Choosing Receiver Batter When Flying Glow

TheMrDrGus

Junior Member
Hi Guys,

This is my first post and I am somewhat new to the hobbie so im sorry if I sound like a newb.
I recently have upgraded from a glow nexstar to a glow .55 OS AX T-34 from World Models. I am wondering what a good receiver battery pack is to use. I am using all standard high torque servos that the ARF recommends. The nexstar I currently have uses a NIMH battery to power its servos and I am wondering if that is the way to go or is it to go LIPO and charge after every run?

Thanks,
Brandon
 

pgerts

Old age member
Mentor
Depending on the radio Equipment you use.

Old - use the NiMh LSD.
Hi volt, like Spektrum - i use a 2 cell "Indoor" LiPo and i get < 200 mAh for a normal flight with a funfly and .60 glow. I get 2 flights on a 500 mAh battery.
 

TheMrDrGus

Junior Member
Depending on the radio Equipment you use.

Old - use the NiMh LSD.
Hi volt, like Spektrum - i use a 2 cell "Indoor" LiPo and i get < 200 mAh for a normal flight with a funfly and .60 glow. I get 2 flights on a 500 mAh battery.

Ok thanks, so when using spektrum, you recommend the 2 cell lipo set up. But using an NIMH will do fine with the spectrum? Also how many flights do you think I could get out of a 4.8v 600maH battery?

Thanks,
Brandon
 

pgerts

Old age member
Mentor
I would not use a 600 mAh NiMh battery to a .55 glow plane today. It seems to be an old battery not suited for the modern servos.
The standard NiMh ody are LSD (low self discharge) with about 2000 or more mAh.
I am using both NiMh and LiPo depending on what i find in my box ready charged.
Some servos do not like the +8 volts from a fresh 2 cell Lipo but i have not found any new or old servos in any of my planes had any problems.
 

TheMrDrGus

Junior Member
I would not use a 600 mAh NiMh battery to a .55 glow plane today. It seems to be an old battery not suited for the modern servos.
The standard NiMh ody are LSD (low self discharge) with about 2000 or more mAh.
I am using both NiMh and LiPo depending on what i find in my box ready charged.
Some servos do not like the +8 volts from a fresh 2 cell Lipo but i have not found any new or old servos in any of my planes had any problems.

Hey there,

I also had another question. The 600mAh i told you about is actually a NiCd instead of a NIMH. Does this change anything? I also have a 1700 mAh 6V NIMH. How do you think that would work with a .55 engine. How many flights out of that do you think I could get. Also my servos are futaba and on the back they say NiCd use only. Does this mean I can only use NiCd batteries with them?

Thanks,
Brandon
 

xuzme720

Dedicated foam bender
Mentor
I am fairly sure that the warning on the servo is for voltage amount, since as you know, voltage varies per cell across differing chemistries. An option that might negate the issues with using different types of packs, nicad, nimh or lipo, is to use a BEC. It will serve as a voltage regulator and provide a proper voltage even if you are using a higher voltage battery without fear of overloading the Rx or servo's. Some have selectable voltage output and have plenty of amps for even digital servos.
UBEC.jpg
 

pgerts

Old age member
Mentor
.. Also my servos are futaba and on the back they say NiCd use only. ..
The servos has to be old. You will hardly find any Cadmium batteries for sale unless old stock or special purpose.
NiMh replaced NiCd for most use many years ago. You can use NiMh as a direct replacement in all RC Equipment together with your old charger. You normally charge (long time balance charge > 36 hours) NiCd with 0,1 C and NiMh with 0,05 C. But as the new NiMh normally has at least twice capaciy - no problems. Also no problems with modern peak chargers.
Old servos normally used both 4 and 5 cell Nixx batteries. 4,8 and 6 V nominal but 6.4 and 8 volts fresh from the charger. Actually no big diff from a 2 cell LiPo.
 

xuzme720

Dedicated foam bender
Mentor
Nicads aren't that high in voltage, even fully charged. About 1.35 per cell was the max I remember. That's only 6.75v on a 5 cell pack. Chances are those servos will operate at the higher voltage but without knowing the actual specs, there's the possibility of letting the magic smoke out of those servos by using 8v on them...
 

Mike oxbig

15% nitro is my cologne
The best and safest option for rx packs in my opinion are lithium iron phosphate or life packs.
They are similar to lipos but are much more stable. Less chance of a puffing or fire and no need to storage charge.

A 2s life pack runs a nominal 6.6v which is lower than a 2s lipo and will not damage any servos rated for 6.0v. I run 1100mah packs on my nitros, two 2100 packs with a buffer on my gas planes and my 90 heli. I
 

pgerts

Old age member
Mentor
You have got some answers - but not all.
Capacity - do not trust what is told on the battery if you have not checked it yourself - with a charger, or in your plane on the ground running the sticks on your radio.
I am always using a battery checker connected to the receiver and showing the battery status outside the plane. The indicator cost is next to nothing.
It is important that you are moving the sticks when checking as the volt is dropping when the servos move.
Better - but not nesessary is to put load om the moving surfaces close to stalling the servos when checking.
This will not only tell you the battery but also the wire and connector conditions.
I will never make a start if my indicator tells other than "perfect". Never do the "LAST" flight ;-).
battindicator.JPG
There are many ways to get power to your plane.
Don´t be blind there are many ways to tell the thruth.
From Sam Speaks number 95 :
story.jpg
 
Last edited:

Mike oxbig

15% nitro is my cologne
One downside, if any, with life packs is that the voltage drops very little from fully charged to discharged. You can't use a volt meter to see the state of charge. It's very easy to overdischarge a pack if you aren't careful.

What I do with a new plane is fly a flight, charge and note the mah used, fly two flights, charge, and so on until I reach about 50% discharge between charges. Usually I try to use a pack that gets me 5 flights between charges.