My soldering station is 60w and it goes to 480°C/896°F. Is it to weak?
It's called Atten 936b and is like this:
Is it high resistance in a cold solder joint?
18650 DIY powerwall 48v
- Thread starter kje
- Start date
It's called Atten 936b and is like this:
Is it high resistance in a cold solder joint?
Korishan
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it's not generally the wattage alone that makes an iron strong/weak. It's the ability to quickly heat back up when applying the tip to a surface. On a PCB, a small thermal mass is usually not an issue. But applying the tip to something like a chunk of metal, now there's an issue.
This is a pretty generic unit, and I've seen reviews of these. They do a decent job overall. However, if you can increase the thermal mass, that'd be a lot better. This would include either switching out the tip for a bulkier tip, or you could even add a tightly coiled copper wire around the tip end of the wand to increase thermal mass.
This is obviously a quick fix. A better option would be to get a 100W unit. But if you can get away with what you already have with some minor tweaks, then why spend the money on something new? Unless you plan on doing a lot of soldering requiring the heavier tip
OffGridInTheCity
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I think you'll find 100w will work fast/smooth getting solder to flow on the cells - particularly the negative end. I notice quite a variation on the + end On some cell + ends, the solder flows almost instantly (Green NCR18650As are this way) and on others it seems to take as much heat as the - end.
When I first started, I bought a 300w monster ( https://www.amazon.com/gp/product/B01MZ3XVL7/ref=ppx_yo_dt_b_search_asin_title ) because @daromer had one but it was way to heavy and... the tip started crumbling after just a few hours of use.
Then I went 'really cheap' 100w but the tip failed fairly quickly. Finally arrived at the 100w Weller and it just keeps working day after day
When I first started, I bought a 300w monster ( https://www.amazon.com/gp/product/B01MZ3XVL7/ref=ppx_yo_dt_b_search_asin_title ) because @daromer had one but it was way to heavy and... the tip started crumbling after just a few hours of use.
Then I went 'really cheap' 100w but the tip failed fairly quickly. Finally arrived at the 100w Weller and it just keeps working day after day
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100kwh-hunter
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100kwh-hunter
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100kwh-hunter
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But if you do lets say 10 cells quick the iron will not keep up with the heating, so you have to wait a few seconds longer between each cel or after 3/4/5? cells.
Clever thinking btw.
Now I ordered a new 150w soldering iron, ERSA 150S: https://www.amazon.com/ERSA-150S-standard-soldering-iron/dp/B000ONTGOO
Yes I have the RC3563. How do I measure?
100kwh-hunter
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rtfm...
Read the fu**ing manual.
I always wanted to post rtfm
Put it on and put the cell in the holder.
Plus or minus direction does not matter much, usually it is measuring with ac and not dc.
But with this type i am not familiair with.
It seems to me it is not adjustable and the plus and minus is designated.
So it must fit.
Beware of the nickel strip pints that are still on the cell, they can give odd results.
Solder can give a bit higher IR than the ones without solder.
I would also advise you to go to the cell dbase of wolf to get the max IR per brand cell.
He did a excellent job of gatering information, especially about the IR in a cell.
In "our" dbase there is no Ir to be found sadly.
Go also on the internet to google for IR
IF a cell must be between that and that ohm, you dont want a cell in your pack with a higher or lower ohm.
But i have found ells that supposed to be rated at max 65 mohm that were still good.
What does tell IR you?
It will give you a quick look on the condition of the cell itself.
On the SOH namly.
I test every cell on IR before i put it in my tester.
A heater has a high IR...Is every high IR cell a heater...NO, this depends on the factory(brand) of the cell(componants used.
A cell that is past his 50%soh is usually high in IR.
I tested a 1000 of cgr18650cg, if we look at the difference between the "90-100%"(very good cells) and the 0-50% (very bad) cells, you will understand why i dont test every cell anymore...evry cell above 60 mohm is imidatly to the death row to become a 0v cell.
Most if not all above 70 mohm are heaters and/or self-dischargers or to low capacity left, below 70% remaining.
This exls has some formulas, just like my other exls, that one is full.
Incl coloring if there is ONE bad value outcome in one of the seven tests.
Maybe i went a bit to far?!?!?
Some test only on the capacity and call it a day.
Its oke for 1 to 5 kwh? but also for 100kwh and expanding?
I must say i am very glad you bought a IR meter, this is your ticket to a saver powerwall.
I am rambling again, sorry.
Use your IR meter and get propper data per cell, reject the ones with 0 or odd or to high or to low IR.....
Then charge them full.
Look out for cells that are slow charging. (charging with 700 mah is 2100mah that is 3 hours for a cell of 2000mah to charge full, so 4 hours of charging? Will get warm?!)
That one heater.
*******5 second touch with the outside of your finger!******the middle piece of your fingers, not the end piece with nail.
40C will feel warm
50C you dont want to long to touch.
60C you really dont want to touch 5 sec.
70C after one second you will remove your finger....
Then discharge, If you did all right, you will have no heaters or odd IR's.
After discharge keep only cells above 80% of new factory capacity.
Charge up again let them settle for a day, note the V per cell, and put them away for minimal 14 days.
After 14 days test voor V again you dont want any cell that dropped more than 0.2 volt, some keep as max 0.5 volt....
Oke you will lose some more cells, but i sleep good a night, especially with my 1a fuses per cell (still have to figure out those heat fuses)...
I hope @Wolf will chime in and want to share his dbase....a bucket of gold, he made.
Dont forget our own dbase, some people put there IR and findings in...
Read the fu**ing manual
.I always wanted to post rtfm
Put it on and put the cell in the holder.
Plus or minus direction does not matter much, usually it is measuring with ac and not dc.
But with this type i am not familiair with.
It seems to me it is not adjustable and the plus and minus is designated.
So it must fit.
Beware of the nickel strip pints that are still on the cell, they can give odd results.
Solder can give a bit higher IR than the ones without solder.
I would also advise you to go to the cell dbase of wolf to get the max IR per brand cell.
He did a excellent job of gatering information, especially about the IR in a cell.
In "our" dbase there is no Ir to be found sadly.
Go also on the internet to google for IR
IF a cell must be between that and that ohm, you dont want a cell in your pack with a higher or lower ohm.
But i have found ells that supposed to be rated at max 65 mohm that were still good.
What does tell IR you?
It will give you a quick look on the condition of the cell itself.
On the SOH namly.
I test every cell on IR before i put it in my tester.
A heater has a high IR...Is every high IR cell a heater...NO, this depends on the factory(brand) of the cell(componants used.
A cell that is past his 50%soh is usually high in IR.
cgr18650cg | 68,04% | 47,6 | | 62,3 | 59,2 | 49,6 | 53,2 | 39,5 | min |
cgr18650cg | 76,44% | 47,1 | | 57 | 57,4 | 48,4 | 54,2 | 53,4 | max |
cgr18650cg | 69,47% | 49,8 | | 62 | 48,6 | 45,5 | 54,7 | 46,0888888888889 | gem |
cgr18650cg | 73,78% | 45,5 | | 56 | 48,3 | 47,5 | | | |
cgr18650cg | 70,18% | 48,1 | | 60 | 54,1 | 55,7 | 40,6 | min | |
cgr18650cg | 63,47% | 45,1 | | 59,8 | 59,6 | 56,1 | 57,9 | max | |
cgr18650cg | 80,67% | 48,7 | | 77 | 50,9 | 55,2 | 51,6142857142857 | gem | |
cgr18650cg | 59,82% | 56,5 | | 60,4 | 50,6 | 47,3 | | | |
cgr18650cg | 74,27% | 45,7 | | 71,8 | 50,3 | 45,7 | | | |
cgr18650cg | 55,64% | 50,3 | | 57,1 | 49,3 | 56 | | | |
cgr18650cg | 76,93% | 49,7 | 104 | | 47,5 | 53,9 | | | |
cgr18650cg | 78,93% | 50,7 | 118 | | 49,9 | 54,5 | | | |
cgr18650cg | 80,36% | 46,7 | 81,6 | | 50,9 | 49,5 | | | |
cgr18650cg | 38,67% | 61,9 | | 63 | 50 | 50,8 | | | |
cgr18650cg | 78,44% | 240,1 | | 62,2 | | 56,3 | | | |
cgr18650cg | 6,36% | 62 | | 60,4 | | 48,5 | | | |
cgr18650cg | 76,89% | 48,8 | | 54,8 | | | | | |
cgr18650cg | 16,09% | 64,4 | | 54,9 | 45,1 | 44,9 | min | | |
cgr18650cg | 71,64% | 49,6 | | 50,3 | 59,6 | 56,3 | max | | |
cgr18650cg | 74,13% | 48,4 | | 57,4 | 51,256 | 49,8518518518519 | gem | | |
cgr18650cg | 21,96% | 69,1 | | 54,4 | | | | | |
cgr18650cg | 54,93% | 52 | | 50,5 | | | | | |
cgr18650cg | 65,87% | 51,7 | | 59,1 | | | | | |
cgr18650cg | 72,93% | 45,5 | | 51 | | | | | |
cgr18650cg | 73,73% | 47,5 | | 58,8 | | | | | |
cgr18650cg | 17,73% | 62,3 | | 76,6 | | | | | |
cgr18650cg | 44,36% | 57 | | 53,8 | | | | | |
cgr18650cg | 25,02% | 62 | | 61,8 | | | | | |
cgr18650cg | 77,56% | 55,7 | | 57,3 | | | | | |
cgr18650cg | 78,58% | 56,1 | | 57,5 | | | | | |
cgr18650cg | 74,71% | 55,2 | | 57,1 | | | | | |
cgr18650cg | 37,73% | 56 | | 59,6 | | | | | |
cgr18650cg | 75,07% | 47,3 | | 59,1 | | | | | |
cgr18650cg | 67,73% | 46,2 | | 58,2 | | | | | |
cgr18650cg | 75,64% | 45,7 | | | | | | | |
cgr18650cg | 38,13% | 60 | | 50,3 | 45,1 | 44,9 | 40,6 | 39,5 | min |
cgr18650cg | 33,16% | 59,8 | | 82,8 | 59,6 | 56,3 | 57,9 | 53,4 | max |
cgr18650cg | 79,02% | 47,3 | | 61,6976190476191 | 51,256 | 49,8518518518519 | 51,6142857142857 | 46,0888888888889 | gem |
cgr18650cg | 12,44% | 77 | | 0-50% | 50-70% | 70-80% | 80-90% | 90-100% | |
cgr18650cg | 27,64% | 60,4 | | | | | | | |
I tested a 1000 of cgr18650cg, if we look at the difference between the "90-100%"(very good cells) and the 0-50% (very bad) cells, you will understand why i dont test every cell anymore...evry cell above 60 mohm is imidatly to the death row to become a 0v cell.
Most if not all above 70 mohm are heaters and/or self-dischargers or to low capacity left, below 70% remaining.
This exls has some formulas, just like my other exls, that one is full.
Incl coloring if there is ONE bad value outcome in one of the seven tests.
Maybe i went a bit to far?!?!?
Some test only on the capacity and call it a day.
Its oke for 1 to 5 kwh? but also for 100kwh and expanding?
I must say i am very glad you bought a IR meter, this is your ticket to a saver powerwall.
I am rambling again, sorry.
Use your IR meter and get propper data per cell, reject the ones with 0 or odd or to high or to low IR.....
Then charge them full.
Look out for cells that are slow charging. (charging with 700 mah is 2100mah that is 3 hours for a cell of 2000mah to charge full, so 4 hours of charging? Will get warm?!)
That one heater.
*******5 second touch with the outside of your finger!******the middle piece of your fingers, not the end piece with nail.
40C will feel warm
50C you dont want to long to touch.
60C you really dont want to touch 5 sec.
70C after one second you will remove your finger....
Then discharge, If you did all right, you will have no heaters or odd IR's.
After discharge keep only cells above 80% of new factory capacity.
Charge up again let them settle for a day, note the V per cell, and put them away for minimal 14 days.
After 14 days test voor V again you dont want any cell that dropped more than 0.2 volt, some keep as max 0.5 volt....
Oke you will lose some more cells, but i sleep good a night, especially with my 1a fuses per cell (still have to figure out those heat fuses)...
I hope @Wolf will chime in and want to share his dbase....a bucket of gold, he made.
Dont forget our own dbase, some people put there IR and findings in...
100kwh-hunter
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Just to give you a idea how i test those buggers.
new tester build
I really regard that i sold my "old" tester, but here is tester 2.0(similar to tester 1.0...) the story will come between the pictures and when i have the stuff (board) up to testing, this one i will keep updated, for the ones that are willing to build one and test on every aspect, this is for...
I almost feel bad for you writing all this. I maybe misunderstood or was unclear. I've done the process you describe. You are kind writing and sharing.
I wanted to ask if there are a way to measure if it's good or poor contact/ low or high resistance on the solder joints I've made on my pack? If I have to re-solder?
100kwh-hunter
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When you also have two separate leads to your IR meter you could measure on the bare nickel/steel casing, but there could be a "film/coating" on the casing, that could give a higher IR
For most cases solder will add something up, but not much, this is not to worry about.
You can keep the value that the meter is stating.
When you going to start to solder again with a beast of 150W you will finf it will work quicker and cleaner.
Ir should be measured before soldering.
Dont feel bad, i just had a writing rant....it happens sometimes.
Oke lets make a simple example.
If you run water thru a pipe at 5000 liters per hour and the pipe is 100mm in dia, you have a free flow.
But if we are going to narrow the pipe down to 10mm in dia, you need a lot of pressure to get those 5000 liters thru it.
Or free flow you wil get maybe 100 liters out of it.
The same thing with your solder, it will be good, i dont think you are going to push them to 10a per cell
Thank you. Then I don't have to worry about all the solder joints I've already made.
Yes, I've Ir-tested all the cells and actually just 1 out of 1680 cells had too high resistance. But I did this after capacity testing and resting. If I do it again I'll do it the opposite way.
Yes, looking forward to the 150w soldering iron.
According to the chart 12mm2 (8awg) can handle 105-125A. Is that correct?
The busbar is 3 feet (85cm) long.
Last edited:
100kwh-hunter
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Direct Currant can flow in two ways.
From solar to your mppt chargers, it is one way.
In your "main" busbar it flows every direction.
Rule of thumb 1mm2 per A one direction, two direction 1mm2 0.8mm
It is correct but i was calculating with 4 to 7 feet, always built in some extra, to prevent cable losses.
For starting up some heavy machinery with a small battery, the cells can do 2A each.
Times the number of cells, in your case: 120 cells, that is max 240A....WOW = 12kwh..
But You are not going to do that.
Calculate the max draw and max surge of your inverter, with the length total needed towards the bms.
Plus the total length of your battery cable.
that is what you will need with this battery, if you are sure you are going to expand you can use smaller wires.
I am getting big, in my situation, if i would start up some machinery and my wife starts cooking and the boiler is cold and the electric heating is jumping on, we will get a max draw of 1a per cell...
We have around 15-1600A on storage, i think 1A is even to much for one cell, i am not really good with calculating this.
But your case: how long is the total length of your cable to your inverter incl main busbar and your battery length.
Lets say 10 to 13 feet.
How much will your inverter do?
Lets say 5kwh/50v = 100A.
= 4 gauge.
Oke now you are going to build a second battery, so the load will be evenly distributed on two batteries.
Yor main busbar will be 4 gauge.
The busbar on your packs can be 50% ( /2 ) smaller = 6 gauge.
Oke 4 batteries, the load will be divided by 4--->25A--->8 or 10 gauge.
ect.
I calculated my system several times, adapted several times, until i was fed up.
What do i want, how much do i need. make it oversize, i was really fed up.
My main bus is 300mm2 and my cables are not even 16mm2 on the big packs (280A/300A lifepo4)
Inverters can do 10kwh, 20kwh surge, a other one is coming extra ----> 4kwh maybe 5kwh.(still no ev's, not cost effective yet)
Without sweating i can do 300Ah, i am in doubt that we will ever pull 15kwh continually...We even had to do a lot of trouble to get to 12.6kwh surche...
Question: what is your end goal?
In what time you want to achieve this?
You want to do it in one step at the time or think ahead?
Those questions incl: But your case: how long the total length of your cable to your inverter incl main busbar and your battery length is
For learning curve: one step at the time, work save.
Or go direct to your total system, one step at the time.
But learn to calculate.
Or use this tool:
www.omnicalculator.com
If you have questions, please ask them and remember there is just ONE stupid question: the question that is never asked!
With kind regards Igor.
PS how do you think i started? lead acid in a camper and some cells to keep my cooler cold, than the freezer, than laptop ect, now i can even use my woodworking shed!
.
From solar to your mppt chargers, it is one way.
In your "main" busbar it flows every direction.
Rule of thumb 1mm2 per A one direction, two direction 1mm2 0.8mm
It is correct but i was calculating with 4 to 7 feet, always built in some extra, to prevent cable losses.
For starting up some heavy machinery with a small battery, the cells can do 2A each.
Times the number of cells, in your case: 120 cells, that is max 240A....WOW = 12kwh..
But You are not going to do that.
Calculate the max draw and max surge of your inverter, with the length total needed towards the bms.
Plus the total length of your battery cable.
that is what you will need with this battery, if you are sure you are going to expand you can use smaller wires.
I am getting big, in my situation, if i would start up some machinery and my wife starts cooking and the boiler is cold and the electric heating is jumping on, we will get a max draw of 1a per cell...
We have around 15-1600A on storage, i think 1A is even to much for one cell, i am not really good with calculating this.
But your case: how long is the total length of your cable to your inverter incl main busbar and your battery length.
Lets say 10 to 13 feet.
How much will your inverter do?
Lets say 5kwh/50v = 100A.
= 4 gauge.
Oke now you are going to build a second battery, so the load will be evenly distributed on two batteries.
Yor main busbar will be 4 gauge.
The busbar on your packs can be 50% ( /2 ) smaller = 6 gauge.
Oke 4 batteries, the load will be divided by 4--->25A--->8 or 10 gauge.
ect.
I calculated my system several times, adapted several times, until i was fed up.
What do i want, how much do i need. make it oversize, i was really fed up.
My main bus is 300mm2 and my cables are not even 16mm2 on the big packs (280A/300A lifepo4)
Inverters can do 10kwh, 20kwh surge, a other one is coming extra ----> 4kwh maybe 5kwh.(still no ev's, not cost effective yet)
Without sweating i can do 300Ah, i am in doubt that we will ever pull 15kwh continually...We even had to do a lot of trouble to get to 12.6kwh surche...
Question: what is your end goal?
In what time you want to achieve this?
You want to do it in one step at the time or think ahead?
Those questions incl: But your case: how long the total length of your cable to your inverter incl main busbar and your battery length is
For learning curve: one step at the time, work save.
Or go direct to your total system, one step at the time.
But learn to calculate.
Or use this tool:
DC Wire Size Calculator
Use our DC Wire Size Calculator to know the wire size needed for your DC electric application.
www.omnicalculator.com
If you have questions, please ask them and remember there is just ONE stupid question: the question that is never asked!
With kind regards Igor.
PS how do you think i started? lead acid in a camper and some cells to keep my cooler cold, than the freezer, than laptop ect, now i can even use my woodworking shed!
.
Yes, I think I'll oversize the busbar.
Twist 4 pieces of 4mm (12awg) = 16mm (6awg) and because busbar is twice that's 32mm (2awg) in total.
32mm (2awg) is rated for about 200A 10-13 feet.
So I have to buy a lot of 4mm (12awg) solid wire (i assume not stranded?).
I've asked around in the shops here in Norway but they don't have 4mm solid single wire. Any tips where to buy 4mm solid wire? Is this ok: https://www.ebay.com/itm/1956595269...Qwc412u6+1TdHNK+TO9lZqYNc=|tkp:Bk9SR7bt1djHYg
Is it correct that if I want to draw 0.5a pr cell continuously on this 120p14s battery pack it's 60a in total?
60a x 50v = 3000w
So 3kWh continuously?
Twist 4 pieces of 4mm (12awg) = 16mm (6awg) and because busbar is twice that's 32mm (2awg) in total.
32mm (2awg) is rated for about 200A 10-13 feet.
So I have to buy a lot of 4mm (12awg) solid wire (i assume not stranded?).
I've asked around in the shops here in Norway but they don't have 4mm solid single wire. Any tips where to buy 4mm solid wire? Is this ok: https://www.ebay.com/itm/1956595269...Qwc412u6+1TdHNK+TO9lZqYNc=|tkp:Bk9SR7bt1djHYg
Is it correct that if I want to draw 0.5a pr cell continuously on this 120p14s battery pack it's 60a in total?
60a x 50v = 3000w
So 3kWh continuously?
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I now got the inverter I ordered. 
It's a Voltronic Axpert Max 8.0 bought from solarpower24 in Italy: https://www.solarpower24.it/negozio...t-max-8000-48-inverter-8-0kw-48-volt/?lang=en
So 8000w of power I can get from this.
I'm excited.
It's a Voltronic Axpert Max 8.0 bought from solarpower24 in Italy: https://www.solarpower24.it/negozio...t-max-8000-48-inverter-8-0kw-48-volt/?lang=enSo 8000w of power I can get from this.
I'm excited.
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OffGridInTheCity
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Yes - the logic/math are correct
I operate my system between 56v and 49.5v so I often use 52v in my calcs instead of 48v as I get rosier numbers.... of course actual run-time doesn't care about 48v or 50v or 52v - it is what it is!One side note. You'll likely see a voltage drop pulling 0.5a/cell. 0.5a/cell continuous (24/7) is pretty hefty and may not be as good for a really long cycle life as say 0.2a/cell. Even at 0.2a/cell on my 121kwh powerwall I see a ~0.3v voltage drop (e.g. 50.3v -> 50v).
Voltage drop due to load affects operations in that you hi low voltage cut-off faster on higher loads - so I'd monitor this / put in the back of you're mind as you get you're system up running.
Of course this affect can be reduced by expanding you're battery and you may already have 'DIY battery addiction' - so my best advice is to leave room to expand, and expand, and expand
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100kwh-hunter
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Advice????--->adiction!
3 times correct.
With kind regards Igor.
I have to get a lot of wire for my busbars.
It's difficult to get 4mm (12awg) solid wire here in Norway. Where did you get your wires from?
Should I just order from aliexpress like this one?: https://a.aliexpress.com/_msP22kW
Then I wonder is it just the copper (conductor?) that's 4mm or is it including the insulation?
Does this chart mean the 4mm wire has just 3.6mm copper and the rest is insulation?
Originally I planned to get left overs wire because I'm a fan of reusing tings. But the thickest leftover solid wire one can get is 1,5mm (16awg).
It's difficult to get 4mm (12awg) solid wire here in Norway. Where did you get your wires from?
Should I just order from aliexpress like this one?: https://a.aliexpress.com/_msP22kW
Then I wonder is it just the copper (conductor?) that's 4mm or is it including the insulation?
Does this chart mean the 4mm wire has just 3.6mm copper and the rest is insulation?
Originally I planned to get left overs wire because I'm a fan of reusing tings. But the thickest leftover solid wire one can get is 1,5mm (16awg).
Last edited:
Korishan
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The measurements are the actual wire diameter, not including the insulation
No, a true 3.6mm wire is 3.6mm metal core. The 12AWG/4mm2 number is that 4mm2 is the actual size of 12AWG. 13AWG would be smaller than 3.6mm2, for example
However, according to this listing on aliexpress, they are including the insulation, this is not standard practice as far as I know.
So based on this chart/listing, if you wanted real 12AWG wire, then you'd want to go with their listing of 10AWG or larger. But it is very confusing. I would recommend going to a different seller, and/or asking this seller to clarify the chart. This chart confuses me as well, considering there's "Conductor Diameter" and then there's "Core Diameter". This number should be the same value, as far as I understand it.