Charging parallel battery banks = multiply the maximum charge current by the number of strings

richardimorse
richardimorse Registered Users Posts: 98 ✭✭
On high Ah 2V e.g. 1200Ah batteries, there are four terminals, basically looks like two 600Ah batteries glued together.

Which made me think, when you do this yourself with two strings of separate batteries, I assume you multiply the maximum charge rate by the number of strings you are using, if a 600Ah battery (2 terminal posts) has a maximum charge rate of 120Adc at 0.2C two strings must be a maximum charge rate of 240Ah and three strings 360Ah

Am I correct ?

Comments

  • mcgivor
    mcgivor Solar Expert Posts: 3,854 ✭✭✭✭✭✭
    edited November 2018 #2
    You are correct the total current will be divided equally between each path in a parallel circuit of equal resistance, if one paths resistance  changes for any reason the current would increase in the other two, in a high resistance case or open circuit. In the case of a short circuit or low resistance  fault in a string, the current would favor that particular string, in extreme circumstances the other strings could dump all their capacity into a single string, which is an enormous amount of current. For this reason it's a good idea to include some form of overcurrent protection, a fuse for example, on each string so if one should develop a short or open circuit the fuses would protect the other string/s.   
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