Hearing Aid Batteries: Answers to Common Questions

While there are rare instances that a hearing aid will use a rechargeable battery, the majority of them use one of the standard Button Cell Zinc-Air batteries. These batteries all operated at 1.35 Volts (sometimes rounded up to 1.4 Volts). Typically, one would differentiate between batteries with their size.

Here you can find answers to some of the most common questions. Hearing aid batteries are extremely valuable items, and hopefully the answers here will help you understand a little more about them.

How can I tell what battery size I need?

Some time ago, hearing aid batteries sizes were standardized and assigned with a color code system to help you remember your battery size. You can check this color on tabs found on the back of the battery. The packaging usually has the color code displayed on it, too. So, even if you can’t remember your size, you can keep the color in mind.

  • Yellow Tab = Size 10
  • Orange Tab = Size 13
  • Brown Tab = Size 312
  • Blue Tab = Size 675

How long do the batteries last?

Depends on your hearing aid. Some require more power, and will drain the battery faster. Digital hearing aids generally use up batteries faster than an analog one, due to the more complicated circuitry in the digital ones.

So, while it’s not definite, your battery life should range from 5 to 7 days. If you’re consistently experiencing shorter life, you should be safe and have your hearing aid checked out. There’s a chance that it may not be working properly. Your hearing health care professional should be able to help you out, and send in your hearing aid for repair if needed.

What happens when I take the tab off my battery?

Zinc air batteries work by mixing zinc with the outside air. When you pull the tab, the battery activates and continues to stay active. You can’t deactivate the battery, so don’t pull the tab if you’re not ready to use it! If you keep the tabs on your battery, you should expect a shelf life of about 3 years (when stored at room temperature). After three years, the batteries probably won’t perform as well as normal.

How should I dispose of hearing aid and zinc air batteries?

Easily: You can throw them away with your normal trash. You shouldn’t accumulate them, though, as this can lead to a fire risk.

Our First Ever Commercial!

Introducing the first ever Battery Mart commercial!

We’re proud to display on our website the first ever commercial for Battery Mart. We’re really excited about it and think it turned out really cool. If you have 30 seconds, we’d encourage you to check it out!

And, in case you’re wondering, the storefront shot is from our Winchester, VA store, and the outside shot is from our Martinsburg, WV store.

You know that feeling… out of energy, running low, when your zip has lost it’s zap. Get back your get up and go with a fresh new battery from Battery Mart.

Whatever battery you need. Batteries for
cell phones, laptops, cameras, golf carts, boats, and cars. Power tools, watches, and hearing aids, and much more.

There’s a good reason why Battery Mart has sold over one million batteries. Get Battery Smart… Go with Battery Mart. In Martinsburg, Winchester, and online at batterymart.com.

Everstart Battery Cross Reference

In the below chart are our best matches to popular Everstart battery part numbers. Please be sure to review the replacement battery for terminal polarity, dimensions, and cranking power to ensure that the replacement options will work in your specific application. Battery manufacturers do change specifications without notice, so we always recommend comparing any replacement against your original battery.

Select your Everstart battery below:

Off-Season Battery Maintenance and Charging

Batteries are like living organisms. They periodically need exercising and maintenance to prevent sulphation from building up on the battery plates. Batteries that sit unused for a long period of time (longer than four weeks) need a maintainer.

Think of ice cubes. The water freezes because it sits dormant. Running water never freezes because the molecules are always in motion.

The same is true for your batteries. Maintaining the battery keeps the molecules in motion. When maintained, sulphation won’t rear its ugly head (just like the ice in a flowing fountain).


Effects of Sulphation

Once the plates become sulphated, the battery sees a reduction of run time or starting capabilities that worsen with time. And, once heavily sulphated, you cannot recover the battery. The battery may take or show a good charge but will not carry a load.

Other problems can occur when trying to charge a sulphated battery. While the charger tries to charge the battery, the battery plates do not accept the charge. The charger stays in constant charge mode and can cook a battery. This can happen more so when there are multiple batteries in the loop. Chargers will only shut off once it sees the battery is fully charged. In other cases the battery is so bad or the voltage is so low the charger cannot read the battery and thus goes straight into its float/trickle mode without doing anything to the battery.

Choosing the Correct Maintainer

The type of battery, either standard starting batteries or deep cycle rechargeable batteries, determines what charger/maintainer to use.

For standard starting batteries any 1 to 3 amp fully automatic unit will work fine. Not designed for deep cycling, standard starting batteries can’t handle multiple discharges. Generally, these batteries are good for 3 to 4 discharges.

Choosing the correct charger/maintainer for deep cycle rechargeable batteries depends on the amp hour or reserve capacity of the battery and whether you want to charge or just maintain the battery. The higher the amp hour of a battery, the higher the charger amps you’ll need to charge the battery. For maintaining only, a lower amp charger will work.

Below is a general size chart for choosing the correct charging amps for many SLA rechargeable batteries:

Battery Amp Hour Recommended Amps of Charger
Under 7 AH 500 – 750 milliamps
7 – 20 AH 1 – 2 Amps
21 – 40 AH 2 – 3 Amps
41 – 75 AH 3 – 5 Amps
76 – 100 AH 6 – 10 Amps
101 – 125 AH 10 – 15 Amps
126AH+ 15 – 20 Amps

You can estimate charging times with the following formula: (Battery Capacity) / (Charger amps) = Charging Time


Connecting Your Charger to Your Battery

Series Connection: Parallel Connection:

BatteryMart.com receives the Bizrate 2012 and 2013 Circle of Excellence Platinum Award

Update September 2014: BizRate announced that BatteryMart.com has received the Circle of Excellence Platinum award for 2014. We would like to thank everyone who has shopped with us for their battery needs. We couldn’t have been granted this honor without you!

BizRate Circle of Excellence Site - MERCHANT Reviews at Bizrate
I’m writing this post to let all of our past, present, and future customers know how much we appreciate all of you. For years, shoppers have been leaving comments about their BatteryMart.com experience on Bizrate.com, one of the largest sources of consumer-generated review content in the world. These completely independent reviews not only help new customers, but they tell how we’re doing.

This month, thanks to all of your comments, we’ve taken the next step. Bizrate announced we’ve earned the 2012 Circle of Excellence Platinum Award. To receive the Platinum award status, retailers like Battery Mart must earn scores of 9.0 and above (out of 10.0) on all seven key customer satisfaction indicators. According to the press release, “The 2012 Bizrate Circle of Excellence Award, a symbol of trust and dedication to the customer, was earned by 94 online retailers, representing the top 1.8% of the Bizrate Insights North American Retailer Network.” (Full press release is here)

We’re extremely excited to receive this award. This is an amazingly huge milestone and we couldn’t have done it with you. Thank you.

Here’s what our customers are saying about us right now:


See more ratings for BatteryMart.com at Bizrate.com
Brought to you by Bizrate Insights


Shorai Battery Installation Guide

Click here for an easily printable PDF of this guide.

Do not throw away the box or any foam packaging until after installation is complete!! Please also be sure to read the included User’s Guide for cautions and information on care and charging…

You’ll need a 10mm wrench or a #3 Philips screwdriver to install the LFX battery, possibly scissors, and whatever tools are needed to remove and reinstall bodywork and to access the battery box.


The factory-installed battery in the BMW G450X is Yuasa lead-acid YTZ7S. Our standard recommendation for Shorai Lithium-Iron is LFX09A2-BS12. The LFX09A2 weighs 3.5 lbs less than the original YTZ7S (or 1.59Kg, ~73% lighter), has less than 1/4 the self-discharge rate, and turns the engine 20% faster!


  • Shorai LFX Starter Battery, with one set terminal screws/nuts pre-attached
  • Spare set terminal screws/nuts (A3 steel, tin plated)
  • Five Shorai Decals, in three sizes
  • Various sheets of high-density, adhesive-backed foam sheets for LFX fitment to stock battery box (if needed)
  • Outer packaging, with specs and dimensions
  • User’s Guide


First, remove the original lead-acid battery from your vehicle, according to the maker’s guidelines. BE SURE to Remove the NEGATIVE terminal bolts and cables first, then the Positive, to avoid possibility of shorting from positive to grounded vehicle parts…

Compare the original battery side-by-side with the new LFX battery. First check that the Polarity (+/- terminals) arrangement is the same on both. If not, contact Shorai directly for advice. Next check that the LFX battery does not exceed the size of the original in any dimension (length, width, height). If the LFX is larger in any dimension such that it cannot be made to fit into the stock battery box, please contact Shorai directly.

Pictured above note that the LFX battery is identical in length to the original battery behind it, and below you can see the LFX is the same width as well, but a bit shorter. We’ve used one sheet each of 5mm and 10mm thick spacer foam to make up the height difference.

The included self-adhesive foam spacers are sized as below.

In this example, we only needed to shim the height. Do the same if the original battery is significantly larger in width or depth, and trim the selected spacers to fit with scissors.

Note! You will find the four terminal nuts (2 are spares) come with foam blocks attached on the nut bottoms. This helps keep the nuts in place during install, and up high where they can catch the bolt threads.

The G450X has a truncated battery box floor, so we’ve trimmed to fit the diagonal shape, then applied the sticky side of spacer to the battery box, as shown below.

The LFX batteries can bolt cable eyelets to either the top or front sides of the terminals. Be sure to Install the POSITIVE terminal cable first, then Negative, to avoid short circuits.

Max torque for the terminal screws is 30kg/cm (26 inch/pound). Do not over-tighten. We recommend the use of a #3 (big!) Phillips screwdriver, as this allows you to apply downward pressure on the terminal screw. That helps the
threads catch, and reduces torque on the terminals. Note that the terminals are not anchored at back, and may twist slightly during install. If so, performance is not affected.

Check that the positive terminal of the LFX battery cannot short against any part of the vehicle; and be sure that the original positive terminal cover, if any, is re-installed on the LFX battery before the battery box cover is fitted.

Weight Savings… Nice!

Shorai LFX batteries are pre-charged to approximately 90% of capacity. Therefore it is not required – nor generally recommended – that the batteries be charged before use in your vehicle. However, owners of Shorai BMS01 charger systems may use the CHARGE mode to fully top the battery, as the BMS01 will insure ideal cell balance and perform diagnostics to guarantee best performance.

Enjoy your Shorai LFX battery!


See http://shoraipower.com for full product details and much more… Please use the on-site CONTACT form to ask us for help with installation, if needed.

Envia Systems Achieves World Record Energy Density for Electric Car Batteries

Envia Systems, of Newark, CA, announced recently that the company’s next-generation rechargeable battery has attained unprecedented results. They’ve achieved the highest recorded energy density of 400 Watt-hours/kilogram (Wh/kg) with their lithium-ion cell.

What does this mean for us? When it’s ready for commercial use, this battery is expected to halve the cost of the battery pack, a giant step towards a 300-mile range electric vehicle. More power, less expensive. The batteries are a major contributor to the price of electric vehicles, approximately 65 percent the car’s total cost to manufacture.

From Envia Systems’ Press Release:

“Since the inception of Envia, our product team has worked tirelessly and logged over 25 million test channel hours to optimally develop each of the active components of the battery: Envia’s proprietary SiC anode, HCMR cathode and EHV electrolyte,” said Dr. Sujeet Kumar, Envia Systems co-founder, president & CTO. “Rather than just a proof-of-concept of energy density, I am pleased that our team was successful in actually delivering 400 Wh/kg automotive grade 45 Ah lithium-ion rechargeable cells.”

“Envia’s new battery technology represents exactly the kind of innovation and breakthroughs that ARPA-E is looking for from the American research and development community,” said ARPA-E Director Arun Majumdar. “We hope that this low cost and high density battery technology enables wide spread adoption of electric vehicles across the country and around the world.”

“In an industry where energy density tends to increase five percent a year, our achievement of more than doubling state-of-art energy density and lowering cost by half is a giant step towards realizing Envia’s mission of mass market affordability of a 300-mile electric vehicle,” said Envia Systems Chairman and CEO Atul Kapadia.

This is exciting news for any enthusiast for electric vehicles, such as the Chevy Volt. The more capacity the battery is capable of, simply put, the further the car will travel. According to GM’s Chevy Volt FAQ, currently the vehicle has a driving range of 25 to 50 miles on pure electricity stored from an overnight charge. While the outside temperature, terrain, and driving style will still effect current and future battery technologies, the possibility of one day seeing up to a six-times increase in range is definitely something to look forward to.

Of course, it may not hurt to approach with some skepticism. There are many exhilarating claims made in the battery industry, and many don’t come about delivering as intended (we here at BatteryMart.com see this even in marketing claims for a simply AA alkaline!). However, if there’s a kink somewhere that prevents this technology from coming forth full-force, the lessons learned here would assuredly lead to more breakthroughs in the future. But, for now, let’s give credit to Envia for their accomplishments!

If you like any additional reading, please check out these links:
Envia Systems’ Website: http://enviasystems.com/
Envia’s Press Release: http://enviasystems.com/pdf/Press_Release_400WHK.pdf
Envia’s Test Results: http://enviasystems.com/announcement/

Battery Activation and Charging Procedure for Dry Charged Batteries

  • Please note: The below information only applies to our Dry Charge conventional wet cell batteries. All of our AGM, Maintenance Free, and Gel batteries do not require acid and come charged and ready to install.

    First and foremost… Take great care when working with your battery!

    Batteries contains electrolyte (sulfuric acid) which is a highly toxic and dangerous substance if it comes in contact with your body. When carrying acid or a battery filled with acid, keep it away from your body. Wear rubber gloves and safety glasses when working with the battery to keep any possible acid from touching your hands or eyes.

    Batteries are also capable of delivering a high current discharge. Any jewelry should be removed and other metal objects should be kept away from the battery to avoid shorting across the battery terminals. It’s best to use only insulated-handled tools when working with your battery, as well.

    Initial Filling of your Battery

    Wet cell batteries like our Dry Charge batteries need to be filled with electrolyte (acid), which is dangerous to the eyes and skin. When working with acid, you should follow these simple precautions:

    1. Wear protective goggles to protect your eyes. If you do splash acid in your eyes, hold your eyelids open while washing your eye with lukewarm water for at least 20 minutes. Have someone contact your doctor immediately for further instructions, while you wash the affected area.
    2. Wear rubber gloves that extend well past your wrists. If you splash your skin, flush continuously with lukewarm water for at least 20 minutes and contact your doctor for further instructions.

    You can purchase electrolyte directly from our website when you order your battery. Simply choose to “Include Acid Pack” and add your battery to your cart. If you have any questions about ordering acid, you can give us a call at 1-800-405-2121. You can also purchase acid at most large auto parts stores.

    Once you have your acid, carefully fill each battery cell with electrolyte. Be sure to not overfill. Fill to a level that is just below the overfill line marked on the battery case. Once the cells are properly filled, replace the caps. Hand tighten only.

    You only need to put electrolyte in your battery once. If you need to fill the battery at a later date, use distilled water to keep your battery cell chambers to the proper level. Keep your cell levels above the minimum mark and below the maximum mark (these should be shown on your battery case).

    Charging your Battery

    Both hydrogen and oxygen are emitted while batteries are charging. Hydrogen is a very flammable gas and oxygen supports combustion. Because of this, you should always place your battery in a clean, well ventilated area when filling or charging your battery. Your chosen workspace should be free from anything that might spark a fire, such as welding, smoking, grinding, open flame, etc.

    Important Note: If you charge your battery at too high an amperage, you may cause the battery to overheat and even explode. Please read your instructions carefully regarding safe amperage charge levels for your battery.

    Initial Charging Procedure:
    Once you’ve filled your battery with acid and the battery caps are hand-tightened, you should charge the battery with a low-amperage battery charger. For best, safest results, a battery should never be charged at amperage greater than 10% of the battery’s capacity. So, if you have a 10 Ah battery, use a 1 amp battery charger. If the battery is 5 Ah, then you should use a 0.5 Amp (500 mA) battery charger. It can take around 10-12 hours to fully charge your battery, so we recommend that you use an automatic charger that will cut the charge off when the battery is fully charged.

    Recharging your Battery:
    When recharging your battery, you should check your cable connections and terminals to be sure they are clean and dry. Automatic chargers are your best options, as these will fully charge your battery and then help to keep it maintained and healthy. This maintenance is also important to keep your battery in good condition if it sits for extended periods of times (but keep an eye on your acid and fluid levels!). For recharging, you can likely use the same charger you used for the initial charge.

    You may also be interested in reading the following article about winter storage and maintenance:
    Off-Season Battery Maintenance
    Here you can learn about keeping your battery safe while it’s not in use, the effects of sulphation, and see some charger recommendations based on your battery’s Amp Hour rating.

    To view our line of products, please click one of these following links:

    You can also find your battery with our extensive look-up: