$72 ANT BMS: Current Report by BMS is only half of the actual current

[jasonhc73]

I think we are venturing into unchartered waters... Considering everyone else just buys a new battery and doesn't get to play with the settings. Just some electrical engineer stuffed into some little cubical gets to have all the fun.

 

[jasonhc73]

I redid my settings again.

This time based on the discharge curve of the LiFEPO4 profile.

BYD BMS

I made a similar wiring harness using a TE header to jst to a batteryGo BG-8S. I have 6 packs and they all have this wiring pattern. Three different batt versions would make it tricky to make a generic wiring adapter. Are there pack identifying markers? I didn't notice any difference in the...

diysolarforum.com

 

[maxx123]

Interesting you set the peak alarm at 3.375
Why so low, or why bother going 3.65 if it a byd.lol

 

[jasonhc73]

Interesting you set the peak alarm at 3.375
Why so low, or why bother going 3.65 if it a byd.lol

That's before the leg up!

 

[Gerlach]

another forum on ant.bms:

200a smart BMS - ANT

Smart BMS: https://s.click.aliexpress.com/e/rhASYNF2 Does anyone have experience with these? I bought it thinking it was 200a continuous, but its only 200a burst and I think only 70a continuous. So if I bypass discharge, I can still monitor my cells which is good, but can I still take...

forum.esk8.news

GitHub - juamiso/ANT_BMS: Python Script for raspberry reading BMS Ant parameters via Bluetooth

Python Script for raspberry reading BMS Ant parameters via Bluetooth - GitHub - juamiso/ANT_BMS: Python Script for raspberry reading BMS Ant parameters via Bluetooth

github.com

Manufacture:

英文首页_蚂蚁兴能_智能低压BMS_十堰小蚂蚁电子科技有限公司

@maxx123 Do you maybe know if the got it up and running. I want to test and see if it will work. I got the same BMS and it works really good. Got all my settings rite on it running a 16s 120ah Lifepo4 setup.

 

[FilterGuy]

All,
What do the current ratings on these BMSs really mean? I have the 300A one and one of the other forums was saying that is only good for around 120A continuous...???

 

[FilterGuy]

Thanks Jasonhc73. I received nothing from the supplier when I bought my BMS even after some emails asking for the app and information.
The forum has certainly helped fill in the gaps.
I did find this video in chinese I think:

Not helpful in IMHO
Here is a link to a zip file that does have a lot of info:

user manual.zip

drive.google.com

The xls file "BMS parameter instruction RV4.6.xlsx" seems to have some useable information on the settings.
I was able to download a zip file from that link.
Hope this helps the project.

An interesting thing I noticed in the install manual. They did not keep the wires all the same length.

The prevailing 'rule' is that they must all be the same length. I have searched high and low for anything to back up this 'rule' and I can't find it. I am not convinced the rule is anything more than folklore.

 

[FilterGuy]

Has anyone had issues with the total voltage being off? On my system right now, the App is saying 27.2V but I measure it at 27.0 V.

 

[maxx123]

All,
What do the current ratings on these BMSs really mean? I have the 300A one and one of the other forums was saying that is only good for around 120A continuous...???

300 amp peak, for 72 bucks it not going to peak at 600amps

 

[maxx123]

An interesting thing I noticed in the install manual. They did not keep the wires all the same length.
View attachment 8803
The prevailing 'rule' is that they must all be the same length. I have searched high and low for anything to back up this 'rule' and I can't find it. I am not convinced the rule is anything more than folklore.

Even the engineers at Daly say must be the same length, Then again you look at BYD 24v battery it does not follow the same rule.

 

[jasonhc73]

Has anyone had issues with the total voltage being off? On my system right now, the App is saying 27.2V but I measure it at 27.0 V.

Yup.
It's just like the current sensor range. You have to fiddle with it to make it match up.
I tried messing with mine and just gave up. It's always 0.1V or 0.2V higher than the measured and what the charge controller shows.

As for equal length wires, I don't see what it matters on the BMS. The BMS is just sensing the voltage, and sometimes putting a small resistive load on the cell. Be that as it may, all mine happens to be the same length, up until they are plugged into the battery connector on the BYD pack.

Equal length does make a difference in speaker wiring and can be quite noticeable if the length starts making the speakers out of phase. But in such short distances (< than 10 meters) I think the relevance is pretty moot.

 

[BiduleOhm]

Shorter is better but it doesnt really makes a real difference anyway, cut your wires the length you want and don't worry about it

 

[FilterGuy]

300 amp peak, for 72 bucks it not going to peak at 600amps

What should I assume for 'continuous'?

 

[maxx123]

What should I assume for 'continuous'?

150A Continuous/300A Peak Burst Current I would play it safe with 120a

 

[FilterGuy]

150A Continuous/300A Peak Burst Current I would play it safe with 120a

Thanks.... Conveniently, 120 is about what I will need.

 

[jasonhc73]

Thanks.... Conveniently, 120 is about what I will need.

The most continuous load I have been able to pull is 94 amps. I had literally everything in my entire house turned on, and that's all it could pull from the batteries.

 

[maxx123]

finally got my replacements, and my cheap trusty voltmeter decided to go strange, if a battery shows 3.2 v my meter shows 4.7v it must be in lithium cobalt mode, lol so i ordered another and no it not a fluke.
The ant.bms took just over a month from China very happy, will hook up when i get my new meter on Friday

 

[ashigaru]

Does anyone know what the precharge setting does on the ANT-BMS?
It seems I get a "precharge failure" on the BMS and it shuts off the system.
I have tried different values such as 20 or 10 or 5 without seeming to make a difference.
Thanks.

 

[jasonhc73]

Does anyone know what the precharge setting does on the ANT-BMS?
It seems I get a "precharge failure" on the BMS and it shuts off the system.
I have tried different values such as 20 or 10 or 5 without seeming to make a difference.
Thanks.

I have no idea what setting to have for this either.
When I run into the problem this is what I do. Unplug the BMS/turn it off. Disconnect the A/C from the inverter/charger. Wait 5 minutes. Plug it all back in. Sometimes that works. Others I just wait overnight and do nothing.

 

[ashigaru]

Thanks Jasonhc73.
I have been restarting my system by switching off the battery and then the AC grid power. Hit reboot on the BMS. Wait maybe a minute then turn on the batteries and then the AC. Seems to be fine for a week or so.