So as you saw in the electrical diagram, the heart of the system is the battery. It’s the big container that holds all of the energy from the solar panels, alternator, and shore power. So it’s a very big decision to make for the overall system.
There are really 3 main battery types to choose from, and they are distinguished by what the “goo” is inside and how it is held in place. I won’t go into battery chemistry and that science talk, but the first two battery types are both based on using Lead Acid “goo” to hold the electricity. The first type is a flooded lead acid battery. This is the old school battery that has water in it, and needs to be refilled from time to time. This type of battery can be spilled if sloshed around. What spills out is acid. So for a 4×4 going through europe and africa, thats not my first choice. These batteries also need to be maintained, the water level checked, the balance of the “goo” checked. So not much interest in that.
The second type of lead acid battery is an Absorbed Glass Matt battery, or AGM. What they basically do in these is instead of having the “goo” loose and flowing around in the battery. It is absorbed into matts inside of the battery. Think of it, like a stack of pancakes. These batteries don’t spill and don’t need any maintenance. This is what i had initially planned for the system. The downside to AGM is that they are even heavier than the flooded batteries, and all lead acid batteries should really not be used down below 50% of their capacity. So say a battery has a capacity of 250 units of power, i should actually only use 125 units of power before recharging it. So in essence its a 125 unit battery.
Well enter lithium ion battery technology.
This is what powers every cell phone, portable computer, and small electronic device. This technology has a lot of positives. First 90% of its capacity can be used without worry. So that same battery with 250 units of energy, can be used as a 225 unit battery! thats a huge gain. And they are a third of the weight of the AGM batteries. The AGM battery i was looking at weighed 164 points for that 125 units of power. A lithium battery with 125 usable units of power weights about 50 lbs. This is a huge difference when it comes to moving around in a small van.
So what’s the downside? Cost. A lithium battery can be 5 times the costs. It’s totally worth it, but we need some help for this one. We have reached out to an awesome manufacturer that we want to work with and we will see if they are going to help us. Keep your fingers crossed.