My price / benefit comparisons of lipo vs lifepo4

[ebikedelight]

After spending the last few weeks comparing price/ benefits/ of using either hi amp lipo or hi amp lifepo4 , I feel that the lifepo4 still is the best all around setup for ebikes when purchasing pre-made packs ecpsecially if a person needs a charger and BMS unit as part of the package .


lowest price for 48 volt style setup on ebike / 48 volt controller _

LIPO

multistar lipo - 6s pack - 10 ah - using 4 packs to get 12s -20 ah - $428 shipped for 4 packs ...total weight of around 11 lbs . This gets you 50.4 volts at the max of 4.2 volt per cell, which many claim will reduce the packs lifecycle to only a few hundred cycles before it needs to be replaced. This price does not include a BMS system or a specialized safe charger .

LIFEPO4

lifepo4 - 16 cell pack - 48 volt - 20 ah battery, charging to max of 3.6 volts per cell for 57.6 volts max charge...weight about 20 lbs ... for $390 shipped , which includes a BMS unit and a safe charger .


For a simliar price the lifepo4 offers :


2. higher overall voltage which should result in better speed/ power

3. BMS unit

4. charger

5. much safer

6. several hundred more charge cycles which could mean years more of use

7. ability to store the lifepo4 for longer periods of time without worry of damage to cells.

heres a link to this lifepo4 battery

http://www.ebay.com/itm/48V-20AH-22AH-LIFEPO4-BATTERY-PACK-POWER-FOR-EBIKE-FREE-CHARGER-NEW-CELL-/261719115196?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2047675.l2557&nma=true&si=LDB2ki9HPIVEGhnOquu8sA%252F2akE%253D&orig_cvip=true&rt=nc

I think the main advantages for the lipo, would be less weight and smaller overall size , but unless a person plans on making their ebike into a stealth racing machine, those 2 advantages may not overcome all the benefits of lifepo4 .

On another note, I once mistakenly overcharged my lifepo4 battery to 4.1 volts on 1 cell . It did not damage it , which helps to prove the resilence of lifepo4 over lipo.

Id like to hear other peoples opinions on this. I was looking for a reason to purchase a hi capacity lipo pack for my next ebike....but after considering all the above, I decided to once again go with the standard 48 volt lifepo4 setup.

I do admit that if a person only needs to commute a short distance , then the 12s - 16000 mah lipo may be the better, cheaper option , ecspecially if the person doesnt need a charger or a BMS unit.

 

[riba2233]

There's the third, best option. It's pack made from high energy, nca 18650 modern brand name (panasonic, samsung) cells.

 

[dnmun]

all useless concern about cycle life. nobody will use their battery for 2,000 cycles in any case. bike will be stolen or new battery as an upgrade will end it's life and you will put it in the trash long before that.

 

[ebikedelight]

all useless concern about cycle life. nobody will use their battery for 2,000 cycles in any case. bike will be stolen or new battery as an upgrade will end it's life and you will put it in the trash long before that.

lol...so you claim " cycle life" is a useless parameter ?

Ive used my 48 volt lifepo4 , for 3 years now, so I can assure you that cycle life is important to some of us.

not all ebikes get stolen either.

 

[ebikedelight]

There's the third, best option. It's pack made from high energy, nca 18650 modern brand name (panasonic, samsung) cells.

What would the price be to construct such a pack that is 48 volt/ 20 ah...and what skills would be needed ?

 

[montyp]

dnmun - From what I understand the 2000 cycle rating is the average per cell and it only takes a one cell to go weak to kill the pack.

So the pack average is probably closer to 1500 cycles. Which is about what I saw on my first ping pack (36V10Ahr) and now I'm seeing now that I'm near the end of life on my second pack (36V15Ahr). I think it is the cycles that have been killing my packs, the BMS, connectors, etc seem to be doing fine. My assumption is that cycle life and "Shelf" life are related.

Although - you are also probably right in that most bikes will not be used to the end of the cycle life.

 

[riba2233]

Depends on your location. For me, it would be around 400€ (shipping and tax included) with included BMS. But you also need to add some assembly cost.

 

[wesnewell]

Placed under the same loads with same capacities, I don't think there will be much difference in the life of lifepo4 and rc lipo. Another thing you have to consider is the higher voltage sag of lifepo4 vs the very low sag of rc lipo. Once you consider that, a 12s rc lipo pack will deliver about the same voltage as a 16s lifepo4 pack at a 3C or higher load. Lifepo4 under 5C load drops to 2.8V per cell, while rc lipo will only drop to 3.9V per cell. That's 44.8V for a 16s lifepo4 pack and 46.8V for a 12s rc lipo pack. And lets not forget you're comparing a 16s 51.2V lifepo4 pack to a 12s 44.4V rc lipo pack. A better comparison would be a 48.1V 13s lipo pack to a 48V 15s lifepo4 pack. In that case the lipo pack will wipe the floor with the lifepo4 pack. As for life of the packs, I don't think you'll see much difference used in the same application since ebike use puts very little stress on rc lipo and a lot on cheap lifepo4 packs. I don't keep track of cycles, but I've got almost 3 years and over 10K miles on my 20C 10ah 24s rc lipo pack. I'm pretty sure I would have killed a 10ah lifepo4 pack long ago drawing 4C from it. That's if it would have fit on the bike.
Another thing most don't realize is that life cycle for lifepo4 is based on <1C discharge rates. Some test as low as 0.2C to get the cycle numbers up. And don't get me started on those 18650 flashlight batteries. IMO, they're worse than lifepo4. BTW, my 20ah 12s pack that I run as 10ah 24s cost ~$275. Already had 14s 20A charger.

 

[riba2233]

And don't get me started on those 18650 flashlight batteries. IMO, they're worse than lifepo4.

Yeah, Tesla must be really stupid for using them! And all power tools manufacturers also!

 

[999zip999]

A123 20ah 24s @ 40amps 601 cycles 7890 miles no bms no problems. 2.3years old. Lifepo4. Charge with 2 ~ 41v ~ 2a. Chargers. Self balance to 0.060 and 3.45v to 3.51v or so. 83.1v after half mile 80~77v

 

[friendly1uk]

LIPO

multistar lipo - 6s pack - 10 ah - using 4 packs to get 12s -20 ah - $428 shipped for 4 packs ...total weight of around 11 lbs . This gets you 50.4 volts at the max of 4.2 volt per cell, which many claim will reduce the packs lifecycle to only a few hundred cycles before it needs to be replaced. This price does not include a BMS system or a specialized safe charger .

$300 worth of turnigy would be better, but 12s is 44v not not 48. Your a cell missing.
Bms and charger shipped is about $80.

I'm surprised to see the lifepo4 at comparable prices.

 

[ebikedelight]

LIPO

multistar lipo - 6s pack - 10 ah - using 4 packs to get 12s -20 ah - $428 shipped for 4 packs ...total weight of around 11 lbs . This gets you 50.4 volts at the max of 4.2 volt per cell, which many claim will reduce the packs lifecycle to only a few hundred cycles before it needs to be replaced. This price does not include a BMS system or a specialized safe charger .

$300 worth of turnigy would be better, but 12s is 44v not not 48. Your a cell missing.
Bms and charger shipped is about $80.

I'm surprised to see the lifepo4 at comparable prices.

so we would actually need a 13s lipo instead of 12s...which would increase the cost of the lipo, even more then the 16s lifepo4 ?

1 other thing i forgot to mention, is when using multiple 6s, hi capacity lipo packs, one would need to spend extra money on connectors and wire, to assemble the packs to get proper voltage/ amps.

In the ebay link i provided , i think its gonna be difficult to beat the price and convenience and performance of a lifepo4 - 48 volt- 20-22 ah battery with BMS and charger for $390 shipped when compared to lipos. .

 

[999zip999]

Someone buy one. 390.00usd. Free shipping. Too cheap ? San Francisco.

 

[ebikedelight]

Placed under the same loads with same capacities, I don't think there will be much difference in the life of lifepo4 and rc lipo. Another thing you have to consider is the higher voltage sag of lifepo4 vs the very low sag of rc lipo. Once you consider that, a 12s rc lipo pack will deliver about the same voltage as a 16s lifepo4 pack at a 3C or higher load. Lifepo4 under 5C load drops to 2.8V per cell, while rc lipo will only drop to 3.9V per cell. That's 44.8V for a 16s lifepo4 pack and 46.8V for a 12s rc lipo pack. And lets not forget you're comparing a 16s 51.2V lifepo4 pack to a 12s 44.4V rc lipo pack. A better comparison would be a 48.1V 13s lipo pack to a 48V 15s lifepo4 pack. In that case the lipo pack will wipe the floor with the lifepo4 pack. As for life of the packs, I don't think you'll see much difference used in the same application since ebike use puts very little stress on rc lipo and a lot on cheap lifepo4 packs. I don't keep track of cycles, but I've got almost 3 years and over 10K miles on my 20C 10ah 24s rc lipo pack. I'm pretty sure I would have killed a 10ah lifepo4 pack long ago drawing 4C from it. That's if it would have fit on the bike.
Another thing most don't realize is that life cycle for lifepo4 is based on <1C discharge rates. Some test as low as 0.2C to get the cycle numbers up. And don't get me started on those 18650 flashlight batteries. IMO, they're worse than lifepo4. BTW, my 20ah 12s pack that I run as 10ah 24s cost ~$275. Already had 14s 20A charger.

But for $390 shipped , that 48 volt lifepo4 with BMS and charger, seems like a solid deal.

 

[ebikedelight]

Someone buy one. 390.00usd. Free shipping. Too cheap ? San Francisco.

I just did today...its on the way...should be here next week.

Once it comes in, I will test each cell for balance .

If you look at the sellers feedback., its quite positive. I took a chance and bought it.

 

[MrDude_1]

The lipo comparison really depends on how you buy it... buy nine 4s hardcase packs and it's only 230 shipped.

 

[ebikedelight]

The lipo comparison really depends on how you buy it... buy nine 4s hardcase packs and it's only 230 shipped.

link please ?

 

[MrDude_1]

The lipo comparison really depends on how you buy it... buy nine 4s hardcase packs and it's only 230 shipped.

link please ?

sure... http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=58976 (they're 24.31 each if you wait a few mins on the page for the discount offer.)

I just ordered some more earlier this week:

 

[ebikedelight]

The lipo comparison really depends on how you buy it... buy nine 4s hardcase packs and it's only 230 shipped.

link please ?

sure... http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=58976 (they're 24.31 each if you wait a few mins on the page for the discount offer.)

I just ordered some more earlier this week:

you would have to buy 12 of those packs total..to get the 20 ah - 12s
system ..right ?

then include shipping costs for all those packs....

 

[ebikedelight]

The lipo comparison really depends on how you buy it... buy nine 4s hardcase packs and it's only 230 shipped.

link please ?

sure... http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=58976 (they're 24.31 each if you wait a few mins on the page for the discount offer.)

I just ordered some more earlier this week:

I think your math is off..

you would need to order 12 of these hard packs...and then pay shipping costs....then look at your final cost..compared to the
$390 lifepo4 battery I gave a link to on ebay....and the lifepo4 comes with a BMS and charger..

so I still do not see where lipos offer any real cost saving when compared to lifepo4 .

If anyone finds a deal where it does, please post it.

 

[okashira]

There's the third, best option. It's pack made from high energy, nca 18650 modern brand name (panasonic, samsung) cells.

What would the price be to construct such a pack that is 48 volt/ 20 ah...and what skills would be needed ?

*cough* Hang around a little longer... :-D

 

[wesnewell]

And don't get me started on those 18650 flashlight batteries. IMO, they're worse than lifepo4.

Yeah, Tesla must be really stupid for using them! And all power tools manufacturers also!

When you can put a huge battery pack in a car, you don't have to worry much about the stress put on it. And those little electric tools don't put much strain on the pack either. I don't know or care what Tesla uses, but if you check, they are going to be building their own battery factory. Do you really think they will stick with the 18650 format. Check out the 18650 cells here.
http://lygte-info.dk/review/batteries2012/Common18650comparator.php
I have and wouldn't use any of them.

 

[aaronski]

Started lead acid. Garbage.
Then 48v 10ah lifepo pack. It was lighter and faster, but still big and wanted more speed.
Upped amps on controller and lifepo sagged horribly at 40a.

Then, after 50-100 cycles, wear and tear on battery started. Bms buggy, so pulled it, charger broke, replaced, a cell died from sag? Jumpered past it, charged to lower voltage, then a cell ripped a terminal.

At that point I bought 2x 6s 2.5 ah turnigy 20c lipo for test. 2.5ah. This cost maybe $50? Fit in my pocket or seat bag. 2 lbs.
50v hot dipped to 48v under 40a load. Rode 5 miles on it for 50-100 cycles and thrashed it. 60a, 70ah peak loads. You'd top out your motor before you could overheat these packs. Finally killed them at a ES hill climb event where I stalled the motor at crazy amp rating for the controller. They melted the solder on one of the leads.

Lipo is fantastic. I do 10 miles a day on a 5ah pack at 48v bike is light and nimble and j can carry it. 50 amp limit and I've run it for years. No bms. If a sub pack dies it's 5 mins to replace.
If a sub pack gets weak, it can be used to power a drill/saw with an adapter. For long rides all weak packs can be strung together for many miles.

 

[mybike]

I would have to agree on aaronski on this.

When I brought 3 lipo packs from hobbyking it was within my budget and later when I could I brought another 3 and I will be purchasing 3 more soon. To me personally I feel they were cheap to buy because you can spread the cost to build them up and If one pack goes bad or more it can be replaced cheaply and quickly.

For what lipos are I think there a good price.

 

[riba2233]

When you can put a huge battery pack in a car, you don't have to worry much about the stress put on it. And those little electric tools don't put much strain on the pack either. I don't know or care what Tesla uses, but if you check, they are going to be building their own battery factory. Do you really think they will stick with the 18650 format. Check out the 18650 cells here.
http://lygte-info.dk/review/batteries2012/Common18650comparator.php
I have and wouldn't use any of them.

Stop, you are just showing your ignorance. You obviously don't have a clue about the topic.