A word about receiver batteries 

Getting back in to the hobby...your videos are invaluable. I honestly had no idea that battery technology had changed so much. Thank-you.

Awesome video Bruce. These past couple of weeks have been sweet and sour for me regarding you. I hate you're not flying, but at the same time, you're cranking out a lot of videos, so we all love it!

Thank you very much for this advice. Just what I needed!

It's nice to learn something new every day. This video has today covered, thanx

Well done Bruce,you made a talk on batteries interesting + I learned something as well. Cheers mate.

Love your old videos , you look so much younger , har ha!

Great video, Bruce. Solid technical advice that keeps us coming back to your channels. I guess we ALL have something to learn. Even MFNZ members. Thanks for pointing out that nobody is perfect.

Thank you very much Bruce, very informative video!

Great post Bruce, keep em coming. You are right, too many people who have been flying a long time don't move forward with the technology ( which actually battery wise, is way cheaper than what they use now )

Excellent info Bruce, as always!

I pulled a 220mah cell with a wrong polarity from a "toy" RC motorcycle I have. My friend purchased a... not so great glider using non-micro servos and a 4 x AA pack! Swapping the leads on the switch harness allowed me to thoughtless continue to use the original charger for the battery, and it saved a considerable amount of weight. Who knows how long a flight time we'll get, but this time around I think it does actually have a chance of flying!

These were great we need more

Good informative video Bruce. I liked the info on the alternative shape and size of the LiFe packs, they look interesting, a no nonsense, makes sense battery, with good power. Nice one mate.. Cheers Steve

Thank you for the info, You Rock !

I power all my receivers with a lemon and a zinc rod.hasn't failed me yet although I am thinking of upgrading to that new fangled lead and acid technology for my next masterpiece. PS I am not a crackpot.

As usual, very interesting.

Wise words Bruce! Rich.

great video, thanks for uploading it :)

I sure got a charge out of this video! Thanks for posting! ;)

thanks for the info I had not heard of these before

And all over sudden, i feel old. It is 2019 now and i do fly a 250g Parkflyer with a 24g Motor, 2 Servos (3.7g) on my trusty 35 Mhz Multiplex Europa Sprint Transmitter.

love your work :) i had issues with these in cars lol

Keep up the tech people!

Great video

Thank you sir!

Thanks, I will take a look at it.

The problem here is not with the NiMH batteries. Depending on the model you may draw 10A peaks from them. The problem is VOLTAGE. At such tough loads the voltage will drop down to below 0.9V/cell. So you start out with 4*1.2V=4.8V which already is marginal, but when you start stalling 2, 3 or even 4 servos then you're down to 3-4V. This is a dangerous territory as receivers will turn off in this range. Just adding 1 more NiMH and you'd be fine. Starting out with 6V, dropping down to 4.5V with multiple servos stalled.

Bruce as always very informative. Thanks so much. Now if you guys could stop beating us at Rugby, everything would be fine. Keep well.

Hi Bruce I have now flown with life battery for 5-6 years without regulator, with std servos,, which is marked 4.5-6v. never had problems, no servos have burned.

Using better quality battery helps keeping the voltage in between safe values, but it's far far away from something you can call "a safe power source and feed to the electronics". High power servos also put a lot of stress on the receiver if they are sucking power from there, so a second step on safety is wiring the servos to the receiver with signal only, and powering them directly from battery. Than, you may want to overcome a battery failing (dual battery array), and many other aspects...

Mad scientist.. you the man lol

Hi there,quality videos! as usual, but I have to just give my thoughts about bec's, Im a guy who likes simple setups as you mention, more stuff more to go wrong, but looking few years back were all the lipo tech started, I been flying all sort of electric planes, small big, helis, and never ever had a bec going wrong, only in one case the speed controller gave up, but rc still working, and on todays massive hi tech 600 700 class helicopter using huge servos and massive lipos, for the Rc they still using a good quality bec, and those choppers could be quite dangerous out of control!, again there are not many cases apart from the odd wrong connected battery, For my 50cc gas planes I like to have some redundancy used in some twin regulators using 2 2s lipos, heavy duty switches plus using twin 2100 mah batteries you end with 4200 mah to power your plane for the whole weekend although I like to charge up before going up! some setups are in a reasonable price range without going in to the expensive power boxes field which I thing they are too big for a 50cc plane, yes for a 100cc with two servos per aileron 2 for the rudder etc, any experience with the dualsky vlr twin reg?. Cheers!!

Totally agree on the LiFe for my receiver duties and try to share the info as much as possible but a lot of people are still stuck on using a BEC. On my surface electric vehicles I might use a BEC only if the ESC's BEC totally sucks.

Got a cheap $20 NiMh receiver pack from amain for our new RC trucks. Figured those are the easiest to work with, safest, and the tried & true battery type when I was into the hobby over a decade ago. First charge it blew up. I coughed up some $$$ and only run Spektrum LiFe packs now.

Just got into 1/8 4wd nitro buggy pick up a thunder tiger eb-4 s3 pro and im installing 2 7.4v 20kg servos for steering and throttle and definitely knowing now I'll get a 2000+mah 2cell lipo to running my 2 highvoltage servos

I like the cylindrical LiFePo4 for gliders. If you choose the components right you can run the whole ship on one cell. Or use two. They still fit most fuselages. Pouch type LiFePo4 are much lighter and bigger. If you have the space for them I guess they are the way to go. And you don't have to solder the cells together.

thanks bruce.

spent 900 on a .50 heli, used a nimh pack for 4 high torque analog servos. when I gave it throttle, 4 of those moved causing a brownout. into the sky it went never saw it again. it was NUTS

i really learned alot thank you,,, do you need a special charger for life or can you se a standard lipo charger

Thanks for the video. So if I'm running all high voltage high torque servos. Do you think staying with the 2 cell lipo would be good?

Barry for lord supreme rc air commander!

5 years ago. wow. crazy to see a different back drop

Btw you are totally right, today my controller alerted me about the "a1 voltage critical". Im using digital servos with nimh.... bad idea

Nimh batteries are generally fine for most applications expect high draw situations as Bruce said. A real problem is that people charge a Nimh battery like a Lipo e.g. charging a 2000mah Nimh at 2A doesn't charge the battery at all because all chargers nowadays are delta peak and are only waiting to see a peak in the voltage. So charge your nimh's as slowly (e.g. 0.1a)as possible and it will be fine :)

Lol thanks for the advice I’m gonna put a 3s lipo on my Tmaxx😂😂😂😂

Thank you for the information. What chargers can be used to charge life batteries?

Oh Nutts! ive just bought x2 5cell 2300mah enloop batterys to power my Hangar 9 60 size P 40 with a laser 100 four stroke engine! 1 to power rx servos etc and 1 to power retracts! Ive anways used them with my IC stuff and had no problems! Also have a 30 cc Edge with a 2s lipo and bec! May change that though! Cheers Bruce

Quite many servos, including the Hyperion Atlas DS09 servos are rated at 5.5V maximum. This means that you still need to use a BEC with a LiFe to bring the voltage down to a spec level. After all the 2S LiFe is 7.2V fully charged.

Bruce, What are your recommendations for figuring out the mAh for LiFe batteries? I can work out the math, but I wonder if there's any tips or tricks you have? BTW: Love the videos! Dave

I was just considering making a regulator for one of my new DLGs, but you bring up a good point about adding more points of failure. I'm planning on using four DS285 servos, although the specs have a torque range of 4.8 to 6.0 volts, is it safe to put a LiFe's 6.6 volts on the servos? Thanks Bruce, another informative video that could save my models :-)

LiFe batteries are also quite convenient compared to LiPo for this application, due to their voltage levels. 3.3V nominal per cell and approx 3.6V when fully charged. Which means a 2S LiFe is between 6.6 and 7.2V - compared to a 2S LiPo (7.6V-8.2V) - 3.8V nominal per cell and approx 4.2V when fully charged.

I use two LiFePo AA batteries for my small gliders

That's crazy. 4s 600ma nicd's are $8-10usd and 2200-2400nimh nimh packs are $30-35usd. NZ has some crazy markups.

Thanks for the update I am running 4.8 to 8.4v servo and was wondering if those 6v pack would work so I checked the spectrum receiver voltage it's about 4 to 9v so I just bought a spectrum Rx 2000 7.4v receiver battery do you think that will work cheers Rick

Battery types are a minefield. I fly a 76cc Bidule tow plane and when on the 'tow' every servo in the model bar the release until flipped, is working very hard maintaining correct attitude, bank and yaw - so the fingers are busy.. I have always used 3000mah LIfe 2S batts x 2 until recently when they seemed to suddenly (overnight) degenerate to a stage where they will only accept about 70% charge. Being desperate I flew with these batts... two flights towing, I lost signal at the same height and same direction of flight and distance from me. The tug rolled over and dived and I guess within 2-3 seconds I had control back - twice. On checking the batts once safely back on the ground, both gone from 70% (being maximum charge) to under 50% in two very short flights. Lesson learnt but I am now changing back to Lipos.

I know this is well old by now. New to the model game. Originally was running my 6v model on a lipo but have swapped to LiFe now. Peace of mind. Only issue is I’m having to make xt60 adapter cables but hey ho. Getting better at soldering in the process.

The only issue is the cable size with those rx packs, you can just use 2 of them to split the power between the two.

Hey Bruce love your work have watched hours of your content . This might be a stupid question but will my 4.8v to 6.0v servos take a 6.6v liFe? Thanks for any help you can give me.

Hey great video Bruce. Can you use Nimh and lifepo together in the same RX? How bout if I plug in two nimh into one RX. Is there a way around two switches? Or will I always need two switches? Thanks for your videos great stuff.

my old futaba use's Nicd 4.8v for the receiver can I use lipo batterys

good your still on here great vid but my question is about the white eneloop battery pack. how do you charge it as i have aquired one and its great but how do you charge it? tia tom

Very good video as always, Did that Jet crash while Rex Kenny was in town?

Get in contact with the guys on the openrcforums forum for that. A lot of the developers hang out there. They would love to see what you have to say and answer questions.

Bruce: I have never used a life battery and would like to know more about them. Maybe a video on them including what not to use them on and why and what to look for so that we don't blow thinks up? How many volts are they? Thanks

Hi Bruce with the 6v battery for a nitro motor which one should i us a 700mah. or 1100.mah hope you can help me as this is my fist plane

Hi Bruce: I have a battery question I hope you can answer. I'm currently working on some 2.4 GhZ conversions of vijtage radio transmitters using the FrSky DHT DIY RF modules. I have a buddy who wants to use NiMH batteries in his. I purchased the batteries from HK and they fit perfectly in the battery box of our World Engines Expert transmtters. My question is ... what charge rate to use for these NiMH 2600 mah cells? I remember the charge rate for the original 600 mah NiCads was C10 or 50~60 mah. Would the same C10 charge rate (in this case ... 2 amps) hold for the NiMH cells? If so, can they be fast charged from time to time? What would be a safe rate for fast charging? I will appreciate any comment. Thank you.

6.6v LiFe is a direct replacement of 6V NiMH. Both batteries, when fully charged, will be at 7.2V!

I'm new at this - your opinion please - I'm flying MICRO size foam planes 1-4 oz. They use 1 or 2 cell lipo. I'm using a DX6E transmitter 2.4 freq. Should the 4 pack Enelope batteries I'm using be okay ? My DX6E gives me a warning when the pack is low. I recharge the pack and that's been working okay so far.

Hi, I'm starting out with gas planes now and have 8 servos to run.. so what voltage is your liFe battery that you have there

Fair point on the voltage of the freshly charged 5 cell NiMh packs but with LiFe being a consistent 6.6V does this not put extra stress on the electronics in the servo (e.g. motor windings)?

I've been out of the game for 10 years, now all my receivers & my hand set are out of date . . All i have left is my servos. I have to start over from scratch, TY on the info on the batteries, I’m now looking for info on tx battery chargers ,

Am I ok to run my servos on a 2 cell A123 battery? The servos are rated to 6v, but I run them on 5cells NiMh battery before.

Hi, which is the right battery for my Glow engine Rc plane and 4 servos? using Spektrum receiver.

So,is it ok to use a 2 cells life battery directly on futaba 2.4GHz FAAST receivers or through a regulator?

just a little question i have a stock losi raminator nitro and it has the losi 6v pack i think 900 mah also. and i have a 7.4 volt 1300 mah dynamite battery to upgrade with. but the orignal battery has a jst connector and the reciever area has the jjst female plug (obviously) how do i change that? i dont want to fry something. and the wire gauge is also much larger. thanks

Good day sir, nice video. What is the best for Futaba 6J receiver-helicopter (light and powerful).

I have 2 planes. They both carry hitec optima receivers, one airplane has 7 digital servos, the other has 5 with 3 electric retracts i think their eflite retracts. What battery for my recivers do you recommend i really need help. Thank you.

Hi. I am building the Giant 2metre wingspan LX Mitchell B25 Bomber. I will also fit the 'model sounds incorporated' sound system with the recommended 3 inch speakers. The sound system will work independently and directly from a Lipo as it has a voltage range of up to 24volts. So no problems for that. The Bomber itself has 10 servos and additional cabin area LED's, and I have been advised to power the receiver independently. The main battery, a purpose built flat pack designed for the model by LX. power the twin 600kv motors. I watched your piece on the Lithium Iron Batteries (LiFePO4) and wanted to get your thoughts on the size required. The main issue will be weight as I will now have 3 batteries. I really enjoy your vids. They are interesting and very informative.............keep up the good work. regards

I'm building a 55" spitfire. 80 amp esc with 5 amps for the radio gear. Seven standard analog servos. Will that ESC provide enough power for seven servos?

Hey i am putting together a 40 size nitro piper cub. I have the spektrum ar6210 receiver and am wondering what type of battery i need to power my reciever and servos? How many volts and mah? I think j have a 2000mah nimh now but it is no good.

Found a dinosaur in a tree out side did you. AA battery pack in the heart of the fossil!

I received a fpv mariner in the case and there is a 6 pin connector which appears to plug into the lipi battery second wire (small voltage wire, I think) My question is -Should I connect this or go straight for the direct connect and keep the transmitter receiver seperate all together

Thank you for the information, I have watched many of your videos on RC. I am newbie in RC. I am stuck on a few questions and couldn't find any reasonable answer so far. My question is.. on the receiver end, how do i determine battery voltage Amps etc? if there are ... FlySky 9x Receiver and ... 2 motors with propellers on both side wings connected parallel with speed control, 2 servos (I don't know its required volts) on both Ailerons, 1 servo on Elevator, 1 servo on Rudder, 1 servo on Landing Gear, 1 servos with Flash light. Now how much volt of current and in what direction i will need to put connection with batteries.

i have a new out of the box plane, it has never been flown/ charged anything and the battery that came in it which is a 600 mah on the first cycle fell short at only 400 mah.. I cycled it again and it came back to a little over 500. is there any way that I might be able to bring it back from the dead up to the required 600 mah and if so is it safe to fly with?

Great Site.I came upon it by accident.Glad i did. Q. I have a 1000w hub motor for my ebike which says i should use a 48v battery.I have linked 4 sal batteries to make up 48 v but performance is poor under load.What would you recommend + - 14 a123 battery cells joined to achieve 48v, or existing battery packs as sold by hobby king .what charger would you recommend ?Looking forward to you reply Thanks John H

Bruce, is it correct to say that since the servo position is sent in pulses the motor windings are only seeing ~6.6V for the width of a pulse (~1.5ms) and at a rate of 50 times a second for an analog servo i.e. duty cycle is low? Also is it reasonable to assume the motor windings are the sensitive part of the servo and not the electronics?

The Life batteries are rated at 3.3 volts per cell. most seem to use 2 cell, so 6.6. There was a warning on one battery site that some of the smaller 17 gram servos are rated 6 volts or below and that 6.6 will reduce the life. Do I need worry?

Is it safe to use a couple of diodes and drop the 7.4 v to 6 v from a Lipo battery? I'm not using any electric motor. This us for a glider. My receiver can take from 4.8 to 6 volts. Looking for a reliable source of power for long periods of time.

Bruce, what about 2s life battery pack on receiver with servo voltage range between 4.8 to 6 volts? LIFe pack fully charged isn't 7.5 volt?

Hey Bruce, can you answer a question for me. I've just moved into electric helis, 550 size, and the manufacturer of my model recommends using a separate 4 cell nimh pack as a backup to the built in ESC, plugging them both into the rx. Is this a good idea or should I disable the BEC by disconnecting the positive supply line from the ESC..

Well, if in doubt use HV servos. But no, in practice most servos don't care squad about a few volts more or less. Your mileage may vary.

Trying to use LiFepo4 battery to replace Nimh for the receiver in my Traxxas Revo 3.3 truck. Will not work. Acts like Nimh when voltage gets low. LiFe is freshly charged and measures 6.5 to 6.6 volts. Tried two different units. Any suggestions?

Hi Bruce, how do you cycle your LIFe batts on a 4 button?? I cant see it in the menu anywhere.

Will a 1300mah 15c 3s Lipo power my 4.3" quanum diy lcd (480x360) and 5.8ghz 200mw video receiver for a decent amount of time (like 10-15 minutes)?

Bruce when you get the time and budget can you please do a proper comparison between Sony FPV cameras and GoPros ? Im building a multicopter so it would be awesome to know what youd think to take aerial videos and pictures. I read GoPros have a weird wide angle and most people prefer to fly Sony cameras instead. Your thoughts. Please thumbs up so he can see.

Bruce, suggest you do a video on power boxes. They are usually waaay too expensive for just a couple of diodes.. Also for info, I use BECs in all my medium sized planes with 2s 1000 mAh batteries and have never had one fail. And they're all chinese :p

Bruce shows how to use a 4 button charger for life batteries in another video.

I am thinking of buying some sort of a 1/4 scale Super Cub and am looking for engine options, something a little different. I will have to to some investigating online. Thanks Bruce

Hi. I watch your vid.s and enjoy them. However, I am an American and our accents are quite different. I am an old man and have a little trouble hearing and understanding everything you say, but I get most of it. The last battery you described went right past me, twice. So,,,what type of battery was it? I would really like to know. Thank you for all the information you give out Richard.

I appreciate your wanting to help. This is a very technical subject and requires a technical presentation. Are you up for constructive advise? Yes.... great.... no.... well sorry its coming anyway. Were you only about speaking to NOT USING AA batteries, and the rest of the facts one would have to figure out for them self? IF that is the case then you made your point. A few things added would have helped. Please speak a little slower. Your accent is touch for some of us. You said the same things over and over. Granted it was said in different ways, but the time could have been used to present more facts. A lot more needs to be said. For some one to employ LiFe batteries, they most certainly should google and get some thorough info. But you are 101% correct. Pilots have no choice but to keep up with the changing times. In all honesty, its not that much to learn but it does take time and commitment ! Thanks for the video. I am sure it will help.