Battery issues need for monitoing Batteries that are in Parallel

Sudden fall off in Voltage on the input to the inverter can normally be attributed to weak or failing batteries I have encountered this on my 48 Volt inverter so designed and installed a battery monitoring system that keeps a 24 hour history of the Solar array and Battery voltages in my installation. The Arduino board records the data and this is uploaded to my cellphone via Blue tooth. Below are the results.

 

 

The light Blue is the Voltages of the Solar array and need to be multiplied by 10 for correct Voltage outputs notice the up and down of the voltages, this was a cloudy day. Notice how battery 3 (red) line the voltage suddenly falls off, the system is setup to charge from electricity if the voltage falls below 44 Volts (80%) and you can see that in the early hours of the morning the voltages start to rise, this is the inverter charging the batteries from the grid. If this battery maintained its voltage as the others do there would be sufficient charge until the sun was up and the Solar array could charge the batteries

Here is the layout of panels on a North facing roof there is space for another 3 also shown is the Solar Geyser which feeds the house main geyser, so the internal geyser (set to 50 Deg C) is filled with preheated water (45 in winter to 80 Deg C in Summer) so the need for electrical water heating is minimal.

Here is the Battery installation

The Inverter and MPPT Controller (great equipment)

 

Solar Power Installation Home (Power Outage Load Shedding) and Other projects

It has been a long while since I last posted anything, doesn't mean I have not been busy ;) Balancing life, work, hobbies and fun time. I have completed a number of new projects from a fully autonomous quad (yes Ardupilot). Solar Power solution for the home (we Live in South Africa  so are now plagued with Load Shedding (Random Power outages due to lack of fore though and planning by our state power utility.) This is mostly at peak times (early evenings) and is totally inconvenient. This spurred me to get all the lighting, security(alarm & electric fence), entertainment (TV & Satelite Radio etc.) and of course the internet computers including the Server which is required for Business.

First course of action was to convert all the lighting to Led and other low power options, secondly calculate the power requirement to run all, then put together a system that was as balanced Solar Panels (collection/accumulation) and Batteries (storage) and Output (load) for a cost effective solution to get these items off grid.

Although this actually fairly basic to do, anyone planning to tackle this must do their home work, it would be very easy to spend a lot of money and be very unhappy with the outcome, seek professional advice if you are not sure.

I settled for  the following a 48 volt system, (high voltage systems means less current and generally a more efficient system)

6 x 300 Watt Solaire Panels  These are almost 2mtrs x 1mtr in size and are connected 3 in series and these 2 sets of 3 in parallel so a total power output of about 130 volts @ 16 amps.

4 x 100 Amp hour Ceil/(Excide) 6SGL 100 Batteries these are gel batteries (no maintenance) that according to the documentation could last up to 8 - 10 years. ( This I have to see as I have had one failure already and am monitoring each battery carefully)

Electronics wise I have gone for equipment that will allow me to double the size of the system. I also chose to use products manufactured here in South Africa as I have already suffered an expensive lesson with a Chinese Inverter that could not be repaired here and had to replaced. The South African company Microcare manufacture a fantastic range of products and have also been very helpful with advice and service. I am using a

Microcare 40 Amp MPPT controller

Microcare 3 KW Inverter

Both are fully programmable easy to use and work very well.

Installation and wiring was a breeze.

On the AC side I isolated the circuit breakers used for lighting in the DB Board, and have wired in the plugs boxes required for the low current items on these circuits and  used the computer red plug boxes with flat earth pins so that high current items can not be plugged in by mistake.