Starting all over again with the new battery technology...need help getting started
 

I have built and flew helicopters and airplanes with the NiMH technology, but had to put it on hold for a while due to an illness. While away I saw the battery technology change drastically. This alone put me off as to getting back into electric flight. To get going again, my first step is to figure out batteries and chargers. Battery and chargerwise I really don't know exactly where to start. I have aircraft and even a few kits yet to go together. I have kept all of my older NiMH batteries so I could best determine CG and reestablish it with lighter batteries. Any assistance would be greatly appreciated. Jim

I have 1200mA NiMh batteries in my glow powered planes which are readily available and work fine. LiPo batteries come in many sizes and I think are what would be best for your helicopters.since they are quite a bit lighter and the technology is constantly improving.

I know LiPos can seem daunting to start, but once you get past a few basics, it really is not too bad. Here are a couple of links to get your started:

https://rogershobbycenter.com/lipoguide/
Lipo basics - TJinTech

As you point out, to get started, you will need a balancing charger and a battery tester. There are a lot of options out there, but it depends on how much power you will need in your applications. Low power set-ups (under 750 - 1,000 watts) can be quite affordable, but price starts to go up quickly if you need higher power.

LiPo batteries have come way down in price. I have been buying Admiral batteries from Motion RC lately (but there really are many good options). Don't get too hung up on the battery specs to start (in particular "C" rating). Again, what you need to focus on is how much power do you need to deliver. That will help you select the battery that best suits your needs.

Finally, I strongly recommend using eCalc (https://www.ecalc.ch/) as a quick way to virtually experiment with battery, motor, esc, prop/rotor combinations. You plug in your specific setup and can see how all the components work together and what happens when you change one.

Do you have a specific application in mind? That would help point you at specific options that will meet your needs without either buying too little and having to re-invest or spending too much on a setup that exceeds your needs.

Thanks for the great response. I'll study up.

C G weight ? It is great ! more amps for the same weight & size. You may get sticker shock on the chargers. What is the current largest / milliamps you have What is your age ? How EXCELLENT is your long & short term memory about PROCEDURES YOU MUST DO ? I ask as I am 81 & have to prevent a battery fire from burning up my house. I would not hear a fire alarm from a basement or garage fire.

Safety is most important with medications & age.

Well, I am 72, but no medications. Lately I have considered just sticking with NiMH since I have chargers, etc and CG is all set. Also, don't know if I want to deal with touchy batteries and a fire hazard. Seems like there should be an abundance of NiMH packs at RC swap meets. As to requirements, I have an array of size needs. After going through my old notes, I believe one of my largest would be 7 cell 2400 mah for a helicopter. I also have airplanes from small to large. Some that I have never fully outfitted and flown.

I am using LIFEPO4 cells from tools. They do not start fires. Are better on lifetime , number of cycles, rapid charge, watts per ounce and safety. The A123 are excellent.
They will not explode & cause plane & field fires like the LIPO types.

Sport flying NIMH are great. Enjoy.

I turned 80 yesterday. Have been using lipoly battery packs for about ten years and have never had an "incident" . The possibility of lipo fires is worth taking seriously, but if you charge healthy lipo battery packs at the proper amp rate, using a proper balancing charger, and don't store them fully charged, there is little to worry about. There are special safety sacks or other containers sold to store them in. I use Brinks locking ammo cases . When lipo batteries have been used and somewhat abused they develop higher internal resistance and may swell up. Continuing to use and recharge "puffed" lipo packs has led to fires. It is never a good idea to leave lipos while being charged and go take a nap, etc. It is good to keep a fire extinguisher handy. We fly in a fire danger zone and are required to have a fire extinguisher ready to use when flying electric powered models. A lipo pack may break open and catch fire in a crash scenario. Buy a good popular brand balancing type charger and power supply or a charger with built -in power supply . There are a number of chargers that will charge from two to four lipo packs at a time .Most chargers will charge Lipo, life, Lion Nimh, NiCad and Lead/acid batteries ( Multi-chemistry chargers). Many electric flyers use a high capacity charger and power supply and parallel charging boards to charge a number of packs at a time. You should learn about electronic speed controls for brushless motors including linear vs switch-mode battery eliminator circuits ( BEC's) that power receivers and servos. Switch mode BEC's , often called SBEC's, are the preferred type as they can handle up to six cell lipo packs and six servos without over heating and causing loss of control. It is also good to learn to use a wattmeter to verify that a given brushless motor and propeller combination are not pulling too many amps causing overheating damage to the motor and speed control and shortening the useful life of your battery packs. We are fortunate nowadays to have RCU and RC Groups forums providing a wealth of advice and information to beginners and "retreads". Enjoy the hobby!!

How does the weight saving apply when comparing NiMH, LIFEPO4, Lipoly batteries?

The answers to this question are beyond my knowledge base. There are a number of very knowledgeable folks on RC Groups "Batteries and Chargers" Forum. It has to do with weight vs energy storage capacity . A brushless motor, propeller and Lipoly battery combination can be considerably lighter than a NiMh and NiCad powered setup while providing more power and duration. For small "parkflyer" models, their overall wing loading can be much lower than was possible with NiMh or NiCad battery power systems. Lipoly battery packs do not need "topping off" before flying or cycling to remove "memory". Lipoly and similar chemistry batteries are not perfect and have a few quirks of their own to be understood. Their usable life can be shortened considerably by over-discharging and by fully charging them and storing them fully charged for long periods of time ( more than a few days). Name brand Lipoly batteries, especially 4 or more cell packs are quite expensive.
An expensive lipoly pack can become unusable/unbalanced , with one bad cell , a balance lead coming disconnected or becoming "puffed" due to over discharging ( to less than 3 volts per cell) or too much amp draw from too large a prop or from crash impact damage. Users can keep battery costs down by charging a few batteries at the field using their car battery to power their charger or portable generators or club power supplies. I charge a bunch of lipo packs the night before a flying session, enough for 4 hours of 6-9 minute flights. If you fly or eventually will fly large electric powered models, you will want a quality balancing charger and power supply with high enough wattage/amp capacity to quickly charge your battery packs. I am currently using an AC/DC 4-port , 80 watts maximum per port, EV-Peak 3260 charger that can charge four lipoly or other chemistry, other capacity batteries simultaneously. Many active flyers of large models prefer to use a much higher wattage/amp capacity single or two-port charger and power supply with "parallel charging boards" to charge a number of battery packs at a time. Take your time to learn the battery and charging jargon and what chargers and charging procedures are being used. Take all advice with a grain of salt and beware of "fan boys" and "hear say" advice and recommendations. Also learn about speed controls and linear vs switch mode BEC's. 40 amp and higher amp rated speed controls will usually have switch mode BEC's which can prevent "brown-out" crashes. Cheap speed controls will often have "linear" BEC's which may be unsafe to use with 3-cell lipos and 3 or more servos.

If you fly very seldom each year ? like only 20 times in nice weather ? I do that. 2 years & ALL LIPOS start to slow puff up. LOTS of money for a little flying. I use a FMA balancing & storage faithfully. LIPO …….. DOES NOT LIKE LONG storage charges. No use all of winter rarely spring or fall. I believe that is what PUFFS them & makes them dangerous afte a few flights.

My A123 LIFEPO4 cells love that treatment. The ones in the B & D vacuum cleaner go down to 5% or less every week. many years on the 90 % pack. There isno danger with LIFEPO4 by A123 company. Do NOT buy the cheapy LIFEPO4 they are crap & will just vent all the life out of them. A123 or nothing else. Best sport flying battery. Each battery is about 3.6 right off the charger. I run them down to a slower WOT speed. Then charge at 4 amps. Both sizes.

So, where do you buy these batteries? I've searched and all that comes up is LiPos and NiMH, but no LiFes.

Be leery of people trying to use scare tactics about LiPo batteries. They are of minimal risk with only a few basic safety procedures. You wouldn't pump gas into your vehicle unless you used an approved fuel pump and properly safety procedures, would you? LiPo cells do not just puff up on their own, that is from negligence of use. I have lipo cells that have several hundred cycles, are years old, and have not puffed up, which are used regularly. Always buy quality cells and avoid the cheapest you can get.

There's no real need to abandon your NiMH cells. They are still just as relevant these days and have become increasingly more inexpensive and longer lasting. A basic 2 channel AC/DC charger (like the Hitec X2 Black Edition) would be all the charger you could ever want for not a lot of coin, and it'll charge every chemistry out there.

As for LiFe cells, there's a lot of different sources:

A123 Batteries, Chargers, Battery Acessories - A123 Batteries - Taildragger Rc, LLC
https://www.amainhobbies.com/search?s=life
https://www.horizonhobby.com/SearchD...ain=&pageView=
https://www.towerhobbies.com/cgi-bin...H=life+battery

Just to list a handful...

I went to my LHS and the guy said that LiFe batteries due to their 3.3 voltage did not work with electirc flight speed controllers so due to that he summarized that for electric flight it had to be NiMH or LiPo batteries. Is this the case?

Your hobby shop person is WRONG. I have about 30 ESC from 3 cell to 4cells From 5 amps to 80 amps, F & R types They operate on the voltage in only.

You connect a fully charged battery & fly it to L V. Pull it out & put in a fully charged different type of battery. A car battery. You never have to reset ANYTHING to get the ESC to run correctly. It operates strictly on input volts IN and output current to the motor. It does not care what chemicals are in the battery...….Exception to that is a BUILT IN LOW VOLTAGE CUTOFF. If equipped & set correctly with a fully charged battery.

BUUTT A battery recharger DOES need to know what chemicals are in the battery. The small plug tells it how many cells are connected. YOU tell it the chemistry. How much current to charge at.

All there is to ESC & batteries. Pick any chemistry you feel comfortable with. DO READ the instructions and warnings. Do not understand them completely ? Post back & we can try to help you.