Hi, i managed to work out how to send pics, I posted them on the forum yesterday.Add a photo to a forum post, UKC is about sharing information. I am sure others are curious.. What I am scary off is seeing "Zipfire" or similar.
Hi, i managed to work out how to send pics, I posted them on the forum yesterday.Add a photo to a forum post, UKC is about sharing information. I am sure others are curious.. What I am scary off is seeing "Zipfire" or similar.
Well those cells in the photos look like low end HC or HCM Sanyo cells with quite a measley out put, my colleagues all have had a good laugh at this thread, considering what we do to poor 18650 cells!!Add a photo to a forum post, UKC is about sharing information. I am sure others are curious.. What I am scary off is seeing "Zipfire" or similar.
Strictly speaking an amp-hour (Ah) is a unit of charge and a watt-hour (Wh) is a unit of energy.Sorry to bang on about this – but it's now my understanding that Ah is not a measure of the capacity of a battery/cell. To get that, you have to multiply Ah by potential difference, so in the case of the 4-Ah / 14.4-V battery mentioned above you obtain the capacity in Wh simply by multiplying 4 by 14.4, which gives 57.6 Wh. And in the case of each individual cell, its capacity is 2 x 3.6 or 7.2 Wh, and since there are 8 of them the total capacity is 57.6. OK?
OK.Sorry to bang on about this – but it's now my understanding that Ah is not a measure of the capacity of a battery/cell. To get that, you have to multiply Ah by potential difference, so in the case of the 4-Ah / 14.4-V battery mentioned above you obtain the capacity in Wh simply by multiplying 4 by 14.4, which gives 57.6 Wh. And in the case of each individual cell, its capacity is 2 x 3.6 or 7.2 Wh, and since there are 8 of them the total capacity is 57.6. OK?
Just to confuse you more, Ah is a unit of electric charge which may be considered a measure of capacity, but only for a specific cell/battery potential.Sorry to bang on about this – but it's now my understanding that Ah is not a measure of the capacity of a battery/cell.
I wrote a paper on “Lithium Ion batteries, what cavers need to know”, wish there was some way to make it available on the site. You can download it from my www.ledcaplamps.com
The photos posted are of low end (in terms of build quality and capacity) we don’t use Sanyo cells anymore, as we have switched to higher capacity cells for our power applications.I'm intrigued Wormster, what do you do to 18650s that makes this thread laughable?
I won't be buying 20,000 though.