I need the largest capacity 18650 batteries I can get for a project. Don't care about unit cost, but I want something that OzBargainers have verified as actually holding their stated capacity.
I've searched the usual suspects banggood, gearbest and ebay, but I just don't know what to trust.
What have you found to be the best? And do higher capacity batteries fail faster than medium (2000maH) ones?
I just replaced my HP laptop battery today. cracked open the old laptop battery and it contain 6 x samsung 18650 2200mAh batteries.
I'm sticking those into a DIY powerbank
How many of the 6 were still good?
I've been feeding my BLF torches with salvaged laptop batteries for awhile now, But I'm reluctant to share this tip with mates because they aren't protected cells.
i've opened 6 laptop batteries over the last 6 months and made 4 DIY powerbanks. I've so far only had 1 bad battery out of the 36 recovered 18650 cells. that 1 bad battery is in a 8 x 18650 DIY powerbank and I'm not sure which battery it is out of the 8 as I haven't done any individual testing upon them. it could even be the powerbank. it still holds enough charge to recharge my phone 5 times or so. but it should charge more than that. also the battery pack will only charge to 86%.
it's a strange situation with all the recovered 18650 batteries. as laptop batteries they were not charging/hold charging or had a terrible life span. now that I've taken them out and put them into powerbanks they seem fine, they hold charge. all good. it could be as simple as their life cycle/capacity/etc had degraded to the point that the internal circuitry of the laptop battery deemed them to be underpowered and hence the laptop battery would not longer function(?).
the battery I opened today I need to test the individual cells.
That's the battery monitor doing that. Sometimes a cell will dip below or above the safe voltage so the controller declares the pack to be dead.
Or maybe one cell is bit weak, you'd need to use an electronic load to test its capacity properly.
And occasionally it just gets confused and needs to be reset.
There's a bit of a conspiracy theory that for 'safety' reasons the circuitry decides a pack is too old after x amount of charges and refuses to let it be used.
@D C: There's a bit of a conspiracy theory that for 'safety' reasons the circuitry decides a pack is too old after x amount of charges and refuses to let it be used.
count me in on believing the conspiracy.
Is it worth buying a bunch of those protection boards off eBay/AliEx and fitting them on these old batteries?
I think most of us have a lot more Li batteries than we think, given how often we might replace phones, laptops, etc.
I'd be keen on having (protected) 3.6~4.2V batteries around given I dabble in basic electronics stuff (mostly 5V/USB based but certainly many ICs happy with 3~5V)
3400mAh is about the largest you can get.
The best way to get large cells would be to buy a brand name power tool or laptop battery pack and dismantle that. Not off AliExpress obviously. Even then, as @scrimshaw says getting cells above 3000mAh isn't easy.
Caution still needs to be exercised, a battery rated 18V & 3400mAh could have 5 cells of 3400mah capacity, or 10 cells with only 1800mAh.
Any tips on brands that use 3400mAh?
I think Panasonic is the only company to make 3400 cells, Samsung might.
I always thought DeWalt had a 3.4Ah battery, seems they only have 3Ah ones. Eg this one: https://www.bunnings.com.au/dewalt-18v-6-0ah-54v-xr-flexvolt… will have 10 x 3000 cells.
Beware of this one: https://www.bunnings.com.au/ozito-power-x-change-18v-3-0ah-l… which will have 10 x 1500 cells, the pack is too large for 5 x 3000 cells.
The RC crowd would be the best people to ask.
Thinking about it, this one: https://www.bunnings.com.au/dewalt-18v-6-0ah-54v-xr-flexvolt… won't have 3000mAh cells in it either.
In order to get 54v it'll need 3 banks of 5 cells (3 x 18v), so each cell would only be 2000mAh.
All too hard, me thinks.
3400mAh is about the largest you can get.
ebay claims otherwise ;)
http://www.ebay.com.au/itm/2X-Flat-Top-18650-6800mAh-3-7V-Li…
These are heaps better & cheaper: http://www.ebay.com/itm/2X-18650-9800mAh-Li-ion-3-7V-Recharg…
5 star rating, you can't go wrong with an Ultrafire battery!
hahaha yes can't go wrong with them ;)
Damn, that would put Elon Musks' battery in South Australia to shame.
eBay is over-run with fakes.
It depends on what you need out of the battery. High discharge would only be about 800mAh - 1600mAh or for low discharge up to 3400mAh for those Panasonic ones which are very good, just don't get cheap fakes.
I needed a bunch of small cells, so I got a few fake 9-cell laptop batteries (sub $20) off eBay.
Pack said they should be 2600mAh, battery wrapper said 1800mAh, testing showed they were about 1300mAh.
You do get what you pay for (I was expecting ~1000mAh so that was fine).
This month's Silicon Chip magazine has a good article on Li-ion cells. It tells you how to charge them etc. They say that the largest capacity in the 18650 casing is about 3700mAh, any claims above that are fraudulent. Typical cells are 1500-3000mAh.
Wow I didn't even know that Silicon Chimp was still published! Was my favorite magazine when I was a kid.
It's still around, dunno if Leo Simpson ever got over his 'conspiracy rant of the month' or 'editorials' as he preferred to call them or not.
Believe it or not, someone is having a go a publishing a new one: https://diyodemag.com/
More aimed at the maker crowd (Arduino, Raspberry Pi, phone apps etc) than the traditional old codger ham radio stuff which is a shift many (eg DSE) failed to notice.
you also need to consider the amp draw. Panasonic make a 3700mah battery but from memory it wont stand up to high amps for long
the samsung 30Q is 3000mah and will take a fair bit more current draw
you pretty much only want:
samsung
LG
Sony
Panasonic
The rest are junk or rebadge
I'd suggest also considering a Xiaomi power bank. If you get a real one, the individual cells are good quality (eg http://goughlui.com/2015/07/12/review-teardown-xiaomi-mi-ndy…) and cheaper than buying individually - although seems a shame to pull apart!
The 20000mAh version has 6*18650s. The ones in the power bank being pulled apart in the video turned out to be LG 3350mAh (LGABF1L1865) - of course no guarantee that will always be the case.
I'll take a punt on that - next deal that comes up for them I'm going to Broden.
Definitely worth a punt given that individually those sorts of cells are well over $12 each. My (genuine) 20000 job seems amazingly powerful so I reckon whatever is in there it must be fairly decent ie each 18650 cell is easily holding well over 3000…. I paid less than $40 for it, so that makes each cell $6.67. Bargain.
I would however suggest being a little more careful than the guy in the video - I was waiting for him to cut open his fingers as he hacked the case apart.
This site - http://lygte-info.dk/review/batteries2012/Common18650compara… - gives a pretty good view on 18650 Li-on batteries.
I have found the Panasonic batteries last better than Samsung and much better than Ultrafire.
I was looking at that and noticed some of the Ultrafire batteries performed remarkably well, then noticed he's put a few 26650 cells in there by mistake. Oopsies.
https://www.imrbatteries.com/18650-batteries/?sort=pricedesc
There are some 3500mAh batteries in there.
Look on YouTube for a guy called jehugarcia (?) He's built electric cars, diy Tesla Powerwalls etc. I've got most of my 18650 battery knowledge from there. They have some very cool battery charging tech I haven't seen in Australia.
Don't think so. On the contrary, higher capacity cells will last longer than smaller capacities, as a cell ages it will lose some of that capacity (even if you don't use it and it's sitting in a shelf)
Other factors like depth of discharge, charging speeds and the temperature will affect the lifespan of a lithium cell.
3000 milliamp hours is the highest capacity you can really buy on the market. I have LG INR cells, this is what I ordered in 2014. https://www.fasttech.com/product/1447304-lg-18650d1-3-7v-300…
I use it in a powerbank. It still works pretty well.