liveforphysics
100 TW
urace4me2 said:liveforphysics said:If you put a LiPo pack in the oven and over-voltaged it to blow it up, it would be fine. Oven would be a great place to charge, good idea.
You mentioned a Ping pack. For energy storage, it's fine. About twice the weight and bulk of LiPo for the same energy storage, but still fine. Now, lets talk about POWER differences. This is what LiPo is all about.
Let's choose Ping's biggest battery, the 48v 20Ah. This is a 2c battery, which tells us that this pack can discharge at 40amps. This battery weighs 20lbs, and can discharge at 1920w.
How much weight in LiPo do you need to match that?
Not picking anything fancy, just economical 30c zippy LiPo packs from hobby city, we can work out what it takes to equal the power of the biggest Ping pack in LiPo. What does it take? It just takes a single tiny 4cell 5Ah zippy pack, and it can all ready sustain 2200w VS the Ping battery 1920w, but the big difference is weight. The LiPo battery is just 1.2lbs vs the 20lbs of Ping battery! Yup, that's about 17 times the power density. It's also about the size of a regular non-flip-type cell phone, VS the size of a couple stacked shoeboxes. If you are looking for energy storage, lead-acid, LiFePO4, NiMH all offer energy storage at low prices if you don't mind a lot of weight and bulk. However, if you are looking for performance and power with a reasonable cost, nothing matches LiPo.
Just incase anyone wanted more specs on the battery I choose to compare power to the biggest Ping pack, here is a link. It's not anything special, just the upper model of zippy LiPo.
http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=8588&Product_Name=ZIPPY_Flightmax_5000mAh_4S1P_30C_
I'm lost, .... 14volts X 3 = 45 volts. 5AH X 4 = 20 AH. That means 12 of these units roughly equals a ping 48 V 20 AH. Each of these 12 units weighs over 500 grams. About 15 lbs. or so? Or did I miss something mighty big?
Power density and Energy density are very different things. If you are involving Amp hours in your calculation, you are confusing energy and power.