Ammo Box .30 Cal Battery Box

thingiverse

This is my 20AH LiFePO4 battery box panel specifically designed to slide into a .30 caliber steel ammunition box. It accommodates a 30A switched circuit breaker, a panel meter for monitoring the battery state, a panel meter for monitoring the charge voltage and current, power supply cooling fans, wide input voltage power supply, powerpole connectors for charge input and battery output, switched USB ports, and a DC socket. The power distribution PCB was custom made on my CNC machine and accommodates auto-resetable automotive circuit breakers and screw terminals. The original models are available in TinkerCAD at the following links: https://www.tinkercad.com/things/7skgvDnMWiN https://www.tinkercad.com/things/aij7RCkeB2j The panel was too long for my Prusa I3 MK2.5S, so, it was split and tabs were created that are bolted together with four 3mm socket hex cap screws. The screw heads are below the side surface and do not interfere with sliding the assembly into the box. The text was made too thick at 1mm. Subsequent printing of other projects showed that only 2 layers is necessary instead of 5. This will cut down on the number of tool changes. The max input voltage for the power supply used is 30V. The powerpole connector used for the charge input is not configured the same as the other four battery output powerpole connectors to ensure the input voltage does not go directly into the battery. An adapter cable was made to allow a standard amateur radio 12Vdc source can be used to power the supply. The adapter cable is short enough to fit in the slot between the fans and meters. The battery output connectors are configured for US amateur radio use. The powerpole connectors can be fixed into their positions by accessing the slots through the holes on the side of the panel. Use wood toothpicks and cut them to length after inserting them. They will fit tight and the connectors will not move once the toothpicks are in place. The power distribution panel has the input from 30A circuit breaker and breaks out the power to 6 automotive auto-resetting circuit breakers. The cover for the power distribution was a bit of an overkill for this project. If I do this project again, I will integrate the PCB mounts into the side of panel2 between the two legs and not cover the PCB. Since everything is insulated, space can be saved by not adding a cover and the PCB will be fixed in place. If someone wants the details of the power distribution PCB and housing model, they can be found at https://www.thingiverse.com/thing:4167217. The fans are designed to come on automatically when the input power is present. This was probably a bad idea and the fans should have a switch to turn them on and off. In fact, the output of the power supply to the battery should be switched so that a diode is not needed to keep the fans and power supply from draining the battery when not charging. The power supply is a 5V-30V wide input voltage variable output buck/boost converter rated at 8A output. The Bioenno battery has a built in BMC and their power supplies are 15V output. So, I set the DC/DC converter output to 15V and limited the current to 4A. The buck/boost feature of the converter allows for charging the battery from a vehicle or a ham station power supply or a solar panel. Note the input voltage must be lower than 30V or the converter could get damaged. The diode used is a schottky diode in a TO220 package. The power through the part should be adequate at 4A without heat sinking it. Parts used in this project: 25x10mm Dual Ball Bearing Brushless fan 2 each: https://www.amazon.com/gp/product/B07KS5P1KV/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 Blue Sea Systems A-Series Single Pole Rocker Circuit Breaker 30A: https://www.amazon.com/gp/product/B000MMDLSY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 Switch for dual USB connector: https://www.amazon.com/gp/product/B0722K5LD1/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 Dual USB Charger Socket Power Outlet 2.1A & 2.1A（4.2A: https://www.amazon.com/gp/product/B01N6S2SNM/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 LED Digital Voltmeter Ammeter DC Digital Multimeter 100V 10A Blue Red LED: https://www.amazon.com/gp/product/B079L33VG2/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 Cigarette Lighter Socket: https://www.amazon.com/gp/product/B07BQ1JYTX/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 DC 28V 5-30A Reettable Circuit Breaker Fuse Reset Blade: https://www.banggood.com/DC-28V-5-30A-Reettable-Circuit-Breaker-Fuse-Reset-Blade-for-Marine-Automotive-p-1321294.html?rmmds=myorder&ID=511525&cur_warehouse=CN 100V/20A 7in1 OLED Multifunction Tester Panel Meter: https://www.banggood.com/RIDEN-100V20A-7in1-OLED-Multifunction-Tester-Voltage-Current-Time-Temperature-Capacity-Voltmeter-Ammeter-Electrical-Parameter-Meter-p-1120289.html?rmmds=search&cur_warehouse=CN Anderson Power Pole connectors, contacts, wire (be sure to use proper size for current capacity): https://powerwerx.com/anderson-power-powerpole-sb-connectors?gclid=EAIaIQobChMI3tX6opzX5wIVT_DACh3qOwgqEAAYASAAEgIbSPD_BwE 100W 30V 8A Step Up/Down Buck-Boost DC-DC Converter Module: Note: I originally bought this from Banggood.com, but, they are no longer available. I found this one which looks identical with the buck/boost capability. https://www.aliexpress.com/item/32611751890.html?spm=a2g10.10010108.1000016.1.57a9185fztpWs4 Terminal Blocks 2 position 7 each: https://www.mouser.com/ProductDetail/Phoenix-Contact/1935776?qs=%2Fha2pyFaduhyGAHO0gKMp7QlgphEWGte0mG7LaVhzkyGuUdntK%2FyXg%3D%3D