Question PS2 Battery

[Kells]

I have been working on a PlayStation 2 portable and I have limited knowledge in using li-ion batteries but I understand the danger in using them. I just bought a bms which is below that I believe will do the job well but the problem is that my batteries are not strong enough to run the ps2 and my monitor with only 2 batteries. I am using 4 batteries to create 7.4v and the bms I selected lets me do this. The one issue I realized after purchasing is that the voltage is 8.4v-5v and I don't know how to control the voltage with this board. Also if someone could link a battery gauge to tell you the battery life I would really appreciate it.

https://www.ebay.com/itm/Intelligen...rentrq:82015d251650ab110644be36fffe665d|iid:1

 

[MRKane]

I dropped one of these into my last build and have been really glad that I did. They're quite big, not immediately responsive, but are cheap and easy to wire up.
I see you're looking at the "red board" there, and the thing I found is that the voltage display needs to be linked directly to the batteries to read correctly, I used a little tact switch as it comes on when the lines are open

https://www.aliexpress.com/item/Min...193.html?spm=a2g0s.9042311.0.0.27424c4d2KyZRB

 

[ahrlad]

You can't adjust the output voltage with that board, it just gives you whatever voltage the batteries have. Your options are to either use a boost circuit to up the voltage or to hardware mod the PS2 to work with lower voltages.

A voltage meter can give you a heads-up before the batteries die, but lithium battery voltage doesn't decrease linearly with use, so you won't find a simple circuit that gives you battery percentage left or anything like that.

 

[Paul3854]

This is a simple battery indicator I'm using which just shows 25% 50$ 75% and 100% with leds, the indicator has a button which turns on the leds for a few seconds. Also if you do get this one, make sure you select the 2s option.

https://www.ebay.com/itm/263216619408