Why do lead-acid (automotive-style) batteries typically only last for a few years of regular use (or x amount of cycles) before having problems?

Obviously, things can't last forever. But, what are the physical differences between an old battery, and a new one? What changes? What exactly occurs (physically) inside the cells that eventually leads to failure?


closed as off-topic by Leon Heller, laptop2d, Dmitry Grigoryev, Lior Bilia, bitsmack Jul 31 '18 at 19:38

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    \$\begingroup\$ Have you done any research to try to answer this question yourself? It's hard to imagine that a quick search didn't turn up a wealth of information. \$\endgroup\$ – Elliot Alderson Jul 30 '18 at 13:45
  • \$\begingroup\$ Research sulfation, it's a well known effect. \$\endgroup\$ – Jeroen3 Jul 30 '18 at 14:04
  • \$\begingroup\$ Well, think about how much vibration they are subjected to... engine vibration, road surface, pot-holes - it's a wonder they last as long as they do... \$\endgroup\$ – Solar Mike Jul 30 '18 at 14:26
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    \$\begingroup\$ Question should be closed - insufficient research. \$\endgroup\$ – Leon Heller Jul 30 '18 at 15:07

Internal deposits build up on the plates. If you take the battery apart, clean up the plates, and give it some fresh acid it will be like new again. Of course cleaning the internals of a lead-acid battery can be dangerous if you don't know what you're doing; the acid will melt skin.

  • \$\begingroup\$ Thanks for a genuine answer. I was curious if that was actually the case. The general consensus seems to be that it's not, but I'm willing to try in order to satisfy my curiosity. I thought maybe the lead plates would simply lose structural integrity and deteriorate, but from a cursory examination with a torch & a probe through the access holes to the individual cells, they appear to be fine. I'll cut the top off with a small rotary blade, and see what I can do \$\endgroup\$ – tjt263 Aug 1 '18 at 4:35

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