Poll: What is your minimum mAh cell you will use for your build

What is the minimum mAh cell you would use for your build

  • 1200 to 1399

    Votes: 1 2.0%
  • 1400 to 1599

    Votes: 4 8.2%
  • 1600 to 1799

    Votes: 7 14.3%
  • 1800 to 1999

    Votes: 16 32.7%
  • Not Below 2000

    Votes: 20 40.8%
  • Below 1200

    Votes: 1 2.0%

  • Total voters
    49

Power 2 Spare

Member
Joined
Jan 4, 2017
Messages
54
No matter what the size of your Powerwall or eBike project is, what is the minimum mAh cell you would consider using in the project? I'm conducting some market research and would appreciate everyone contributing. Thanks!
 
"Market research" to what purpose?
 
daromer said:
"Market research" to what purpose?

I am approached by a lot of people to purchase cells or packs. Since my minimum mAh cell is 2800 for my buildI have a shit ton of cells from 1200 to 2799 that could be distributed to other DIY'ers or Vapersdirectly or via eBay. I would rather get these cells into the hands of people who can use them for a good cause instead of them going to a recycling bin.
 
My best cell is 2900 I'm always looking for cells
 
jdeadman said:
My best cell is 2900 I'm always looking for cells

He wasn't talking about your best cell. What is the lowest mAh rating you're willing to use in a powerwall, or other battery pack application.

I personally think I'd go with about 1800mAh as my minimum. Much lower than that and you need a lot more to compensate for the lack of capacity. Space may be unlimited in my situation, but I still don't want to make that many packs over all for a little bit of storage.
 
For big builds no less than 2000mah. Even for power banks. However for packs for my UPS I will be using 1200-1800. I consider above 1800 acceptable.

edit - I did vote >2000mah, but I allow the Opus' error margin. If a cell is >1850, I keep it. If it is less I re-test it.
 
I so far processed about 3000 cells. Never came across one with more than 2300 mAh. Only about 15 % have more than 2000 mAh. I am using a somewhat professional celltester (Junsi iCharger 4010 Duo) to meseaure cell capacity andI discharge to 3,0 Volt.I have the impression most of thetester that are used by people here,are way off, when it comes to cell capacity. Further, some people dont even know there discharge current. They just put it in the tester. I very much doubt, that a 4-way tester will discharge each of the four cells with 1A. A lesser discharge rate will lead to falsly high capacity measurements. One should keep that in mind.
 
Herbi said:
I so far processed about 3000 cells. Never came across one with more than 2300 mAh. Only about 15 % have more than 2000 mAh. I am using a somewhat professional celltester (Junsi iCharger 4010 Duo) to meseaure cell capacity andI discharge to 3,0 Volt.I have the impression most of thetester that are used by people here,are way off, when it comes to cell capacity. Further, some people dont even know there discharge current. They just put it in the tester. I very much doubt, that a 4-way tester will discharge each of the four cells with 1A. A lesser discharge rate will lead to falsly high capacity measurements. One should keep that in mind.

I guaranteeyou that if you got one of my prized med packs you would see cells over 3000mah even with your tester.
 
Herbi said:
[...]
I have the impression most of thetester that are used by people here,are way off, when it comes to cell capacity.

Further, some people dont even know there discharge current. They just put it in the tester.

I very much doubt, that a 4-way tester will discharge each of the four cells with 1A.
[...]

I'm pretty comfortable with using Opus's to measure capacity. Despite their notorious 'inaccuracy'. Think of it like a meter rule, which does not measure exactly 1000mm. What does it really matter, when all we are really doing is gauging RELATIVE capacity. It doesn't -- at all! So long we know which are the duds, and the relative capacities of each cell to build semi-balanced capacity packs..

It's very hard NOT to notice the current of the Opus. When one inserts a cell to charge/test it changes the screen to display current. One has to actively change the display mode to get it off that readout ... me personally, I like to leave them sitting on the voltage display ... so I am forced to press a button to do this, only after the current is flashing on the screen. And yes, the Opus is a four way charger, which works at a max of 1000mA per slot. I really don't know why you would doubt this pretty mundane fact of life ...

OP: thanks for this poll, I too am interested in the possibilities of uses for my lower capacity cells. From the initial results, it looks like not too many voters would be interested in my lower capacity cells, but then ... I'm not really targeting that kind of folk ... I always expected it would be the tinkerers / noobs that might be interested in buying them.

All that said, I have very different standards depending on the packs Im building. EG 'temporary' or 'giveaway' packs I make, I choose the lower end. If I'm making something to be portable, EG to recharge my quadcopters in the field, I pick my absolute highest capacity, for energy density reasons (I'm carrying them all!).

And finally, I am starting to base my decisions for powerwall use based on what % of original (new) capacity remains ... IE I would now lean towards using a 1500mAh cell that was originally rated at 2200, over an 1800 that was made as a 3000. Totally made up numbers, but you get the idea ... its all relative.

PS the cells I use are ALL harvested, IE used. They are well into their lives. This means their capacity is changing ... I'm trying to find cells that will change as little as possible over time. This is more important to me (now) than their actual capacity.
 
Geek said:
For big builds no less than 2000mah. Even for power banks. However for packs for my UPS I will be using 1200-1800. I consider above 1800 acceptable.

edit - I did vote >2000mah

About the same here. 2000mAh+ for larger projects and powerbanks, and 1500mAh to 1999mAh for smaller stuff.
 
All of the cells I use are above 2000mAh for 14.4V and up projects, and are on average about 2450mAh. If they are below 1950mAh, I usually use them for lower end projects.

For below 1500mAh, I give them in away in small USB battery packs for a small price.

For 1000mAh and below, I use them for special projects: as AA replacements! As while they don't have as much capacity as two Eneloop in series, they pack much much more firepower!

I tried this with my razor with 1 cell , and holy shit was it powerful fully charged! It easily did a 15 min job in 5 min, even less if I used a high current cell which didn't sag as much.

I also tried it with a toy car which used 4AA in series, and let me tell you, it actually became a bit dangerous, as its acceleration went up to the sky!
 
I would use anything 2000mAh and up for larger projects like an eBike or power wall.
Smaller projects like flashlights, starter batteries, and portable power boxes I'd use 1000-2000mAh.
Cells below 1000mAh are too close to end of life for me. I find that they have a rather high internal resistance and take a long time to charge.
 
Newbie alert.

I would have thought 2,000mAh +

But I would have thought HBpowerwall would have chimed in by now as he seems to have the most experience and most cells processed.

YMMV.
 
Herbi said:
I so far processed about 3000 cells. Never came across one with more than 2300 mAh. Only about 15 % have more than 2000 mAh. I am using a somewhat professional celltester (Junsi iCharger 4010 Duo) to meseaure cell capacity andI discharge to 3,0 Volt.I have the impression most of thetester that are used by people here,are way off, when it comes to cell capacity. Further, some people dont even know there discharge current. They just put it in the tester. I very much doubt, that a 4-way tester will discharge each of the four cells with 1A. A lesser discharge rate will lead to falsly high capacity measurements. One should keep that in mind.

back up a second. What??? Have you never got any grey Panasonic? They are up around the 3000mah mark.

Someone send this guy a grey please!!!


I started off with selecting >1500mah, but then as I hit my 1120 cell count, I started weeding out the lowest capacity ones. This has continued to where I have nothing <1700mah, a few dozen 1700-1800 cells, but a good few hundred 1800-1900 cells. I can't decide whether to keep sourcing more packs and swapping out the low cap cells or not. Packs are costing me money!

Also, I've got a lot of space for my wall. So that's not a constraint.
 
Daveyboy said:
Herbi said:
I so far processed about 3000 cells. Never came across one with more than 2300 mAh. Only about 15 % have more than 2000 mAh. I am using a somewhat professional celltester (Junsi iCharger 4010 Duo) to meseaure cell capacity andI discharge to 3,0 Volt.I have the impression most of thetester that are used by people here,are way off, when it comes to cell capacity. Further, some people dont even know there discharge current. They just put it in the tester. I very much doubt, that a 4-way tester will discharge each of the four cells with 1A. A lesser discharge rate will lead to falsly high capacity measurements. One should keep that in mind.

back up a second. What??? Have you never got any grey Panasonic? They are up around the 3000mah mark.

Someone send this guy a grey please!!!


I started off with selecting >1500mah, but then as I hit my 1120 cell count, I started weeding out the lowest capacity ones. This has continued to where I have nothing <1700mah, a few dozen 1700-1800 cells, but a good few hundred 1800-1900 cells. I can't decide whether to keep sourcing more packs and swapping out the low cap cells or not. Packs are costing me money!

Also, I've got a lot of space for my wall. So that's not a constraint.



Davey, it does depend what cells you have. It does depend how that charger is discharging. Perhaps you should get a cell with a known capacity - ie brand new and genuine - and see what you get. You are either having really bad luck, or your charger is indeed underestimating your cells capacity. I believe my Opus, and RC chargers, even the cheap ones, to be fairly accurate. Obviously the results vary between them, but they are consistent.
 
TerryTexas said:
daromer said:
"Market research" to what purpose?

I am approached by a lot of people to purchase cells or packs. Since my minimum mAh cell is 2800 for my buildI have a shit ton of cells from 1200 to 2799 that could be distributed to other DIY'ers or Vapersdirectly or via eBay. I would rather get these cells into the hands of people who can use them for a good cause instead of them going to a recycling bin.

Well hit me up for anything over 1,800mAh. How much do you want for them ? and do you test them as follows ?

My small trial so far has been petty dismal.

By the time I do the following:-

A) A triple charge and discharge.

B) Eliminate batteries under 1,800mAh

C) Eliminate hot batteries.

D) Eliminate batteries that have serious discharge issues after a month

I have few batteries left.

15% would be great. It seems to be closer then 10%. That's a lot of batteries to test and then throw away (or use on other projects) 85%+ as they are not, IMO suitable for my powerwall project

Non OEM are the worst as they use cheaper and lower capacity batteries. But that is why they are inexpensive.
 
Back
Top