The cells and the BMS arrived today. Much better delivery time than expected for the cells, which is nice. Because these showed up so soon I don't have anything ready to build this battery so probably a little while before an update. I'll probably just use 6mm2 wire with crimp on ring connectors for the battery interconnects. This will give a current handling of about 50A which is spot on for the Anderson Powerpole connectors I'm using.

50A should be enough for 2 100W SSB radios operating simultaneously with a little headroom. The max current draw from the cells is 3C, giving a max of 30A from the current bank, but I can upgrade the size if I do need to run multiple transmitters simultaneously.


Original Notes:

Oh8stn did a build using 38120 Headway cells here: https://www.youtube.com/watch?v=SJGKuriGRok

One source of those cells: https://www.evworks.com.au/headway-38120-10ah-cell-lifepo4-cell-3.2v-10ah

They also have another cell in a different form factor that has more capacity for a similar price.

Another video, this time with bigger headway cells: https://www.youtube.com/watch?v=gGsrWXnz8U4



He has another video with a bigger BMS unit. The one he used was the BesTech 50A 4S LiFePO4 BMS



Ordered BMS from here: https://www.ebay.com.au/itm/12V-100A-LiFePo4-Battery-BMS-LFP-PCM-SMT-System-4S-x-3-2V-Battery-Balance/123309373325?_trksid=p2485497.m4902.l9144


12V 100A LiFePo4 Battery BMS LFP PCM SMT System 4S x 3.2V Battery Balance


- Protection circuit board is the heart of battery pack, must to have to avoid battery pack from explosion, fire and damage
- It will protect battery pack from overcharging, over-discharging over-current and short circuit
- With equilibrium function to keep each cell in balance and good service life
- Used for 4 series 12V LiFePO4 batteries, comes with 5P-250mm wires
- Choosing the correct protection board and applying it appropriately is vital to the longevity your batteries


- Discharge
- Continuous Discharging Current: 100(MAX) A
- Instantaneous Discharge Current: 150 A
- Charge
- Charging Voltage: 15 V
- Charging Current: 10(MAX) A
- Overcharge Protect
- Over-charge Detect: 3.75±0.05 V
- Protect Delay: 0.5 S
- Over-charge release: 3.65±0.1 V
- Balance
- Detect Voltage: 3.60±0.05 V
- Release Voltage: 3.60±0.05 V
- Balance Current: 36±5 mA
- Over-discharge Protect:
- Over-discharge Detect: 2.0±0.1 V
- Over-discharge Detect delay: 0.1 S
- Release Voltage: 2.25±0.1 V
- Over-current Protect:
- Detect Voltage 150 mV
- Detect Delay: 9 mS
- Current Detect: 200±10 A
- Release Condition: Cut Load
- Short-circuit Protect
- Protect Condition: Load Short Circuit
- Detect Delay: 250 uS
- Release Condition: Cut Load
- Temperature Protect : / / ℃
- Resistance
- Inner: ≤25 mΩ
- Self-Consumption
- Working Current: ≤20 uA
- Sleep Current (when Over-discharge): ≤10 uA
- Working Temperature
- Range: -30/+80 ℃
- Size: 70*51.5*10mm / 2.75*2.02*0.39"

TODO: Add photos from Ebay site to show wiring


Ordered Cells Here: https://www.aliexpress.com/item/6-8PCS-3-2V-rechargeable-LiFePO4-battery-5000mah-32650-lithium-ion-polymer-cell-pack-for-12V/32890171295.html?spm=a2g0s.9042311.0.0.6b0e4c4dOTrB0n



1. Voltage:3.2V (limit voltage:2.2-3.65V)

2. PVC Capacity:5000mah

3. Cycle times: about 1000 

4. Brand new LiFePo4 batteries,used for e-bike,e-bus.

5. Size:32650 battery (32*65mm )

6.Max discharge current:3C(30A)

7.Max charge current:0.5C(5A)


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