Top Balancing "How to"

[Just John]

I ended up saying eff it...bought the PS that is now on Will's site and got a good faith return in case these dials are messed up. Luckily 1 day shipping.

Having taken apart both the power supplies (yours and the one Will recommends), internally the only difference is a 5v at 2 amps section for the USB port. Same parts in the same locations, different display board and smaller fan.

But a bad solder joint is likely on the one you returned. There isn't a lot of testing or quality control done at these prices.

Cheap power supply for top balancing (tested and works well).

First, a link to the cheapest 30 volt, 10 amp supply I could find on Amazon. There are others on occasion that go on special for a dollar or two less, but this one is pretty consistently the cheapest I could find. https://smile.amazon.com/gp/product/B07512KQDW/ An alternative that is not as...

diysolarforum.com

 

[Gazoo]

Am I overthinking this?

Yes because your PS is defective. And I don't think moving the cable to to opposite end of the pack will make any difference since you are topping 4 cells and it definitely has nothing to do with the voltage fluctations of the PS. However if topping 8 or more cells I think it's a good idea to have the cables on the opposite end. Good luck with the new power supply.

 

[Draconius]

Ok...did I get another bum PS? Just hooked this badboy up by directions. Turn current to max, voltage to 3.65, CV light was on. Turned unit off, hooked up leads and the voltages dropped to 3.4 (you can see my DMM into the PS to show near matching readout) and switched to CC mode. I also tried having PS unit on while connecting the positive then negative leads. Just let it run as is?

This video (

) shows similar situation, so guessing it's good and just leave it be?

 

[Boondock Saint]

Ok...did I get another bum PS?

If your batteries are not fully charged, and they aren't, then you expect a little voltage drop which has been echoed in numerous threads. Fortunately you only have a few cells to contend with using the small 10A supply and should see the voltage rise as they become more charged. JustJohn will steer you right on this, he's been at it a long time and had my back! (more than once)

 

[time2roll]

Ok...did I get another bum PS?

Is it rated 10amps? If so that is all you get. Voltage will rise as the cells become charged. 10 amps charging 1,000+ Ah will take some actual time.

 

[Just John]

Ok...did I get another bum PS? Just hooked this badboy up by directions. Turn current to max, voltage to 3.65, CV light was on. Turned unit off, hooked up leads and the voltages dropped to 3.4 (you can see my DMM into the PS to show near matching readout) and switched to CC mode. I also tried having PS unit on while connecting the positive then negative leads. Just let it run as is?

This video (

) shows similar situation, so guessing it's good and just leave it be?

Set voltage to 3.65v while not connected, turn current to max. Connect and ignore voltage displayed as long as current is 10 amps or above. When current starts to drop and constant voltage light comes on, then pay attention to the voltage displayed.

 

[Draconius]

Thanks both. At least this on doesn't seem to be going ape-shite with jumping to 3.8volts and crap.

 

[Just John]

Thanks both. At least this on doesn't seem to be going ape-shite with jumping to 3.8volts and crap.

Yes, bouncing around current and voltage is not good. Steady 10+ amps means you are charging as fast as the supply will output. It will take time.

 

[musashi1707]

Thanks both. At least this on doesn't seem to be going ape-shite with jumping to 3.8volts and cr..

Just dropped in the last couple pages, my mistake if this has been answered but..

You did set the voltage at the PSU (and confirm with multimeter) BEFORE you connected to your cells, right?

 

[Draconius]

Just dropped in the last couple pages, my mistake if this has been answered but..

You did set the voltage at the PSU (and confirm with multimeter) BEFORE you connected to your cells, right?

Indeed I did. Even did the manual suggested, set voltage, turn off, connect load, turn on method vs while on, screw on positive then negative leads. Both gave same experience. My PS is now at 3.51 with my cells ranging from 3.378 to 3.392 while charging. Getting about 0.010 ever 60-80 minutes.

PS stats in CC mode
Volts: 3.51
Current: 10.3
Watts: 36.15

 

[Draconius]

YUS! Broke through that 3.35-8 layer and jumping up. 40 minutes later and now at 3.455.. and onto CV mode!!

 

[Draconius]

0.1 AMPS!!! DISCONNECTION AND REST TIME!!!!!

 

[John Frum]

YUS! Broke througg that 3.35-8 layer and jumping up. 40 minutes later and now at 3.461.

Check the cell deltas after 1 hour rest and then again after 12 hours.
Report back please.

 

[Draconius]

Check the cell deltas after 1 hour rest and then again after 12 hours.
Report back please.

I'm not going to be building the compression box/BMS probably for 24 hours. I presume I should leave them in Parallel for the 24 hours or just separate the batteries after 1 hour and keep them separate?

 

[John Frum]

I'm not going to be building the compression box/BMS probably for 24 hours. I presume I should leave them in Parallel for the 24 hours or just separate the batteries after 1 hour and keep them separate?

separate them
Then you can see which ones settle more.
The parallel part is not at all necessary.
Its not well known but, you can charge the cells individually and get a fine top balance.

 

[John Frum]

There is a lot of chicken blood magic surrounding top balancing.
All that is required is to fill the cells to ~3.65 volts and terminate the charge with the same tail current.

 

[Just John]

separate them
Then you can see which ones settle more.
The parallel part is not at all necessary.
Its not well known but, you can charge the cells individually and get a fine top balance.

Perhaps I am the reason for the 0.1 amps, that is where my Riden terminates. You are correct, individual cell charging to top balance is perfectly valid and works just as well. If it wasn't automated in the Riden software, I would not go below an amp. I should probably try the third party software that lets me change that.

 

[Draconius]

Check the cell deltas after 1 hour rest and then again after 12 hours.
Report back please.

Here are the cell voltages at 0amps, 1 hr in parallel and disconnected. Cell one was closest to PS. These numbers look OK? My dispute window is closing on AliExpress and want to verify all is well. To me, the numbers all look ok. There was some ballooning on the silver vent caps which is too be expected (pic attached). I do NOT have a way to test discharge except my BMS (lithiumbatterypcb.com). Gotta hook that badboy on anyway after I build my compression box and slap it in my van.

Time	Cell 1	Cell 2	Cell 3	Cell 4
6:06pm	3.627	3.627	3.626	3.626
7:03pm	3.552	3.552	3.552	3.553
7:04pm (no busbars)	3.549	3.551	3.551	3.551

 

[John Frum]

Here are the cell voltages at 0amps, 1 hr in parallel and disconnected. Cell one was closest to PS. These numbers look OK? My dispute window is closing on AliExpress and want to verify all is well. To me, the numbers all look ok. There was some ballooning on the silver vent caps which is too be expected (pic attached). I do NOT have a way to test discharge except my BMS (lithiumbatterypcb.com). Gotta hook that badboy on anyway after I build my compression box and slap it in my van.

Time	Cell 1	Cell 2	Cell 3	Cell 4
6:06pm	3.627	3.627	3.626	3.626
7:03pm	3.552	3.552	3.552	3.553
7:04pm (no busbars)	3.549	3.551	3.551	3.551

Excellent so far.
lets see how the are after 24 hours.

 

[Draconius]

Excellent so far.
lets see how the are after 24 hours.

Will report back. They're just sitting there compressed without busbars.