RCCrawler Forums - DX5R Battery Mod to DX5 Pro

So I had a DX5R that according to the menu should be able to handle 8.4v.
My Intention was to grind out some of the plastic in the battery compartment so that i could use a dual 18650 battery sled. cut the plug from the origional 4x AA sled and solder it to new thread and done.

4x rechargable AA batteries came to 4.8v at 2400mAh cuttof voltage is 4.1v though I am not sure on the mAh from 4.8v to 4.1v its probably much less than 2400mAh.
2x rechargable 18650 batteries are 8.4v at 3000mAh with a cutoff voltage of 6.4v. Here the actual usable mAh is very close to 3000mAh and at a higher voltage that may provide longer run times for the transmitter.

Unfortunately when I plugged in the 8.4v battery pack the DX5R would vibrate whenever I turned the power off. I found this post on a different web site.

Quote:

06-01-2017, 08:31 AM #80
rayzcar
Tech Regular

Quote:
Originally Posted by rayzcar View Post
Thanks for the heads up. Will discharge the battery down. I did email Spektrum in case they have another recommendation.
Just updating regarding using the SPMB2000LITX LiIon battery with my DX5R. Reply from support:

"The radio needs a hardware change to support that battery pack. You'll need to send it in for it to become compatible. As shipped, it only supports NiMH and Alkaline."

Uh... no. As previously mentioned by other posters, once the voltage drops to low 8s or 7s, it will turn off without vibrating.

Support also suggested to run the update which I did via SD card even though it was the same version, so I no longer get the "registration" screen when I turn it off.

I didn't want to send off my remote so I started designing a battery mod that would alow me to use a castle BEC to conect a 20v dewalt battery to the base of my remote. easy to charge, no stupid battery door screws to fuss with every other week when the dang thing dies. Well I didn't finish this for reasons you are not privileged enough to get to know. But I will get around to it and post back later on.

So I decided to send in My DX5R for this hardware update rayzcar mentioned, brief transcript of email with horizon

Quote:

Me: my shiznits all broken (I dont have the origional message as it was a web page support message thing)

Horizon Hobby Product Support: There is an update that the Horizon Service Center will need to do to your DX5R to accept using lithium batteries. We can send you a pre-paid postage label that will pay to have the transmitter shipped to the service center. We need your full name, phone number and email address. The label will be sent to your email address for you to print off. You will box up the transmitter and label and take to any Fedex facility.

Me: What does the update change?

Horizon Hobby Product Support: The update allows the transmitter to work with lipo batteries without the update the transmitter flickers and will not power off using lipo batteries. The service center performs hardware so the transmitter will work properly using lipo batteries.

I had done some modifications to the battery tray and door so I didn't send those in but sent in my TX in its original box, no RX, no manual stuff. Print free shipping label send off and wait.

I don't know less then 2 weeks later I get what I think is my DX5R with hardware update back. It turns out the hardware update is replacing the DX5R with a brand new DX5 Pro.

The DX5 Pro came with steering wheel adapters of different sizes and angles, and an optional grip as well, no RX. Everything you would expect in a DX5 Pro no RX box to contain.

After poking around Spektrum's website I find the DX5R and DX5 Pro use the same 1.04 firmware. All the menus look the exact same to me.

So I begin grinding out the battery compartment and plug in my 8.4v dual 18650 battery sled, works great, no vibrating, glad I saved my profiles before sending in my DX5R, they loaded right into the DX5 Pro.

Oh and since I didnt send in my old battery tray and battery cover, I have 2 of those now to modify, extra battery plug is handy, and maybe I will use the extra lid to mount the DeWALT battery mod to.