User Manual: Click here to download the manual (PDF)
BMS For 16 cell, 48v volt Lithium-iron-phosphate DIY batteries.
100 amp continuous charge or discharge current.
Low Temperature Charging cutoff at 0c.
The Apps allow you to monitor SOC (state of charge), Current, Voltage, cell balance, temperature, and more.
Bluetooth Module is included, Balance wires are included, USB module is an additional purchase.
Final assembly, testing and calibration is done in Naples, Florida. Units with 8 gauge wires and/or crimped lugs are assembled in Naples, FL. The BMS is manufactured in China.
To view or change Parameters, there are 3 ways to connect to the BMS. All 3 applications are free.
- iPhone App: Overkill Solar Mobile App
- Android App: Overkill Solar Mobile App
- USB module to PC/desktop application.
Click here for Software Downloads and Support Resources.
A great resource for general DIY power education is www.Mobile-Solarpower.com
FYI for experimenters: The BMS communicates with a 5v TTL UART at 9600 baud. It is directly compatible with Arduinos, etc.
We have written a new Arduino library for the BMSs, now available on the downloads page. The beta version allows you to read all the monitoring parameters and switch charge and discharge on/off. Future releases will have full read/write capability. A python library is also in the works.
Just got my 16S! It fired up and worked great. Great Bluetooth communication. Some of the best quality I’ve seen from china. USA based Overkill provides the added detail that you will likely not get from overseas. The one page colorful instruction sheet gives you extended comfort that if you do something wrong, you’re not stuck with it. You just call customer support.
Petr (verified owner) –
After all, I managed to find time to put everything together, when attaching balance wires, something did not play out. BC12 wire was missing (next to black BC11 is nothing), and obviously never inserted into connector – the white silicon glue was covering connector where the wire should be.
Happy me, found another connector with similar wiring, pull the pin with wire out, installed where it should be, checked all voltages, plugged into BMS and a wire went up in smoke. Is this a different BMS for different voltage? Something else? No response whatsoever, seems like I have to mill completely new enclosure and install a different brand, probably couple days of work up in smoke 🙁
Petr contacted firstname.lastname@example.org and eventually got the BMS working after fixing the defective wiring harness.
We had a batch of wires that were populated at the wrong positions, and the wires themselves don’t normally get tested before shipping.
If there is a problem like this, the wires or the whole BMS can still be replaced at no cost.
This unit has been working great for 8 months now. It’s been very easy to use. The bluetooth app and programming have been very convenient. It just does everything a sensible and utilitarian BMS should do without complaint.
The only quirks are one of my three temp probes always read 10*F off the other two. I was able to shut this input off in the app to ensure the temp protections aren’t kicked on without cause. The battery capacity reading is usually 10-15% off the mark, but it’s still impressive considering it’s no smart shunt.
I purchased 2 of these, and turned Balancing on after charge (no balance during charge). My batteries were quite a bit off (one set of the 2 especially) and they were 280ah, not just 100ah LiFePo cells.
Bottom line, Balancing at 3.5 or 3.6 per cell worked fine, under 24 hours, and they were good, <4 millivolts. But trying to balance these at 3.35 or 3.45 is not worth the time, it might take days.
Very happy with the instructions, and quality. I will be purchasing more from Overkill Solar.