Author Topic: Made a DC-DC Regulated Baofeng Battery Eliminator  (Read 9095 times)

Offline Greekman

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Made a DC-DC Regulated Baofeng Battery Eliminator
« on: January 12, 2015, 12:40:18 PM »
Some time ago, I bought a Baofeng Uv-5R battery eliminator.

When I got it, I found it to be defective, opened it up and troubleshooted it.

Here is a pic as was



So few days ago I received the parts to change the internal circuit to a DC-DC converter and add some heatsinking.
The original hardware consumes 40% of the energy and transforms it to heat.
Nominal losses of these DC-DC converters is 10%. Specs

In disassembly



Cutting an opening for the converter heatsink.



Lacking any good tools I cut the window out with MANY consequitive passes of an XACTO no11 blade and a similar scalpel. …

Heatsink installed and epoxied.



I bought from ebay a piece of aluminum heatsink that had the proper dimensions to extend further a bit.
Yes, my hand slipped some times…

On the inside…

Test fitted



Assembled



While the heatsink is anodized and thus non-conductive I took no chances, I installed the converter with a piece of heatsink double sided tape.

Voltage was set to 8.4V, the Real max voltage of a Baofeng battery. It is test-functioned and it works!

Offline Smurf Hunter

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Re: Made a DC-DC Regulated Baofeng Battery Eliminator
« Reply #1 on: January 12, 2015, 04:57:02 PM »
I assume it takes 12 volts DC as input and then regulates down to the 8.4 volts?

Nice work.


Also, I've heard mixed answers, but do you know if it's safe to leave the UV5R powered on while sitting in the charging cradle?

Offline Greekman

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Re: Made a DC-DC Regulated Baofeng Battery Eliminator
« Reply #2 on: January 13, 2015, 12:50:09 AM »
yes it is a standard eliminator case...

No, I never thought of it.
I assume you do not intented to transmit, do you?
else the issue will eb common to all devices thta have lithiumion batteries and are left On when charging.
That will take some lokking into (check BatteryUnivercity)

Offline Carl

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Re: Made a DC-DC Regulated Baofeng Battery Eliminator
« Reply #3 on: January 13, 2015, 06:09:15 AM »
I assume it takes 12 volts DC as input and then regulates down to the 8.4 volts?

Nice work.


Also, I've heard mixed answers, but do you know if it's safe to leave the UV5R powered on while sitting in the charging cradle?

Yes,but it can eventually shorten battery life due to overcharging the battery...I leave my radios sitting in the charger in use and off,and have seen no issues ...so far as the charge is pretty low current when the battery is fully charged and I son't think is is enough to cause battery degradation...I also leave my 5 laptops charging and batteries last a 'normal' lifetime ( 3 to 5 years)


I almost forgot....Good regulated adapter Greek Dude.

Offline Greekman

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Re: Made a DC-DC Regulated Baofeng Battery Eliminator
« Reply #4 on: January 13, 2015, 09:36:11 AM »
wait till you see my next one!
I have the parts but i have run out of room...

Now, regarding batteries ( I ddi not want to be too techy and I have already expanded on it in a flashlight thread here)
but was Actually kills the batteries is the higher temp meaintained while on the charger.
A properly designed charger will stop charging and then wait for the voltage to drop some (like 0.1-0.2V in Li-Ions) Then it will restart the charging

Offline Greekman

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Offline Smurf Hunter

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Re: Made a DC-DC Regulated Baofeng Battery Eliminator
« Reply #6 on: January 13, 2015, 12:44:33 PM »
I just need one person to vouch that the ebay charger is not totally crap and I'll get two of them.


Offline Carl

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Re: Made a DC-DC Regulated Baofeng Battery Eliminator
« Reply #7 on: January 13, 2015, 12:49:00 PM »
I just need one person to vouch that the ebay charger is not totally crap and I'll get two of them.

You decide:

 https://hamgear.wordpress.com/2012/07/12/whats-up-with-waccom/

Offline Greekman

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Re: Made a DC-DC Regulated Baofeng Battery Eliminator
« Reply #8 on: January 14, 2015, 08:56:52 AM »
A small update:

yesterday night I spend some time manually programming the radioa nd checkign repeater accesss.
In the end the heatsink was a bit warm. Less that lukewarm, or so...I think it should be there.

On more pic


Offline stoneman

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Re: Made a DC-DC Regulated Baofeng Battery Eliminator
« Reply #9 on: April 03, 2019, 06:16:49 AM »
Hi all, sorry to revive an old thread but I am researching this currently.
I have several Baofeng UV5R's. I also have 5 BF-888s (cheaper Baofengs). For 4-5 years I have run my 888s handsets switched on constantly and sat on charging cradles constantly. We use them for comms around a large farm, one in each workshop, building etc. They have been great but just bought a load of UV5Rs to replace them with (only because we wanted the functions of UV5Rs, the 888s are still working perfectly). I want to leave permanently on charge so they never fail if a transmission is made by someone.
I don't care about battery life (no probs with 888s after all this time), they cost pennies after all so that's not an issue, the only issue I have concerns about is SAFETY. Does anyone know if it's SAFE to leave UV5Rs (Li-Ion) constantly charging like this? I dont care if I damage radio or battery, I am only concerned with trying not to burn the place down
Any advice appreciated. thanks

Offline Smurf Hunter

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Re: Made a DC-DC Regulated Baofeng Battery Eliminator
« Reply #10 on: April 03, 2019, 09:21:37 AM »
Hi all, sorry to revive an old thread but I am researching this currently.
I have several Baofeng UV5R's. I also have 5 BF-888s (cheaper Baofengs). For 4-5 years I have run my 888s handsets switched on constantly and sat on charging cradles constantly. We use them for comms around a large farm, one in each workshop, building etc. They have been great but just bought a load of UV5Rs to replace them with (only because we wanted the functions of UV5Rs, the 888s are still working perfectly). I want to leave permanently on charge so they never fail if a transmission is made by someone.
I don't care about battery life (no probs with 888s after all this time), they cost pennies after all so that's not an issue, the only issue I have concerns about is SAFETY. Does anyone know if it's SAFE to leave UV5Rs (Li-Ion) constantly charging like this? I dont care if I damage radio or battery, I am only concerned with trying not to burn the place down
Any advice appreciated. thanks

Yes, you can indefinitely leave them receiving while on the charging cradle.  I highly recommend NOT transmitting like that.  Remove from the cradle, hold in your hand as designed.  There are a few technical reasons, but this is widely accepted practice across radio brands and models.

Offline Greekman

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Re: Made a DC-DC Regulated Baofeng Battery Eliminator
« Reply #11 on: April 03, 2019, 01:46:40 PM »
I beg to differ. Leaving any charger always on is not a good idea,  in general.
Much more having a lithium  battery on it.  Their fire is a metals fire,  very hard to extinguish.
If you are to do it, do it properly. Use genuine baofeng batteries and in a metal can or plate.

How about this... Have a spare full battery next to each radio station.  Then the battery on the radio becomes a spare
« Last Edit: April 03, 2019, 01:54:18 PM by Greekman »

Offline stoneman

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Re: Made a DC-DC Regulated Baofeng Battery Eliminator
« Reply #12 on: April 18, 2019, 02:27:59 PM »
hi, I didn't get a notification here but glad I found the thread again!
I am currently looking at using two old Motorola Handie Pros (which use NiMH batteries) instead of the Baofengs altogether. But that's not great because I have a whole load of BFs here and will have to buy more Handie Pros which are rare as rocking horse 5h!t these days!
Greekman - Could you elaborate more on doing it "properly" please? Maybe I could set up a charging station to make it safe to leave the BF's on charge permanently? would a tin can be enough? Thinking about it, I am not sure I have anywhere safe enough even for that in our trailer home! bit of heat up the walls will ignite them I am sure. Maybe back to the motorolas :(

Offline Greekman

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Re: Made a DC-DC Regulated Baofeng Battery Eliminator
« Reply #13 on: April 20, 2019, 02:48:10 AM »
Hmmmm how many radios do you need to keep constantly  on?
How many Frequencies do you need to listen to?
The idea is to listen to the Motorolas,  and grab the baofengs then.

 Btw,  i would be interested in knowing the festures that made  you look awsy from the "dumb" 888s.
Common belief is that their simple operation is a plus for team use.