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Best value ($ per mAh) on 18650 cells?

rhd

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It's camping time, and the latest iteration of my tent light is requiring some additional 18650 cells. I think I probably need 12, but wouldn't mind grabbing a few more.

I'm not looking for the "best" 18650s, nor for the ones with the highest capacity, nor the ones capable of impressive drain specs. I know there are sellers on this board with really fantastic cells for sale, but that's not what I need for this project. I'm looking for the best value, which is an attribute that, to me, for this project, is measured in terms of mAh per dollar.

Any recommendations?
 





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Find a new/used laptop battery that uses 18650s in series. Open it and harvest the cells. You can get 6 or more cells for 15-20$.
Since you're a "DIY" type of guy I'm sure that'll be right up your alley.
 
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If capacity is not too important to you, I think this battery is a good choice for quality - price - capacity.

Also the seller is in the USA, and if you buy more than 3 units, you can make a price offer.

I don't think seller ships it to Canada, if that's where RHD lives....

Edit: BTW, do you want protected cells? A multi 40 battery setup might be risky, but I'm sure you know what you're doing. :)

Good luck!
 
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rhd

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Genuine SANYO 18650 2600mAh Rechargeable Battery - Red (Pair) - Free Shipping - DealExtreme

2 for 14$, 2600mA cells, i don't know about the drain specs but i use these all the time & they are awesome :D

That might actually be a rather bad value, at least relative to some other options. $7 for 2600mAh is not optimal.

If capacity is not too important to you, I think this battery is a good choice for quality - price - capacity.

Also the seller is in the USA, and if you buy more than 3 units, you can make a price offer.

Usually US sellers will ship to Canada if you ask. Again though, that might not actually be a hugely awesome value. $6 for 2550 mAh is the same mAh per $ as paying $4.70 for 2000 mAh. Not hugely awesome.

Find a new/used laptop battery that uses 18650s in series. Open it and harvest the cells. You can get 6 or more cells for 15-20$.
Since you're a "DIY" type of guy I'm sure that'll be right up your alley.

I've done this before with used laptop packs, and it's part of the reason that I need to replace 12 of the cells in this device a year later. If I could do it with new laptop packs, I'd be all for it. But I have no idea where to find a new 6-cell laptop pack for $15 to $20 :(


Okay, now we're talking. Are you actually endorsing these? I wasn't completely sure since you used the confused smiley. But if you've used these, and think they're decent, that's sort of what I'm looking for.

There are a number of ~2000mAh to 2500mAh options, on various sites and eBay, for around $2.50 to $3.00. The challenge, is that the value disappears if they're really 600mAh. But the value would still be there if a 2500mAh is really 1800mAh, because even at that level, for under $3, it's a good mAh per $ ratio.

So that's sort of my intent here. To find a cell that someone has some experience with, and thinks is at least somewhat in the neighborhood of the advertised claims. Another example, I can get 10 "UltraFire" cells for around $20.
Lot 10 x 3000mAh 18650 Rechargeable Li Battery UltraFire Li-ion 3.7V | eBay
10PCS/LOT 18650 3.7V Rechargeable Battery 4000mAh for LED Flashlight Free ship | eBay

Since I don't usually buy those kind of cells, I have no idea whether they're usually "labelled 3000 mAh but actually 500mAh" or more like "labelled 300mAh but actually 2000mAh". It makes a huge difference.
 
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I hear soshine makes some pretty decent protected cells, but I think the classic Sanyo ur18650F 2600mAh should do fine. Heck, maybe you can find some of the 2200mAh ones for even cheaper
 
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HAHA, one of the items in your link is a 4x 5000mAh 18650s for $10.
4x 18650 battery 5000MAH The contact point is flat for Laptop batteries 18650 | eBay
Laughed my bu
tt off. :crackup:
Indeed. I believe the new Panasonic 3400 mah are the most powerful 18650s you can get right now, or I suppose do the lack of availability currently, you can't get. There is some general debate over the ability for them to create cells for the private sector that would be more powerful and just not release them individually to the public. Regardless I doubt that's a true 5k cell, probably just marketing hype.
 
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rhd

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HAHA, one of the items in your link is a 4x 5000mAh 18650s for $10.
4x 18650 battery 5000MAH The contact point is flat for Laptop batteries 18650 | eBay
Laughed my bu
tt off. :crackup:

I don't understand why you're laughing... those batteries clearly have the word "GOOD 18650" stamped on their casing, so obviously they're just fine ;p

I think I'll probably just grab these:
http://www.ebay.com/itm/10-x-3800mA...e_Batteries&hash=item1c268a0445#ht_500wt_1180

I mean, $15, for 10, is like $1.50 each. If they were even 1500mAh, I'd be thrilled, at that price. Remember guys, capacity is really not too important. If a cell was like 500mAh, then there'd be a bit of concern because I'd be adding a lot of weight for almost no return. But apart from extremely under spec cells, 1500 vs 2200 is more or less irrelevant here.
 
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That might actually be a rather bad value, at least relative to some other options. $7 for 2600mAh is not optimal.

Usually US sellers will ship to Canada if you ask. Again though, that might not actually be a hugely awesome value. $6 for 2550 mAh is the same mAh per $ as paying $4.70 for 2000 mAh. Not hugely awesome.

You've gotta remember that the budget batteries are usually far below their stated mAh, often being recycled crap batteries in fake wrappers. That $6/2550mAh is actually a very good deal at that capacity, and so would $4.70 for 2000mAh, but you're very rarely going to get those capacities unless you stick with some of the name brands, and if the brands aren't faked. Low-balling with 18650s is liable to get you very garbage batteries (1400mAh for a 2200mAh for example) that'll end up costing you more in the long run than some real, decent batteries from a trusted source.

The best values I've found after cursory read of the flashlight sites and a battery test site pointed me to some XTAR 18700s, which you can get in a group buy at BudgetLightForum for about $6.75 each, or a little more if you wholesale it (link on that page). These XTARs are the next step up from (legit) Trustfire Flames 2400mAh. You can also try the Sanyos at BuyInCoins.com for ~$6/2600mAh.

These are really the best prices you can get for actual capacities. eBay, DX, etc. have all been hit with lots of fakes from the distributors even if it wasn't intended. It's just how it goes with stuff from China.
 
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rhd

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Yes, ok, I see clearly, I will propose you a Panasonic batteries, and you're gonna buy that crap Ultra-poop-fire, shame :undecided: :na:

I appreciate your suggestion - truly. This is just a case of specific parameters not matching up with the suggestion. Remember:

[regarding fantastic cells], that's not what I need for this project. I'm looking for the best value, which is an attribute that, to me, for this project, is measured in terms of mAh per dollar.

Panasonic: $5.95 for 2550 mAh is 430 mAh per $1

With those Ultra-poop-fires, at $1.50 each, and a rating of 3800mAh (BS of course) they'd only have to exceed 645mAh to better fulfill my parameters (best mAh per dollar).

I know you've got my best interests in mind. You're trying to hook me up with some quality cells. I certainly appreciate that.

But I've got a lot of really good quality 18650 cells. That's all I buy really, which is part of the reason that I don't have many crappy ones one hand. I have a number of AW IMRs, a bunch of the IMRs from BestInOne, and I've got a dozen or so of the red Sanyo cells. You don't have to sell me on the virtues of quality cells.

But believe it or not, there are times when the raw mAh per $ spec is all that matters - that's the deal here.
 
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I don't understand why you're laughing... those batteries clearly have the word "GOOD 18650" stamped on their casing, so obviously they're just fine ;p

I think I'll probably just grab these:
10 x 3800mAh 18650 rechargeable battery UitraFire JJ0 | eBay

I mean, $15, for 10, is like $1.50 each. If they were even 1500mAh, I'd be thrilled, at that price. Remember guys, capacity is really not too important. If a cell was like 500mAh, then there'd be a bit of concern because I'd be adding a lot of weight for almost no return. But apart from extremely under spec cells, 1500 vs 2200 is more or less irrelevant here.

Hahaha :crackup:

Yeah, I was surprised that you chose the really really cheap ones.
Capacity might not be as relevant, but safety is, especially while 40 of those hooked up in a camping tent.

Not to scare you or something, but here's an example of a creepy incident you don't want to have especially around your family.

Ultrafire 18650 3000mA exploded

If you do choose these cells, I'd love to know the real capacity. :beer:

Cheers!
 

rhd

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(1400mAh for a 2200mAh for example) that'll end up costing you more in the long run than some real, decent batteries from a trusted source.

See, that would be fine. If the cells were 1400mAh for $1.50, it would be a better choice in this scenario, than 2550mAh for $6. In fact, the same would be true if it were 800mAh for $1.50.

Again, my sole parameter is mAh per $. It's touching that other people are applying additional parameter's that aim to protect my best interests here. However, truly, I gave you guys my parameters, and I didn't forget or overlook any ;)

My parameter is highest mAh per $, with perhaps a secondary qualification that the cell would have to be at least 500mAh, or it starts to be not worth it's own weight (literally). But that's it. I don't have any secondary considerations. Maximizing that one single ratio, is my objective.

Yeah, I was surprised that you chose the really really cheap ones. Capacity might not be as relevant, but safety is, especially while 40 of those hooked up in a camping tent.

Again, I didn't forget any parameters. These are going into 4-packs that have integrated protection PCBs. Each cell is fed (on its own) into the PCB, which provides for safe charging, safe discharging, and cuts off the entire pack if a single cell fails. Safety is not an issue. (Well, it IS, but it's a concern that has already been addressed independently of the cells)
 
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Again, I didn't forget any parameters. These are going into 4-packs that have integrated protection PCBs. Each cell is fed (on its own) into the PCB, which provides for safe charging, safe discharging, and cuts off the entire pack if a single cell fails. Safety is not an issue. (Well, it IS, but it's a concern that has be addressed independently of the cells already)

Haha, I didn't realize that the cell holders had protection PCB's.
That's really cool!
Once again, you've never failed to amaze us with your nice builds, from lasers to battery packs. :wave:

Cheers!
 




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