|x||Nickel-based (NiCd and NiMH)||Lithium-ion (Li-ion)||Lead-acid (Sealed or flooded)|
|Should I use up all battery energy before charging?||Yes, fully discharge once every 1-3 months to prevent memory. It is not necessary to deplete the battery before each charge. Over cycling wears down NiMH.||No, it is better to recharge more often; avoid frequent full discharges.|
Yes, on batteries with a fuel gauge, allow a full discharge once a month to enable reset
|No, it is better to recharge more often; avoid frequent full discharges. Deep cycles wear down the battery. Use a larger battery if full cycles are required.|
|Should I charge my battery partially or fully? ||Allow full charge without interruptions. Repeated partial charge can cause heat buildup. (Many chargers terminate charge by heat. A fully charged battery will re-heat, causing overcharge.) ||Does not matter. Charging in stages is acceptable. Full charge termination occurs by reading the voltage level and charge current. Charging a full battery is safe and does not cause harm. ||Does not matter. Charging in stages is acceptable. Full charge termination occurs by reading the voltage level and charge current. Charging a full battery is safe and does not cause harm. |
|Should the battery be kept charged when not in use?||Not critical. Manufacturers recommend a 40% charge for long storage. (Open terminal voltage cannot determine state-of-charge.) Store in a cool place. Battery can be fully depleted and recharged. Priming may be needed.||Best to store at 40% charge or 3.75-3.80V/cell open terminal. Cool storage is more important than state-of-charge. Do not fully deplete battery because Li-ion may turn off its protection circuit. ||IMPORTANT: always keep battery fully charged. A discharged battery causes sulfation (insulating layer in the cell). This condition is often irreversible.|
|Will the battery heat up during charge?||Yes, towards full charge. The battery must cool down when ready. Discontinue using a charger that keeps the battery warm on standby. ||No, little heating is generated during charge. A large laptop battery may get lukewarm. Do not allow the battery to heat during charge.||No, the battery should remain cool or lukewarm to the touch. The battery must remain cold on maintenance charge.|
|What are the allowable charging temperatures?|| Important: Rechargeable batteries can be used under a wide temperature range.|
This does not automatically permit charging at these extreme conditions.
The maximum allowable charge temperatures are shown below:
|Slow charge (0.1)|
Fast charge (0.5-1C)
|0°C - 45°C (32°F - 113°F)|
5°C - 45°C (41°F - 113°F)
Charging a hot battery decreases the charge time. The battery may not fully charge.
|0°C - 45°C (32°F - 113°F) 5C° - 45°C (41°F - 113°F)|
Temperature sensor may prevent charge or cut off the charge prematurely.
|0°C - 45°C (32°F - 113°F)|
5C° - 45°C (41°F - 113°F)
Warm temperature lowers the battery voltage. Serious overcharge occurs if the cut-off voltage is not reached.
|What should I know about chargers?||Best results are achieved with a fast-charger that terminates the charge by other than temperature alone. Fastest full-charge time: Slightly over 1 hour.||Charger should apply full charge. Avoid economy chargers that advertise one-hours charge. Fastest full-charge time: 2-3 hours.||Multi-level charges shorten charge time. Charge must be fully saturated. Failing to do so will gradually decrease the capacity. Fastest full-charge time: 8-14 hours.|