Newbie
Joined: 01/11/2014
Location: AustraliaPosts: 4
| Posted: 09:38pm 02 Dec 2014 |
The battery logger is easy as it is already an open source project under my other username simat here. https://github.com/simat/BatteryMonitor
Here is some of the information for my 24 volt LFP battery
[alltime]
timestamp = '20141203151409 '
maxvoltages = [3.463, 3.49, 3.465, 3.503, 3.462, 3.462, 3.516, 3.512, 27.86]
minnoload = [3.214, 3.099, 3.211, 3.2, 3.2, 3.193, 3.232, 3.186, 25.71]
minvoltages = [3.096, 3.086, 3.076, 3.085, 3.047, 3.103, 3.086, 3.084, 24.7]
deltav = [0.004, 0.322, 0.322]
amps = [-37.6, 245.7]
ah = [53.91, 170.056403, 273.13, 6227, -519.28, 378.55]
maxvoltages is the maximum voltage measured over the time period of each cell and the pack as a whole
minnoload is the minimum voltage measured over the time period of each cell and the pack as a whole with a load of less than 10A
minvoltages is the minimum voltage measured over the time period for each cell and the pack as a whole
deltav is the difference in voltage between the highest and lowest cell in mV measured over the time period, the first reading is the lowest difference, the second in the maximum difference with a load less than 10A, the third is the maximum difference
amps is the maximum charge and maximum discharge current measured over the time period, negative is charge
ah is the DOD of the battery in Ah measured over the time period, my pack has a nominal rating of 360Ah, the first figure is the lowest DOD, with 0 being 'full', the second figure if the average DOD over the period, the third figure if the maximum DOD (360 should be empty), the forth figure is the number of samples the average is taken over, the fith figure is the total charge in Ah, the sixth figure is the total discharge in Ah. There is a minute between samples.
The MPPT controller is more complicated as I cobbled it together using my Motorola (Freescale) 68HC12 based generic controller PCB connected to a single sided PCB that I designed with four buck switching circuits one for each solar panel and associated circuitry. If anyone is interested I will dredge out the circuit diagrams and post them.
I was thinking of updating the design and splitting the power circuitry up into single channel buck circuits, one per PCB. It this way you would make up as many circuits as you have solar Panels. Each one would have a connector to be connected to a pwm output and a couple of A/D inputs on a microcontroller PCB of ones choice. If there is any interest in this maybe we can start a new thread.
Simon
Off grid 24V system, 6x190W Solar Panels, 32x90ah Winston LiFeYPO4 batteries, BMS (Cellog8+JLD404 Ah meter+ homemade Battery logging + supervision), Latronics 4kW Inverter, homemade MPPT controller