Battery too good to be true? - Page 1
Forum section: electronics / general

author: ActuatorJames
author_rank: Newbie
timestamp: April 11, 2023, 09:46:44 pm
content: Hello, I'm currently tasked with searching for a battery for a product and specifically I need a 3.7V 1500mAh battery. Of the ones I have found on the market, they are usually at least 8mm thick but we have one in house that was purchased from amazon that claims to be a 3.7V, 2500mAh battery and it is only 3.7mm thick despite having similar dimensions to the 1500 I've already found. This feels suspicious to me but I have limited experience with batteries. So here it is:https://www.amazon.com/2500mAh-battery-Rechargeable-Lithium-Connector/dp/B07BTTRCTTand here is 1320mAh that I have already foundhttps://www.mouser.com/datasheet/2/346/rena_s_a0008891254_1-2281547.pdfSo my question for people with experience in battery selection is as the title suggests, is this battery too good to be true? I did see that it says not for high current applications so maybe it has a lower C rating, but I am not sure. Thanks for the help!

author: helius
author_rank: Super Contributor
timestamp: April 11, 2023, 11:15:47 pm
content: Many rechargeable cells from the far east are sold with untruthful specifications.Go ahead and buy it to experiement, but if you are an engineer selecting parts for a project you should not do so on eBay or Amazon. "Sold by Wing Deli." Do you get buffalo sauce with that?Use a real distributor (the kind that publishes a line card).

author: mzzj
author_rank: Super Contributor
timestamp: April 12, 2023, 04:46:27 pm
content: umm, your batteries are quite bit different size?3.7 x 56 x 78mm Net Weight: 35g.6 x38x 61mm 26gVolume-vise we have 0,01616 L vs 0,01391 LSanity-check for the chinese fiqures would be to compare energy density per weight and per volume to upper end available from reputable manufacturers.Your "amazon special" comes out as 556Wh/liter whereas the Renata battery would be 340Wh/lRenata is probably not leading the capacity race so lets take a look of few phone batteries:LG G5 470Wh/LiPhone 11 490Wh/lSo... very unlikely that your amazon special has rated capacity. Could be anywhere 50 to 100% bloated number.

author: Siwastaja
author_rank: Super Contributor
timestamp: April 12, 2023, 05:00:17 pm
content: Random Ali/Ebay China li-ion junk: divide capacity by two and accept the risk of them randomly blowing up and catching fire.Not worth your money IMHO.

author: RoGeorge
author_rank: Super Contributor
timestamp: April 12, 2023, 06:58:26 pm
content: Quote from: ActuatorJames on April 11, 2023, 09:46:44 pmSeems OK by its size.Note that this is a low power battery, can not deliver high current (e.g. for drones), and can not take high current during charge, only 0.5C. It's for small power devices, as mp3 players, etc. The capacity is written on it, and very easy to measure. If it were to lie, they wouldn't write anything on the cell, and write instead a cryptic model-number.Capacity is important, but so is the lifetime or the max supported current, charging time, etc. Depending on the destination, capacity might be less important, so you may see a lower C battery costing 3-4 times more than the one with higher C, and that is usually because of other parameters/specs more costly to reach than a big capacity.

author: jc101
author_rank: Frequent Contributor
timestamp: April 12, 2023, 08:15:45 pm
content: Is this any good?https://www.mikroe.com/li-polymer-battery-37v-1500mah39.5 x 63 x 6.1mmAvailable from Mouser and Digikey.I have used the 1500ma and 2000ma versions and have been very happy with them.