frontpagef12_26 | Staff posted Apr 20, 2026 07:31 PM
Item 1 of 7
Item 1 of 7
frontpagef12_26 | Staff posted Apr 20, 2026 07:31 PM
4-Pk HW 9V 1400mAh Rechargeable Lithium Batteries w/ USB-C Charging
w/ S&S$12
$33
63% offAmazon
Get Deal at AmazonGood Deal
Bad Deal
Save
Share
Leave a Comment
21 Comments
Sign up for a Slickdeals account to remove this ad.
Sign up for a Slickdeals account to remove this ad.
I feel that the charging port opening /cut tolerances are super tight. Half the time, the USB are super tight to fit in and almost feel like it doesn't fit
That being said, I wouldn't use these over non-rechargable lithiums because discharge will be much more rapid.
As for using rechargeables in smoke detectors, I bought a set of Tenergy 9V NiMH 250mAh batteries back in Sept, put them in my smoke detectors, and they are still working fine 6 months later. That set requires a 9V charger, though, so these batteries having USB-c charging is a nice feature.
Overall, despite the false capacity claims, this seems like a decent deal.
Edit: These may not be very good for smoke detectors, but are otherwise fine for high-drain devices. See my comment below for more info.
Sign up for a Slickdeals account to remove this ad.
Our community has rated this post as helpful. If you agree, why not thank punkdigerati
As for using rechargeables in smoke detectors, I bought a set of Tenergy 9V NiMH 250mAh batteries back in Sept, put them in my smoke detectors, and they are still working fine 6 months later. That set requires a 9V charger, though, so these batteries having USB-c charging is a nice feature.
Overall, despite the false capacity claims, this seems like a decent deal.
For a fire alarm it's possible for it to think the battery is completely fine, but it be right at the end of the usable capacity, a fire start and take out the mains power, and the fire alarm going off to be enough to kill the rest of the capacity without ever having alerted to a low battery. This is obviously a very rare scenario, but it's one that doesn't happen with alkaline and even NIMH at least has some detectable voltage drop near the end of capacity, but with enough capacity left to still function.
Even though these are advertised as perfect for smoke alarms, I wouldn't use them for that application.
Leave a Comment