Buggies Gone Wild Golf Cart Forum - View Single Post - So..Who's selling a good BMS system for a 48V Lithium Ion Leaf pack?

DaveTM · 12-21-2022, 04:42 PM

So...I may be going "down the rabbit hole"....and the wrong rabbit hole as well.

Today was the attempt to separate the existing LCD screen from the "board" it was attached to (via 33 soldered pins) while trying not to damage that little board.

At first, I attempted to do what I've been "practicing" to do and melt the solder while also trying to "wick out" the solder. Ok...solder would melt....but not wick out enough to separate the two boards.

Different approach #2--Took a small fine file and "filed down" (carefully) the pins that stood up on the board side....in an attempt to have less "pin surface" for solder to stick. Again, tried melting and wicking....not enough to separate.

And at this point, I'm not concerned that I've damaged the board as I was very careful on the "filing" part to not cut thru that board material. But....who knows?

Different approach #3--Since I can't seem to wick out enough solder from each of the 33 (mebby 34?) tiny PITA pins, I considered cutting the pins to separate the two boards.....but I did not have tiny wire cutters that would fit in that small space. So, (and you can begin to cringe now) I decided that if I can get the boards apart, I could remove each little pin from the small board that I needed. So.....out came the hacksaw with a fine tooth blade, and I cut through the plastic side of the existing LCD screen (which is getting replaced).

LCD was getting trashed anyway. So...as Pic #1 shows here was my post hack saw cut, with a few pins removed. Removal went fairly smooth when you can do this one at a time. Pic #2 shows the aftermath of the little pins.

And finally, pics #3 & #4 show the new LCD attached to the board.....but not yet soldered to the board.

Now, when I got the screen and board back together, I tried to just plug it into the BMS. The screen powered up....but I got only a completely white screen. I could hit the touch screen, and "beeps" would occur, but I still had no idea of what the beep was doing.

I attribute this to the pins not being soldered. A close look (using my magnification headset) shows some pins are not touching the round female receptacle. Anyway...that's my guess.

I'm done with this for the day and will attempt the solder part tomorrow or Friday. All I know is tiny pieces of solder make for tiny solder footprints. I also know that there is only an outside chance of this solving the issue anyway....but for $12 and a slow boat from China.....why not?

Any thoughts.....please post!

12-21-2022, 04:42 PM	#38
DaveTM Gone Wild Join Date: Oct 2012 Location: Southwestern Pa. Posts: 6,215	Re: So..Who's selling a good BMS system for a 48V Lithium Ion Leaf pack? So...I may be going "down the rabbit hole"....and the wrong rabbit hole as well. Today was the attempt to separate the existing LCD screen from the "board" it was attached to (via 33 soldered pins) while trying not to damage that little board. At first, I attempted to do what I've been "practicing" to do and melt the solder while also trying to "wick out" the solder. Ok...solder would melt....but not wick out enough to separate the two boards. Different approach #2--Took a small fine file and "filed down" (carefully) the pins that stood up on the board side....in an attempt to have less "pin surface" for solder to stick. Again, tried melting and wicking....not enough to separate. And at this point, I'm not concerned that I've damaged the board as I was very careful on the "filing" part to not cut thru that board material. But....who knows? Different approach #3--Since I can't seem to wick out enough solder from each of the 33 (mebby 34?) tiny PITA pins, I considered cutting the pins to separate the two boards.....but I did not have tiny wire cutters that would fit in that small space. So, (and you can begin to cringe now) I decided that if I can get the boards apart, I could remove each little pin from the small board that I needed. So.....out came the hacksaw with a fine tooth blade, and I cut through the plastic side of the existing LCD screen (which is getting replaced). LCD was getting trashed anyway. So...as Pic #1 shows here was my post hack saw cut, with a few pins removed. Removal went fairly smooth when you can do this one at a time. Pic #2 shows the aftermath of the little pins. And finally, pics #3 & #4 show the new LCD attached to the board.....but not yet soldered to the board. Now, when I got the screen and board back together, I tried to just plug it into the BMS. The screen powered up....but I got only a completely white screen. I could hit the touch screen, and "beeps" would occur, but I still had no idea of what the beep was doing. I attribute this to the pins not being soldered. A close look (using my magnification headset) shows some pins are not touching the round female receptacle. Anyway...that's my guess. I'm done with this for the day and will attempt the solder part tomorrow or Friday. All I know is tiny pieces of solder make for tiny solder footprints. I also know that there is only an outside chance of this solving the issue anyway....but for $12 and a slow boat from China.....why not? Any thoughts.....please post!