This build was half done for many months. I first put it together and ended up shorting a cell for a few seconds, burning my thumb and forefinger trying to put out the small flame. The new BMS, a “Turmera 32650 20A BMS” has the convenience of having the balance lead points right beside where they correspond on a 4S battery. This reduced wiring and left a very clean implementation. The problem with this is that they are exposed, and I needed to be careful not to short any of the nickel strips while spot welding them to the open pads. Moreover, the main output has an unusual positive and negative terminal within a few millimeters of each other, lending to more accidents if one isn’t careful when affixing the output cable.
The DenCo Batt Mk X is the 10th design revision of the DenCo 6Ah 32700 (32650) series. Its main differences from the previous iteration are the aforementioned Turmera 32650 20A BMS, and an ABS-printed voltmeter/USB bracket (instead of PETG). These were commissioned to Print-a-Thing at https://printathing.com. The bracket design was created by AD6DM DenCo™ and can be found opensource here: https://www.thingiverse.com/thing:4165670. This custom bracket is sized for a 32650 pack, and fits on top of the cell holders one can buy on eBay or Aliexpress.
This battery omits the charging barrel plug, as the BMS is a common port BMS. Common Port has been split in the past for simultaneous charging capability, but in this case it is more difficult to get a solid hold on the small pads for positive and negative, so simul-charge-discharge will have to happen with a powerpole splitter. This omission simplified the build.
Also new is the holographic AD6DM DenCo™ sticker on the side, printed at Sticker Mule.
This is by far the cleanest build so far.
General Specs:
Created: December 8, 2021 (after months being used and tested naked).
Cells: BatteryHookup 32650 6Ah 3.2V LiFePO4.
BMS: Turmera 20A ASDL-4S-10236 V2 4S LiFePO4 BMS.
Configuration: 4S1P.
New since last make: BMS, ABS bracket and epoxied components, branding sticker.
Current Owner: AD6DM Dennis.
Cell Specs:
Battery Hookup 32650 LiFePO4 cells
NOMINAL VOLTAGE: 3.2V
CAPACITY: 6000MAH
WATT HOURS: 19.2WH
FULLY CHARGED VOLTAGE: 3.65V
FULLY DISCHARGED VOLTAGE: 2.5V
MAX CONTINUOUS CHARGE: 6A (1C)
MAX CONTINUOUS DISCHARGE: 18A (3C)
MAX PULSE DISCHARGE (10 SECONDS): 60A (10C)
CELL WEIGHT: 141 GRAMS OR 4.97 OUNCES
BMS Specs:
Make: Turmera
Model: ASDL-4S-10236 V2
Continuous Discharge: 20A
Pulse Discharge: 40A
Nominal Voltage: 3.2V
Chemistry: LiFePO4
Cell Type: 32650
Charging Voltage: 14.4V
Balancing function: Yes (tested)
Charging cutoff: 14.6V (tested)
Overcharge detection, balance detection, overdischarge detection, balance voltage, or overcurrent detection specifications were not provided by manufacturer.
