22 hours ago, DeepBass9 said:

So this is a real phenomenon. Which is why I am going to rotate my batteries. There is no downside to this and only upside.

My opinion: It's all down to temperature. The first and last batteries have exposed sides and see larger temperature swings.

In a car the cell closest to the engine always fails first... cause hot.

Whatever it is, I am convinced its environmental... cause it's either that or years of training and  working with electrics and electronics have missed this "bunching up" of electrons on the negative side... nevermind physics 144 at university level... I'd have to go and have a chat with prof Saayman.

Utility control systems are DC. This means huge battery banks and plenty of them (thousands).

Utilities rely on batteries at every sub-station and then they duplicate their control systems and their battery banks so no one failure will cause them to lose control. This is how it is done in every utility around the world.

These banks are treated with respect, they have a dedicated specially ventilated room with monthly checks with meticulous records kept of specific gravity and exactly how much water each 2V cell uses. These records are then analysed to trend any failing cells. This used to be a human exercise, before software was developed.

And cells do fail by the way, all the time.

Eskom used to, ( I don't know if they still do), have a number of banks of spare batteries doing nothing but ageing, so they could source replacement batteries of a similar age to any that failed.

I can say in that situation, (in which I have had a 35 year career of electrical trouble-shooting), I have seen this outside cell failing trend in these cared for battery banks, ( and in my line I would of).

Obviously, I have heard of it elsewhere, ( like here on the forum).

I don't doubt it is something that exists out there.

My point is, when environmental differences are also ruled out, when the proper care is really taken, this trend of the outside cell failing, doesn't exist.

Edited December 21, 20196 yr by phil.g00

4 hours ago, phil.g00 said:

I have seen this outside cell failing trend in these cared for battery banks, ( and in my line I would of).

I suspect you meant to say you have NOT seen this trend 🙂

I'll let the "would of" slip this once 🙂

 

6 hours ago, plonkster said:

suspect you meant to say you have NOT seen this trend 🙂

Yes, you're right there is a missing "NOT".

I haven't come across this in the many years that I would've been asked to sort it if it existed.

And in a past life, I had the very boring task of overseeing the battery records in my area. ( Which is why it's now done by software).