Originally Posted by JimD
A low current draw over an extended period of time can ruin a battery but it doesn't always.
Really this shouldnt harm a battery unless it drains completely and then stays that way for an extended period of time. (more than a couple days) It could hurt it is the battery drains very low every day due to a larger amperage running through it while idle and repeatedly goes through that cycle for a period of time. Still whether it would take months or even years for it to fail is subjuect to debate.
There have been many battery tests where many of the same batteries were subjected to this behavior over time and they get varng results. The problem is that noone can predict with accuracy when a battery will fail.
One tiny drop of acid more of less can affect life or one grounded plate or particle on the plates with in the battery can also cause deteriorated longevity.
As batteries are used a smll amount of lead is released into the liquid as a by product. this lead settles over time and grounds out the battery plates. from bottom up. that is why some consider new batteries sttrong and older ones weak. that is because they are actually weaker dues to the less amperage they are capable of delivering.
There is a lot of science behind batteries and how they work, degrade and otherwise but there is no way they can predict that it will last 37.123 months. If that were the case then every American that owns a car that has a battery in it can sue for intentional damages stating that they were intentionally buit that way.
WAIT, i may have just hit upon somethng. Maybe we do have a case. food for thought.