b35853

My Feedback: (2)

I need to get rid of some weight on a plane
I'm using a Futaba TX/RX the 4.8v Ni-Cad battery
pack is the heaveist thing on the plane.
What kind of battery pack choices do I have
besides the NI-Cad, to lighten up the plane.

Japanman

A lot guys here use NiMH packs of between 110- 250mah with no problems and significant savings in weight.
You need to be cafefull of the state of charge of your pack and watch flight times from what I hear- if your pack goes dead your plane goes wack [:@]

I have just got my first NiMH pack and it weighs 30gms at 350mah... I am still sorting out a charger for it and the plane to put it in...

I bought the cells and soldered them up to make my own pack- a very economical option - lead $2.10 cells $4.00... !

I bought the cells from www.batterystation.com -

J.M

BMatthews

[link=http://www.unipros.com/cbpsite/mainasp.asp?session_id=166685&cmd=&promoid=]cheapbatterypacks.com[/link] worked out great for me and they have some great options.

There's a Gold Peak 160 mah @ 0.1oz and my suggestion is the Gold Peak 400 at 0.27 oz. With 4 cells, soldered wire joiners, lead and shrink jacket you can have an all day pack that only weighs 1.1 oz. Both of these options are a buck a cell and they have the leads as well. They also provide made up packs for a slight charge.

If you go with the 160 mah option I'd suggest getting a few and fly 3 or 4 flights then swap out to a fresh pack. 3 flights if it's a full house aerobatic model with short but intense flights and 4 if it's a 2 or 3 channel trainer.

I placed my first order with them a few months back and had everything packed to a T inside of a week. And it doesn't hurt that they are an RCU advertiser that you would be supporting. So it hellps you, helps a good supplier and helps the site survive.

PS: If you use the custom pack maker option and select the GP400's,2x2config,22ga wire and Hitec connector the price ready to install is only $7.

bigchap

i use a sanyo 4.8v 110 mah pack,it doesn't last more than 3 flights but they are very cheap.

combatpigg

My Feedback: (3)

I get 30 minutes of time with a 300 MAH NIMH that is powering a pair of HS55s and ELECTRON RX. I have found out the hard way that the 5th flight on the same charge can cancel out all the fun I had on the first 4 flights[]! I buy individual cells and use RADIO SHACK de-solder braid to make the jumpers.

Japanman

What are you guys using to charge your NiMH packs?

J.M

combatpigg

My Feedback: (3)

HEY JM, I thought I told you that BREAK TIME IS OVER[>:][>:]!! I have taken LM 317, [6 volt regulators] and fixed value resistors to limit the current to 1/10th the packs' rating. Another way is to cut into the radio systems' wall wort charger and insert a resistor to limit the current. I field charge my 300 packs with a HOBBICO FFC and they get slightly warm, but it will cook a 150 pack or below.

BMatthews

Standard pack chargers with a resistor inline in the cord to control the current is also fine. Use a meter to pick the value to limit the current and solder it inline. Or better yet put a switch in line to short out the resistor as well so then you can still charge the regular packs. Note that the LED won't come on so plug the charger in first on the full rate, check the light is on and THEN flick the switch to set the lower rate.

Japanman

You are right..! Last night I weighed the MiG with everything, in a dummy run to get a balance point to work from. All good. It wieghs
350g all up- but that`ll hit 400 all glued together... go work that out in Oz`s...

What are you guys using as a charge rate to work out the total charge time for wall chargers for NiMH? is it the same (1.6 times mah) as NiCad?

J.M

flyinrog

My Feedback: (1)

my lhs was big into the aerobird brand for a while and the flight battery is 300 mAh and the pack is about an inch cubed just solder on a futaba connector.. I charge all my stuff with my Tx charger (commonly referred to a wall wart) at about 50 mah/hour my smallest pak is 150mah charged at about 2.5 hours on my "wall wart"...welcome aboard b35853 ..Rog

combatpigg

My Feedback: (3)

JM, as far as I know [AFAIK] you want 1/10th the packs' rating for a 14 hour charge or no more than the 100% of the packs' rating for a fast field charge. I do my charging on a raised cookie sheet.

Japanman

...Thanks C.P that would be 1.4 times the capacity on a trickle charge...
the 100% charge capacity at fast charge makes sense- from what I read NiMH is more easily damaged by overcharging than NiCad.


J.M

jdwardus

My Feedback: (2)

I USE AAA RECHARGABLE DURCELLS FROM WALMART AND BATTAERY CASES FROM RADIO SHACK ALL MY REACEAVERS IN MY SMALL PLANES ARE GWS WITH HITEK HS 81 AND HS 51 SERVOS. I CHARGE THESES BATTERYS WITH MY JR FUTABA AND HITECK CHARGERS. I HAVE DONE THIS FOR SOME TIME AND IT WORKS GOOD FOR ME ALL TO GETHER THE COST IS ABOUT $12.00 BUCKS