Batteries

Batteries are a BIG deal…as nearly everything runs on them.

Why is it that devices that run on batteries ALWAYS die when you need them the most?

How many of you have had a cell phone call dropped because your battery died?

How boring can a lesson get, right?

WRONG!

Keeping Your Device Going

• A little humor…– even this young kid

understands the importance of keeping the camera running...with an external battery.

– http://www.danelopower.co.uk/battery-phone-and-pda-battery/

Usages• Entertainment– Microphones– Headphones– Remotes (TV, Toys)

• Work– Cell Phones– Cordless power tools (drills, sanders,

leaf blowers)• Other

– Hybrid Cars– Battery Back Up Systems – Computers,

Hospitals, etc.

• What other devices can you think of that use batteries?

Replacing an INTERNAL B&D tool battery.

Why so many types?Main types of batteries:• General Purpose

– "Heavy Duty" is a big misnomer; these are really "puny duty". General Purpose are very susceptible to leaking.

• Sealed Lead Acid (SLA)– Used in UPS (battery backups for computers and TVs…the only true

source of surge protection • Alkaline

– one time use • Mercury

– used in watches • NiCd

– original rechargeable, had a memory effect if you charged while the battery was not completely drained.

• NiMh– longer lasting, NO significant memory effect.

• LiON and LiON Polymer– Found in most current cell phones and laptop because they do not

mind being "topped off" (charged daily)...i.e. NO significant memory effect. But you should still allow the battery to show some signs of discharge BEFORE recharging for maximum life of the battery. But it is not necessary to deplete the battery...in fact, LiONs do NOT like to be deeply discharged.

• Lithium – Newest latest greatest. Longer run time with less weight ...great for

cordless mice and other compact devices.

Battery Life

Disadvantages of Rechargeables• Do not like to be completely discharge (esp. LiON) • Cost more initially…usually need two sets to cycle the batteries.

Tip: Carry a set of Lithium's as a backup to your rechargeable. • Takes time to recharge • They die suddenly…most batteries that do not have smart chips

inside of them and so do not REALLY know how much is remaining.

• 1-2% self discharge PER day…especially NiMh • Require a great deal of “management” • Require electricity and a charger to recharge • Very little compatibility between chargers and types of battery. • They can blow up…cause fires...here is a battery that blew up at

my house...and very fortunately did not cause a fire...

Advantages

• MUCH less expensive over time • Provide longer run time at a higher power

rating in most cases

- Cons seem to outweigh the Pros, huh?– There is good news…at the end…at least with

AA and AAA

Battery Ratings• Rechargeable batteries are rated

by how much power they will deliver over a period of time, called…Amperes per Hours. – Except most consumer batteries you

are familiar with are rated in milliamps per hour, mAh.

• The HIGHER the mAh, the better...but not all batteries are created equal. – Two batteries of the same rating

(even of the same brand) may perform completely different.

– Many devices need a certain voltage to power up the device.

– And, the more power they start with, the quicker they loose the power.

Charger Differences • The top two are

pretty basic, delivering the SAME amount of current (i.e.. charge) to all four batteries.

• The charger on the bottom is a SMART charger (it has a computer chip) …and is a much better charger because EACH battery gets it own specific, dedicated charge that is JUST right for the internal resistance of the batter, whether it be between brands or with in the same brand.