Deals: Batteries for things (mostly U.S.)

I figured I’d start a thread on good prices for batteries for things. I’ll start with the ones I’ve found, which are generally those the best price and good reviews. Please add any you find.

(all of these are Amazon Prime with prices of March 2016 unless otherwise noted)

CR123A Lithium Batteries
Tenergy Propel 40-Pack $44.49 ($1.11 ea)
Tenergy Propel 12-Pack $15.75 ($1.31 ea; purchase in late 2015 had expiration 2020)
Streamlight 85177 12-Pack $18.66 ($1.55 ea; no dates on packaging at all)
(I’ve bought both brands before; I initially thought the Tenergies I had were bad because my Aeon MultiSensor 6 kept eating the batteries every 3 days, but it turned out to be a bad sensor. The replacement sensor has run on the Tenergies for 2 months now and is still at 100%)

CR2 Lithium Battery
Tenergy Propel 10-Pack $15.69 ($1.57 ea; purchase in late 2015 had expiration 2020)

CR2450 Lithium Cell Battery
BlueDot Trading 10-Pack $6.99 ($.70 ea; no expiration date)
(These are $6.99 when Amazon sells them (camel^3), but they are currently out of stock this week)

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For the more common sizes, AAA up through D, plus 9 volts, I really like the Kirkland batteries sold at Costco. They tend to come in top 5 in battery quality tests by most independent reviewers, including consumer reports, but at really excellent prices. They are much better quality than Amazon basics or most off-brands.

http://www.consumerreports.org/cro/news/2014/10/batteries-that-last-when-you-need-them/index.htm

A note about lithium batteries in home automation devices

Also, it’s helpful to remember that lithium batteries have a different discharge curve than alkaline batteries, and consequently battery reporting can be way off for lithium. They typically stay high for a long time and then drop very quickly.

This “flat curve” is considered a plus by people who favor lithium, as it means you get more power out of them for a longer time. But in battery monitoring situations such as many home automation use cases, it can really throw off your ability to predict when the battery will fail. for this reason you may want to implement a time based replacement strategy for lithium batteries rather than relying on battery reporting.

But since that may mean you are removing the battery while it still has viable life, it can somewhat increase the project cost. At our house we use batteries that were removed on a time schedule from critical functions like home automation and put them in a box we use for non-critical functions like gaming controllers. So we do use the lithium batteries until they are completely depleted, but not in Home Automation devices.

http://batteryuniversity.com/learn/article/choices_of_primary_batteries

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As usual I learned something new from you @JDRoberts That explains what happened to a few zwave devices I have. Thank you!

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There was another thread about this somewhere. Digikey.com and arrow.com have some of the best prices I’ve seen on coin style batteries, and they are not fake. I’d venture that 99% of the panasonic/sony coins on Amazon are, that’s from my very thorough investigation of 4 orders and 3 were fake. My maths sucks…but Amazon is a risk for this type of item.

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Yup me to, just replaced a motion sensor battery which last battery report was 63% but it was completely dead

Was it a lithium battery?

it certainly was. Thats the second lithium battery that died in the last two weeks with a fairly high last battery reading.

While discussions on battery behavior is a good thing to have, I created this thread just to discuss and share good prices on batteries. Can we please restrict this thread to that?

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Done…

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4 years later, I finally ran out of replacements CR2s for my Lowes IRIS gear. The batches I bought all had an expiration date of 2020. I ended up needing more, so I found:

Tenergy CR2 (no longer called Propel) 750mAh
10-pack $16.19 ($1.69 ea), 20-pack $28.89 ($1.39 ea)

AmazonBasics CR2 800mAh
12-pack $17.99 ($1.49 ea)

This time I went with 24 of the AmazonBasics.

I’ve been using EBL rechargeables in my Iris and other sensors. Converted my ST presence sensors to 2 AA’s (they stay in the car’s. ) Most batteries I use rechargeable. Less heavy metals in the landfills the better.

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I read the EBL RCR2 were larger than regular CR2. Do they fit?

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yes they do

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I think I’ll buy them for my next round of replacements. Thanks for the recommendation!

$13.49 for 8, Prime ($1.68 each)

They seem to sell 2 different charger+battery combos:

$23.49 for 8 + charger, non-Prime
$22.99 for 8 + charger, Prime
(check other sellers)

$26.49 for 8 + charger, non-Prime

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Some discussion here on RCR2 vs. CR2 for Iris sensors: https://community.hubitat.com/t/anyone-using-rechargeable-cr2-batteries/25367/14
The interesting thing is that several comments are the RCR2 cost 3x the CR2. That’s certainly not what I’m seeing - $1.69 ea vs. $1.49 ea in my most recent purchase.

Thanks for the confirmation @tommyincville. I’m down to my last 6 CR2’s and I really want to use rechargeable batteries. Almost all of my sensors are Iris, so these will be perfect.

How long have these lasted in your sensors before having to replace with a fresh battery?

My first set of the EBL RCR2s arrived last week. I have a pair of side-by-side Iris contact sensors on windows I rarely open (e.g., really only reporting temperature). I just replaced the batteries in both; in one I have a new Amazon Basics CR2 and in the other I have one of the EBL RCR2 I fully charged. I’m using it as a test to see how the battery life compares and what the reporting looks like. Both read 100% after 1 week.

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Thanks for the reply. Mine comes in tomorrow, and I plan on doing the same tests, as well as on a couple doors that are frequently used.