Many of the items we use every day rely on old-fashioned lead-acid batteries. Most of us know that when the battery in our car goes out, we need to be careful because of the acid inside of it. Fewer know that the same lead-acid batteries are used in golf carts, electric scooters and even motorized wheelchairs. There have been attempts to switch to other types of batteries, though this hasn’t yet occurred on a wide scale. Lead acid batteries don’t just pose a health risk to those maintaining them. This is why valve-regulated lead-acid batteries or the VRLA battery was invented. They are leak proof and don’t require risky maintenance like adding water to the battery.
They’re also heavy, limiting the range of the device that it powers. Many general purpose batteries are also bad for the environment. The VRLA battery reduces the risk of problems outside of controlled disposal processes, but you still have to contend with lead.
One of the most promising alternatives to lead-acid batteries is lithium-ion batteries. Lithium-ion batteries or Li-ion batteries are more expensive than lead acid batteries. That’s slowed down their initial use, though their overall life-cycle cost could be lower than lead-acid batteries because they can last so much longer. Another benefit of lithium ion batteries is that they can be kept at any state-of-charge. For example, there are warnings to fully charge your cell phone because if you don’t fully charge it each time you do, the lithium-polymer battery’s “memory” resets to half-way full. The same issue can be found with lead-acid batteries; if you don’t fully charge it when you’re recharging a car battery, it may never be able to fully recover its charge due to sulfation. Conversely, NiCD and NIMH batteries must be fully discharged periodically. Yes, you have to let the battery run out, and you have to do this to prevent the same “memory” issue.
Another problem with lead-acid batteries is their slow charge time; that’s prevented rechargeable batteries from moving into the industrial sector that consumes so many of them. For example, lead-acid batteries used in forklifts take a long time to charge though warehouses need them 24×7. Adding a fuel cell to the fork lift that charges the battery reduces this wait time, but now you’re adding to the cost in a business where margins are modest. It is cheaper to just swap out lead-acid batteries. The fuel cell cannot completely replace the lead-acid battery because it can’t put out as much power. For example, the fuel cell could power the forklift as it travels across flat ground but the lead-acid battery must be engaged when the forklift is carrying a heavy load up a ramp. The popular solution here is a deep cycle battery, one that can discharge nearly all of its capacity. You can use them as starter batteries, like the standard car battery, but they’re also used for long, slow power draws like cathodic protection and powering industrial equipment like forklifts.
In general, the heavier the application, the less suitable the fuel cell or battery. However, this hasn’t stopped engineers from switching to batteries to replace internal combustion engines. An automatic guided vehicle system in ports runs 24 hours a day. It can’t be held back by charging intervals or refueling. Lithium-ion batteries are being used in AGVs to replace the very large lead-acid battery with a smaller, lighter one that can be charged more quickly, often fast enough that the AGV can be sent on its next run. Yet batteries are not yet powerful enough to replace engines in the heaviest of heavy duty vehicles. Environmental conditions preclude batteries in other cases. We know that lead-acid batteries are prone to fail sooner in cold weather, and other batteries suffer the same problem. Extremely hot weather as well as cold weather can cripple a hybrid car’s battery.