Battery bank made from 3 series of 2 parallel LGDAS31865 cells

[antoniu200]

Hi! So, today I took apart 2 laptop battery banks: both have the same specs on paper (10.8V & 4400 mAh), however one reads 5.8V and the other one 11.4V. The new one is the one reading 5.8V and the 11.4V one can't hold a charge for more than 10 minutes when used in the laptop it was designed to work in.

What could be my issue here? I don't want to be swapping battery banks with a chance of blowing something up. The new battery bank has never been charged from what I know about it.

Also, the new battery bank uses LGDAS31865 cells and the old one uses LGAAS31865 cells. They have the same specs, so..?

[sam_sam_sam]

Re: Battery bank made from 3 series of 2 parallel LGDAS31865 cells

Let see some pictures of what we are talking about

[antoniu200]

Re: Battery bank made from 3 series of 2 parallel LGDAS31865 cells

These are some images, the first three represent the first (old, 11.2V) power bank.
The last two images represent the last (new, 6.1V) power bank.

[stj]

Re: Battery bank made from 3 series of 2 parallel LGDAS31865 cells

meter the individual cell-pairs.
a common issue is one battery fails and effects the one in parallel with it.

[antoniu200]

Re: Battery bank made from 3 series of 2 parallel LGDAS31865 cells

I measured the pairs the first three images are with the old battery bank, the last three, with the new one.

[stj]

Re: Battery bank made from 3 series of 2 parallel LGDAS31865 cells

good,
the fact that all the pairs match indicates they are o.k.
just give them a good charge.

if one pair had been under 2v it would have been a problem.

[antoniu200]

Re: Battery bank made from 3 series of 2 parallel LGDAS31865 cells

And this should get them to their nominal 3.6V?

[sam_sam_sam]

Re: Battery bank made from 3 series of 2 parallel LGDAS31865 cells

That depends on protection board it has some of them will not charge the batteries if the voltage is below a certain point

Here is how you can check if this is the case or not put the battery pack on charge —> IF YOU CAN leave the back part case off —>only do this if you can get the battery pack back out the computer

With the battery on charge does the voltage go up in value if does then you are good to go —>
After the batteries finally finished charging then check each set of batteries for there battery voltage are they all the same which means are they all 4.something and the something the same if not then either batteries have issues or the battery protection board has some kind of issue

It more than likely that the battery set has some type of issue meaning that the batteries might become heater cells if the voltage can not get to 4.2 volts if you kept trying to charge them until they reach 4.2 volts if this is the case you need let us know there is a difference set of instructions on how to deal with this —>this would explain why your running time is real short

Charging voltage does not go up

If it does not then you will have do the following but be careful with what I going to tell you next

You need to make SURE that you have the positive terminal and negative terminal are marked on each battery before you start —> make sure that the battery positive terminal goes to the positive terminal on your power supply and the battery negative terminal goes to negative terminal on the power supply

If you have a adjustable power supply go to the next step
If you do not have a adjustable power supply do not do the following until you have one

You can do the following

Set your power supply at 4.2 volts @ 500 milliamperes and change the battery until the battery voltage reaches 3.2 volts do this on each set of batteries

Which means that you will have to do this three times

( if you are tempted to charge them until they reach 4.2 do not do this unless you are watching them meaning that you check them that are not getting hot as the voltage goes closer to 4.2 they are more likely to do this if are becoming bad )

If any part of what I have here you do not understand PLEASE ASK
I will be happy to explain it to you in more details

I want you to be safe and understand what you are doing

This type of batteries you need to very careful with if you are going to work with them

I have work them a lot and I have made two big mistakes before ( one time ) the battery has gone thermal and burst into flames


[ Hacking episode that when horrible wrong—> ( pouch type )

(one time it was a really stupid mistake I should have have known better but I did not know what type of package type it was I was prying apart a metal case with plastic end pieces) ]

The other time it was that I was using a battery spot welder and welding the positive terminal and misjudged where the edge of the positive terminal was and when in between it and the battery housing the battery just started hissing but did not go thermo and burst into flames I removed it quickly

I have also have had it where not having the battery spot welder not set correctly burn a hole into the battery housing not good either ( battery just leaking )

I hope this helps

[antoniu200]

Re: Battery bank made from 3 series of 2 parallel LGDAS31865 cells

Well, bad news. My laptop broke, so I have to order a 10 dollar cable from eBay to get it fixed. Also, I managed to assemble the battery bank, but got nothing to test it on. Will try once the laptop is working and post back the result (hopefully no batteries get blown ).

[stj]

Re: Battery bank made from 3 series of 2 parallel LGDAS31865 cells

10$ cable ?? what bs is that?
gold-pressed latinum plated??

[antoniu200]

Re: Battery bank made from 3 series of 2 parallel LGDAS31865 cells

It's a DC02001FR10. Don't worry, I know what I'm buying.

[brethin]

Re: Battery bank made from 3 series of 2 parallel LGDAS31865 cells

It's a DC02001FR10. Don't worry, I know what I'm buying.

The lcd cable.

You may know what your buying but not what your doing if you broke that cable sadly.

[antoniu200]

Re: Battery bank made from 3 series of 2 parallel LGDAS31865 cells

Well, there was a short apparently between the connector on the Motherboard and the cable. I was in a rush when I connected them, I should have done this when I had time, but I just wanted to see that laptop assembled, as I took it all apart and cleaned it with Isoprophical Alcohol 97% and put the platic pieces of the laptop a full day in a perfumed garbage bag, as I bought this laptop used 2 months ago and it came smelling like cigar smoke. I didn't have time to clean it thoroughly until now, so now, when I had a couple of days off, I wanted to get it cleaned. However, I was running out of time and assembled it in a hurry. And this is what happened. I'm glad I didn't mess up the connection between the LCD cable and the actual LCD display, so I don't have to buy a new LCD too.