There is a lot of information on the internet about proper battery care, but unfortunately it is often only half-truths, as there are different types of batteries, for example lithium polymer [LiPo] or nickel cadmium [NiCd], and both batteries need to be treated completely differently in order to enjoy them for a long time. For a better overview, I have now categorised these batteries and summarised the most important information.

Each battery cell must be labelled with exactly what type of battery it is, and by that I don't mean the shape and size, but rather what materials were used in its manufacture, as this determines how the battery should be charged, stored and discharged.

Lithium batteries

Lithium batteries are very sensitive and must always be handled correctly, otherwise their service life and capacity can be greatly reduced, or there is a risk that the batteries will catch fire.

General information about lithium batteries

Charging cycles:

Lithium batteries have a maximum number of charging cycles, because after each charging cycle, the battery is no longer 100% charged, meaning it loses a small amount of capacity. After the specified charge cycles, the battery has less than 80% of its capacity and is considered to be no longer usable. A charge cycle is the discharge of the battery to ~30% and then a recharge to 100%.

Discharging to 50% and charging to 80% is considered less than 1/4 of a cycle, because the battery is subjected to significantly greater stress when it is charged above 80% and discharged below 40%. So if you keep the battery between 50% and 80%, you can significantly extend its service life (maximum charge cycles)!

The worst thing for a battery is to repeatedly charge it between 80% and 100%, as this can significantly shorten its service life.

My tip

If not necessary, do not fully charge the battery and, if possible, do not discharge the battery below 30%.

If a battery is deeply discharged, its capacity is immediately reduced. Attempting to charge batteries that are significantly below the minimum charging voltage is even dangerous.

Temperatures

Most lithium batteries are very sensitive to temperature (see the specific technology for exact details).

High temperatures

Above ~40 °C, the cell ages significantly faster, meaning that the battery swells and loses capacity.
Above 100 °C, thermal runaway occurs.

Low temperatures

At too low temperatures, the current output decreases significantly. It even makes sense to use part of the battery charge to warm up the batteries so that they can deliver enough current under load. There are even special batteries that have heating wires integrated into the cell to warm the cell from the inside and thus faster than from the outside.

Charging a battery at too low temperatures (below ~ 0 °C) can lead to lithium plating. In extreme cases, this creates an electrically conductive connection between the poles, short-circuiting the battery and rendering it unusable. In any case, lithium deposits on the negative pole, leading to a reduction in capacity.

Storage

When storing batteries, it is important to ensure that they are not stored at extreme temperatures, as they age more quickly at high temperatures and the cell voltage can fall below the minimum specification at low temperatures.

Ideally, the battery should be brought to an ideal cell voltage at which there is neither a risk of deep discharge due to self-discharge nor an excessively high cell voltage at which the battery ages significantly faster.

Danger

If pouch cells age, they swell up and should no longer be used, as they may burst (leaking acid and acidic gases) or suffer an internal short circuit due to the high pressure, which can lead to a fire.

Cells that have been deformed by a fall can still short-circuit during storage and start to burn. This is because the insulation layer may be weakened and the ageing process (swelling of the cell) causes the increasing pressure in the cell to tear the weakened insulation layer (short circuit).

If lithium batteries catch fire, they cannot be extinguished with water or by burying them, as the components for a fire (oxygen and fuel) are chemically bound in the cell and are released when burned. Internal short circuits can cause damaged batteries to start burning for days after an accident, which is why an electric car must be monitored by the fire brigade after an accident.

Lithium ion

Advantages:

Lightweight
High voltage density

Disadvantages

Sensitive to cold temperatures

{tab Specs}

Nominal voltage:

Min. end-of-discharge voltage:

Max. end-of-charge voltage:

Ideal storage voltage:

Self-discharge / month at 20 °C:

Min. operating temperature

Max. operating temperature

Ideal operating temperature

Cell types:

Power density

Lithium polymer [LiPo]

Lithium iron phosphate [LiFePO4]
Advantages

Cell balancing is not absolutely necessary



Disadvantages

Heavy due to design

Lithium cobalt dioxide [LiCoO2]

Nickel batteries
Nickel metal hybrid batteries [NiMh]
Nickel metal hybrid batteries are the direct successor to NiCd batteries and offer even higher power density. In the Sub-D design, a NiCd battery can store a maximum of 1500mAh, but NiMh batteries quickly became available that offered more than twice the capacity with the same size and only slightly higher weight.

Nickel cadmium batteries [NiCd]
Unfortunately, nickel cadmium batteries are now only available to a limited extent in Europe, as they are heavily regulated by the EU because cadmium is highly toxic and can cause great damage to the environment if not disposed of properly.

Advantages:

Very good cold resistance

Disadvantages:

Memory effect
Low capacity and high weight compared to newer technologies (NiMH, lithium)
Care:

Due to the memory effect, batteries only perform at their full capacity when they have been completely discharged and then recharged. The older the cell, the shorter the time after charging during which it can deliver its full power.

Lead battery [Pb]

Advantages:

Good cold resistance

Disadvantages:

Low capacity and very heavy compared to newer technologies (NiMH, lithium)

Alkaline batteries
Please note that alkaline batteries are not rechargeable, meaning that these batteries cannot be recharged.

Advantages

Good cold resistance

Disadvantages

Not rechargeable

In addition to this article, I recommend the following links to all RC enthusiasts:

https://oscarliang.com/lipo-battery-guide/