Battery Hookup new listing “Case 100x 3.3v 2200mah - 200x 18650 Lifepo4” for $100.00 + shipping

[sam_sam_sam]

I have a question about this GTI solar controller

https://www.ebay.com/itm/32631398408...BST1E0VNMMJPT9


It says that it can accept 10.8 to 32 volts DC voltage
or
solar panels

Solar Panels
36cells-Vmp:18-21V:Voc:20-30V

60cells-Vmp:26-30V:Voc:34-38V

72cells-Vmp:35-39V:Voc:42-51V

is this what I am looking for but I am confused about what they are saying about this (36 , 60 72 cells and voltage range

because the solar panels that I have are 30 cells each ( the no load voltage is 20. something ) and if I parallel them to have 60 cells or are they referring to cells in series then I would still have 60 cells in series this is another story but if this is the case then why the difference in battery voltage input is limited to 32 volts

[eccerr0r]

This is a "limited range" mppt "microinverter" (despite it being over 1KW it's still a 'microinverter' since it cannot handle long strings, usually meaning Vmpp of 100V or higher. Expensive mppt inverters have a larger voltage range.)

They have two versions there. You pick the one that your panels match. They have a version for 30(?)/36 cell and 60/72 cell.

In any case the auction you wrote did say "1. The inverter is designed to handle PV panels as input source only and will not work with batteries/wind turbines as input source." so I'm not sure what you mean abut battery voltage limit.

Indeed there is a Voc limit and minimum on the two versions. They will not run if you exceed or go below. If you try to hook up a 30 cell panel to the 36-volt version it will not work (voltage too low, no damage). Also won't work if you hook up a 72-cell panel to the 18-volt version (this case it may leak magic smoke.)

Yes, if you connect two identical 30-cell panels in series you get a 60-cell panel. It's always a tradeoff: more cells in series is less wire but cannot deal with shading as well - parallel connections deal with shading better.

It seems people tend to have 36-cell for offgrid use (because the 18v can readily be used to charge 12V lead acid batteries without a charge controller) and 60-cell for grid tie. However solar panels are solar panels, get the voltage that works.

[sam_sam_sam]

However solar panels are solar panels, get the voltage that works.

That what I figured out that solar are solar panels all I am not sure what voltage


Please read the description of this GTI if what they are talking about the switch for turning off the MPPT controller and using the battery power is this possible or is this hypothetical scenario and might not really work or does it really work the way it is says in the description

https://www.ebay.com/itm/40581058497....c101465.m3507

[eccerr0r]

if it does what it says, then yes this one it's valid to use battery as a source, and you can ebay NAD it if it doesn't work.

[sam_sam_sam]

if it does what it says, then yes this one it's valid to use battery as a source, and you can ebay NAD it if it doesn't work.

Thank you for your reply I going to find out if it will actually work the way it is described in this listing for this device

[eccerr0r]

almost done trying to mod a (good) 24V6Ah to 12V12Ah pack of the same form factor...granted it'll be a gimped 12V12Ah pack that's limited at 15A which is only a little over 1C... need more wire...

The bad one is bad. That one cell's self discharge probably means I have to port out that cell so I can charge it separately in order to get 12V@~4+Ah from the pack.

[eccerr0r]

FFFCCKK the hacked BMS is not working after mod ! Maybe I should use the repaired one on this pack...

oHHH I found my f**kup! bad assumption that B4 is hooked up properly! It's not!

Yup I think I fried one of the balancers due to the connection f**Kup These are the days I wish I had a FLIR camera to pinpoint which one, but my finger temperature sensor seems to point it in that general direction.

[sam_sam_sam]

FFFCCKK the hacked BMS is not working after mod ! Maybe I should use the repaired one on this pack...

oHHH I found my f**kup! bad assumption that B4 is hooked up properly! It's not!

Yup I think I fried one of the balancers due to the connection f**Kup These are the days I wish I had a FLIR camera to pinpoint which one, but my finger temperature sensor seems to point it in that general direction.

I have made the wrong assumption before when trying to modding something that is why I tested the heck out of it to see if it still works as was designed to do with the modding in place but that just me trying to make sure I can not get to fail

I found some inexpensive 12 volt BMS boards that do not have the balancing function on them
I also found a BMS board that the balancing function is on a separate circuit board which will be convenient to use in a project that I need a higher current circuit capacity board and just need the balancing function just for charging the battery pack


https://www.ebay.com/itm/235974682699?var=536446917743

I was not sure if a BMS balancing balancing function would be possible with an ic chip that does multiple battery cells and changing it's configuration
I am not disappointed that it might not be possible to reconfigure because still have a use for the BMS protection boards that I remove from these battery packs and reuse them on low current battery cells and make it much higher current capacity but in a smaller footprint than what the original setup is now

[eccerr0r]

Oh I might have dodged a bullet...
Couldn't figure out what was wrong. I N/C'ed the extra interstitials instead of leaving them and it seems to stop getting hot now.

[eccerr0r]

Hmm... weird... or maybe not so weird.
I charged up my first not-waterlogged 24V6Ah to 12V12Ah hack to 14.4V and then drained it approximately 4 ampere hours, now it's sitting at 13.18V (all cells are around 3.29 or 3.30 volts). Minus age wear I suppose this should still have at least 6Ah left in it... so far this actually seems to be about right. Wonder if I should charge it up again or see what happens if I drain another 4 ampere hours.
Next I need to figure out what I want to do to stop using alligator clip wires to attach to it... mainly because passing more than 3 or 4 amps through these clip wires is starting to cause them to heat up (though wasting a few of these clip wires in parallel helps...)

[sam_sam_sam]

Hmm... weird... or maybe not so weird.
I charged up my first not-waterlogged 24V6Ah to 12V12Ah hack to 14.4V and then drained it approximately 4 ampere hours, now it's sitting at 13.18V (all cells are around 3.29 or 3.30 volts). Minus age wear I suppose this should still have at least 6Ah left in it... so far this actually seems to be about right. Wonder if I should charge it up again or see what happens if I drain another 4 ampere hours.
Next I need to figure out what I want to do to stop using alligator clip wires to attach to it... mainly because passing more than 3 or 4 amps through these clip wires is starting to cause them to heat up (though wasting a few of these clip wires in parallel helps...)

I just soldered to the tabbing and be done with it that is what I have done with the one I split into two separate battery packs

[eccerr0r]

Will need to solder something to the pads on the BMS. However I have to admit I did a poor job on resoldering the tabbing back to the BMS. I suspect it won't be an issue until I draw 15A from the pack...

[sam_sam_sam]

Will need to solder something to the pads on the BMS. However I have to admit I did a poor job on resoldering the tabbing back to the BMS. I suspect it won't be an issue until I draw 15A from the pack...

Drill a small hole in the center of the tabbing to make it easier to solder but when you do this run the drill very slowly and put a piece of wood on the bottom of the tabbing so that it lays flat on the top use a paint stick and make it like a sandwich maker sure to use a very sharp drill bit you do not need a very big hole either

Using a drill press would make this process easier to do if you have one

[sam_sam_sam]

I would suggest that you open every battery pack I just found one battery pack with a battery cell leaking a little bit and I separated
every battery cell in this battery pack if I find an more I will put all those battery cells together and used them until it takes a crap

Even more bad news about these battery packs I have six out of six that are leaking at one battery pack cell in five of them and one of it two of them

I should have waited until I had taken all 12 of them are before I split one of them but that okay I will just rebalance the packs that I have to take apart and all of the battery cells that are leaking are going to go together so that when they make a mess it will be a big mess to take care of and the BMS balancing board will not be inside of the battery compartment because of this

Of course it is the end that is crimped that is starting to leak a little bit

I going to try to take the tabbing off of one and see if I can do it with out destroying it and reuse it if possible
I already separated one pack into individual battery cells but I cut the tabbing in half on each one but I have to do this many I try to do it in such a way that I might be able to reuse them

I am thinking it a quality issue when they were made

The battery backup will not take the battery holder and fit in battery compartment so I have get electrical fish tape to put space between battery cells and still have enough for the battery pack to fit which I was hoping that it would fit with the spacer but that a no go and I need some for the tabbing on the positive side of the battery cells to keep from shorting out

I have the same issue with the battery enclosure that I was going to make a 24 volt 12 amp hour battery pack for the battery enclosure will not fit the battery holders not enough room more fish tape for as well

[eccerr0r]

what do you mean by leaking?
hmm...i do see some rust but nowhere near as bad as the really bad one, just a speck, at least that second one I opened and converted.
I'm hoping that I can detect issues from capacity issues ... really don't like the idea of opening all of them...what does the leaking look like?

[sam_sam_sam]

what do you mean by leaking?
hmm...i do see some rust but nowhere near as bad as the really bad one, just a speck, at least that second one I opened and converted.
I'm hoping that I can detect issues from capacity issues ... really don't like the idea of opening all of them...what does the leaking look like?

Do not count on that you literally have to check the crimp end and if you see any thing that looks like rust it is not rust it is leaking they still will have good results until it really leaks badly then is when they fail in that direction and if you look very closely you will see it has stain the plastic insulation disk and it will be in the fish tape that is covering the tabbing and it will be under the heat shrink tubing where the crimp end is

I am taking this precaution because I do not want it to spread to other cells I have seen in power tool battery packs and all it does is spread I have had it where it bad enough to break the spot weld area so I would clean it and reinstall the tabbing just to have the same thing happen again a few months later and now it is worse and has spread to other battery cells next to one that was leaking so now when I have tool battery packs that have issues and I see this I take them apart and get rid of the leaking ones

I also did not want to take all of them apart either and I am glad I did take all of them apart to check if any other ones were leaking or what made me check them is took the heat shrink tubing on the outside of the battery pack and I thought that the lithium battery battery smell was kind a strong that what made me peal back the fish tape to look at the crimp end of each battery cell

And especially since you had a battery pack that was damaged with what looked to me like it had been leaking made look at the ones that I have taken apart already but now I have to separate more battery packs than what I had planned on doing

The plastic pry bar that I bought from Harbor Freight for splitting apart battery cells that are super glue together or removing pouch battery cells that they got glue happy with it does a wonderful job for this purpose a lot better than using metal tools do this job

[eccerr0r]

Not sure what you mean, these batteries are not even IP65 and it was clearly externally sourced water intrusion, it was sitting in a puddle and eventually water will get in. There is no water from inside the batteries that could leak out, but humidity and condensation can happen but it's only a limited amount which could explain the slight bits of rust I see. Due to living in a virtual desert I don't see further condensation occurring.

[sam_sam_sam]

Not sure what you mean, these batteries are not even IP65 and it was clearly externally sourced water intrusion, it was sitting in a puddle and eventually water will get in. There is no water from inside the batteries that could leak out, but humidity and condensation can happen but it's only a limited amount which could explain the slight bits of rust I see. Due to living in a virtual desert I don't see further condensation occurring.

Let take your reasoning for a moment how do you explain why it is always on the crimped end on the battery cell and not on the other end of the battery cell second I have the feeling that the battery cells get a little bit to warm and build up some pressure and either the CDI leaks a little bit and then it does not seal very well and just keeps slowly leaking out

Now would agree with you that if steal coated with nickel coating gets scratches on it or very poorly coated and starts rusting which looks different than battery leaking electrolyte leaking from fumes

Another thing is we do not know how cramped the battery compartment is on these devices that these battery packs are and at what amperage they are charged at and how fast they are discharged at so who knows what conditions they are running when in service

The other problem I have with your explanation is that if all of the tabbing showed rust then I would probably agree with you that it could be condensation which is causing it but when you see the plastic insulation disk is discolored and then it coming from inside of the battery cell I will take some pictures of what I am talking about later on today

I still think that they are a good buy but you have to look at them closely when you plan on putting them in use
So if I counted right I have at least six battery cells that have signs of leaking which like I said earlier I going to put all of them together and make a battery pack and use them for testing proof of concept of different things that I have questions about weather or not is feasible to do or worth doing