Batteries & Concrete Floors

The following is from a publication from Interstate Batteries called TechTalk ©
While this article deals with automotive batteries specifically, it can apply to many other types of batteries we use in HAM radio.
Fact or Fiction
Will today’s batteries be damaged or discharged by letting them sit on concrete?
NO!
Why then do so many people believe that concrete is a battery enemy? Years ago, batteries could have been electrically discharged by sitting on a concrete floor. My dad reminded me time after time, "Set that battery on wood! I know batteries discharge on concrete because I’ve witnessed it!" And he was right at that time.
Historical Basis
You see, the idea that concrete drains batteries does have some historical basis. Many, many years ago, wooden battery cases encased a glass jar with the battery inside. Any moisture on the floor could cause the wood to swell and possibly fracture the glass, causing it to leak. Later came the introduction of the hard rubber cases, which were somewhat porous and had a high-carbon content. An electrical current could be conducted through this container if the moist concrete floor permitted the current to find an electrical ground.
The wise advice of the old days to "keep batteries off concrete" has been passed down to us today, but it no longer applies because of the advanced technology of today’s batteries.
Battery Discharging
The fact is, all batteries self- discharge whether they’re sitting on the shelf or on concrete. This is why manufacturers regularly rotate their inventory. As the temperature increases, a battery’s self- discharge level also increases. Some lead acid batteries discharge 4% - 8% per month at a temperature of 80°F. The level of self-discharge is also contingent upon the type of lead plate alloy plus the age and cleanliness of the battery.
If the battery has a surface layer of acid or grime, which is electrically conductive, it self-discharges more rapidly. This surface layer may actually allow you to measure the DC voltage across the battery’s poly case (using a 10 meg-ohm digital voltmeter). For that reason, we recommend that you always keep batteries clean.
In Summary
That block of wood may not be necessary today, BUT it won’t hurt either.
In HAM radio, we may use different types of batteries. Regardless of what we use, it is good practice to treat our batteries with care. After all, we will need them to be at their best in emergencies. 

---