LargeScale88

Hello. I bought a DSM2 Spektrum Dx-7 about 2 years ago. I just had a couple questions on batteries and radio maintenance. Is there a memory battery in these radio that has to be replaced every so often? How about the main battery? How often does that have to be replaced?


Also, about the charging part, I usually just charge the plane 9 or 10 hours the night before I go flying, and I plug it in even the battery voltage is not down a whole lot. I put it on the charger that came with the radio, so its a slower charger. Is this good or bad for charging the radio?

Thanks everyone!

Jason

BuschBarber

My Feedback: (2)

For the past 4 years or more I have been using either Lipo or LiFe batteries in all my transmitters. There is really no reason to use NiCad or NiMh batteries. Eneloop Tx batteries are OK, but they still require significant time to charge.

LiPos and LiFe are fast to charge, hold their charge for months, and safe to use as long as you are careful while charging and have the correct charging equipment.

Here is a Youtube video discussing a LiPo conversion for a DX7:

http://www.youtube.com/watch?v=mIqSn2QVKsk

BarracudaHockey

My Feedback: (11)

JR/Spektrum did away with the watch batteries years ago and went to non-volatile memory for model storage.

fizzwater2

My Feedback: (61)

The slow charge is the best way to charge the NiMh battery that came with the radio.

Lipo and Life batteries are good, but if you forget and leave your TX on for a long time, plan on replacing the battery..

I've got a 9.9V LiFe in my DX7, works well. I am not a big fan of NiMh batteries, used 1100 mah NiCd batteries in my JR 9303's and 8103's.

LargeScale88

So the only battery in the transmitter is the main 9.6v battery?

Thanks

Jason

LargeScale88

Thanks everyone else for the information. I may consider going lipo, because I run lipo for my receiver batteries and love them, I just didn't know you could do that for the transmitter.

Thanks

Jason

LargeScale88

BuschBarber, what Lipo battery are you using?

The video was using a Rhino from Hobby city, are these the ones that you have been using?

Thanks

Jason

BuschBarber

My Feedback: (2)

I have been running 3cell LiPo Tx batteries in my two 9303's, for over 4 years. I purchase 2500mah batteries and remove them for charging once a month. Some caution about the 12.6v fully charged. Some just charge them up to 11.7v. Others add two Radio Shack Diodes to drop the voltage. If you use LiFe batteries, the voltage is 9.9v.

Most new radios are coming with LiPo or LiFe Tx batteries. I have a DX8 and purchased the appropriate 4000mah Tx battery. It lasts for a long time between charging. It has circuitry in the battery that shuts it down if the voltage goes critical. That pack is particular to the DX8.

fizzwater2

My Feedback: (61)

Jason - yes, the only battery in the DX7 is the 9.6V one - there is no memory backup battery to worry about.

BuschBarber

My Feedback: (2)

I have been using Tx LiPos from TrueRC. I hook the Balancing Tap to my FMA 10S charger every so often. Never a problem. I am now using LiFe Rx packs in all my aircraft. Every few days, I pull them out and charge for 10 minutes to Top Off. I have used Hobbico LiFe and EpBuddy LiFe.

BarracudaHockey

My Feedback: (11)

Thats correct. If you've heard of the issues with the CMOS getting wiped if you leave the switch on and the battery dying? Thats because it saves everything you did to NVRAM when you turn it off, if that doesn't happen successfully you get the BACKUP ERROR and off goes the radio to Horizon to get reset.