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Call me crazy. I get some wild ideas, but sometimes they are good, sometimes not so good. So you guys are familiar with 18650 cells right? Wonder if you could build battery packs out of those like we used to in the sub c cells days? All these new electric cars coming out are starting to use these cells. Maybe weight becomes a factor because of the metal casing they are in? Seems like in some ways the configuration would be butter suited to some hulls. Maybe the capacity would be lacking or the amp capability wouldn't be there. I'm just thinking of alternatives. I have my reasons why that I don't want to get into just yet.
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32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was -
I'd like to add. I was thinking about constructing a couple 4s packs to run in parallel. I'm reading that they have more energy density vs lipo but then they won't support as much amp draw. The way I was thinking (if it will fit) is 8 cells per pack for about 5200mah each and then those two in parallel for about 10,400mah. Might work well in a play boat but probably nothing with high amp draw. I'm just getting tired of battery suppliers start out great then can't keep up with demand and then they start half assing stuff to keep up with the demand. Seen it a couple times now and as we know, the performance of our boats relies greatly on the battery performance.32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was -
I think they are both LiPo cells. I have also read that the cylindrical cells do not have near the C-Rating as the flat packs. BUT, if you build a high voltage pack by sticking a bunch in series, like 8-10s, then the current requirement will drop if you put in the right motor/prop. Maybe a space savings? I'm still not sure how those cells will like even 100A draws, which is 3000W on 8s and 3700W on 10s. Due to weight, not sure of the feasibility of a 2p pack.
Maybe you should use a Viking burial boat to try it out, just in case it flames! LOL!Comment
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some guys are already making betteries out of 18650`s . but they are using them in planes .
volantex vector pro ,proboat veles 29 , traxxas spartan, hobbyking/tfl pursuit ,ft009 with rescue riggingComment
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Where the current is much lower and the peak amp draws are much less than boats...Comment
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I'm seeing a max discharge current of just 20A. I then checked the IR spec, they are at 15-20mOhm! That's a tanked LiPo battery! They are manufactured for low current draw over long periods of time, like for laptops...Comment
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Mostly, but many 20A+ 2500mAh cells can provide 50-100A or more in 1 second bursts. Also the airplane guys prefer these because they hold up to crashes better. They rarely have a fiberglass shell protecting lipo's like boats do.
I use them in my airsoft gun, which I think is similar to a 380 brushed motor, and they're perfect. I also made a receiver pack for a nitro buggy before I converted it to electric. Now I use it to test receivers and power arduino projects. The main usage for 18650's are the $2 LED flashlights I get from China. Nearly as bright as the $30-50 Coast LED flashlights.Comment
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32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) wasComment
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Well weight won't be an issue. Each cell weighs 1.05oz so that would be just over 8oz. A 3300 revo 4s pack weighs 9.56oz32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) wasComment
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Yes, 20A per cell. For 150A continuous you'd need 8 cells in parallel or 32 cells total for a 4S 160A pack. To match that revo pack it would be 30oz+ with wires.Comment
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18650s for minis and 26650s for full size classes are in the naviga rule book, as an alternative to LiPos. They are not LiPo they are LiFePo4 so have a lower voltage than LiPo they are also heavier for the power or the weight, but they are a much more robust cell, less suseptable to overdisharging, with a high cycle life, and the chemistry doesnt like burning as much. There are now rectangular LiPo like packs LiFePo4 packs that are robuster than LiPos without the weight and form factor penalty of the metal case.
The originals are A123 cells the 26650s had a very high power density at the time and 3s2p 26650, was roughly equivalent to the 2s 5000mAh we got with 280g 6 or 7 yerars ago, a little more power, but with a chunk more weight, they were pretty popular, the 3s 1100mAh 18650, was never really competitive with 110g of LiPo for minis which was 2s 1800mAh at the time,but things have moved on a lot for LiPos and they have been outclassed, now for the same 280g we have 50% more energy, I haven't seen an 18650 or 26650 pack being used for many years. Although they hasve been cloned a lot since I last used them, most offer higher energy density but less power density, for torches and laptops etc, I havent heard of any with more power density than A123s, which are a genuine constant 30A for 18650 and 50A for 26650. The best way to buy 26650s was as a twin pack of dewalt 32v(Europe) or 36v(USA) batteries, which contain 10 A123 cells each, for the same price as 10 loose cells from A123. The typical 2000+mAh 18650 is only good for about 5A continous before the voltage drops to the same level.
I still have mine, and they will never go back in a boat. I really must get around to stripping them out of their 3s packs and making a 4s5p lightweight car battery from them.Paul Upton-Taylor, Greased Weasel Racing.Comment
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Anything on the li-air cells ? I was reading on them and mostly last years info expecting production this year. They had five times capacity of current batteries. I think they are comparing tool batteries mindyou.Comment
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32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) wasComment
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