Survivalism & Self Sufficiency Topics > The HAM Radio Board

Made a DC-DC Regulated Baofeng Battery Eliminator

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Greekman:
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!

Smurf Hunter:
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?

Greekman:
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)

Carl:

--- Quote from: Smurf Hunter 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?

--- End quote ---

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.

Greekman:
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

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