Can you mix different capacity lithium batteries?

Yes, you can mix different capacity lithium batteries, whether a normal 12V 100Ah battery or a Lithium server rack battery. You can combine different capacity batteries in parallel. You cannot combine different capacity batteries in series. There are a few points you need to consider when wiring in parallel. Let’s explore these three points.

What makes a good battery pack?

Battery packs with well-matched cells perform better than those in which the cell or group of cells differ in serial connection. Quality Li-ion cells have uniform capacity and low self-discharge when new. Adding cell balancing is beneficial especially as the pack ages and the performance of each cell decreases at its own pace.

Do nickel based batteries match each other?

Cell matching according to capacity is important, especially for industrial batteries, and no perfect match is possible. If slightly off, nickel-based cells adapt to each other after a few charge/discharge cycles similar to the players on a winning sports team.

Can you use multiple lithium batteries in parallel?

Here is a diagram for multiple lithium batteries in parallel. You can add individual battery switches after the fuses. From the main busbar, it can go to your inverter, charge controller, or generator. The negative cables can go to a busbar, then a shunt, then another busbar.

When should a battery pack be balanced?

Assuming the battery pack will be balanced the first time it is charged and in use. Also, assuming the cells are assembled in series. If the cells are very different in State of Charge (SoC) when assembled the Battery Management System (BMS) will have to gross balance the cells on the first charge.

What happens if a battery pack is cycled?

When cycled, all batteries show large capacity losses over 18 cycles, but the greatest decrease occurs with the pack exhibiting 12 percent capacity mismatch. Battery packs with well-matched cells perform better than those in which the cell or group of cells differ in serial connection.