6 Panisonic 2900mah Batteries for $10

Batteries and Chargers Rechargeable Batteries
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>>>>>5800/6 != 2900…? how did you determine that there would be 6 panasonic 2900’s in there?

The original answer is now lost in the fog of time. I think someone guessed that 2x2900 = 5800. And since Panasonic is the only one who makes 2900 cells, they had to be Panasonics.

Someone bought a pack and confirmed this. Ever since then, the hunt has been on for 5800 packs. And since Acer packs were found originally to contain the panasonics, we have been concentrating on Acers.

>>>>>i was just hoping to garner info on why this pack was picked or preferred

It contains Panasonics, arguably the most preferred 18650 for flashlights.

Price also plays a big role in this. For whatever reason, the acer packs have been selling for $9-$16 for six cells. Other brands have been selling for more. That’s why the concetntartion on 5800 acer packs. Other brands contain less powerful cells for more momey. Hard to beat new 2900s for $1.66 to $2.66.

As Mr. Pyro points out, they can be wired in different configurations, so that both helps and confuses the issue. However, I could be wrong, as there are no hard and fast rules with these packs, but with six cells, a 5200 pack should be 2600 cells. 5600 would equal (theoretically) 2800 cells, etc.

>>>>>>also, i cannot see where any pack says it’s country of origin due to quality of ebay photos he uploads…

Once again, in a perfect world, the packs say country of assembly and country of cell origin, two DISTINCT clues.

Once again, Korea = Samsung or LG, great cells.

Japan = Sony, Sanyo and Panasonic, great cells.

If you can’t see the picture well enough to read it online, you can look up the model number online and it will tell you: number of cells, mah and country of cell origin. As I said before, I have seen one pack out of maybe 50-75 that did not say cell country origin.

>>>>>must i stick with 5800 packs?

USUALLY, the higher mah batteries are the most desirable, so a 2200mah cell has less power and therefore is less desirable becuase it puts out less power.

That is about everything relevant that I know about the current hunt for the 2900 grail.

Hope this helps.

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thanks all for replying my particular questions. I’ll start the hunting for sanyo one :slight_smile:

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>>>>>because I rarely use SRK handburner, and when I do, not for long

I have been so lucky with my two SRKs. They seem to be originals, but they don’t get overly hot. Warm but not hot.

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>>>> I probably grip it tightly with dogleashes sometimes in the same hand for an hour at least: I dont

Oh I’ve never used mine for an hour. It does get warm, but I have had lights burn up from getting too hot, so I don’t let either of my two SRKs get credit-card melting hot. They might actually get that hot eventually, but I have never let them go far. I switch to low power to let it cool down.

I actually like my TRJ12 better. It has nore of a center-weighted light. Not a thrower by any means but not a completely flat flood light either.

Are you using really nacky batteries? If you’re overdriving the cells, they could be getting hot and causing the problem.

My lux readings on the SRKs seem pretty in line with others.

But then again, leaving the srk on for an hour probably isn’t a problem per se. I bet it does get pretty hot.

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sorry I was on my phone and couldn’t help ya

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Wow, second pack all cells are charged to 3.68 without variance! These are nice packs if he has anymore, second pack was so much easier than the first, no sparks anywhere for a newbie pack puller.

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good job. I think when the cells have a higher charge and they are all at the same voltage means it was charged more recently. when the cells sit for awhile they seem to settle at slightly dif rates. the batteries I got have great runtimes.

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>>>> I got some shrink wrap for when they get too bad.

The nicks present a possibility of a short. Some feel that it is a minor hazard; others feel that it is a significant hazard. For the penny or so it costs per battery, I cover each one with TRANSPARENT shrink tube. It makes em look slick as heck; covers any leftover gooey residue; and stops wear to the original label. It also preserves the data about battery source, original charge, dates, etc. that I put on the orig. label to measure life over time. With 300 or more batteries I would never remember this stuff unless I wrote it on the battery.

Plus, it allows me to write notes on the shrink tube about charging dates, etc. This allows me to rotate cells so I’m not always using the same one. I have over 30 2900s at last count. Those notes I can erase as the cells fill up, but the notes on the original label remain untouched because they are UNDER the shrink tube. Using this rather rudimentary tracking system and frequent DMM use, I have already identified batteries that just don’t hold a chrge period (down to like 3.70 after 30 days) and ones that won’t charge more than like 4.13 volts after 10-15 charges.

I also put on the pos. terminal a solder ball on 4 out of 5 because I have quite a few lights without driver springs. I looked everywhere because the shrink tube would hold the button tops in place but could find no affordable source of buttontops.

Then I sort ’em all in shotgun shell boxes with labels about contents. I put labels on those so I can find what I want.

With all these li-ion batteries, I would not want to be the firefighter to put out my house if it ever caught fire. But most I store in a huge root cellar in a miners cabin. The cellar stays at 62 degrees pretty much all year round. The cabin is on our Death Valley property. So I don’t have all the batteries with me down south while I escape th heat, but here are a few:

I know I’m kinda anal about all this, but when I wasn’t I was literally tripping over batteries everywhere.

>>>>>hold at 4.21 after about a month sitting.

Your 2900s held at 4.21 after a month? Wow! You must have the world’s best batch(es). I’m jealous. I started a representative batch at 4.21 May 31, and they’re already down to 4.17 (3); 4.18 (1), and 4.19 (1) after 7 days. These are from three new packs, one used pack and two loose 2900s from fasttech. I have plenty of OTHER cells that stay at 4.2 volts, but not the 2900s.

Actually from what I read, it’s best to store them under 4 volts, so it’s probably good that they drop voltage. It prolongs battery life, or so they say.

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Just received my pack and all cells measured 4.02 It took me about 10 minutes to pull them out and I was trying to be careful since this was my first laptop pull. Thank you to the op now my small 18650 battery collection just doubled in size

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Ok you guys know that storing your batteries at full charge causes rapid deterioration of the mAh of the cell. For storage, discharge them to 3.75V and put them in a cool spot like the produce drawer of the fridge…not the freezer….or Death Valley…:slight_smile:

Thanks again Ubehebe….aka The Battery King!

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Being that you also live in southern California, you can appreciate having charged batteries in case of a blackout. I don't have nearly as many batteries as Ubehebe. With the number of batteries I have, I want them all fully charged.

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I bet the “king” doesn’t have any of these rare Sony 18650s in his collection. And who stores batteries for the long term? Batteries are meant to be used. lol

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If you put batteries in myfridge my wifE will burn the bacon and refuse. To do dishes ....

Refrigerator??? That's nuts...mine are fully charged and ready for action.. Storage in cool spot. Means. Back of the closet

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I thought this was for AA’s, usually they don’t go over 2700.

Disappointed :stuck_out_tongue:

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btw the SONYs in the pic above are rewraps from a pack I did couple weeks ago

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I finally pulled the cells from mine. It was my first, and it went well. No fire, explosions or nicked cells. All were between 2.55-2.68V. They're charging now. I still need to clean them up a little, but I could use them as-is if I wanted to. There's another first. These are my first 18650's outside of bike light battery packs. I don't have any pure 18650 lights though, just 26650 lights with 18650 adapters.

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These NCR18650 cells are nice, thanks PyTech for the heads up.

Got around to unpacking the NCR1850’s, and no sparks or nicks. Once the one end of the pack is popped, it is easy to work the edge along to free things up. Finger nail and some isopropyl alcohol cleaned up the glue.

Voltages were 2.374, 2.347, 2.348, 2.373, 2.348, 2.347. Using a Thunder AC6 hobby charger, with 1A discharge down to 3.0V: mah readings were 2372, 2530, 2326, 2269, 2219, 2347 respectively.

The Panasonic datasheet rates these cells with discharge down to 2.5V, but my charger is fixed at 3V. So, should be able to to add a bit more capacity to compare to new cells. Does anyone know what that difference is, however small that might be?

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These cells have been holding a charge very well.

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Bought one of these as the affordable 5800 market seems to have dried up for a bit:

http://www.ebay.com/itm/Acer-11-1v-Genuine-Laptop-Battery-White-5200mAh-58Wh-UM08B31-/140854800590?pt=Laptop_Batteries&hash=item20cb99b0ce#ht_6165wt_1394

Obviously they’re 2600 Sanyos, just like the pack says.

Cells were 2 volts and took 5 charges to hold a charge, but they’re holding now. Seem to work dandy.

Now that I have a lux meter, I need to get a hobby charger to start checking capacity on these batteries.

Hoping to expand my collection to all 2600+ cells and giveaway anything less in the mah dept.

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>>>>>With the number of batteries I have, I want them all fully charged.

Yeah ditto on that one. I know keeping them ramped up to 4.2 volts shortens their lives, but I’m not really concerned about a shelf life shortened by a couple hundred full charges. No big deal for me. I’ll just get some more. :wink:

Every Home Depot in OC and LA (while I’m down here) seems to have 2-3 packs. It’s not like they’re hard to find for me.

Even when I’m in DV, the nearest HD always seem to have 2-3 packs also every time I visit every coupla weeks.

Although I am letting a couple boxes sit fallow for maybe 6 months and see how far they really do drop in retained voltage.