I decided to build a lithium battery for my Yaesu FT-897D because the official Yaesu Ni-Mh batteries are far too expensive to import here (Then you need the special charger too!)
At present when operating portable, I have been running a lithium battery external to the radio (often a higher voltage battery through a little power supply)
So I grabbed some battery packs made up of four 2200Mah 18650 cells each, three of these adds up to 11.1v at 8.8Ah, this is plenty for my short trips !
I planned out how to fit them inside, and there’s more than plenty of space, see image ๐
My preliminary notes were:
The three packs are each four 18650 cells in parallel
Totalling up to 8.8Ah per pack at 3.7v
At full charge it will be at 12.6v and at empty about 9-10v
I have measured how much power the radio draws, and on monitoring it draws around 8w, on transmitting around 18w (at 10w TX power, go figure) so thatโs only 1-2 amps, super easy for these lithium batteries.
I’m just waiting for my BMS to arrive from China (battery management system)
As that has over current protection, over charge protection, over discharge protection and short circuit protection for the batteries
Then I’ll use some padded sticky foam to mount them in such a way they’ll get ventilation from the existing fans and good to go!
Gallery below!
Great article, fantastic photos! I have an FT450D that I’m looking to run off battery.
good luck with it!
I don’t think that one has a battery compartment, so you’ll have to make an external pack!
Such a cool project! How much setup does the BMS require usually?
No setup for this one!
Just connected each pack to the corresponding pads on the board (0v, 4.2v, 8.4v, 12.7v) and it balances them and keeps them healthy!
Isnโt it bad for the radio to run it below 13 volts?
I think below 10 volts isn’t great.
I would think 13+ volts would be easy to do now days? No?
Not exactly. 4* lithium cells will create 16.8v which is too much for the 897d.
And at the low end it’s just 1v higher than the 3 cell battery..
hello , good article, consider using LiFeP04 cells instead of the LiION ones. Its a different chemistry and the single cell voltage is a little lower per cell – So 4 in series will give a nominal voltage of 13.2v. this combination of cell is perfect for the radio.. also , if you use not 18650 size – but 26650 size , ( they do fit well ) then your 4 in series capacity is around 6 A\Hr. you can fit 2 “packs” in the radio, and use the radios battery switch . A /B. In addition the LED lights for BATT A B also work corectly because the battery voltage is now correct.
awesome! Thank you ๐
Hello again ,
Sorry forgot to mention of course that due to the larger capacity of the 26650 LiFeP04 cells, you can make a suitable short cable from the packs and run it out the back and then install on the end the same power connector that the radio uses. This means you can run 100 watt if you wish.
Mfg
DJ0DJS
Awesome article.
I wanna use third pin to sent battery-info signal to radio.
May it need a MCU.
Welcome to communicate.
battery info signal ? I didnt know it communicated with the official pack,i though t it just checks voltage ?