TinyBMS

This is a BMS designed for e-bikes originally but seems robust enough for a moderate powerwall build at about half the price of Batrium.
Has anybody used one of these?
https://www.energusps.com/shop/product/tiny-bms-s516-150a-750a-36

• Series cells: 5 to 16
  
• Cell voltage: 0.80 to 4.50 V
  
• Cell balancing: 150 mA, dissipative
  
• Charge/discharge current max: 750 A*
  
• Discharge/Regen current peak: 150 A
  
• Discharge/Regen current sustained: 60 A**
  
• Charge current peak: 100 A
  
• Charge current sustained: 40 A**
  
• Interface: USART (USB / Bluetooth / CAN)

I'd be interested in peoples thoughts on this too. I don't see much of anything on BMS' for single-pack systems; we need more of that because not everyone is building powerwalls and is ok spending $500+ on a Batrium setup.

What is the problem too spend 500 for a good quality hardware were safety is first priority!

I'm recycling ebike batteries and what do think what it's most common problem/faults are?

Bms failures!......., 80% off all the battlers I have recycled The cells have full capacity!
Sometimes I'm thinking that factories want too sell frequently batteries instead off a battery that will work for longer....... Or people a lazy and forget too charge the battery frequently even they don't use the bike in the wintertime?.....

Good quality and good product doesn't always mean high cost. As being discussed in the other thread (http://secondlifestorage.com/t-Nano-help?page=1), working with good quality inexpensive parts (note, not cheap) can yield a very effective and durable product. The reason why a lot of those bms' fail is either because they were made with cheap (and I mean in the since that the materials, craftmanship, quality, and rapid manufacturing with disregard to anything else) components, or the soldering was a botched job so things in parallel doesn't evenly share the load, or it was the wrong part for the job to begin with (ie, putting a FET that has a max current of 5A and asking it to meet or exceed that 5A for prolonged times; close to 100% capability/capacity).
One or all of these could be the reason why those bms' on the scooter packs (that Jehu got started selling and are now flooding our market) failed. In several videos that showed those packs, I could easily see that some of the solder points weren't solid.

So, just because something is low cost, doesn't rule it out as effective or capable. There is a fine line between the two. I personally do a LOT of reading, checking, cross referencing, and thinking about a purchase for days before I commit to any one product (regardless of what it is; especially online purchases; and super especially for those from China or similar locations).

Joost, have you checked the components on those bms' to see what part failed? If you watch The Combat Engineers video about checking the bms', he goes through step by step process to see what parts are working and what's not. Maybe you could take those bms', replace the faulty part with a better one, and sell it for a profit. Just a thought

@Joost2, I guarantee none of those packs had a TinyBMS or any BMS over $100, so while I agree with your point, it doesn't apply here

It looks like an interesting product but for me only having 150 mA discharge for balancing is next to useless on any reasonable size setup

Yeah the balancing is a bit weak on it being that its designed for fresh, matched cells. I spoke with the developer about it he said it would be relatively simple to add a daughter board that'll balance at almost any current

That now sounds more interesting to be able to customize the Ballance current. Or at least have it be variable depending on the seperation of each cell

You could in theory have multiple daughter boards for balancing each with a set current load and be able to choose how many to use in parallel to increase balance current

Hmmm. Worth a closer look. Anyone have this setup?

I've got one on order, it's going into my eboard, I'm making it with a swappable 7S and 10S pack that'll be plugnplay to the BMS. Only needing 1 BMS for multiple voltage configurations or even chemistries is actually quite cost effective.

Cool you'll have to let us know how it goes

I was very tempted to get one myself. I have a smaller project that need one and Batrium is a bit to big for that hmm

I see from a google search that the tinybms was sold in a couple other forums as a group buy last year but didn't see much else being posted about it.

Then I would guess that it works. generally you hear more about a product if it fails than the other way around

Scepterr, I'm interested to see what you think of TinyBMS. They failed to respond to any of my emails.

Any updates guys? How's the tiny BMS treating you?

I am surprised at how few options there are out there. I am an opensource guy and the thought of using Microsoft(esp connected to internet) does not appeal to me one bit, I am sure Batrium are great guys but I want to see the code, .net=yucky. An Arduino or arm board would be a fraction of the power requirements and way less chance of something going wrong(update/virus). Better yet an esp8266 solution could just host a webpage allowing configuration. Just need a breakout board, voltage divider and something for balancing.
If anyone comes across anything please pm me. Batrium looks very nice but closed source, .net and dedicated windows machine isn't my cup of tea.

Everythings-stuck-together said:

I am surprised at how few options there are out there. I am an opensource guy and the thought of using Microsoft(esp connected to internet) does not appeal to me one bit, I am sure Batrium are great guys but I want to see the code, .net=yucky. An Arduino or arm board would be a fraction of the power requirements and way less chance of something going wrong(update/virus). Better yet an esp8266 solution could just host a webpage allowing configuration. Just need a breakout board, voltage divider and something for balancing.
If anyone comes across anything please pm me. Batrium looks very nice but closed source, .net and dedicated windows machine isn't my cup of tea.

Click to expand...

It sounds easier than it is, i'm working on something just like this and have it working for the monitoring part and need to implement the balancing but it's a bit clunky.

I have working 14 1S balancers with ESP8266, sending data to grafana since more than a month, when I have a decent result I will post the info, there are many factors to consider and some errors I made like cable thickness and a low resistance resistor that made to fluctuate voltage when activate the resistor as you can see in picture 1 (above graph is from a pack with 2.2 Ohm resistor and below is from 2x2.2Ohm resistor in series and a thicker cable), that makes the charger fluctuate too while charging a doesn't go to float state.

But as you can see in picture 2 it balances, after 3 days you can see how the yellow pack, pack 10, balances.