Open Island

   power a plug form model engine, I have do some test with my power supply: Bearly heated at 2.21A 1.19V 2.5A seems fine 1.39V 2.79A seems the be limit. Target:  make a Arduino controlled constant amp controller  There are lot of DC DC converter, claim to have 3A, but it's the chip claim. See this MP1584 is used in most small boards.( 2338 is latest chip recommended by MP) It's easy to see that the inductor is often not big enough, schematic required 10uH, but most of those small boards are only 4.7uH. Plan is to  1. add enough inductor.(not sure what is the diode for? it's not on the schematic ) to see if it would provide enough Amp. 2. use arduino board to measure current and with DAC to put voltage on the feedback pin. in order to light up at 2.5A. 3. Using enable pin to on and off the device. Test 1 I did try to control a mosfet with arduino and use INA219 to do current control, but the N-mosfet I use D4184 is not designed for low gatedrive.  It has oscillation problem

  https://item.taobao.com/item.htm?_u=7boo1l33af8&id=42935368105&spm=a1z09.2.0.0.7fde2e8dj6p3hs 全新力做,5A降压恒压恒流模块,带MPPT功能，用太阳能电池板给电池充电可提升充电电流一倍以上，有效缩短充电时间，减小太阳能电池板体积。可为蓄电池、锂电池等充电，带转灯控制，方便观察充电状态。可配多功能电压表，输入电压、输出电压、输出电流、输出功率都可以直观显示，完全可脱离万用表使用。可做为大功率LED驱动模块。  如需防反灌 理想二极管请点以下链接：    8A   http://item.taobao.com/item.htm?id=42364220733  15A  http://item.taobao.com/item.htm?id=42364220733 操作说明： 模块本身已带散热片，加大加粗大磁环电感温升更小，高频长寿命电解电容。 MPPT效果实测双比： 测试条件：18V/50W单晶太阳能板，7.4V/5AH锂电池，12月早晨10点左右在阳台。太阳不大，晒在身上暧暧的，防盗窗挡住了部分太阳。 MPPT不起作用时的充电电流0.896A， （光线比较强，相机快门比较快，表头上数字在拍照片时显示会不全，懂点摄影的朋友应该都明白。) MPPT值调至太阳能板最大功率点时的充电电流1.651A，提升近一倍的充电电流，效果相当明显。     需要外壳请点以下接：  http://item.taobao.com/item.htm?id=13621241047

Of course there are cheap chinese BMS, I have few, some are not even working on cutting off voltage.  And I don't think cutting off should be job of BMS, a good BMS should : monitor voltage with out dran out current with divide resistor not bound to chemistry, could be Lipo, Life..etc monitor temperature of each cell or connection able to communicate wire or wireless Better to be sleep   https://www.instructables.com/Arduino-LTC6804-Battery-Management-System/ Base on LTC6804, SPI interface. The BMS is configured for a battery pack are composed of A123 LiFePO4 cylindrical batteries in 12S8P configuration. The A123 cells have the following characteristics: LTC6804 can monitor upto 12 cells, wih arduino lib https://github.com/dcaditz/BMS_V4 and could be available as PCB from tao Another good code, with presentation on 6804 https://github.com/ayushagrawal/BMS-Arduino not sure what is the difference on 6802-1, it works also on 12 cells. 6802-2 could be addressed  There is a newer versio