YellowHawk

I may buy a transmitter from a friend at work. It's a Futaba 8UA. Inside the TX there's a battery holder, not a battery pack. The holder is loaded with rechargable (old) nicad batteries. Can I replace those with new nimh batteries and still use my wall wart Futaba charger to charge them? Thanks.

Mikke

...Yes, I think why not??. I also bought a used Hitec Flash 5X transmitter with a 600 Mha-batterypack included.I replaced the pack with a 8 piece-AA-holder, where I insert my 2950 Mha-Nimh-batteries, which can be charged either individually in a regular charger or as a pack via the TX . That is my understanding of the matter.... Make sure contact-surfaces in the holder are clean and the coils in good shape
Good luck!
Mikke

piper_chuck

My Feedback: (12)

Yes, but I've never been comfortable with individual cells for airplane applications. As Mikke said, clean the contacts regularly. As far as charging with the wall wart, yes you CAN do it, but it'll take a long time. The typical charge time for a 600 mah pack with the wall wart is about 12 hours. The nimhs will likely have 3 or 4 times the capacity and will require 3 or 4 times as long to charge. As long as this limitation is ok with you, the wall wart will be ok.

spiral_72

You'll want to charge the NiCads at 10% the rated capacity for 12 hours. If it's a 2100mAh pack, charge it at 210mA for 12 hours. Your charger (wall wart / whatever) should be sized to approximate these specifications. If you charge at 5% thier rated..... it'll take twice as long (theoretically)

PS. just about any charger / wall wart etc. will have it's specs on a printed plate. Voltage supply, current supply, frequency (50/60Hz) etc.

armody

My Feedback: (10)

Can I Ni-cd charger be used on Nimh batteries? can it be harmful? if not how long we have to increase its charging duration?


Thanks

Mody

bruce88123

Good info here
http://www.rcbatteryclinic.com/

aerowoof

you are asking for truoble using a battery holder with spring contacts and individual cells.they are prone to intermiitent contact and should be avoided.even futaba has discontinued the battery back that had the button contacts like a 9v battery for the 7u and other tx's.

bruce88123

My 7U doesn't have that kind of contacts. Yes, the battery does but the TX side doesn't. Uses spring contacts to connect to the battery.

mscic-RCU

My Feedback: (6)

According to the people at Mr. Battery, the walwart will not completely charge NIMH batteries. You should charge them at 10% of their rated capacity. Individual batteries are not a good idea, a pack is the only way to go.

k3 valley flyer

My Feedback: (18)

I used battery holders in several Futaba radios for many years with no problems. However, based on the experience and advice of others I did discontinue the practice. I stay with Ni-cads because they are easier to maintain and weight in a TX battery is not an issue.

jaka

Hi!
NiCad:s easier to maintain...???
No way!
NiMh cells ...soldered to a pack is the way to go . More power than old NiCad:s (2900 mAH instead of 1100mAh)in the same size of (R6 or AA), No memory effect. You can use the same wall chager (Futaba, JR) as before (50-100mAh).

aerowoof

bruce88123
should have read pack not back typo. those contacts you refer to in the 7u are considered spring contacts and are prone to breakage from corrosion and itermiitent contact.check with Tony Stillman at radio south,Pete Waters at Kraft midwest or dave at radical r/c

aerowoof

I had one of those contacts break while changing the battery and instead of soldering in a splice to a female connecter ,I bought the tool and connecters and did a crimp.here are the photos.

rmrosique

got a CP Pro and I want to know :
1.- Is it possible to use rechargeable batteries in the Transmitter? (NiC or NiMh)
2.- Can I charge the batteries in th transmitter?
If it is possible, what kind of charger do I need to connect the Transmitter to a wall outlet? (120Volst AC)

Thanks