Okay I've started but what direction to take.

Hello all,
I've been engrossed in HBpowerwalls videos for a while and I wondered about trying something like this. For ages. I happened across some laptop battery packs at a market and picked up 14 for 27. I got 79 what appear to be good cells and 1 which was obviously for recycling.

Where do I go from here I need a multimeter and a charger/discharger to test voltage and mAH but the choice is huge.

Would appreciate some recommendations in the sub 100 mark.
I'm a little pleased as this lot only took 40 mins and I only cut myself 5 times.

Gloves is a must, I already learned the hard way.

You must buy a charger/discharger/capacity tester, many of us use de Opus BT C3100, with this you won't need the multimeter.

With few cells as you have and if you have a lot of time, I wouldn't make any other charger as many have too with tp4056, this is to speed the process and charge with tp4056 an use the opus only for capacity test.

While testing cell capacity you have to think what to do with them, that will determine if you need more cells or the way you will join them in packs, and the aditional hardware you will need (BMS, Charger, Inverter, etc).

Regards

I would say you still need a multimeter. Preferable one that is good so you can make sure the Opus have good voltage readings!!

Many people forgot the important things in the system that protect it from failures! Like BMS, breakers that can be controlled by the BMS or other devices. Stuff that will make sure if something goes wrong it doesnt go to bad.

So meanwhile you test and collect cells make sure you collect all safety gear.. Those parts arent cheap.

Good luck!

Yeah, a multimeter is always needed if you tinker with any sort of electricity. I wouldn't know what do to without a multimeter. Doing power related stuff without a multimeter is like equipping your workshop with powertools but skipping a powerdrill. You can do it, but it probably makes things pretty awkward really soon.

And for the rest, that really depends on how far you want to go and how many cells there are to come.

If 79 is your final cell count then I would get a IMAX B6AC v2 if you need something that runs off the mains or a IMAX B6 Mini if you have a DC source available. In terms of chargers/dischargers these things are pretty solid, relatively inexpensive and versatile tools. You can charge your cells (and most other cells and batteries if there is a demand) and discharge them to check the capacity. 79 cells, one at a time, takes a moment, but it is probably not worth it to invest in specialized equipment.
If you do this there is one thing to consider though. The B6 (the whole family) unlike other devices and unlike other SkyRC devices perform a CCCV discharge. It gives you the total capacity and not the usable capacity at a certain discharge current you would get with a CC discharge. If you start using the B6 you cannot directly compare the results to any other ones.

I processed several hundred cells using four B6. I tried the Opus but was really disappointed with the shockingly bad build quality on these things. Fan noise is not acceptable as well as I was doing all this in my livingroom. It is not only loud but also a VERY annoying kind of noise. If I would have to do something like this again I would probably try the SkyRC MC3000 next. Or build a testing device myself. Or just stick with the B6 if the scale is the same as before (no more than some hundred cells).

If you know you will go further then you already have to think about going bigger to keep your sanity. That will be more than 100 pounds though.
Charging will then be a job for either a good amount of TP4056 (I built a little setup with eight of these) or a bigger charger than the B6. I have a SkyRC D400 as well that supports 20A on its outputs, very well suited to charge 20 cells in parallel at the same time and another 20 on the other channel, if needed. That is a bit overkill though because you won't be able to discharge/test them this fast unless you go massive right from the start with several Opus or something similar.

And as for multimeters, you can check Gearbest and Banggood for the China only models from Fluke. They are genuine Flukes for the chinese market and we are not really meant to know about them, but yeah, we do. They are still more expensive than the usual suspects but are a good investment. If you aren't prepared to pay 50 to 100 pounds for a multimeter though, which is totally fine, then go with something from Uni-T. Will get the job done as well.