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Hello from Iowa
#1
I spent a few days reading and learning and plan on taking baby steps on my first project. 

Discharge tests TAKE forever!!  Sad
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#2
Yes discharge tests take a while. Use non smart chargers to charge near terminal voltage 4/2v,3.6 etc depending on cell chemistry
later floyd
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#3
(11-21-2020, 11:28 PM)Jrombou Wrote: I spent a few days reading and learning and plan on taking baby steps on my first project. 

Discharge tests TAKE forever!!  Sad

Welcome to the group :-) Most of us discharge at 1000ma which will normally take just over a couple of hours for a fully charged cell, you might be discharging at a lower rate. Good luck with your project
Follow my Powerwall journey here: 
Youtube: https://www.youtube.com/channel/UCjXT8KJnEzo-DJHFRR1W8jg

Building the following:
20kWh Powerwall
8kW Solar
30kW Heating system
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#4
(11-21-2020, 11:28 PM)Jrombou Wrote: I spent a few days reading and learning and plan on taking baby steps on my first project. 

Discharge tests TAKE forever!!  Sad
It does take time.   I use 3 x OPUSs on my office desk and process 12cells / day using 500ma discharge.   That's over 200 days to process the 2500 cells I need for my latest pair of 14s88p batteries made from RING packs.   For me, I don't mind doing this a bit each day as the cells need to set and then building the packs takes time and I have to buy the cells over time....   so I do it in parallel / slow motion.   However,  after a couple of years of slow and steady I'm nearing 10,000 cells (108kwh battery bank).

BUT I understand, to speed things up that's why people build charge/discharge stations of 5 or 10 or 20 OPUSs or mega chargers etc.   And 1000ma discharge is faster but my OPUSs would overheat so I went 500ma because I didn't understand in the early days about cooling them properly and now I stick with it for consistency.  

You don't say your goals / timeline but you can extrapolate after you do your first X cells / get a process down...  and then see what you need to do.
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#5
OffGridInTheCity Wrote:
Jrombou Wrote:I spent a few days reading and learning and plan on taking baby steps on my first project. 

Discharge tests TAKE forever!!  Sad
It does take time.   I use 3 x OPUSs on my office desk and process 12cells / day using 500ma discharge.   That's over 200 days to process the 2500 cells I need for my latest pair of 14s88p batteries made from RING packs.   For me, I don't mind doing this a bit each day as the cells need to set and then building the packs takes time and I have to buy the cells over time....   so I do it in parallel / slow motion.   However,  after a couple of years of slow and steady I'm nearing 10,000 cells (108kwh battery bank).

BUT I understand, to speed things up that's why people build charge/discharge stations of 5 or 10 or 20 OPUSs or mega chargers etc.   And 1000ma discharge is faster but my OPUSs would overheat so I went 500ma because I didn't understand in the early days about cooling them properly and now I stick with it for consistency.  

You don't say your goals / timeline but you can extrapolate after you do your first X cells / get a process down...  and then see what you need to do.
To be honest I just started the accumulating cells for simple home automation projects. I have many sensors throughout my home that I wanted to operate on battery. Spent a lot of time with different ESP's and fine tuning the sleep mode of various chips.

Now with the recent Derecho experience I thought about building a small system (1kWh) so that I can provide a backup to my home automation hub and build onto that as the painfully slow processing continues.

I am undecided on the actual voltage level that I will use but figured if I use a P approach I can build on that to increase voltage S when I get to that point.

I built a few TP4056 stations for charging and picked up a Zanflare charger that would provide discharge ability(I'm using 500ma setting). The batteries I have are recycled and have a Nom discharge of ~ .440 and so far a pretty consistent ~2200mah capacity give or take 10ma with 4.2v.

Currently I am trying to understand the Ir report that the Zanflare provides. Not sure how accurate that reading is.

So far I have about 139 cells, so in between tests I am getting familiar with the next step. One thing that is unclear is the wait time between preliminary charge and moving to the testing stages. How long is long enough? I have been waiting about a week before putting them in discharge/charge.

I am a tinkerer and even if this is a slow process I am learning a lot.
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