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

[eccerr0r]

Hmm...

Someone take a look at eBay item 297006119990 ... a "60V 30Ah" (1.8kWh!) Li-ion battery for just under $100 USD+shipping ... is this real or is this chinese "inflation" (like those UltraFire cells)...

If this is real, this is $56/kWh in new cells(!)

[sam_sam_sam]

that seems to disappear once in a while... hmm, seems those fly off the shelf like hotcakes?

and damn. forgot to go get some of those modem cells... though couldn't figure out how to get the old cells out of my eeePC battery pack without destroying the plastic...

You get your self a cutting blade


https://www.homedepot.com/p/Anvil-2-...-ANV/309996641

It makes opening plastic enclosures very easy to do the blade does not go in very far into the plastic enclosure but does break the plastic weld in most cases

The one that I was referring to uses the 32700 battery cells I might get one if they get them back in stock again

[sam_sam_sam]

Hmm...

Someone take a look at eBay item 297006119990 ... a "60V 30Ah" (1.8kWh!) Li-ion battery for just under $100 USD+shipping ... is this real or is this chinese "inflation" (like those UltraFire cells)...

If this is real, this is $56/kWh in new cells(!)

There is no way to know for sure but at this price I personally would not take the chance you could get a better deal at Battery Hookup for the same amount of money yeah you might have to pay for shipping and maybe the BMS protection board

Now if you get real lucky you might get a decent BMS protection board it might not be a balancing type though the switching power supply might be decent but probably would not want to max it out and I would tell you——> you should recap it if you go down this route

I doubt very seriously that the battery cells are of a high quality I would be very surprised if they were good quality

I have not had very good luck with Chinese battery cells like the ones you mentioned above or one that do not put the manufacturer name on them there are exceptions to this but there is no way of knowing unless you test several times and see if you get basically the same results multiple times

I do not like eBay sellers that do not show the battery heat shrink tubing that was used on the battery cells because sometimes you can tell if these are knock offs or something to just stay away from

[eccerr0r]

speaking of the heat shrink, at least for shrinking a whole pack together, where can get this stuff?

[sam_sam_sam]

speaking of the heat shrink, at least for shrinking a whole pack together, where can get this stuff?

Battery Hookup sells it but you have to know what size you need and I have bought some from them and I bought the largest they have

https://batteryhookup.com/collection.../products/test

Right now the widest that they have in stock is 150mm

Here is an eBay seller that has some

https://www.ebay.com/itm/23317369162...Bk9SR5qStrjRZQ

This eBay seller also has different sizes of battery pack heat shrink tubing and also has fish paper as well I need to order some fish paper myself

I found an eBay seller that sells a full case of 32700 battery cells they even listed the Chinese manufacturer they even publish the test results which is what you would expect from good quality battery cells

I went to manufactures website to see for myself weather or not they provide the test results and they do

The cost of each battery cell is $11.00 each to me this might be a little bit higher than it should be in my opinion

https://www.ebay.com/itm/28640666128...Bk9SR4Crs7rRZQ

Would I buy these battery cells properly if I was building a brand new battery pack for something important IF you can trust the eBay seller and if you can trust the battery manufacturer for accurate battery testing

I would prefer to buy one battery cell for testing purposes but unfortunately the eBay seller is only selling the hole case of battery cells

The issue with getting battery cells in a case is that when you test them for amp hours they are all over the place so they are definitely not matching each other which is biggest issue that I have run into it does not always happen but it does sometimes

You just have to test more battery cells to get matching battery cells for a given battery pack that you are building

[eccerr0r]

$275 for 25 LiFePO4 32650s at 6.5Ah is too high ... that's over $500/kWh.

[sam_sam_sam]

$275 for 25 LiFePO4 32650s at 6.5Ah is too high ... that's over $500/kWh.

I would agree hold hardly this would not be my first choice unless it was Japan made I might consider it but I would have to weigh do these battery cells have current capability if they do not then they would not be worth the money it might not be one I listed it might be the other listing the one that I saw the data sheet and it shows that at 5c it nearly 1/2 the amp hour rating to me this is not worth the money

[eccerr0r]

Now how do we open shrink wrap battery packs such that they can be salvageable and repacked...

---

FUUQ

I got a pack that's way under voltage... ugh...

[eccerr0r]

And on another note, I gave my power company 16kWh of free electricity last month...
... and of course the idea is to charge batteries instead of that...

[sam_sam_sam]

Now how do we open shrink wrap battery packs such that they can be salvageable and repacked...

---

FUUQ

I got a pack that's way under voltage... ugh...

This is an issue that is not easily answered because are you mounting them on the wall or are they loose on a table
If they are on the wall and done with battery holders as spacers then I do see a reason for heat shrinking a battery pack
If they are loose on a table then yes you need to heat shrink wrap the battery pack to keep it from getting into trouble

If you have a pack way under voltage I would recommend that you check the individual battery cell rails to find the reason for the low voltage this sometimes indicates self discharge sin drum there is no cure for this situation as far as I know other than removing the battery cells that are doing this

I have a lot of battery cells that have this issue and I thought about building a battery pack that has all battery have the self discharge sin drum and see how well they preform when all battery cells are the same way

I know that when you remove these battery cells from a pack and replace them with used battery cells that are not self discharging they preform a lot better until more battery cells start having the same issue but you do get more use out of them

This is where a 3D printer would come in handy and make heavy duty battery holders that you can easily to remove when they have an issue and replace them with used battery cells nthat are in better shape and keep using them until more of become that way

[sam_sam_sam]

And on another note, I gave my power company 16kWh of free electricity last month...
... and of course the idea is to charge batteries instead of that...

This is where you need to have the right battery charging system that does two things simultaneously and very accurately

To monitor the voltage levels of each battery pack and needs to monitor the balance of each battery pack

I have been giving this a lot of thought lately and how can I implement this concept the biggest challenge I see with this concept and this approach is what to do when you have all of your battery packs fully charged and there still enough sun light available for charging more battery packs but you do have them made and you are have power available what do you do with it

My biggest concern and issue is to find the right BMS that actually works correctly for this particular purpose and unfortunately I have not found the right solution for this particular issue

From my testing with this new procedure that I use with my battery testing machine and multi battery cell rails and BMS balancing board and the individual battery cell voltage monitoring module I come to realize that not all BMS board are not created equally so you have to test them and see how they function and are they going to work for your application

Because ideally I would like to have a solar system that can do two things one to charge my battery pack under test and run my single battery testing machine simultaneously with out using power company power or this is the plan

[eccerr0r]

Does battery hookup have a satisfaction guarantee? I sort of expected these batteries to be good...

[eccerr0r]

hmm... now that it's sunny outside again I can waste some power charging these batteries...
The power supply I just fixed... yup I can feed 4-5 amps into these packs though I had to mod it a bit to get a bit higher voltage out of them. So yeah at least some of these packs are definitely good - much better than a lot of batteries I've worked with, lead acid and all -- dumping over 100W into a single pack...wow. Won't do this long term, probably will dump 150+ watts into multiple packs at the same time instead.

Alas that one dud I got... doesn't seem to want to charge. Wonder if it should be the sacrificial lamb at the surgery or should I try to get a replacement?

[sam_sam_sam]

Does battery hookup have a satisfaction guarantee? I sort of expected these batteries to be good...

Yes they do but it has been my experience that they really want to see some type of test results I never had issues getting a partial refund when it did not meet the description that was given for a particular battery pack but then again I use the same battery testing machines that they used.
When DOA ones I gotten a full refund and shipping cost as well

[eccerr0r]

Is a "test results" photo of merely connecting a DMM to the terminals sufficient? Either the BMS is bad or there's some really bad cells in the pack...lithium ion voltage should NOT be this low.

Tried charging an the impedance of the pack is really high so the voltage goes up with the charging voltage unlike the other packs...

[eccerr0r]

and I really need a better charging solution. This modded linear PSU generates too much heat, then again, just wasting solar power...
Granted it would be a better payoff it charges faster instead of just generating heat.

[sam_sam_sam]

Is a "test results" photo of merely connecting a DMM to the terminals sufficient? Either the BMS is bad or there's some really bad cells in the pack...lithium ion voltage should NOT be this low.

Tried charging an the impedance of the pack is really high so the voltage goes up with the charging voltage unlike the other packs...

From what I can tell and my experience has been shown them the charging graph for the charging and discharging cycle that is all I need to do with them in the past

I am not sure what they would if you do not have the battery testing machine that have what else you would need for them to do an adjustment to what you were charged I can not answer that question but I sure they would tell you what else you would need to do for a refund of some type

It been my experience that if the ESR value is high then these battery cells are at the end of their useful life but I do not only go by this because sometimes this is misleading information there are several different reasons for this when I see a very steep charging curve on the graph chart that tells a lot about the health of a battery cell which would not be good

[eccerr0r]

It's dead. A 24V pack that measures less than 4 volts, can't charge, doesn't discharge. Dead BMS or bad cells? Shorted cell?
Seems most likely the BMS is dead, or would a shorted cell cause both charge and discharge to cease?

I charged a few of the another pack successfully though not completely as no reason to at this point, the good pack behaves as normal, the dead pack does not even come close.

[sam_sam_sam]

It's dead. A 24V pack that measures less than 4 volts, can't charge, doesn't discharge. Dead BMS or bad cells? Shorted cell?
Seems most likely the BMS is dead, or would a shorted cell cause both charge and discharge to cease?

I charged a few of the another pack successfully though not completely as no reason to at this point, the good pack behaves as normal, the dead pack does not even come close.

Post a link to one you bought from them so I know which battery pack

To answer your question if the battery cell rail voltage difference is too great it will lock the battery pack from charging or discharging this is normal behavior

How easy is it to get to the BMS connector check each battery cell when you are doing this start at the most negative terminal position and those two wires then move both meter leads to the next position and do this process until you have checked battery pack cell you will probably find some dead cells in this pack if the voltage between battery cells are balanced for the most part then you probably have a bad BMS protection board

I have had this happen to BMS protection boards if you over current them they will play dead or have some weird voltage reading and you can not charge them or put a load on they will not do anything at all

I you are talking about the ones that I recently bought a case of them and test them and post the results they probably should not be over 15 amps unless you put a heat sink on the mosfets because at 3.5 amps it does get warm to the touch when charging

If we are talking about the ones that I have been testing and posted the test results it is not very difficult to get to the individual battery cells but to test the wires in the BMS connector is not going to very easy to do unless you remove the glue that was used in the connector to the connector on the board

Here is my take on this if you are having issues with this pack and want to get to the bottom of the issue you will be better off if you just take it apart and test each individual battery cell and see how close are the voltage to each other

Then you will know for sure if the BMS protection board is the issue or is it case of bad battery cells then you will have more information to provide them for a partial refund for that battery pack

What I would do is if you have bad battery cells take pictures of both types battery cells that have good voltages and ones that have bad voltages reading with the meter results showing and the picture of the battery cell in question and before you split the battery cells from each other

I would do the picture in such a way that you show the bad battery cell voltages and at least one good battery voltage in the same picture meaning that the meter and the battery cell that has issues in same picture

This might be enough for them to make a decision on your behalf

[sam_sam_sam]

and I really need a better charging solution. This modded linear PSU generates too much heat, then again, just wasting solar power...
Granted it would be a better payoff it charges faster instead of just generating heat.

Why not use a good design switch power supply regulator ic chip for this purpose there are some really good ones out there some are more expensive than others ones and if you do a Google search you should be able find one to build

The XL4015 one is an example of one that works pretty good the only issue is that it's maximum voltage is 40 volts if I remember correctly I know for sure that it has a 5 amp maximum circuit capacity

They are not very expensive on eBay and they are very plentiful in quantity and very easy to use the ones that have the voltage and current meters are more expensive but are convenient to use and hook up to use and from what I have seen on YouTube is that you can parallel them to get more current output

They have these back in stock again

https://batteryhookup.com/collection...ith-bms-56-kwh