Lithium-ion vs LiPo

[6mm Lapua]

So I got to thinking today, why do rc’s all use LiPo instead of lithium-ion? From my limited research and knowledge lithium-ion sounds superior to to LiPo in almost every way. Any wisdom from more knowledgeable guys?

 

[305HemiGuy]

So I got to thinking today, why do rc’s all use LiPo instead of lithium-ion? From my limited research and knowledge lithium-ion sounds superior to to LiPo in almost every way. Any wisdom from more knowledgeable guys?

Great question. I've often wondered the same.

 

[CrashBoom]

Lipo supports much higher discharge rates than Lion.

 

[Dan B.]

There is no difference whatsoever. The industry just went with LiPo because it rolls off the tongue so well, and you just end up sounding weird if you have to say “LiOn.”
“What do you mean, LiOn? Ain’t no lions around here. And why are you saying it like that?”
But if they would’ve went with LiOns from the jump you can bet the best batteries would come from a factory called Simba Cells.
Clearly I have no clue…

 

[Cheez]

Here’s some information from a well respected vendor….Basically, the difference internally is the LiIon cell has a liquid electrolyte while the LiPo, which is also a lithium-ion technology, uses a gel for the electrolyte. Anyway, always use a charger designed for the appropriate chemistry.
Q. I'm confused, isn't LiIon the same as LiPo? Also, why don't you recommend LiPo packs? I like that they're cheap so what's wrong with that?

A. Yes, LiIon and LiPo are similar. But critical differences aren't so much in their chemistry (they're actually very similar) but in their methods of construction. This is the key to understanding our recommendation for LiIon versus LiPo.

This is because the LiPo is built in a poylmer bag. This gives it the characteristic brick shape as the individual cells are flat-rectangles, which are overlaid upon one another. The shape is also the giveaway for the LiPo vs. LiIon where these packs are built within cylindrical metal shells (typically aluminum).

Note; the Po in LiPo refers to the polymer in it's construction (aluminized polymer bags). Anyway, the individual cylindrical shells, because they're made of metal instead of thin polymer bags means they're more resistant to physical damage. By the way, this metal shell is the same technology used in old school NiCds and NiMH (and alkaline cells, for that matter). It's been around forever because it works!

There are downsides to these metal shells. First, the metal is a bit heavier than the plastic bag use in LiPos. Second, simple geometry dictates two cylinders contain less volume than two flat cells (capacity). Third, they're more expensive to produce.

Against these disadvantages are upsides. Like metal shell is FAR more sturdy. This turns out to be a crucial advantage because metal protects better against inadvertent damage (like a pack shifting during a maneuver and bumping up against the hard edge of a former). If this happens to polymer style packs, the dent may result in it puffing. Or in a fire. Need I mention our models are constructed of flammable materials like balsa, foam, and fiberglass?

 

[dure16]

Lipo supports much higher discharge rates than Lion.

Ding ding

 

[razorrc]

I believe you can get higher capacity in the same amount of space with LiPo.

 

[Rowdyray]

@CrashBoom hit it on the head. As far as what us RCers want. With a bit more maintenance.

@Cheez got a little more technical but, spot on.

In laymans terms. LiOn batteries were made for the average idiot's cordless tools. They can be charged with a basic charger, last a long time and left for weeks with minimal damage to the life of the battery. Could you imagine the house fires if Lipos were used for cordless tools?

 

[Dan B.]

Here’s some information from a well respected vendor….Basically, the difference internally is the LiIon cell has a liquid electrolyte while the LiPo, which is also a lithium-ion technology, uses a gel for the electrolyte. Anyway, always use a charger designed for the appropriate chemistry.
Q. I'm confused, isn't LiIon the same as LiPo? Also, why don't you recommend LiPo packs? I like that they're cheap so what's wrong with that?

A. Yes, LiIon and LiPo are similar. But critical differences aren't so much in their chemistry (they're actually very similar) but in their methods of construction. This is the key to understanding our recommendation for LiIon versus LiPo.

This is because the LiPo is built in a poylmer bag. This gives it the characteristic brick shape as the individual cells are flat-rectangles, which are overlaid upon one another. The shape is also the giveaway for the LiPo vs. LiIon where these packs are built within cylindrical metal shells (typically aluminum).

Note; the Po in LiPo refers to the polymer in it's construction (aluminized polymer bags). Anyway, the individual cylindrical shells, because they're made of metal instead of thin polymer bags means they're more resistant to physical damage. By the way, this metal shell is the same technology used in old school NiCds and NiMH (and alkaline cells, for that matter). It's been around forever because it works!

There are downsides to these metal shells. First, the metal is a bit heavier than the plastic bag use in LiPos. Second, simple geometry dictates two cylinders contain less volume than two flat cells (capacity). Third, they're more expensive to produce.

Against these disadvantages are upsides. Like metal shell is FAR more sturdy. This turns out to be a crucial advantage because metal protects better against inadvertent damage (like a pack shifting during a maneuver and bumping up against the hard edge of a former). If this happens to polymer style packs, the dent may result in it puffing. Or in a fire. Need I mention our models are constructed of flammable materials like balsa, foam, and fiberglass?

Great info, man. Did you get that off a fly-guy site?

 

[dmaynor]

If you really want to know this is the book I learned from: https://us.artechhouse.com/mobile/Practical-Battery-Design-and-Control-P2320.aspx

Its worth pointing out I didn't really know much about batteries before I got into RCs. The inability for 3 people to clearly define what the C rating was for sent me in search of learning material.

 

[SrC]

I believe you can get higher capacity in the same amount of space with LiPo.

Bingo, you win the prize.
True IMHO. Just more practical this way and easier to shape them to size.. And yet Lipos are much more volitile. Less safer in their packaging. LiOns have a better packaging. You never see Lipos in a scale EV vehicle. Only Lion based types.
Some of the early 1/10 Arrma's actually had LiOn cells. They went bye bye.

 

[Lennart]

If you need a battery for an rc car just buy a good lipo.
I planned on building a LI ion battery so I can compare my two batteries side by side:

Lipo got way more grunt and li ion got lower grunt for way longer. Li ion also has more capacity at under 3.6volts per cell, so its just slower or more "voltage drop".

But most EVs and electric bikes or bicycles have those ion cells for more capacity and safety.
Nowadays more smartphones have lipos because they support the "fast charging".

I hope this helped somebody

 

[Cheez]

Great info, man. Did you get that off a fly-guy site?

Nope…someone you are familiar with. @jbeech

 

[Cheez]

There is no difference whatsoever. The industry just went with LiPo because it rolls off the tongue so well, and you just end up sounding weird if you have to say “LiOn.”
“What do you mean, LiOn? Ain’t no lions around here. And why are you saying it like that?”
But if they would’ve went with LiOns from the jump you can bet the best batteries would come from a factory called Simba Cells.
Clearly I have no clue…

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