Can you make individual batteries? NoNatgreen said:And...is it worth the effort? Is it significantly cheaper? Where do I get started?
Gypsy Freedom said:18650 lithium ion cells, aside from the thermal run away problem do not have that great of life cycles 300-500 cycles. some places claiming 800. i can get more than that out of flooded lead acid.
while 3.7 or so is the nominal voltage for a lithium ion cell(18650s for ex) a fully charged cell is over 4 volts. if you put 4 in series you have more than 16 volts. only a few inverters out there that can handle that without faulting.
if you use only 3 in series then you run into a problem of finding an inverter that will not shut of due to low voltage before you have used up the capacity of the battery. yes there are a couple out there, but they are not cheap.
due to these 2 issues you typically cant access much of the battery capacity. so your cost per useable amp hour goes up
most of the cheap BMS (battery management system) units out there have extremely low through put. if you want a BMS that can handle powering a 2000 watt inverter, that is going to cost some $
there is not much to gain with trying to replace a 12v rv/boat system with a cheap lithium ion (18650) battery
geogentry said:But as your lead acid ages the available voltage drops. no, the amp hour capacity drops. but as lithium batteries age, they lose capacity as well.
Apple company claims at least 1000 cycles from their device batteries. there is a big difference in claiming, and guaranteeing, they are also not using 18650 form factor.
You should not charge a Li battery over the nominal. To charge the battery to the maximum voltage will overheat the battery and drastically shorten its life. this is completely false, to get any where near full or even 80% capacity you need to charge above nominal. standard full cell for lithium ion is about 4.2v with an empty cell at about 3.0v. sure staying away from the high end and low end a bit will give more life. but at the nominal voltage you are claiming to charge to the battery is only about half full.
And that is why you have a BMS no, a battery managment system is to protect the battery. it has nothing to do with what voltage an inverter is capable of using
Sure you can. 50% just like the lead acid your using what? only discharge your lipo to 50% kinda negates the benefits of lithium
Sigh. This is not the place to teach you how to divide up the series banks, with a BMS on each, and thus does not require that one BMS handle all the current. sigh... lol a 4s BMS rated at 10 amps will monitor 4 batteries in series and safely allow 10amps of current. if you were to wire them in series you would still only get 10 amps. in order to get more amps you would need to wire multiple BMS modules in parallel. and to get enough current capacity to power a 2000 watt inverter you would need many
It seems you are not aware that Tesla uses a battery bank comprised of 18650 batteries in the electric car. actually i am quite aware that tesla used 18650 lithium ion cells in their earlier models, but the current model 3 uses a new form factor. the 2170 also refered to as the 21700.
Tesla uses Lithium-ion rechargeable batteries in its cars. The Tesla Model S and Mode X use the18650 battery.Oct 13, 2018 nice copy and paste quote with out properly attributing it
It seems Tesla does not agree with you seeing as tesla when they were using 18650 cells, put them together to form around a 22 volt module and now runs closer to 50 volts in their model 3 modules i dont think they are saying they would make a simple and cheap replacement for a 12v rv battery they also charge their cells to about 4.17v for a full charge
It would work. And work well. I will say that that video that was in a previous post on this thread is excellent. The cost for the battery he shows is just slightly higher in cost then the ones using the 18650. And it is massively easier. I recommend you check out that video and the website that is listed in the description underneath the video. A ton of information.justawfulgamer said:The 18650 idea seems like a really cool one. I wonder how well that would work for off grid purposes
justawfulgamer said:The 18650 idea seems like a really cool one. I wonder how well that would work for off grid purposes
what would i search for on ebay? whats the name of that battery? i also wonder how many 18650 batteries it would take to make a 12v 100ah or so battery, like to replace an rv one.geogentry said:It would work. And work well. I will say that that video that was in a previous post on this thread is excellent. The cost for the battery he shows is just slightly higher in cost then the ones using the 18650. And it is massively easier. I recommend you check out that video and the website that is listed in the description underneath the video. A ton of information.
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justawfulgamer said:what would i search for on ebay? whats the name of that battery? i also wonder how many 18650 batteries it would take to make a 12v 100ah or so battery, like to replace an rv one.
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