Overkill BMS

[JJJJ]

I noted there is a lot of discussion on this topic, so if this question has been answered please forgive me.

I glanced at the Overkill BMS manual. Did I see that there is an option to use an USB cable to attach this to a computer?

What is the range for the phone app?

Thanks again

 

[John Frum]

I glanced at the Overkill BMS manual. Did I see that there is an option to use an USB cable to attach this to a computer?

Yes, I have one but have not tried it.

What is the range for the phone app?

Hard to say.
Probably ~30 feet like most bluetooth devices.
Its limited by the weaker of the smartphone bluetooth tx/rx device and the bms tx/rx device.
tx = transmit
rx = receive

 

[KGeorge]

I am about to purchase the Overkill 120. My first entry to BMS's. Does the blue tooth application work on an i-phone?

 

[MrNatural22]

I am about to purchase the Overkill 120. My first entry to BMS's. Does the blue tooth application work on an i-phone?

Yes it works very well. The iPhone app seem to be much easier to use and it’s worth the $5 to get the deluxe paid version.

 

[Loadtoad]

I have my battery sitting on my workbench in my workshop that is at least 50 feet from my house. I still have connection with the steel garage door down between my phone and the BMS. It still works. I couldn't believe that it would stay connected that far and with the door closed.

 

[KGeorge]

Yes it works very well. The iPhone app seem to be much easier to use and it’s worth the $5 to get the deluxe paid version.

Thanks you so much for your help.

 

[KGeorge]

I have my battery sitting on my workbench in my workshop that is at least 50 feet from my house. I still have connection with the steel garage door down between my phone and the BMS. It still works. I couldn't believe that it would stay connected that far and with the door closed.

thank you very much for you help, that would have been my second question, how far.

 

[JJJJ]

I had a question on the USB option. Are there jumper or switch settings on the USB option which lets you set the base address. This feature would let you use multiple batteries and be able to reference them by ID codes on your computer.

 

[richard cabesa]

Can you run multiple units and monitor them all on the phone app? Do you just name the batteries 1-2-3-4 and pick them one at a time from the device list?

 

[curiouscarbon]

@richard cabesa yes if you have more than one overkill BMS, each with its own bluetooth module, each one will show up separately in the iphone/ios Xiaoxiang BMS app. You can even identify them individually based on the unique MAC address. Hope this helps. It's only possible to monitor one BMS at a time with the phone. Must disconnect from one and connect to other.

 

[KGeorge]

Thank you,

In studying the wiring diagrams it appears that if a BMS disconnects the battery as it should do in the case of overcharge, under voltage etc., the solar controller gets disconnected also and it is now powered only by the erratic voltage of the solar cells and prone to destruction. So a BMS doing its job can destroy an controller?
What am I missing here?

 

[JeepDaddy]

it’s worth the $5 to get the deluxe paid version

I agree, but it's $7 now.

 

[Deleted member 23531]

Yes, I have one but have not tried it.

I have the 24V Overkill BMS and the alternative to bluetooth is a 2-wire pigtail which I think is serial / UART communication, so I think you'd need to use the TXD/RXD lines from a microcontroller or raspberry pi.

Does the blue tooth application work on an i-phone?

Yes. I paid $7 for the "advanced" settings/features though.

Probably ~30 feet like most bluetooth devices.

The range is incredible on the bluetooth module they include with the Overkill BMS. Also, because you can tape it up in a more exposed spot. I am able to connect at a distance of about 15m, through multiple walls, metal doors, low-e windows, etc. Basically from my backyard workshop all the way to half my house. By comparison, the range of my Victron MPPT is abysmal, probably because it's burried deeper in the enclsoure and in my battery box which houses all the electronics.

 

[Anit767]

Yes it works very well. The iPhone app seem to be much easier to use and it’s worth the $5 to get the deluxe paid version.

Which app are you using?

edit
i presume it’s this one.
https://apps.apple.com/us/app/xiaoxiang-bms/id1375405426

 

[MrNatural22]

Which app are you using?

edit
i presume it’s this one.
https://apps.apple.com/us/app/xiaoxiang-bms/id1375405426

Go to the overkill webpage downloads and use the one overkill lists.

 

[curiouscarbon]

Thank you,

In studying the wiring diagrams it appears that if a BMS disconnects the battery as it should do in the case of overcharge, under voltage etc., the solar controller gets disconnected also and it is now powered only by the erratic voltage of the solar cells and prone to destruction. So a BMS doing its job can destroy an controller?
What am I missing here?

You are not missing much. When my LiFePO4 pack with JBD BMS is in undervoltage protection, and I plug it into a battery charger, the charger gives up saying error and no charge. Immediately after disabling the undervoltage protection the charger sees the actual battery voltage and is able to charge.


For this reason, some people suggest connecting the solar charge controller directly to the battery terminals, maybe with a fuse in for good measure. Definitely want to feel good about trusting the charge controller in that setup.

But also be aware that in the case that your solar charge controller receives no sun for a long time, it will drain your batteries. With a big battery this is much less of a problem.

 

[MrNatural22]

Thank you,

In studying the wiring diagrams it appears that if a BMS disconnects the battery as it should do in the case of overcharge, under voltage etc., the solar controller gets disconnected also and it is now powered only by the erratic voltage of the solar cells and prone to destruction. So a BMS doing its job can destroy an controller?
What am I missing here?

Will had a post on this subject. Take a peek. ?

Trying to destory my SCC's: I can't do it!

So I took every EPEver/Victron/PWM/Renogy solar charge controller, and tried to fry it by connecting it only to solar panels, and not to a battery... guess which one survived? EVERY SINGLE ONE! I couldn't destroy any of them, and I left them connected to a high voltage array (80 volts) for 4+...

diysolarforum.com

 

[Bleedingblue]

@richard cabesa yes if you have more than one overkill BMS, each with its own bluetooth module, each one will show up separately in the iphone/ios Xiaoxiang BMS app. You can even identify them individually based on the unique MAC address. Hope this helps. It's only possible to monitor one BMS at a time with the phone. Must disconnect from one and connect to other.

I hope so. I bought 4 of them and have yet to install my batteries

 

[curiouscarbon]

I hope so. I bought 4 of them and have yet to install my batteries

I have made two custom DIY LFP battery packs, both using the 4S Overkillsolar/JBD BMS. Both have their own individual bluetooth adapter. Both show up in the iOS version of the XiaoxiangBMS app, separately, as individual devices. I can connect to one at a time and read data and config and write config.

One pack is 4S LFP and one is 3S LFP (yes you can use the 4S Overkillsolar BMS with 3S but it’s not supported or described in their manual).

hope this helps

 

[Bleedingblue]

I have made two custom DIY LFP battery packs, both using the 4S Overkillsolar/JBD BMS. Both have their own individual bluetooth adapter. Both show up in the iOS version of the XiaoxiangBMS app, separately, as individual devices. I can connect to one at a time and read data and config and write config.

One pack is 4S LFP and one is 3S LFP (yes you can use the 4S Overkillsolar BMS with 3S but it’s not supported or described in their manual).

hope this helps

It does. As long as I can change and read the 4 different BMS it's good to go. I have 4 chargery bms that I need to get rid of then. Never used those bad boys.