We had not noticed any degradation of the 12v 25 Ah Lithium battery pack in the last year despite its continued usage almost every single day.
BHPian Chhanda Das recently shared this with other enthusiasts.
Increased the Lithium battery’s capacity to 35 Ah
It has been over a year since my son made the 12v 25 Ah Lithium battery pack and I thought about letting you all know about the present situation.
First, let me share the information about a temporary setback. The LiitoKala branded 18650 Lithium cell charger that we were using died all of a sudden due to an ant infestation inside it.
When we started looking at 18650 Lithium cell chargers, we were appalled at the sky-high prices and decided to make one on our own. After a little bit of research, we decided that the cheap TP-4056 printed circuit board (PCB) module would suit our requirements perfectly.
Please note that this TP-4056 PCB module is available in a few different variants. We got the 1 ampere-rated ones with current protection and micro-USB input. This would allow us to power it from almost any power source like computers, solar charge controllers, smartphone power banks, etc as long as the source current did not exceed 1 ampere.
We also got a USB combination ammeter-voltmeter with a maximum current capacity of 3 amperes and a voltage range of 3.5-7 volts to measure the amount of power being drawn.
As you can see above, the TP-4056 PCB modules’ input ends have been connected to each other in parallel. This was done solely to minimize costs since we got just one USB combination ammeter-voltmeter and coincidentally had just one spare micro-USB male to USB male cable lying around. The wires were salvaged from the dead/defective laptop battery packs from which we got the 18650 cells for refurbishing/salvaging. The 4 bay 18650 cell holder in the image above was originally intended for a 4S configuration but we didn’t have any use for it anymore. So my son turned it into a 2 bay 18650 cell holder. He didn’t remove the original connections in the 4 bay cell holder so that he could use it again in a 4S/3S configuration if necessary.
Now he could finally increase the capacity of the 12v 25 Ah Lithium battery pack. Please note that we had not noticed any degradation of the 12v 25 Ah Lithium battery pack in the last year despite its continued usage almost every single day. The original configuration was 3S11P. He added 5 sets of refurbished 3S cells (Total 10 Ah) in parallel to that, resulting in an increase in capacity by approximately 40%. I won’t bore you with the details of the procedure since that has already been discussed in detail near the beginning of this thread.
First, the BMS was removed from the battery pack.
Then the 15 cells were added in the proper orientation for matching the 3S configuration of the older cells.
Spot welding completed
BMS attached and connected
The present configuration is 3S16P and the total capacity is 12v 35 Ah. This 12v 35 Ah Lithium battery is approximately equivalent to a 12v 70 Ah Lead-Acid battery when it comes to the amount of usable power. Mission accomplished!
Disclaimer
We followed all precautions/procedures mentioned above and earlier. If you want to copy all this then please do so at your own risk.
I hope that you all found this interesting and I wish you all happy and safe drives ahead.
Check out BHPian comments for more insights and information.
Source: Read Full Article