Sunday, April 10, 2022

100 Year Old Battery Technology

Lead acid batteries have been around for over a hundred years. So how come with all the new lithium batteries out there are they still in common use? Odds are very good that the battery in your car is a lead acid battery -unless you drive a Tesla. There are good reasons a gas or diesel vehicle has a lead acid starting battery and a Tesla has lithium.

In short, price, weight and energy density. The battery in a fossil fuel vehicle has one major job, to start the vehicle. A lithium battery could do the job, but why spend the money on a much more expensive battery? Lead works. A Tesla has a huge battery bank. Lead acid is heavy as . . . well, lead. It also lacks the energy density of lithium. For electric cars to make any sort of sense at all a lighter and more energy dense battery is the way to go.

Lithium works great in power hand tools. The power and light weight make sense in something you have to lug around all day. Who wants to use a 50 pound cordless drill? Cell phones and other electronics benefit from compact and energy dense batteries. 

For a while Elon Musk’s power wall was going to be the big thing for off grid houses. You don’t hear that much about it lately. One model was discontinued and they’ve been tweaking the designs. They are  kinda spendy. Personally, I’m still using lead acid batteries with my house solar electric system. It’s a  huge price savings and the weight isn’t an issue since the house isn’t driving down the road at 80 mph. 

My small solar electric systems that I use for camping are still using lead acid. They are heavy, but the systems are small and only use one deep discharge battery. The weight penalty is acceptable. 

However, I did consider using a lithium battery for a 50 watt solar electric system I was going to bring on a long canoe trip. Weight was an issue in a canoe, especially when it came time to do a portage. As it turned out the trip didn’t come together so I never spent the money. 

Lithium batteries are pretty good, but expensive enough that you have to decide if your application really needs them or not. Industrial scale production brings the price down and that helps. In the long run lithium will probably be replaced with some cheaper and even more energy dense. There’s a lot of incentive to engineer in that direction.



  1. Everyone makes the assumption that clever people will always come up with something newer and better. Maybe they will...maybe they won't. It's entirely possible that we have reached "peak" battery efficiency/energy capacity vs weight. We may find something far superior for energy storage than batteries. Or we may have reached the apex for portable energy storage. We see the same assumptions made about space travel. Everyone assumes we will eventually find a way other than raw chemical energy to climb out of our gravity well. Again, maybe we will, maybe we won't.

    1. There's some high density battery tech that looks great in the lab but never makes it to production. Super capacitors have potential but only recently have they made it into consumer goods.

      Space travel is an interesting case. Like you say, lots of maybes. People don't realize how much energy is packed in our current chemical energy. That's one reason why we don't even have much for electric planes. Sure, you can get a small plane off the ground,but there's not much energy to go anywhere.