape shipped to my door ($389) in about a week and it gave me 21Ah out of it using it a 1C.
(Until my bike got stolen and I never recovered the battery )

So for $389 shipped I got a 756wh battery.. NOT BAD.
YMMV

Click to expand...

You can say you had a good battery... Initially. But that doesn't mean your battery will still perform as well after 50 cycles. That's another important aspect to consider with battery. Do you have a link to this seller? Therevis maybe online feedback about him.

Click to expand...

It doesn't matter the seller, it's still a duct tape battery AND I got lucky.
FWIW, After 100 cycles is when I recorded the WH usage...

ElectroSurf3r said:

sangesf- your pack's equivalenty $194.50, plus it's a duct tape EBAY batt...
Next time make your own duct tape pack! Much more rewarding, and it's cheaper.

Click to expand...

AND it came with a BMS and charger AND it was rated for double the cycles of LiPo. (at essentially the same price!)

I AM making my own duct tape pack...
(I'm getting the konions from docbass).

sangesf said:

I AM making my own duct tape pack...
(I'm getting the konions from docbass).

Click to expand...

Everyone knows whom to blame now for new year Konion shortage. :lol:

sangesf said:

ElectroSurf3r said:

I AM making my own duct tape pack...
(I'm getting the konions from docbass).

Click to expand...

Click to expand...

Nice. 8)

parabellum said:

sangesf said:

I AM making my own duct tape pack...
(I'm getting the konions from docbass).

Click to expand...

Everyone knows whom to blame now for new year Konion shortage. :lol:

Click to expand...

ACTUALLY... I originally was going to order 3 Xs the amount of packs from Doc, but I then figured, that would be unfair to others, so I only bought a few packs.

P.S. For those that want to see Nep's graph..

Price alone would be a stupid way to base your decision. After your opening statement, you start listing the other reasons to buy lipo, which when added to the price make it a smart way to make the decision.

Rather than choose by price, choose based on what you need. To me the biggest decision point is this.

Can you ride there and back on one charge? If yes, then you can keep your charging stuff at home and charge in a safe location. But if charging lipo at your destination is going to be a problem, then a more stable when charging lifepo4 might be the choice.

Another point just as important will be the c rate. A 10 ah pingbattery is a poor choice for a controller of more than 15 amps. So if you have a 20 amp controller or larger, you have to buy a bigger ping. But if you have a very short trip, you can carry only 5 ah of lipo and still run a 40 amp controller, or larger with more expensive lipo.

I found a 36v 20 or 48v 15 ah pingbattery a very good choice for my commuting needs. I use about 60% to get there and 75-100% to get home depending on wind direction.

But ALL of my bikes that are run for fun use lipo, so I can hammer the throttle down for fun. The way I use em, the lipo is the expensive battery, and in my dreams I'd see an actual 400 cycles.

I did get 700 cycles out of the first ping, and still have a long way to go to wear out the second.

sangesf said:

]
It doesn't matter the seller, it's still a duct tape battery AND I got lucky.
FWIW, After 100 cycles is when I recorded the WH usage...

Click to expand...

Why the seller doesn't matter if it's a duct tape battery? Even if it's duct tape, battery can still be bad quality, isn't it?

By the way, recycled Konions from DoctorBass seems to be of really good value for money if these batteries can handle 800-1000 cycles as described. I'll look at that to see if it worth it.

dogman said:

Price alone would be a stupid way to base your decision. After your opening statement, you start listing the other reasons to buy lipo, which when added to the price make it a smart way to make the decision.

Rather than choose by price, choose based on what you need. To me the biggest decision point is this.

Can you ride there and back on one charge? If yes, then you can keep your charging stuff at home and charge in a safe location. But if charging lipo at your destination is going to be a problem, then a more stable when charging lifepo4 might be the choice.

Another point just as important will be the c rate. A 10 ah pingbattery is a poor choice for a controller of more than 15 amps. So if you have a 20 amp controller or larger, you have to buy a bigger ping. But if you have a very short trip, you can carry only 5 ah of lipo and still run a 40 amp controller, or larger with more expensive lipo.

I found a 36v 20 or 48v 15 ah pingbattery a very good choice for my commuting needs. I use about 60% to get there and 75-100% to get home depending on wind direction.

But ALL of my bikes that are run for fun use lipo, so I can hammer the throttle down for fun. The way I use em, the lipo is the expensive battery, and in my dreams I'd see an actual 400 cycles.

I did get 700 cycles out of the first ping, and still have a long way to go to wear out the second.

Click to expand...

Yes, of course needs are the most important part. For max fun only lipo makes much more sense. But from my understanding lipo has about half the lifepo4 maximum number of cycles. For your use, wouldn't you be better buying 1 lipo at 48V15AH (didn't do the math) initially, and when this lipo finished its 400 cycles, changes it to another brand new lipo at 48V15AH? (maybe 1 year later?).

Then you would have 2 lipo for the price of 1 lifepo4 without the burden of additional weight. The number of cycles is slightly lower, but you have more flexibility to swap the batteries, weight advantages and possibility to change to a brand new set of batteries when needed.

I have two of these (10 ah version)
http://www.ebikessf.com/50v15ah-lifepo4
One fully managed lipo 48v 10 ah
And a bunch of zippy and turnigy packs.
I also maintain bikes and packs for several avid ebike riders here in San Francisco
I always come to the same conclusion , the r/c stuff is much cheaper.
I am still trying to figure out a good way to avoid over discharge for inexperienced users
I have tried cycle analyst, cell logs and another brand lipo alarm.
The thing you never factor with ping and similar is the tendency for a failed bms to kill the pack. The r/c stuff is currently my favorite.
I use a bulk alloy shell charger and a Hyperion 1401 charger
Just rode my 12 s 5p mega pack made of turnigy 5.8 ah packs. No management just ran a single cell log. Used about half the pack on my ride across the golden gate bridge and around the area. The mega pack cost about $800 and is 44v 29ah
My 10 ah managed packs cost about $600 each and I am always suspect of the bms function. My friends have had bms failures that killed their $600 packs. The problem is you get no feed back from the bms once it has failed you just get one final ride where your 10 ah pack never cuts off at LVC and you ruin several cells.

OR just buy more battery than you'll ever "need" and don't use a BMS. Simple.
(The reason I have 36v(12s) 60Ah Thunderskys on my (non-testbed) bike.)

I can ride 100 miles a day, if I wanted to.. No need to worry about if I need to charge at home or away.

LiPo really is good for short, WOT, fun trips.
LiFePo4 is really best suited for longer trips were charging on the road (safely) is paramount.

You are ignoring the need again. The main reason I use the lifepo4 for my commute is not money, it's for putting my bike on charge at work and ignoring it during the day without worries. I'm much more comfy packing lifepo4 to the workplace. All I need is a very very cheap second charger that I keep at work. But if my round trip was 15 miles instead of 30, everything would change since I could easily just charge only at home.

I commuted on the first pingbattery for 3 1/2 years before it finally died due to a bad bms. That was a pretty good value for the money. ( roughly 50 cents per discharge) I know that people have gotten better cycle life from lipo than I have. I just take my lipo out and flog it every discharge. A commute would be much easier on the cells I'm sure, so I would expect them to last better than the ones I've raced, and flogged on the dirt trails.

What's so cheap about a lipo 48v 15 ah pack? Assuming you pay about $50 per battery after shipping, 9 5s 5 ah packs is $450. Plus you'd need two chargers since carrying one daily beats them up too much. Yes, still cheaper than a new ping shipped, but if you run 200 cyles a year you are going to need to pay the price again much sooner than the ping if it lasts 700-1000 cycles.

Say your $450 of lipo lasted 400 cycles, that's more than double ( $1.25) the $.50 per cycle my first ping cost. Add another $150 for lipo chargers, and you reach about $1.50 per cycle. That first ping had the 1c cells, and the chargers have improved so chances are the cost per cycle is not so much different given the current price of a new ping. Assuming you got 700 cycles from a new 48v 15 ah ping, the cost is closer to a buck a cycle than fifty cents. But still perhaps at least 30-50 cents per cycle cheaper than lipo, and that includes the price of the charger, when the lipo calculation did not.

Of course though, if your need is for more than 20 amps, ping wouldn't cut it, and A123 lifepo4 would be much more expensive.

I forgot to factor in dropping the pack on the floor. I have seen numerous packs that died early from dented cells. I can see getting your money's worth out of a ping if you protect it from physical damage. This is easier said than done. I still have one of my LiPofe4 packs in operation permanently installed in a battery case on the seat tube of a factory made ebike. I use the bike as my grocery getter / kid hauler and I do enjoy the peace of mind a full managed less flammable battery gives. That being said I still feel the lipo is cheaper for most people in my group of friends that I ride with. These friends have a few Ebikes and a few batteries and they switch the batteries from bike to bike. All the batteries have been wrapped in dense foam and taped and the battery bags have stong hold down straps. Still once the battery becomes removable it gets dropped and goes on rides improperly secured bouncing along getting dented. This results in under 100 cycles before something goes wrong like bad bms or physically damaged cell. With an r/c pack you could probably replace one of the 4 small packs that is most damaged and revive a damaged 10 ah pack.
Of course an easy management / charging set up for r/c packs is a different story.