On Wed, 4 Dec 2019 20:17:48 +0000, Martin Brown
wrote:

snip

Leaving them flat for a long time or overcharging them will both
seriously shorten battery life.

As will the charge rate (rather than charge level), something where
most people thing bigger / quicker is better. ;-(

I specifically buy chargers where the rates are either 'mild' (where
the cells don't heat noticeably whilst charging) or are charge current
limited / adjustable (and I can ensure the above).

When racing RC cars in the very early days, the (Nicad) cells were
built into the vehicle and so were raced and re-charged nearly
continuously thought the session.

When we moved over into removable packs, they were often fan cooled
after use and during recharging, to try to minimise damage.

I believe in the case of some chemistries, the rate of charge can
impact the charge density. A slow charge can form fine crystal
structure and therefore a greater energy density but a smaller surface
area and so a slightly lower discharge rate.

Talking to a wedding photographer a few years ago he used the highest
capacity NiCads he could find but would cane them re recharge rate,
killing them a short period. However, he accepted this 'cost' as part
of his overheads because he often had little time between shoots to
get the batteries recharged again.

Cheers, T i m