Battery: Do's and Don'ts

Each battery had unique needs that must be met to obtain reliable service and long life. The table below summarizes these needs and advises proper handling of each battery type.
Optimal handling may not always be practical in real life. Deviations for the ideal are acceptable but will lower the life expectancy of the battery to some degree. Exposure to heat may be the larger deterrent.

Nickel-cadium (NiCd) Nickel-metal-hydride (NiMH) Lithium Ion (Li-ion) Lead-acid (Sealed or flooded)
Used in Two-way Radios, Power tools, medical equipment. Similar applications as NiCd; higher density  Cell phones, laptops, video cameras.  Motorcycles, Cars, wheelchairs, UPS.

 

Do:

Do:

Do:

Do:
Charging

-Run the battery fully down once per month; try to use up all the energy before charging.

 

-Run the battery fully down once every 3 months.

 

Charge this battery often. The battery lasts longer with partial rather than full discharges.

 Charge this battery immediately after use.

Must always be kept in a charged condition. The battery lasts longer with partial rather than full discharges

 

Don't:

Don't:

Don't:

Don't:

-Leave battery in charger for more than 2 days because of memory

-Avoid getting battery too hot during charge

-Over-cycling is not advised.

-Leave battery in charger for more than 2 days because of memory.

-Avoid getting battery too hot during charge

-Do not use if pack gets hot during charge. Also check charger.

-Over-cycling is not advised

-Fast charge not possible on these batteries


Charging Methods

Constant Current, followed by trickle charge when full.
Fast Charge Preferred over slow charge.

Slow charge = 16 hours

Rapid Charge = 3 hours

Fast Charge = 1+ hour(s)

 Constant current, followed by trickle charge when full. Slow charge not recommended. Battery will get warm towards full charge.

Rapid charge =  3 Hours

Fast Charge = 1+ hour(s)

 Constant Voltage to 4.20V/cell (typical). No trickle-charge when full. Li-ion may remain in the charger (no memory). Battery must remain cool. No fast charge possible.

Rapid Charge = 3 Hours

 Constant voltage to 2.40/cell (typical), followed by float held at 2.25V/cell.

Battery must remain cool. Fast Charge not possible; can remian on float charge.

Slow Charge = 14 hours

Rapid Charge = 10 Hours


Discharging

 Full cycle does not harm NiCd.

NiCd is one of the most hardy and durable chemistries.

 Avoid too many full cycles because of wear.
Use 80% depth-of-discharge.

NiMH has higher energy density than NiCd at the expense of shorter cycle life.

 Avoid full cycle because of wear. 80% depth-of-discharge recommended. Re-charge more often. Avoid Full discharge. Low voltage may cut off safety circuit.

Avoid full cycle because of wear. Use 80% depth of discharge. Recharge more often of use larger battery. 

Low energy density limits lead-acid to wheeled applications.


Service Needed

 Discharge to 1V/cell every 1 to 2 months to prevent memory.

Do not discharge before every charge.

Discharge 1V/cell every 3 months to prevent memory. Do not discharge before each charge No Maintenance needed. Loses capacity due to aging whether used or not.

Apply topping charge every 6 months. 

Occasional discharge/ charge may improve performance.


Storage  Best to at 40% charge in a cool place. Open terminal voltage cannot determine state-of-charge. 5 years and longer storage possible. Prime battery if stored for longer than 6 months.  Store at 40% charge in a cool place. Open terminial voltage cannot determine state-of-charge. Prime Battery if stored longer than 6 months.

Store at 40% charge in a cool place. (40% state-of-charge read 3.75-3.80V/cell at open terminal)

Do not store at full charge and at warm temperatures because of accelerated aging.

Store always at a full state-of-charge. Do not store below 2.10V/cell; apply topping charge every 6 months.

Disposal  Do not dispose; contains toxic metals; must be recycled. Should be recycled. Low Volume household NiMH may be disposed.   Should be recycled. Low volume household Li-ion may be disposed. Do not dispose; must be recycled.