DM-1701 mods!

PU7TKM
Posts: 23
Joined: Tue May 21, 2024 12:13 pm

DM-1701 mods!

Post by PU7TKM » Thu Jul 18, 2024 9:15 pm

Just simple mods I've done to the 1701.

1- Belt clip to the chassis

The belt clip attached in the battery is stupid. Once I fell to the ground and my radio also fell, and was held just by the earpiece wire, while the battery was still attached to my belt. The battery attachment is not strong enough to hold the radio on these scenarios.

Image

This was an easy one. I unscrewed it from the battery, then cut the sides of the screw holes with a sheet metal scissor (maybe a good normal scissor will do), so they'd become "C"'s instead of "O"'s. After that, I removed the two upper chassis screws and replaced them with similarly threaded longer ones.
Now the belt clip's on the chassis, providing better support.

It is slightly more difficult to remove/reinsert the battery now, but completely doable.


2 - USB-C Charging

I'm proud of this one. I have the habit of converting anything possible to USB-C, and I decided that the 1701 wouldn't be any different.
After I disassembled the battery, I noticed there's plenty of space inside to fit a TP5100 board and a USB-C trigger board.

Image Image

This was a little bit more technical, but nothing extraordinary. I started by tearing the battery down, which is MUCH easier if you start with a small slotted screwdriver at the bottom of the battery. The actual battery cells are smaller than the case, and there's a lot of space on the bottom end of the battery (where the charging pins are).

Image


To open it, just turn the battery so the sticker is facing you, and insert a screwdriver on a gap on the bottom end of the battery. There's nothing there, so it's safe to do so.

Image

When you get some leverage, carefully pry the sides of the battery open.
Do not open the battery case yet. The back is held by glue on the sides, and the battery cells are also held to the case with two foam-like adhesives.
First work the battery case sides

Image

Then, after the case glue is defeated and the battery is seemingly loose, you'll need to unstick the battery from the adhesive from the two sides. We'll call them "flat side" and "shell side", as one's flat, and one's a shell, like a tub.
Now, carefully pry the sides apart to see the cells inside.
There are two lithium batteries, stacked one atop of the other. Prying the case apart too much will pull these batteries apart, as each one is glued to one side of the case, and this can cause serious damage to the battery, so you don't want to pull them apart too much.

You need to pry them open as much as necessary to just use some tool to pull the battery out from the adhesive on the flat side. I used the same metal screwdriver I used to pry the case open, but I took great care to not poke the battery, or even bend the battery, as this can cause a short circuit.
There's enough space to even use your fingers for that, if you got thin fingers, I guess.

The adhesive is not strong, so you'll just need patience to apply a bit of force outwards, and the adhesive will slowly be overcome.

When the flat side is separated from the battery cell, you'll notice there's still two wires soldered to the flat side, which supply power to the radio. At this point, I've just rotated the flat side 90° and sticked it to the adhesive, to hold it in place.

I, then, unsticked the battery from the shell side, and then moved it up slightly, over the two "notches" on the case (which are the two screw holes), to make plenty of space on the bottom end of the battery for the USB-C trigger and the TP5100 board.

After that, I tapered the bottom part of the shell case with insulating tape, to isolate the original charging pins (You could also use kapton tape).
I've then measured where the USB-C Trigger would be and the TP5100 board would be. Then I cut a hole for USB-C with a Dremel.

I've set the USB-C Trigger to 12V, and I've set the TP5100 to 8.4V. I've also modified the TP5100 board to charge at 1C rate. Usually these boards comes as 2C, but you just need to unsolder one of the R100 resistors to cap it back to a much safer 1C rate.
Image

One thing to note is that I've installed the TP5100 downwards, with its status LED "facing" the original charging pins. I've drilled a hole through the case, in that spot where the pins are the most far apart, and filled the hole with a dab of hot glue. Waited the glue to solidify, cut it to shape with a precision knife, and now I have a charging indicator light.

After that, I've just soldered everything together, kept the same craddle charger connections and soldered the TP5100 output to the battery charging inputs. When everything was in place, I've checked whether the battery was charging, and after confirming, I used hot glue to secure the boards in place.

Now just glue the flat part of the battery case back, with a bit of super glue, and it's back in shape!

And there you have it. USB-C charged battery. And charges relatively quick, too!


I'm a tinkerer by heart and I like to mess with these cheap devices. If I do something new, I'll post again.


73's

PU7TKM
Posts: 23
Joined: Tue May 21, 2024 12:13 pm

Re: DM-1701 mods!

Post by PU7TKM » Tue Jul 23, 2024 1:34 pm

3- Slightly better water resistance

I was under the weather these days and was a bit afraid if the 1701 would take it.
I disassembled the radio later on, and found a bit of water intrusion on the chassis (luckily not on the board), especially coming from behind the battery. Probably the water hit the radio from the top, then made its way down through the gaps of the battery against the chassis.

On reassembly, I used a bit of black silicone glue through all corners and holes to give it a better chance of enduring some rain. Obviously not waterproof and I'd consider wasted if dropped in a water pool even for a second or two, but it'll fare better during rain.

Image

Not difficult at all to do. Just use a string of silicone through all corners and holes and spread it a little. After reassembled, use the spill over to "close" the gaps even further.
Should take a rain like a champ now.







4- Better dust proofing on the antenna connector/Better water resistance as well?

One of my antennas was "leaving" its dust protection ring on the antenna connector.
I found it looked quite ok, and I guess it wouldn't harm leaving it as a permanent fixture. It's also neat for when I'm just running a wire, like when on the car.

Image

It got stuck on its own, but eventually was dropping off. I used a dab of superglue to hold it in place. Should come off whenever needed (hopefully not so soon).

Bonus- How the battery is inserted/removed now, with the belt clip on frame


youtu.be/JSL8SEC-3lU

Should be default, really.

EA4IAU
Posts: 16
Joined: Fri Apr 12, 2024 10:24 am

Re: DM-1701 mods!

Post by EA4IAU » Wed May 28, 2025 8:05 am

Hello PU7TKM!

I am thinking of making something like this, but for scratch, I only have one question.

Is the middle contact pad soldered to anything? or is it just disconnected?

73!

BA7IQE
Posts: 43
Joined: Thu Aug 29, 2024 12:34 pm

Re: DM-1701 mods!

Post by BA7IQE » Mon Jun 09, 2025 9:14 am

EA4IAU wrote:
Wed May 28, 2025 8:05 am
Hello PU7TKM!

I am thinking of making something like this, but for scratch, I only have one question.

Is the middle contact pad soldered to anything? or is it just disconnected?

73!
the middle contact pad disconnected.

KA1CM
Posts: 459
Joined: Tue Nov 28, 2023 4:14 pm

Re: DM-1701 mods!

Post by KA1CM » Mon Jun 09, 2025 9:50 am

BA7IQE wrote:
Mon Jun 09, 2025 9:14 am

the middle contact pad disconnected.
Hi BA7IQE, Do you have any photo inside of the pack? any BMS, what kind? Or just only two cells?

Thanks,
Charlie,

EA4IAU
Posts: 16
Joined: Fri Apr 12, 2024 10:24 am

Re: DM-1701 mods!

Post by EA4IAU » Mon Jun 09, 2025 10:17 am

Thank you BA7IQE!

I will get to work then.

EA4IAU
Posts: 16
Joined: Fri Apr 12, 2024 10:24 am

Re: DM-1701 mods!

Post by EA4IAU » Mon Jun 09, 2025 10:18 am

KA1CM

From the photos in the OP, it seems like it's a single Li-Po cell bag with the typical 3 pin connector

Edit: I suspect OP is the same as this guy:
https://www.reddit.com/r/Baofeng/commen ... all_built/

In that post, there is a link to a photo of the type of battery the baofeng has. It's kind of obscured, but perhaps it answers your question

KA1CM
Posts: 459
Joined: Tue Nov 28, 2023 4:14 pm

Re: DM-1701 mods!

Post by KA1CM » Mon Jun 09, 2025 11:39 am

EA4IAU wrote:
Mon Jun 09, 2025 10:18 am
KA1CM

From the photos in the OP, it seems like it's a single Li-Po cell bag with the typical 3 pin connector

Edit: I suspect OP is the same as this guy:
https://www.reddit.com/r/Baofeng/commen ... all_built/

In that post, there is a link to a photo of the type of battery the baofeng has. It's kind of obscured, but perhaps it answers your question
It is impossible to have only one Li-Po cell. the battery is 7.4v. If you have a chance, please take some photos.

Thanks,

BA7IQE
Posts: 43
Joined: Thu Aug 29, 2024 12:34 pm

Re: DM-1701 mods!

Post by BA7IQE » Tue Jun 10, 2025 1:43 am

KA1CM wrote:
Mon Jun 09, 2025 9:50 am
BA7IQE wrote:
Mon Jun 09, 2025 9:14 am

the middle contact pad disconnected.
Hi BA7IQE, Do you have any photo inside of the pack? any BMS, what kind? Or just only two cells?

Thanks,
Charlie,
The battery pack is 2 cells,I've modified it to USB C charging
Attachments
1701 batt1.jpg
1701 batt1.jpg (117.82 KiB) Viewed 1131 times

KA1CM
Posts: 459
Joined: Tue Nov 28, 2023 4:14 pm

Re: DM-1701 mods!

Post by KA1CM » Tue Jun 10, 2025 11:42 am

BA7IQE wrote:
Tue Jun 10, 2025 1:43 am

The battery pack is 2 cells,I've modified it to USB C charging
Thank you so much for the photo. Seems like bare bone batteries with no BMS whatsoever.