I think that I used to know about battery charging but as 40 years go by ...... I need to charge a 75AH battery. In my days it used to be considered that a 10 hour charge/discharge (ie 7.5 amps per hour) rate was most efficient. However I do not believe there is any reason why a battery of this type could not be charged for a longer time at a lower rate (ie for ease 3.75 amps for 20 hours) and still achieve full charge. Is my memory playing tricks on me or did I never learn properly in the first place? Logic behind this question is that the domestic battery chargers appear to have a cut off at 70AH batteries and almost double the price for another 30AH. (I am quoting what the manufacturer states is the recommended highest battery capacity). Would appreciate comments but be kind to an old man!!
This might be getting a bit dated now; eg, there is no mention that NiCd is no longer allowed to be sold in Europe...
I find it a bit cute that the most common li-ion cell used to build battery packs - the 18650 cell - is said to be 18mm in diameter and 650mm long. That is more than two feet long ;)