Blackout Pack

Geek

Geek

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Joined
Aug 15, 2017
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Just thought I would show off a pack I built with some junk cells.


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^ A Handy silicone wrap from a travel mug held 8 cells just nicely.


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^ Mini packs assembled


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^ The final product. 3s8p. Approx 8ah @12v

Any suggestions as to what enclosure I should use, I haven't found one yet. I estimate it can run my LED lights and charge my phones for about 8 hours in the event of a blackout.

I don't have photos, but I did break 2 fuses moving the pack. Glass axial fuses are a lot more delicate than they look.

Fused at 1a per 2p. On reflection I should have gone 2a, because I wish to charge at 4a.
 
Just a quick update. Each parallel group is pretty well matched - within about 200mah, according to the Opus. After about 5 cycles - typically 3.5v - 4.1v - the center pack has drifted about 0.05v, a bit further than expected.

I don't plan to balance this pack, until I get a rough idea how many cycles it will get before going out of balance. Then I am going to make it 4p. The idea is to get a pack - maybe 5p-6p that doesn't require much balancing. Then I will add a BMS.

The pack was built as a bit of an experiment. It so far only gets very light loads, a 3w LED light. The idea was to use cells of a very wide spread capacity and see how they perform.
 
Nice. Now fill the box with rice for moisture control and stability
 
This is how you learn how to use these batteries. I have been at this for almost 2 years and I'm still learning

As for a container for these cells I am a fan of re-using things and my next project is a portable powerwall that fits in a Pelican Case. But have a look around. I've used cardboard boxes, Lexan (clear plastic ), Old Lead Acid (LA) battery cases. if it fits it's perfect
 
The clear plastic box brought an idea... as a thought have a pack encased in clear resin and then cut the pack in half to show the cells off (cut the pack so that the cells are cut through the center from +ve to -ve) and then cover it over with thin layer of resin...

then..... take one half of the pack and then fix it to a flat wall to make it look like the pack is sunk in the wall..... then hide your real powerwall. lol..
 
completelycharged said:
The clear plastic box brought an idea... as a thought have a pack encased in clear resin and then cut the pack in half to show the cells off (cut the pack so that the cells are cut through the center from +ve to -ve) and then cover it over with thin layer of resin...

then..... take one half of the pack and then fix it to a flat wall to make it look like the pack is sunk in the wall..... then hide your real powerwall. lol..
Click to expand...

Actually rebelrider.mike gave me the best idea. I will find some jars and put some packing around them. Perhaps even a little silicone.
 
So, my partner decided to confiscate my battery to run her reading light. She saw my LED lamp running off it, and stole it! :p Apparently I am still not allowed to bring any more batteries home from work.

Drift is not more than 0.05v so far (per parallel group). Pack still needs an enclosure.
 
Obviously you should bring home more batteries and create a new pack that'll last longer than the one she stole, so when she sees your pack running when her light goes out, she'll steal that one and you'll get your old light back!

(or something like that)
 
Mazlem said:
Obviously you should bring home more batteries and create a new pack that'll last longer than the one she stole, so when she sees your pack running when her light goes out, she'll steal that one and you'll get your old light back!

(or something like that)
Click to expand...

Next pack will be about 40P and 6S or 7S for a 24v UPS. Just need to figure out what the max input voltage is for my Powergaurd 1500va UPS is. Not going to use the UPS to charge, just as an inverter. I also need to figure out how efficient it is, so I can figure out how many amps the pack will have to supply.

I plan on using all the cells I have that are below 2000mah. I'm saving my good cells for a bigger project. I don't have many above 2000mah, as most I have harvested are from worn out laptop batteries.
 
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