Cheap 10s Lithium BMS

[dnmun]

they provide electrical isolation of the cases so the cells do not short out to higher cells in the series. hot glue keeps the cans from grinding against each other and wearing through the insulation sleeve on each can.

 

[DudeeBalls]

Those spacers would also keep them from rubbing against each other of coarse but I don't have to tell you that. Wish I had access to a 3D printer so I could print a bunch a up. There was a Da Vinci on sale a few weeks back for $300 but it wasn't worth it to me just for this and it's not like I could've used it to print entire battery cases since it could only print small objects (not sure it would've been worth it even if I could).

 

[Grizzl-E]

Lol yea you may want to get into one time sink of a hobby at a time.

 

[Nobuo]

The guy in this youtube also uses an interesting little lcd BMS meter but doesn't look as detailed as the other. I hope I can find a cheap semi bulk source for those 18650 spacers/holders that I've seen used here and there on some youtube's and elsewhere cause they seem like they'd make changing out a bad cell a 100 times easier than using hot glue.

Hi, I'm that guy :lol:

I also made that battery in the picture with the green LCD meter below the BMS (just standard 30A greentime BMS). That battery meter is the same in both the video and the battery picture (https://www.electricbike.com/wp-content/uploads/2015/03/BatteryDIY10.png) , and has nothing related to the BMS, it is just installed next to that BMS board.

The battery meter is in essence a voltmeter with preconfigured modes (12v, 24v. 36v, 48v, SLA and 2s to 15s lithium-ion measurements) that you can configure with two small buttons on the PCB. There are also 6 extra functions you can configure (3 of them installing a small momentary button in the hole behind the lcd) soldering (bridge) two spots near each function indicated on the PCB.

If you buy, and you want to use the extra functions F1 to F6, you must be sure the PCB has behind the electronics soldered for the functions. Because there are boards that has not soldered fundamental parts to work (so just work as metering with the elemental battery type and voltage, and you need to add a switch to Off and On the meter)


left meter can have F1, to F6 functions spots iron soldered and bridged to make them work, meters on the right side DON'T have F1, to F6 functions installed


This is the battery meter:

http://www.aliexpress.com/item/DC-12V-48V-48V-36V-24V-Lead-ACID-Lithium-Battery-Capacity-Tester-Monitor-Meter-LiIon-Battery/32273493343.html

These are the full specifications and functions explained:

https://drive.google.com/open?id=0B8UWKkPeL6BbVXlIUUJrRkV5aGs


PS: I've used a bunch of those 10S 30A (~20A real) BMS's on your main post, They are basic, but really fail-proof, and I can confirm it has balancing function working perfectly. Just needed to be cautious when soldering the wires to the PCB, small space.

 

[DudeeBalls]

Thanks for the very informative post. It would be cool to have something like that with a low voltage alarm and individual cell voltage displays. I love the idea that this item uses of a total usable battery percentage being displayed rather than voltage so you can have something to glance at while riding and not have to think about to much. Unfortunately there don't seem to be any 10s low voltage alarms let alone one with a total usable battery percentage and individual cell voltages (but how cool would that be). Something like the Cell-Log 8M but 10s and with total usable battery percentage.

How do I make sure I get the ones with the extra options or is it just luck of the draw and if so can I add those little resistors or whatever they are myself? On a separate note I wonder if adding something like a little dip switch might be helpful for the six options so as not to have to solder every time you want to enable or disable an option.

I don't know the specs of my controller for my old Crystalyte 408 front hub motor kit but I've been told on the forum that it's most likely around 20A. Do you think that the ebay BMS I posted would be enough for my kit even taking current peaks into account? If not could you recommend a reasonably priced 10s LiPo BMS maybe around 20-30A (maybe a greentime one).

 

[Nobuo]

Indeed it is built-in low voltage alarm, however only for the whole battery voltage. You just need to add the buzzer speaker. (explained in the manual)

Just sent that pic to the seller to be capable to identify the boards (there are several versions)

I think that BMS will work perfectly for your use. it will hold near 20A continuously for sure

 

[DudeeBalls]

Thanks