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Battery Now that we have chosen what we will build the generator in, we need another important component -- a battery to store the energy and to be able to use this energy. Most of the time we think of batteries, portable components that store energy ready to be used on demand. A few thoughts have to go into this to purchase the best available storage device (battery) for our project. Here we will discuss the chemistry of several different batteries, their positive and negative aspects of each chemistry. Then, how large of a battery can we actually and comfortably fir into our device's container and lastly -- budget. How to get the best bang for our buck! A battery uses certain anodes cathodes and stores this energy using a different chemistry. Here we are going to lightly touch on some of the more important subjects. There is however a free course, unaffiliated to me, that will definitely teach you way more than what we are going to cover here. https://alison.com/course/battery-technologies?utm_source=bing&utm_medium=cpc&utm_campaign=424620871&utm_content=1348002735336832&utm_term=kwd-84251063629114:loc-190&msclkid=18921f637f83109f8f127d01a6db51b5 If you take the course, I hope you will enjoy. Below, in our first photo it displays how the battery charges, stores and then gives back its energy to you. Next, we know of our car batteries being lead acid which we are all very familiar with. They only last 2 to 3 years and gives the car power when it is not running and the car in return, when running, will automatically keep the battery charged. When and if the battery goes out, it stops starting the car and usually needs to be replaced. Sometimes however, we may just need to recharge using an external charger. We have lead acid, gel batteries, meant for heavy loads, such as starting cars, boat motors ect. The positives are they are less expensive and can issue, on demand a strong current to start a motor. The downside is they are heavy. They have to have lots of fresh air because of chemical expansion and contraction which in turn needs to breath which can give off dangerous fumes. You can only usually safely discharge to 50% without damaging the battery which means if you have a 20 ah battery, its really a 10 ah battery. Each time you deep discharge it the cells themselves get damaged. We know of nicad and they are good enough for 50% discharge as well. Life cycles are about the same 200-500 (full discharge/recharge) they are heavy as well. They do well in all kinds of weather as like the lead acid. They too, have a strong current to be able to start motors. Next we have lithium batteries. As we know from years past about the dangers with straight lithium batteries they can explode. They are lighter than the lead, gel and nicad batteries. They have a long duration of usage as well. You can safely, and protect the battery life by charging to 90% and deplete to 20 percent. Thus, giving you at least 30% more time between charges. This type and the lifepo4 batteries generally are not strong enough to start a car engine. They can store their current state of charge much longer, up to a year. The dangers are high heat and they do not like the cold weather. Infact, anything below 32 degrees can forever damage the battery. The life cycle for these generally are from 500-800 charge cycles. The last type of battery we will discuss here is lithium but called lifepo4. They use a lot less lithium in their chemistry and have proven to be a safe alternative for energy storage and use. They are lighter than lead acid but the same size. They Have all the benefits of lithium in fact, but manage to do things longer and better. They are safer than lithium batteries with no runaway power and can tolerate heat a bit better. These too are limited to cold weather usage however with the same debilitating 32 degree min temperature. They have 2000-5000+ life cycle when they reach 80% life. Which means about 10 years and they still have 80% storage capacity. Makes your investment longer for return a wee bit sweeter. Most of us will be looking for 12 volt batteries. A bit cheaper than 24v-48v batteries and many of the components we may already have or available are very easy to find using 12 v. Sometimes, as you will see in the next post of what we chose and why you will desire to have a 24v battery or more Ah (amp Hours) and yet you already bought a certain battery. Well, we can combine 2 batteries of the same type and same voltage and ah together Usually the maker of the battery would really like you to have 2 of the same exact batteries, which realistically is also promoted to have success at keeping your batteries good. If you have a 12v battery but now you want it to run a 24v inverter then your not lost -- just pick up a second battery and wire it up serially. Below, you can see a diagram serially wiring to batteries together. This keeps the same ah but doubles your voltage. If you need more or desire for a longer lasting battery (more AH) than you can wire them up parallel with the same second battery as illustrated in the last included diagram. If you can help, we would truly appreciate and need it -- Thank you https://gofund.me/5b4a16c6 Any little bit helps and we truly are grateful. The next post we will discuss what we chose for our science project, why and why we added to it.