Charging a lead acid battery at high temperatures can cause serious damage to the battery and even lead to explosions. When a battery is overcharged, it may experience: Reduced Battery Life: Exaggerated use increases internal resistance, reducing the number of cycles performed.
Personally, I always make sure that anything connected to a lead acid battery is properly fused. The common rule of thumb is that a lead acid battery should not be discharged below 50% of capacity, or ideally not beyond 70% of capacity. This is because lead acid batteries age / wear out faster if you deep discharge them.
When the electrolyte levels in a flooded lead-acid battery go down exposing the plates, always use distilled water instead of acid when topping off a flooded lead-acid battery. During the charging and discharging processes, water that undergoes electrolysis and evaporation is lost from the battery. This leaves a concentrated sulfuric acid solution.
This means that if you (accidentally) short-circuit a lead acid battery, the battery can explode or it can cause a fire. Whatever object caused the short-circuit, will probably be destroyed. Because lead acid batteries can supply such high currents, it's important to assure that you use the right wire thickness / diameter.
The only applications that a lead acid battery is operated for longevity are when they are discharged for short periods (less than 50 percent) and then fully recharged. One application that fits this need is vehicle starting. Applications for stationary storage can have stratification and sulfation problems.
Because lead acid batteries can supply such high currents, it's important to assure that you use the right wire thickness / diameter. If the wire is too thin, it causes too much resistance and thus may overheat, causing the insulation to catch fire. Lead acid batteries can be very dangerous, so you have to be very carefull with them.