Hi guys,

I have two SY-4SAW2 mobo. Both have barrel battery.
Mobo1, that I use currently:
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Mobo2:
[img]

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I'd like to use the second mobo.
The voltage of mobo1's battery is: 0,37 V
The voltage of mobo2's battery is: 0,5 V

My questions are:
Are these batteries rechargeable? So can they charge themselves? But how? Or how can I charge them?
Because both mobo reset the bios settings if I don't switch them on for about 20 minutes.
Can I use an external battery (3V) without desoldering these barrel batteries? Because I don't have a soldering kit. With the help of pins J20 1 and 4, I know, but won't it destroy the mobo or something else?

And what can I configure with pins J23? This info isn't in the manual.

Which mobo should I use?

Any help would be greatly appreciated. Thank you in advance.