5 cell receiver pack

[Kez]

I have been using standard 4-cell (4.8V) packs for my receivers. In an attempt to give the servos more power, I have just made up a 5-cell pack. When fully charged, the pack delivered 6.5V and then settled to 6V.

I connected the pack to the radio in my boat and worked the rudder and throttle servos to check if all is OK. After about 2 minutes, the throttle servo stopped. Further investigation showed that the servo was fried (although no visible signs). It is an Airtronics from the 90's (#631).

I am not sure if it is just mere coincidence or the new pack fried the servo. A lot of radios are designed for dry cells and the voltage from 4 fresh alkaline cells is easily 6.5V. What's your experience on this?

Thanks,

Kez

 

[gil sonsino]

Kez

Seems a mere coincidence for me once I've been working with 6 vts on my radios for years and never burnt a servo till now.Maybe the tired 90's servo decided to retire! .

Gill

 

[nitrotoys]

All My boats run on 6v packs, I even have a 5 cell sub C pack, Never have burnt up a servo, have futabas, JRs, and all have worked fine.

did it go out from water?

Did you dunk it the last time out?

Tom

 

[dave roach]

Look on the box because some servo are made for 4.8volts so do:nt use a 6.0volt battery. you need to get a servo for 6.0 volts. I had the same problem and the guy at the hobby shop was showing me the lable on the box.Good luck

 

[topfuel443]

yep, what dave said. most servos can run either 4.8 or 6volts with no problems. however there are a few that require either 6 or 4.8, but not both.

~James

 

[John Knight]

Gabe,

All my radios use 6.0V. Fresh batteries put it about 6.3 - 6.4V and have never fried anything. Use mostly Hitec servos which normally can use either 4.8 or 6.0V.

John

 

[topfuel443]

John, Be aware that there are a certain few hitec (as well as other brands)servos that can NOT be used with 6 volts or either they MUST use 6 volts.....ask me how I know. I too should have read the package. they are all listed on www.servocity.com Of the few that can not be used with either voltage are rarely used in our applications though (boats).

James G.

 

[Kez]

Thanks all for your replies...

I was only dry testing the radio after installing the 5-cell pack. so water was not the culpit.

From your experience, I think it was probably a servo designed for 4.8V and I fried it using 5-cell. I will try to find the specs from the Airtronics web page but I am not sure if they still list this servo.

One of the other reason that I tried 5-cell pack is for redundency. From time to time, a cell will go south no matter how much care I gave the pack (cycling etc). A dead cell in a 4-cell pack will result in loss of control for sure. A dead cell in a 5-cell pack will still work and I know it is time to toss the pack.

Regards,

Kez