Here is a good used source for 18650 batteries

[sam_sam_sam]

Re: Here is a good used source for 18650 batteries

Here is the link for 4.2 volt @ 26 amp hour battery packs that I mentioned above
I bought the amount that I need and there are still some left

https://batteryhookup.com/products/new-7-2v-30ah

I have tested one battery pack it does test at a little bit over 26 amp load test parameters are 4.2 volts down to 2.5 volts

One note after I did the first battery pack and I saw that the roll off voltage was around 6.00 I set the parameters 8.4 charging and 6.0 for discharging

Well I have tested 5 of them so far and they all are very very close to each other and I have already put the two and half battery packs on a cutting board for the first level the second level has two battery packs on it and now I am testing the other battery pack to cut in half for the second level once I do this I will have to wire the the battery packs together to make a 20 volt battery pack with the BMS protection board and put the charger together to charge the battery pack for the battery operated compressor I used a marine battery enclosure and a cutting board to mount the battery packs I will post some pictures of it when I get the first level wired together

The third level will have the BMS protection board with an inline fuse holder

The two half battery packs I going to reconfigure for another project and use the remaining half’s because they do not have enough tabs on one half of it but it still can be mounted on something else

I was very pleased with how the battery pack mounting went the bottom of the battery packs have two mounting round tubes that stick down about 1/4” so I drilled two round hole to accommodate the two round tubes which have a hole in the center of the tubes that are on the bottom of the battery pack and they are very secure to the cutting board used #6@1” metal screws for the mounting of the battery packs

[sam_sam_sam]

Re: Here is a good used source for 18650 batteries

Here is another offer from Battery Hookup

https://batteryhookup.com/products/1...0-3-7v-5000mah 21700 battery cells $1.64 per cell X 110 battery cells in battery pack = $180.00

I bought one of these to replace some tool battery packs that are very unbalanced
It took a few hours to disassemble this battery pack but well worth the money because I have already charged up four of them and from 3.1 volts to 4.2 volts was well over 4 amp hours now discharging them down to 3.0 volts where the normal voltage roll of voltage usually is

The voltage looked good on each battery cell bank very balanced between battery cell banks

When I said that it took a few hours to disassemble the battery pack I meant that it took that long to remove all the tabbing from every battery cell

One note about the description from Battery Hookup about the BMS protection board does take a little doing to remove it I would recommend that you cut the wires from the BMS board before you try to completely remove it from the battery enclosure it will make it easier to install your own BMS board because there are small tabbing soldering holes for the BMS board wires to go from your own BMS board

To reconfigure the battery voltage would be fairly easy to do you would need to cut the battery tabbing down the length of battery cell bank or just remove it and use single row tabbing instead but not the amp hour reconfiguring would much harder to I am not saying it impossible but would require a lot of work the reason I am saying this is because the tabbing is very easily ripped off of battery cells if not done properly because it the fuse type of tabbing that was used to me the easiest way to do this might be use a small cut off disk and lightly cut the tabbing off enough to separate the battery cells from each other

You could turn it from 110 amp hour to 50 amp hour and get a higher voltage if you want to do that

If I buy another one when I have the money for it and if Battery Hookup still has them in stock

I would like to take one and reconfigure it so it would be 12 volts and who knows how many amp hours I could get from this battery pack the enclosure is very well made one note I would not recommend removing the battery cells from the battery cell holder it would not be very easy to get all the battery cells to line up so you snap the battery holder back together it does have screws that hold it together

If I did buy another one I would probably just test each battery cell bank and not each individual one the test would still be valuable because you would know how many amp hours each bank would have and if each bank basically has the same amount of amps hours

Test results so far are 1744 milliamperes hour at 3.83 volts

[sam_sam_sam]

Re: Here is a good used source for 18650 batteries

Here is another offer from Battery Hookup

https://batteryhookup.com/products/c...-batteries-new

These are very nice battery cells for the price but there is one thing you need know about these battery cells is that they are not balanced battery cells they are from exactly the same amp hours to as much as half amp hour difference between individual battery cells

I would highly recommend that if you buy them make sure that you have a battery testing machine of some sort so you match the amp hours

[sam_sam_sam]

Re: Here is a good used source for 18650 batteries

Here is another offer from Battery Hookup

https://batteryhookup.com/products/1...0-3-7v-5000mah 21700 battery cells $1.64 per cell X 110 battery cells in battery pack = $180.00

I bought one of these to replace some tool battery packs that are very unbalanced
It took a few hours to disassemble this battery pack but well worth the money because I have already charged up four of them and from 3.1 volts to 4.2 volts was well over 4 amp hours now discharging them down to 3.0 volts where the normal voltage roll of voltage usually is

The voltage looked good on each battery cell bank very balanced between battery cell banks

The temperature of the battery that you are seeing in normal for these battery cells it is set to read in *F instead of *C

Test results so far are 1744 milliamperes hour at 3.83 volts @ 1.47 hours

Parameter are as follows

The graph function is very primitive but gives you enough data information to know if you have a problem with the battery cell

SkyRc MC3000
charging voltage 4.2
resting time is 240 minutes to allow enough time for battery temperature to reach room temperature again for the second phase of the testing
discharging voltage 3.0
amperage is set to 1.00
battery temperature cutoff is set 40*C

The temperature that you are seeing for this type of battery cell is normal it set to display in *F but you have to set it in *C

One note the temperature reading on the last battery cell is always a couple of degrees off from the other battery cells I am thinking that just a little off because even when there no battery in it it always shows a couple degrees different

One other note the results are being shown on a very old iPad that is not supported by Apple anymore but it good enough for doing battery testing for this battery testing machine iPad screen is set to not to shut down the screen meaning that it set not to shut off unless I use the power button to turn it off / because if it not set this way when you wake it back up sometimes it resets it self and you lose the data

My other SkyRc battery testing machine is also the same way you have to keep the screen from going off or you lose all the data as well it the one that can do 6 battery cells for up to 24 volts battery packs