Hi Everyone from UK

[Earlonics]

Hi
Paul from the UK, I'm currently Harvesting Batteries, 1400 todate found this site by watching Average Joe and HBPowerwall great sources of information. Hope to learn more and share anything I learn. 

[chuckp]

Hi Paul

Welcome to the forum, you'll find some cool guys here doing some great work and a wealth of useful information.

Look forward to seeing the progress with your build. We all love a few photos in here.

Chuck

[Earlonics]

Thanks Chuck,

[hbpowerwall]

Welcome to the community

[Earlonics]

Not sure why this image uploaded on its side but here is my current Batteries, in prep for my build...14s100p I would like to know two things, probably already posted somewhere so if someone can point me in the right direction,I'd be grateful.
1) I've sorted my batteries into packs, using the rpacker program. Do the batteries need to be fully charged when you are soldering or spot welding them together?
2) what is the max difference between individual cells in a pack should you go with resistance. Just curious what others think.

[chuckp]

Not sure why this image uploaded on its side but here is my current Batteries, in prep for my build...14s100p I would like to know two things, probably already posted somewhere so if someone can point me in the right direction,I'd be grateful.
1) I've sorted my batteries into packs, using the rpacker program. Do the batteries need to be fully charged when you are soldering or spot welding them together?
2) what is the max difference between individual cells in a pack should you go with resistance. Just curious what others think.

Hi Paul

1: The charge in the cells when building your packs/modules should be equally charged, full charge, part charge, discharged is not an issue so long as they are all the same. Problem would be if you were to connect a discharged cell in parallel with charged cells, the charged cells would try to balance and equalise the voltage in the discharged cell. At the very least you would blow your cell level fuse/s as soon as you connected it. Worse case you could damage the cells with the high inrush/discharge of current from the other cells. Be cautious when working with fully charged cells as the combined available current they could potentially pass starts to get very high the more cells you have in parallel.

2: I personally don't use cells with an IR greater than 75 mohm. Unfortunately I only have an Opus tester at the moment and it's not a reliable test. I need a four wire Kelvin tester to be accurate Wolf is the man to talk to about IR. Anyway I digress, it really depends on how you intend to use your cells. The majority of us have a large quantity of cells in parallel and high storage capacity and don't tax our cells to much. I test all my cells at 1A charge/discharge, my build is designed to draw no more than 0.5A/cell. However in reality at the moment I draw a maximum of 0.35A/cell. As my wall grows my load will become much lower, I plan on eventually reading less than 0.1A/cell. With a charge/discharge of 4.05V/3.40V per cell. Since I'm not overly stressing my cells the IR isn't that much of an issue for me and my packs/modules tend to stay fairly balanced. If on the other hand you are going to be pulling high loads from your build and taxing the cells to there limits, then I would recommend that you match the cells as closely as posible, in and between packs.

Also make sure you match the capacities between your packs and that they are all at the same voltage before connecting them in series.

[Earlonics]

Thanks for your detailed response, I have a number chargers li500, VC4S, fanflare etc, and like many others find they are all different on the measurement of IR so I invested in a 4wire tester and tested every cell with the tester. My thought is that if every cell is IR tested using the same meter even if the meter is slightly out at least all measurements would be out by the same.
I've just started building my busbars but having trouble sourcing fuse wire in the UK, anyone with advice on this, I would appreciate it.
Thanks again
Paul

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BTW I dont tend to use Forums any advice on if I'm posting in the right place,should I post my questions somewhere else, like I said I'm new at this.
Did my previous picture get upload as I dont see it, again any advice from anyone if I'm doing something wrong ??

[chuckp]

Thanks for your detailed response, I have a number chargers li500, VC4S, fanflare etc, and like many others find they are all different on the measurement of IR so I invested in a 4wire tester and tested every cell with the tester. My thought is that if every cell is IR tested using the same meter even if the meter is slightly out at least all measurements would be out by the same.
I've just started building my busbars but having trouble sourcing fuse wire in the UK,  anyone with advice on this,  I would appreciate it.
Thanks again
Paul

---

BTW I dont tend to use Forums any advice on if I'm posting in the right place,should I post my questions somewhere else, like I said I'm new at this.
Did my previous picture get upload as I dont see it, again any advice from anyone if I'm doing something wrong ??

l

Hi Paul

Any questions are welcome, you’ll find a ton of useful info and help from the members, the FAQ’s is also a great source of information.
If it’s a build question post it in Battery Pack Design, Planning, and Building.
Details and documentation of your build, post in DIY Battery Project Builds.

No your pictures didn’t upload. Once you put them into the loader you need to click on them to insert into your post.

I use glass lead axial fuses rather than wire.

Looking forward to seeing your project build progress.

[Earlonics]

Thanks for your detailed response, I have a number chargers li500, VC4S, fanflare etc, and like many others find they are all different on the measurement of IR so I invested in a 4wire tester and tested every cell with the tester. My thought is that if every cell is IR tested using the same meter even if the meter is slightly out at least all measurements would be out by the same.
I've just started building my busbars but having trouble sourcing fuse wire in the UK,  anyone with advice on this,  I would appreciate it.
Thanks again
Paul

---

BTW I dont tend to use Forums any advice on if I'm posting in the right place,should I post my questions somewhere else, like I said I'm new at this.
Did my previous picture get upload as I dont see it, again any advice from anyone if I'm doing something wrong ??

l

Hi Paul

Any questions are welcome, you’ll find a ton of useful info and help from the members, the FAQ’s is also a great source of information.
If it’s a build question post it in Battery Pack Design, Planning, and Building.
Details and documentation of your build, post in DIY Battery Project Builds.

No your pictures didn’t upload. Once you put them into the loader you need to click on them to insert into your post.

I use glass lead axial fuses rather than wire.

Looking forward to seeing your project build progress.

Thanks again Chuck will take on board your advice and guidance