Any battery that needs to be designed must have variable cells that act as voltage units, all these cells come in different voltages and capacities. In order to design a battery pack that has different voltage or customizable sources, you would have to use different cells with different voltages and then make it work by adjusting their working with each other. Cells need to be put in the parallel setting if you need more current, the physical configuration can change simultaneously depending on the type of the battery pack that you need to develop.
Development of battery pack design for high power lithium battery
Following are the things that you may require when designing a battery pack with variable or different voltages;
Solder versus weld
Nickel strip is used for making contact with when different battery packs are aligned with one and the other while welded together. Soldering on the other hand is dangerous for the cells. It can even melt or disturb the cell assembly that is left in parallel or cause a shortening if the heat inside becomes too high. This temperature difference is not so noticeable until it is too late. And for making a 3.7V Lithium Battery it is essential that you choose the solder Vs. the welded version of the setup thoughtfully.
Heat shrink tubing
The next thing that you need to pull off the manufacturing of a battery pack with variable voltage is the heat shrink tubing. It helps to hold the battery pack in place, it can hold the small packs in place but as the weight increases, the structural strength becomes a necessary thing. This can be done by using the fish paper or any structural material folded and compressed in such a way that it is placed over the top and bottom of the case in which the battery resides. If the battery is needed to be transferred then you must tape the battery pack together for the ease of handling.
Another thing that you should be very careful about when building the lithium battery packs with variable voltage is that you must at all costs avoid the shortening of the cells. This may occur if the cells are in linear form or placed in series, try to then place them parallel to each other and go for the rest of the process rather smoothly.
Battery holders must be designed in such a way that they have enough space to accommodate all the elements that you want to incorporate into it. This is a must-have especially for the 14.8V Lithium Battery as the number of cells begins to vary depending on the different voltage scope that is needed such as having short, long, and wide cells. Also, make sure that there are no sharp ends of the cells that you have incorporated into the battery holder otherwise chances are that it will cut off the security paint or enamel and cause a serious shortening which will disrupt the whole battery pack.
When batteries especially the 22.2V Lithium Battery system is incorporated into a battery pack the expansion and contraction of these elements take place during charging and discharging. Potting the battery is not a good idea at any capacity until unless such dimensional change is ever required. You can literally include a foam pad into the battery holders for the sake of absorbing the stress of battery expansion. But beware of going too far with it as you don’t want the pressure to be built at such a capacity where it would totally blow off the whole system.
Cases and cabinets
Many batteries in continuation of their life cycle emit hydrogen and in rare cases the oxygen too. This essentially means that the battery system that you are designing is a closed system and there is a chance of these gases expanding or blowing up the whole thing. Many lithium-based batteries that have to serve their purpose in an enclosed or weatherproof environment then you have to take into thought the cases or cabinet section of battery designing.
But remember that when designing the batteries with variable voltage a system for releasing and absorbing of the hydrogen and flooding the internal system with inert gases must be practiced. Make sure that when using closed cabinets there is an essence of vexillation in there for releasing the hydrogen gas that accumulates.
Although only the basic design-oriented and mechanical things are illustrated in this article, you can use this analysis for determining your particular fit or design that you want for your new battery. In such a way that it changes resistance and voltage when needed and poses no threat to itself, the device in which it is going to be used in and the surroundings. If you deem yourself fit for the job then it is recommended that you hire a professional helping hand in order to complete the job.