What exactly is an Energizer ER-P550?

Energizer ER-P550

The Energizer ER-P550 is a cordless telephone battery used in many different (mostly Sony) cordless telephones. The Energizer ER-P550 Battery is a direct replacement for the Sony BP-T38 battery pack.

We have provided detailed information on the Energizer ER-P550 battery in the following discussion. Hopefully this discussion will give you the knowledge you need to make a more informed buying decision when purchasing a replacement battery pack for your telephone.

What are the specifications of the Energizer ER-P550 battery Pack?

Most Energizer ERP550 batteries are rated at 3.6 volts and 1200 mAh (Mili-Amp Hours). Sometimes you will see higher or lower mAh ratings. The mAh number is the measurement of the "capacity" of your ER-P550 battery pack. The higher the Mili-Amp Hour rating, the longer your run time. For example, an 800 mAh cordless phone battery will give you twice as much talk time when compared to a 400 mAh (half of 800) battery pack.

What is the normal useful life of a Energizer ER-P550 Battery Pack?

Most consumers get between 3 to 5 years of service from their Energizer ER-P550 phone battery before needing a replacement. This lifespan depends, of course, on individual patterns of usage.

But I thought all Energizer ER-P550 batteries were rechargeable. So why do they wear out?

True, the Energizer ER-P550 battery is a rechargeable battery pack. Unfortunately, we still have not invented "the perfect battery" and since there is no such thing as a perpetual motion machine, the Energizer ER-P550 will unfortunately eventually need to be replaced. Every time you charge and discharge the Energizer ER-P550 battery, a chemical reaction occurs inside the battery cells to store or release the electricity you rely upon to power your cordless telephone. Part of that chemical reaction uses up a tiny portion of the NiMh chemistry in your Energizer ER-P550 battery pack. Eventually those chemicals are depleted and once that happens, your will need a replacement.

My Energizer ER-P550 battery has a black wrapper. I see different colored telephone battery packs available. What is the deal? Is that ok?

Yes, that is ok. As we just mentioned, several different companies manufacture and market their own version of the Energizer ER-P550 battery design to consumers. Many times these companies use different colored plastic shrink wrap as part of their marketing and "branding" efforts. We have seen green, blue, yellow and white to name a few! Rest assured, the color of your Energizer ER-P550 plastic battery wrapping is cosmetic only and not important. What is very important is that the form factor (size), polarity (orientation of the positive and negative wires in the plug) and the voltage of your ERP550 - all must be exactly the same.

How do I make certain I'm getting a quality replacement ER-P550 battery pack?

It can be difficult to sort out the variety of offerings out there on the internet. You can find websites selling replacement Energizer ER-P550 batteries at prices from $6.95 to $19.99 for what looks like "the same" (at least in the pictures) Energizer ER-P550 battery. Our 10 years of experience in the battery business had taught us that you usually do "get what you pay for". So you need to use some common sense. In this particular example, there is definitely something wrong with the two price extremes. Certainly $19.99 is way too much to pay for a Energizer ER-P550 battery pack. Somebody is just trying to make a lot of money! And in most cases, $6.95 is just too good to be true. We get concerned about the quality of the materials (battery cells), safety features, and quality control process to insure the correct precision fit and finish of the ER-P550 battery. At some of these low prices, one begins to wonder whether or not you are actually getting a brand new ER-P550 battery or not? Unfortunately there are probably some "refurbished" or damaged goods out there on the market. In addition many of these low teaser rates do not include shipping or handling charges. Oftentimes that "$6.95" Energizer ER-P550 cordless phone battery ends up being $17.99 or much more once the hidden shipping and handling charges are added at the end of your checkout proceedure. So make sure you are looking at the final total price of these "great deals".

What should I look for when buying a replacement Energizer ER-P550 battery?

If you are interested in buying a quality replacement for your Energizer ER-P550 battery, go with a proven company that offers at least a 180 day money back guarantee, a one year no hassle warranty, gives you a toll free customer support telephone number, and clearly identifies the total cost of the purchase including any shipping or handling charges upfront.