Understanding Lithium Polymer batteries

Kratos

Member
I mean to plug in batery and charge, go fly, come back put to charge again... dont think about 20-80% and other stuff, just like phone... also dont think about military boxes and fire stuff...
 

Motopreserve

Drone Enthusiast
No. They don't exist for these craft. I don't believe that other types of battery technology have enough "oomph" to handle to load.

But try to think of your attention to these matters as a commitment to safety instead of a hassle :)
 

Kratos

Member
You have batteries in cars, and you dont think about them like these in multirotor... anyway batery tehnology is at low level today, maybe in couple years they will invent something better, till then lipo :(
 

eskil23

Wikipedia Photographer
You have batteries in cars, and you dont think about them like these in multirotor... anyway batery tehnology is at low level today, maybe in couple years they will invent something better, till then lipo :(
Well, actually you do have to take care of you car battery too. Just not as carefully as a LiPo. The thing with LiPos are the capacity to weight ratio. You won't find any other battery that can give you more than 10 mAh per gram.
 

Kratos

Member
so that is the point of LiPo :D Is there batteries that are little hevier but have same output? So there is no other than LiPo for multirotor?
 

Motopreserve

Drone Enthusiast
I also keep an eye on my car battery - especially this season when it regularly gets below zero (f). But that neither here nor there....

You are obviously welcome to try other battery technologies on these rigs. For me, I took everyone else's trials and errors and went with their conclusions. Personally, I think about like this: I have a lot of time, energy and money in the air. I'm ok with keeping track and caring for the batteries if they will help me protect that investment.
 

Bartman

Welcome to MultiRotorForums.com!!
I mean to plug in batery and charge, go fly, come back put to charge again... dont think about 20-80% and other stuff, just like phone... also dont think about military boxes and fire stuff...

the tendency for LiPo's to catch fire comes from the early days before everyone was using balance chargers. most of the fires we hear about today are being caused by abused batteries with high internal resistance values or damaged batteries

you still need to be very safety conscious and practice safe charging habits but the risk of fires is reduced if you are using a good quality balance charger.
 


AH-1G

Rob
Question. I'm preparing to build a hex that will run on a 6S battery. The telemetry hardware is 12v (ie 3S). Is there some type power regulator I need to have? Like wise for 4S lights?
 

Motopreserve

Drone Enthusiast
You can get an adjustable BUCK converter that will allow you to step the voltage down. You just need to solder in/out and measure the output with a multimeter.

There are also fancy PDB that have several outputs at various vintages built right into them. If you're in the designing stage - that might be a neater option.
 


Motopreserve

Drone Enthusiast
As long as you can solder those up in a way that works (looks like they're for PCBs???) and the amperage is sufficebt for the gear you're trying to run - I guess that would work.
 

I have a couple of packs that have gone a bit puffy. Not sure why they are about 18 months old. I used one on the weekend and nearly crashed at the end of the flight. Fully charged and I had used 2750 mah from a 5000 mah pack. I have never gone past 4000 ma and most of the time 3500.
Are my packs about to die? First ones I have had do that.
Regards
Crispy


Sent using fat fingers on the iPad thingy
 

stevemaller

Heavy Lifter
I have a couple of packs that have gone a bit puffy. Not sure why they are about 18 months old. I used one on the weekend and nearly crashed at the end of the flight. Fully charged and I had used 2750 mah from a 5000 mah pack. I have never gone past 4000 ma and most of the time 3500.
Are my packs about to die? First ones I have had do that.
I think you answered your own question. Not "about to die", but "dead". It's exhibiting all the warning signs. And I'd be very, very careful about even storing the battery at this point. I have a battery discharger that I use for any battery that's even 1/2 as sick as yours. Take it slowly down to a ZERO charge, then dispose of it.

As to why this happened, remember that these things are very complex devices with very touchy chemistry. Even if you buy the very best quality batteries, there's always a chance that some impurity or other issue with the chemistry will degrade over time, even with proper charging practices.

Just out of curiosity, what kind of battery is this?
 

Motopreserve

Drone Enthusiast
Agreed. Best to play it safe and not risk more damage.

There is a method for discharging them completely involving salt water I think. You'd have to google it, I don't recall the particulars.
 




RC pilots need the best available batteries that are not only cost effective by means of recharging capability but the highest energy density that is possible to obtain. At this point in time Lithium Polymer batteries are the best fit-for-purpose batteries available on the market today for RC and some other businesses.

ENERGY DENSITY:
Typical energy density is defined as either the amount of electrical energy per unit volume or electrical energy per unit weight. While both are important it is the weight of the batteries that is most critical for VTOL type aircraft such as helicopters and multirotors.

While it may be possible NOW to achieve much higher energy density batteries they would likely be very dangerous due to the use of toxic, unstable or radioactive ingredients etc. or might be of value for making explosives etc. and would not be allowed for public use.

FUTURE: One of the major benefits of fuel cells, i.e., batteries that use hydrogen is that one of the two battery reactants, i.e., is obtained from ambient air while the other, i.e., hydrogen has the highest energy density per unit weight of any reactant available today. But to achieve the highest energy density per unit volume, the hydrogen has to be highly compressed. That is possible now using low weight carbon fiber canisters. Keep in mind that the Multirotor motor and prop sizes must be large so as to reach the sweet spot for using a complete fuel cell system as the extra canisters etc. take up space and weight as well.
 


Top