Cordless Drill Battery Articles

How should I store the cordless drill batteries?

I have a nice cordless drill that came with two rechargeable batteries. However, there are times when life gets in the way and I'm not using the drill at all over the course of several months. When I return to the drill, both of the batteries have died.

How should I store the Makita BL1860B batteries when they are not going to be used for several months? Is there a way to do so such that they'll have a charge when I need them next? Are there any steps I should be taking when storing the batteries so lengthen their overall lifetime?

Batteries in general have several points worth concerning their usage. Yes, you are asking about storage but it is worth knowing that their storage strategy is influence by their usage frequency as well. Which type you have is important. There is not one overall method.

Lithium Ion Batteries

Like most batteries they should be stored at room temperate and not in direct sunlight. Some sources mention that storing it slightly warmer can help it perform better but the consensus is storing it at 15°C (59°F) is ideal. A dry area is also an important factor.

In general we are advised to store the battery in a partial discharge state. Storing the Makita BL1850B battery in either a fully charged or discharged state can actually harm the battery. Most manufacturers recommend storing these batteries in a 30-40% charge level. Charge level can be determined usually by battery temperature. The better you take care of it the longer it will last. I don't see myself ever testing the charge level but since I use my drill a lot I get a feel for when its getting down in charge since it starts to lose its torque.

The above tactic is sound but it is important to fully discharge the battery every 30 or so cycles of use to reset the batteries Digital Memory. The digital memory effect is a failure mode whose effect results in the transmission of improper calibrations of the battery's fuel gauge to a device. To correct the digital memory effect and properly re-calibrate the fuel gauge circuitry simply do a full cycle discharge/recharge every several dozen charges. There is no real.

Nickel-Cadmium Batteries

Similar temperature and moisture suggestions exist for NiCd in that they should be stored in a cool and dry location. Between -20 °C and 45 °C (-4°F - 113°F) is recommended but I have seen several sites suggesting that freezing should be avoided.

The batteries themselves should be stored either fully charged or fully discharged. Note that they have a higher discharge rate when compared to Li-Ion batteries but are not permanently affected by this discharge.

If you plan on storing these batteries long term (more than a couple of months) it is important to use them periodically to prevent crystals from forming and shorting the cells. The crystals can lower battery performance and the extreme one can cause damage that is irreversible. While modern NiCd's don't have a true internal memory problem, the crystal formation factor can effect the battery in a similar way.

Nickel Metal Hydride Batteries

Depending on what you read these Makita BL1830B batteries had a rough start when used for power tools. They have been getting better but were not as widely accepted until more recently due to their disadvantages.

As far as temperature and periodic use the NiMH and NiCd have the same approach. The important difference is that NiMH have the highest discharge rate and it is more important to periodically use it to prevent damage. Some people have made special cradles to allow a trickle charge to prevent this effect although that is more for your standard AA,AAA batteries.

Refer to your manual

Assuming you still have it there could be more specific instructions included with your device.