Alan H.

Further to my earlier post which was released in error......
A few months ago I bought 4 x 3.2 volt 100 Ahr cells (new) from a company called Cinch-IT in the Cape. 12 volt BMS (excluding temperature sensor) was bought on a special from a supplier advertising on BidorBuy.
I also purchased 4 x 3.2 volt 50 Ahr cells (2nd life) from Electromann as I had already purchased a 12 volt 55 Ahr BMS (with temperature sensor) from them a year or so earlier. Must say that these cells looked the worse for wear but so far have behaved faultlessly. 
Aluminium flat bar were used for the links/busbars. A2 stainless steel hardware was used throughout. Purchased a battery box ex. Electromann for the 100 Ahr pack and used an off-the-shelf ABS electrical box which I modified to suit the 55 Ahr pack.
Various blogs stated that all the cells should be brought up to the same state of charge using numerous methods. I chose to charge up each cell separately (bit laborious) with a dedicated single cell charger (bought cheap ex. Battery Experts) prior to coupling everything up.
Was it worth it? Depends primarily on the price and quality of the cells. Also, good quality BMS's are not cheap. In addition, don't expect much in the way of component guarantees if it is a DIY project. If you make a stuff-up you could be left with an expensive paperweight at best - or potentially cause real harm to oneself. Safety first! 
All in all I saved around R3000 on the 100 Ahr build and close to R2000 on the 50 Ahr build (excluding my time) when comparing them to middle of the range batteries. Obviously not talking Blue Nova prices here!      
       

Further to my earlier post which was released in error......
A few months ago I bought 4 x 3.2 volt 100 Ahr cells (new) from a company called Cinch-IT in the Cape. 12 volt BMS (excluding temperature sensor) was bought on a special from a supplier advertising on BidorBuy.
I also purchased 4 x 3.2 volt 50 Ahr cells (2nd life) from Electromann as I had already purchased a 12 volt 55 Ahr BMS (with temperature sensor) from them a year or so earlier. Must say that these cells looked the worse for wear but so far have behaved faultlessly. 
Aluminium flat bar were used for the links/busbars. A2 stainless steel hardware was used throughout. Purchased a battery box ex. Electromann for the 100 Ahr pack and used an off-the-shelf ABS electrical box which I modified to suit the 55 Ahr pack.
Various blogs stated that all the cells should be brought up to the same state of charge using numerous methods. I chose to charge up each cell separately (bit laborious) with a dedicated single cell charger (bought cheap ex. Battery Experts) prior to coupling everything up.
Was it worth it? Depends primarily on the price and quality of the cells. Also, good quality BMS's are not cheap. In addition, don't expect much in the way of component guarantees if it is a DIY project. If you make a stuff-up you could be left with an expensive paperweight at best - or potentially cause real harm to oneself. Safety first! 
All in all I saved around R3000 on the 100 Ahr build and close to R2000 on the 50 Ahr build (excluding my time) when comparing them to middle of the range batteries. Obviously not talking Blue Nova prices here!      
       

I agree with Jakes. I have used Ryobi power tools for years and have had no issues. Currently using a Ryobi 18v cordless impact driver to re-do my roof joists. What a pleasure. Different matter if you are a contractor. Go for a more professional tool and take the (cost) pain. Another bonus for me is if it gets banged up or dropped I don't have to go into a corner and weep - unlike what happened to my expensive Bosch. The current Ryobi HandyLine range of power tools are another matter altogether.