Best battery for high capacity / high discharge.
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- Kurt_
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Hi! I'm looking for a battery that will drain safely at approximately 2.4V 8A or 3.7V 4A... without exploding. The high-current part of the circuit is regulated by a transistor, but can be adjusted anywhere from full power to no power, so the battery will essentially be a short circuit. Size is a large factor.
Due to size and capacity, Lithium Ion is the logical choice. But I worry that when shorted (Rather, dishcarging at 5-6A) they will catch on fire, especially when insulated by a case. (3.7V 2700mAh)
NiMH work, but don't have a large useful life for high discharge. (2x 1.2V 2700mAh)
Lithium Iron Phosphate has caught my attention, not requiring a protection circuit, able to store about the same energy as a NiMH AA, and storing about 3.2V 2700mAh in a single 18560 cell ('A' size).
My question is if there is a way to make lithium ion batteries work for this application or if I should just forget it. In addition, if there is any other type of battery I should consider.
Due to size and capacity, Lithium Ion is the logical choice. But I worry that when shorted (Rather, dishcarging at 5-6A) they will catch on fire, especially when insulated by a case. (3.7V 2700mAh)
NiMH work, but don't have a large useful life for high discharge. (2x 1.2V 2700mAh)
Lithium Iron Phosphate has caught my attention, not requiring a protection circuit, able to store about the same energy as a NiMH AA, and storing about 3.2V 2700mAh in a single 18560 cell ('A' size).
My question is if there is a way to make lithium ion batteries work for this application or if I should just forget it. In addition, if there is any other type of battery I should consider.
Hey, sup?
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Re: Best battery for high capacity / high discharge.
I go with lead-acid batteries, since my application of use needs an inexpensive solution for mobile needs for accent lighting, audio system and bright headlights, since its a bicycle, it doesn't need ultra-lightweight materials, seeing that I have the muscle to handle moderately heavy weight.
I choose 12 volt systems since its the most universally understood voltage for DC powered mobile applications.
I choose 12 volt systems since its the most universally understood voltage for DC powered mobile applications.
- Kurt_
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Re: Best battery for high capacity / high discharge.
I'm talking about handheld-type devices with high discharge currents. That's where things get tricky: the smaller cell sizes can output less current.
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- Triton
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Re: Best battery for high capacity / high discharge.
what kind of handheld device are you making that has that high of a current draw?
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- Kurt_
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Re: Best battery for high capacity / high discharge.
I can't get in to specifics. But it is basically a small battery powered resistance heater. It heats a 1"x1" area to 200 C via conduction. The battery is connected through a power transistor to the heating element, so the flow isn't entirely unregulated, but it is still essentially a shorted battery.
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Re: Best battery for high capacity / high discharge.
For that application I'd recommend... fire. Something butane based should be able to do that well and be nice and compact, with just a simple valve to control the heat. If you need precision control, a microcontroller connected thermal sensor and an actuator could be programmed to handle it.
Either that, or get a hold of whatever materials those extremely quick warm-up/cool-down soldering irons use. I have one from Radio Shack that can get hot enough to melt solder in about a second, and it uses two AAs.
That kind of heat would be a serious issue for Li-Ion unless insulated extremely well, the cells that I checked all said to keep them below 150F maximum. The kind of drain you're talking worries me as well, I would definitely check out the datasheets for any battery you want to use before considering them.
Either that, or get a hold of whatever materials those extremely quick warm-up/cool-down soldering irons use. I have one from Radio Shack that can get hot enough to melt solder in about a second, and it uses two AAs.
That kind of heat would be a serious issue for Li-Ion unless insulated extremely well, the cells that I checked all said to keep them below 150F maximum. The kind of drain you're talking worries me as well, I would definitely check out the datasheets for any battery you want to use before considering them.
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Re: Best battery for high capacity / high discharge.
If you're just gonna go for heated seat for winter weather comfort, then you don't need such extreme discharge. Besiides the lithium ion batteries you are looking for could easily power a car radio for 6 hours at FULL BLAST.
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Re: Best battery for high capacity / high discharge.
You could use a battery to charge up a capacitor and then discharge the capacitor as much as needed. Just, takes time is all to charge it up.
Of course, it will need all the correct circuitry
Of course, it will need all the correct circuitry
- bentendo64
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Re: Best battery for high capacity / high discharge.
How long does it have to discharge these large currents for?
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- Triton
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Re: Best battery for high capacity / high discharge.
for current capacity your best bet is lead acid, but if weight/size is a major concern i'm not sure what would be a good choice
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Re: Best battery for high capacity / high discharge.
Yea, I guess this would be your only optionTriton wrote:for current capacity your best bet is lead acid
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- Kurt_
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Re: Best battery for high capacity / high discharge.
I figure if I limit it to ~5 amps of current draw from the battery then I can use an 18650 Lithium Ion battery. So yeah, that.
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