Building a battery using 18650 li-ion cells

In the video above I build a 6s9p battery using li-ion cells. The final battery is a 14s9p for my electric bike. I just did a video of the 6s9p part to keep the video short.

 

 

Advertisements

Li-ion cells and cold temperatures – Part 2

26F Cold tests 2 Descr

Please click on the image to enlarge it.

After the first cold tests I decided to go a step further and do some tests with even colder temperatures to see the behavior of the cells.

For the Orange tests the cell was padded this way:

IMAG0765

Side view with padding on the sides removed:

IMAG0764

These tests are interesting for people like me that uses lithium ion cells in cold climates. Especially in my case, I use the cells in an electric bicycle. It’s important to have some sort of thermal insulation on the battery when riding in cold temperatures, the performance improves dramatically and the battery cycle life is preserved.

Li-ion cells and cold temperatures

Image

Please click on the image to enlarge it.

I was curious about the behavior of lithium cells at low temperature. In particular I was expecting capacity loss and voltage sag  compared to the standard test temperatures of 20-25°C.

The tests above were conducted on a single cell, a Samsung ICR18650 26F, discharged at 1C.

The voltage sag and loss in capacity are lower than I expected. I am planning to do some -10°C tests to have even more data to compare.