Loading... Please wait...

Advanced Search | Search Tips

Battery Basics

batterypic.jpg10 Tips on Extending the Battery Life of Battery Powered Lawn Mowers and Garden Tools

Here are several tips on how to get the most out of a single charge of the batteries in a battery powered electric lawn mower.

Most of these are related to any electric battery mower where the batteries are charged by plugging the battery charger into an electrical outlet:

1. Make Sure The Batteries Are Fully Charged
Battery chargers have a light indicator which will go from red to green to indicate when a battery / batteries are fully charged. If you want the electric mower to go as along as possible before the juice in the batteries is fully used, only use the mower when the batteries are fully charged

2. Raise The Mower Height
Experts agree that it is healthier for the lawn to cut the grass at around 3 inches or so. The higher the grass, the more moisture that will be retained in the ground. So, simply raise the height of your mower.

3. Mow the Lawn More Frequently
The more frequent you mow the lawn the shorter the grass will be when it is mowed which in turn will cause the mower to work less hard. Especially with the constant rain that some parts of North America, the grass is growing very, very fast. So, don't mow your lawn only on Friday evenings or Saturday afternoons per a usual summer. Mow twice a week.

4. Do Not Use the Optional Mulching Blade
The mulching blade can use more power from the batteries. And, it's not really the optional mulching blade itself; rather, it would be the containment of the blades of grass staying inside the mower base making the engine use more power. Compare this to when a mower is not used in mulch mode but when the bagging option is used or when the grass leaves the mower as soon as it is cut to the side or rear of the mower.

5. Avoid Early Morning Mowing
For lawn mowers using batteries, it is a good rule to not mow the lawn in the morning at all since over night, dew forms on the grass. Mowing the lawn when the grass is wet, either from the morning dew or from a recent rain storm makes the mower work harder, consuming more energy. If you wait until after all of the morning dew has evaporated from the grass, it will be easier to mow, take less of an effort from the mower and thus allow the batteries to run longer in a single mow.

6. Self-Propelled Feature
Any mower that is self propelled requires more energy. In the case of an electric lawn mower, that energy is from the batteries. So, simply stop using the self propelled feature will reduce the amount of battery energy consumed. You will get a better workout than if you used the self-propelled feature.

7. Batteries are made to be used, so use them
Just like couch potatoes, batteries need exercise. The chemicals in Lithium-Ion batteries respond best to regular recharging. So if you have a laptop, don't keep it plugged in all the time; go ahead and let it drain to about 40 or 50 percent of capacity, and then recharge your computer.

The life of a Lithium-Ion battery can be measured in charge cycles. A charge cycle occurs when 100% of a battery's capacity is used. Let's say you use 50% of your battery one day, charge it overnight, and then you use 50% of the battery again the next day. Even after charging it back up again, you'll have only had one charge cycle occur. Most batteries are rated for a useful life of at least 300-500 charge cycles, but high-quality, properly maintained batteries can retain up to 80% of their original life, even after 300 cycles.

8. Periodically calibrate your battery
Most batteries that have a "fuel gauge", should be periodically discharged to zero. This can be accomplished simply by letting it run until it reports a low-battery state and suspends itself. (Do not let your battery deep discharge, as explained in the next item.)

The gauge that measures the remaining power in your battery is based on circuitry integrated into the battery that approximates the effectiveness of the battery's chemical compounds. Over time, a discrepancy can develop between the capacity that the internal circuitry expects the battery to have and what the battery can actually provide. Letting your computer run down to zero every month or so can recalibrate the battery's circuitry, and keep your computer's estimates of its remaining life accurate.

9. Don't practice so-called deep discharges
Most tools will suspend operation if the battery drains too low. Even if your tool stops, though, most batteries that are in good working order will still have a reserve charge available. This reserve will hold the computer's working memory in state for a little while. A deep discharge has occurred when even that percentage of reserve power is used up. The tool will have turned off completely, and sometimes you'll notice that it will have lost track of the correct date and time. Deep discharges will strain your batteries, so try to charge them frequently.

10. Store your batteries properly
If your laptop or portable device isn't going to be used for a while, you should remove its Lithium-Ion battery, if possible. Even if the battery can't be separated from the device, it should be stored in a cool environment at about one-half charge. Cool temperature is recommended by experts because that can slow the natural discharge that batteries will undergo even when they're disconnected from their device.

I've seen some people go even further and recommend that spare batteries be stored in the refrigerator. I don't think this is a very good idea; I'm concerned about condensation that might build up. Don't put your batteries on ice, but keep them out of the sun.

Ultimately, I believe that buying spare Li-Ion batteries is a losing game, because the batteries start degrading as soon as they're manufactured. Usually those spare batteries spend most of their time sitting in a charger, losing useful life. If you need extended operating run times, some tools make available an adapter cable to convert to regular electrical power for continued operation.. And, of course, by taking good care of the battery you already have.

Lithium-ion batteries can hold a charge for many months. It is best to store a lithium-ion battery with a partial or full charge. Occasionally, a lithium-ion battery with a very low charge is stored for a long period of time (many months) and its voltage slowly drops to below the level at which its built in safety mechanism allows it to be charged again. If the battery is going to be stored for several months it's a good idea to take it out and recharge it after a few months. Better yet would be to actually use the battery every few months and then leave it partially or fully charged.


Advantages of Lithium Ion Batteries Compared to Other Rechargeable Batteries
LiPower.jpgLithium-ion batteries have several advantages. They have a higher energy density than most other types of rechargeable batteries. This means that for their size or weight they can store more energy than other rechargeable batteries. They also operate at higher voltages than other rechargeable batteries, typically about 3.7 volts for lithium-ion vs. 1.2 volts for NiMH or NiCd. This means a single cell can often be used rather than multiple NiMH or NiCd cells.

Lithium-ion batteries also have a lower self discharge rate than other types of rechargeable batteries. This means that once they are charged they will retain their charge for a longer time than other types of rechargeable batteries. NiMH and NiCd batteries can lose anywhere from 1-5% of their charge per day, (depending on the storage temperature) even if they are not installed in a device. Lithium-ion batteries will retain most of their charge even after months of storage.

So in summary; lithium-ion batteries can be smaller or lighter, have a higher voltage and hold a charge much longer than other types of batteries.

What are the disadvantages of Lithium Ion batteries compared with other rechargeable batteries?
Lithium-ion batteries are more expensive than similar capacity NiMH or NiCd batteries. This is because they are much more complex to manufacture. Li-ion batteries actually include special circuitry to protect the battery from damage due to overcharging or undercharging. They are also more expensive because they are manufactured in much smaller numbers than NiMH or NiCd batteries. Li-ion batteries are becoming less expensive and over time we should see their price decrease significantly.

Lithium-ion batteries also require sophisticated chargers that can carefully monitor the charge process. And because of their different shapes and sizes each type of Li-ion battery requires a charger designed to accommodate its particular size. This means lithium ion battery chargers are more expensive and more difficult to find than NiMH and NiCd battery chargers.