Battery Question: I am looking for a back-up battery for my a77. My first thought was to go with original equipment, but after checking I have some confusion and could use some advice...

Jim 100 Loc: Everett, Washington

I am looking for a back-up battery for my a77. My first thought was to go with original equipment, but after checking I have some confusion and could use some advice from those who know. The original battery is 7.2V, one I found is 7.4V. Would the higher voltage cause any damage or is .2V insignificant?

The original is 11.8 Wh. Two I have found have 14.8 Wh and 15.8 Wh. Does anyone know what this difference in watt hours would mean. Longer life? Shorter Life? Nothing important?
Thanks

GENorkus Loc: Washington Twp, Michigan

Jim 100 wrote:

I am looking for a back-up battery for my a77. My first thought was to go with original equipment, but after checking I have some confusion and could use some advice from those who know. The original battery is 7.2V, one I found is 7.4V. Would the higher voltage cause any damage or is .2V insignificant?

The original is 11.8 Wh. Two I have found have 14.8 Wh and 15.8 Wh. Does anyone know what this difference in watt hours would mean. Longer life? Shorter Life? Nothing important?
Thanks

I not electrically trained but do know that Watts can be referrers to as the ability "to do work". Therefore higher number of watts should mean more work, or longer life.

mas24 Loc: Southern CA

Jim 100 wrote:

I am looking for a back-up battery for my a77. My first thought was to go with original equipment, but after checking I have some confusion and could use some advice from those who know. The original battery is 7.2V, one I found is 7.4V. Would the higher voltage cause any damage or is .2V insignificant?

The original is 11.8 Wh. Two I have found have 14.8 Wh and 15.8 Wh. Does anyone know what this difference in watt hours would mean. Longer life? Shorter Life? Nothing important?
Thanks

What you normally would be concerned with is the MaH of a battery. I have seen MaH on third party camera batteries higher than the OEM batteries. I have rechargeable AA batteries that are 1.2 volts and AA alkaline batteries that are 1.5 volts. Both batteries cause no problems for me.

mas24 Loc: Southern CA

mas24 wrote:

What you normally would be concerned with is the MaH of a battery. I have seen MaH on third party camera batteries higher than the OEM batteries. I have rechargeable AA batteries that are 1.2 volts and AA alkaline batteries that are 1.5 volts. Both batteries cause no problems for me.

Higher MaH is not a danger factor as volts would be. I meant to add that.

TonyP Loc: New Zealand

Jim, no problem with 7.2V.
As regards the amp hours, a lot of the Chinese third party batteries quote higher amp hours as a marketing ploy.
More amp hours, theoretically you should get more shots.
BUT, they don't always tell the truth.
I've checked a couple of these cheap(er) high amp hour batteries and found them to be at worst as much as 40% lower than what they have quoted.
Caveat emptor.

Edit. We refer to amp hours here. Similar applies to watt hours although I have never seen camera stuff here in NZ referred in wh..

TomV Loc: Annapolis, Maryland

I am a long time Sony user. I shoot with the a77ii and the a99ii now. I used to buy off-brand batteries since they were much less expensive. Over time, they do not hold up. I had Sony batteries last much longer, none have failed, even those over 7+ years. My off-brands have begun to fail after a couple of years. You get about 100 or so shots and they are dead. I have tossed them and now only use the Sony brand.

Longshadow Loc: Audubon, PA, United States

Mathematically, a 15Wh battery will last longer than an 11Wh battery. Similarly, a 2000mah battery will last longer than an 1800mah battery. The voltage should be the same. (In reality, it will depend on the manufacturing process.)

jmizera Loc: Austin Texas

TomV wrote:

I am a long time Sony user. I shoot with the a77ii and the a99ii now. I used to buy off-brand batteries since they were much less expensive. Over time, they do not hold up. I had Sony batteries last much longer, none have failed, even those over 7+ years. My off-brands have begun to fail after a couple of years. You get about 100 or so shots and they are dead. I have tossed them and now only use the Sony brand.

I don't own this particular camera, but I've shot thousands of hours with numerous Sony video cameras. I've tried a wide range of aftermarket batteries over the years, and they never hold up as long as Sony batteries. Both in terms of run time, and useful life. There's a reason they are so much cheaper.

mas24 Loc: Southern CA

I only trust two aftermarket camera batteries. They are Watson and Wasabi. That's it. And Watson, the one I buy, have performed well for me.

mas24 Loc: Southern CA

TonyP wrote:

Jim, no problem with 7.2V. br As regards the amp ... (show quote)

The OP was concerned about 7.4 volts, not 7.2 volts.

BebuLamar

.2 volt is no problem. When fully charge both would deliver slightly higher voltage than 7.4.
Wit that said the cheap third party won't deliver the mAh rating

Jim 100 Loc: Everett, Washington

Thanks everyone...I think I will stick with OEM

BebuLamar

I was using my IPhone so I made the short post.
1. The voltage of the OEM battery and the third party I think would be the same and around 7.4V but they would be at this voltage for only a short time after charged. So the third party manufacturer simply claims the higher voltage.
2. The mAh rating determines how long the battery last. The more the better and has no effect on the camera. However depending how the specify the mAh there are a lot of lee way for the third party to claim higher rating while they are actually less.

jeep_daddy Loc: Prescott AZ

TomV wrote:

I am a long time Sony user. I shoot with the a77ii and the a99ii now. I used to buy off-brand batteries since they were much less expensive. Over time, they do not hold up. I had Sony batteries last much longer, none have failed, even those over 7+ years. My off-brands have begun to fail after a couple of years. You get about 100 or so shots and they are dead. I have tossed them and now only use the Sony brand.

John_F Loc: Minneapolis, MN

My concern with the higher wattage batteries is safety. The amount of power of a battery is directly proportional to the amount anode, cathode, & electrolyte volume. Each camera has a fixed volume of space for the battery so the battery must be fixed in size. More anode etx volume must came from insulation and battery wall volume. As a battery delivers power or is being charged there will be heat released through IR loss. This means the battery walls will expand and contract so minor wall & edge cracks can occur and grow. I believe Wikipedia has a lithium ion battery article where you can learn about battery construction. Generally, the anode, electrolyte, cathode, and insulation are rolled up layers. To get more cathode + anode the insulation layer has to be skimped or the battery case wall thinned.