BESTON Rechargeable 9V Batteries, Lithium ion 650mAh 9 Volt Battery with Quick Charge Micro USB Port (4 Pack)

I sincerely hope to enjoy this product. In fact, it's fantastic in the right circumstances. br>br>However, I've discovered two major flaws in this product, as well as one major flaw. br>br>First, this is NOT A 9V BATTERY. This is a 2S Lithium Polymer battery on the inside, with a nominal voltage of 7. 4V. This adds up to a total of 8 when fully charged. As shown in the diagram above, the voltage is 4V. This means that any voltage-sensitive devices will almost certainly malfunction, and any battery gauges will almost certainly be inaccurate. Most devices that use a 9V battery should still work fine, and these batteries will not sag nearly as much as traditional alkaline 9V batteries when under heavy load. To be honest, I was hoping that the circuitry would boost the voltage to 9V, but there is none (boo!). ), so you'll get the unprocessed 6-minute version. Any 2S LiPo battery with a voltage of 4V will suffice. br>br>The second problem is caused by Physics rather than the manufacturer. To be honest, traditional 9V batteries are pretty bad, but this battery performs much better under heavy load than alkaline batteries, which is ideal for my needs (running Arduinos with motors, etc. ). This, however, can be a double-edged sword. These batteries ARE protected, so they will turn off the power if the battery voltage drops too low (to prevent damage to the batteries). This runs out VERY quickly with a CLAIMED 650mAh charge (more on that below). In short, the battery performs exceptionally well under high drain, but it depletes its energy more quickly than you might expect. br>Again, this isn't a PROBLEM; it's just something to keep in mind. br>br>No, the PROBLEM is that the capacity is a blatant lie in and of itself. It advertises itself as a 9V 650mAh battery all over the packaging. This could make one believe it has 9 * 0. 650 = 5. 85 Watt- hours of energy on hand That'd be fantastic! br>There is one issue: It's a long way off. I opened the battery because I'm a curious person, and everything was in working order- A microcontroller is controlling a fairly standard 2S protection board (with no boost circuit for 9V-DC). darn). When I looked at the individual LiPo cells, however, they revealed the battery's dirty little secret: They don't use 650mAh batteries, for example. The cells used have 500 mAh written on them. br>When you combine the lack of a 9V output with the blatantly false capacity, you get a battery that doesn't even come close to the 5. 8 Wh. They only contain one, according to the cell's own marking. There are three of them, each with 85Wh. 7Wh. br>This means that the energy in these batteries is LESS THAN 2/3 of what they claim to be. br>I understand that different battery chemistries have different nominal voltages, and if the batteries delivered on the 650 mAh promise, I'd be willing to overlook the energy difference (we'd still be getting nearly 5Wh). After all, 9V NiMH batteries have the same voltage problem as 9V NiCd batteries! br>However, these batteries do not live up to their billing. br>The 650 mAh figure is a complete fabrication. br>It's no surprise that they run out of steam so quickly. br>br>Look, the batteries aren't that bad. They appear to be well-made both inside and out, and while I'm no expert, I don't see anything particularly concerning on the circuit board-- The batteries are set up for balance charging, and shorting out the terminals will, as you might expect, activate the short-circuit protection. The battery has a much higher current output than a traditional alkaline battery, and it charges quickly. br>These batteries would be fantastic and easy to recommend if they were just *honest* about their true specs. Instead, my mouth is tingling with a sour taste. br>They're good batteries, but I'd go with a more trustworthy brand.

Kenneth Frederick

| Apr 21, 2021

Boo. You have no idea how to charge these batteries properly because they come with no instructions. I plugged mine into chargers, and a blue light illuminated. I had no idea what that meant, but since the blue light was still on and the batteries were cool to the touch after four hours of charging, I knew the charging source was working properly. Did this mean the batteries were defective? Apparently not. Other Amazon users claimed that the blue light meant they were fully charged, so I guess everything is fine. That is, up to this point. It would make life so much easier if manufacturers simply included manuals and instructions.

Nathalie HUMPHREYS

| Jun 23, 2021

Good value, but a little shaky.   One of the four is faulty, blinking red/blue when charged for the first time. Voltmeter confirms that it will only charge to a maximum of 8 volts. 13vdc. The remaining three "good" batteries have a maximum capacity of eight volts. 33 vdc. This isn't a problem for me because I'll be connecting these in order to get at least 24vdc. What is a (smaller non-contiguous non-contiguous noncontiguous noncontiguous The connectors on these are a few thousands of an inch too loose to securely connect, as shown in the images. The first image shows how the two connected lie at an angle due to their looseness, whereas a different brand (the green one) connects much more securely. Yes, a squeeze with some pliers will fix this, but I'm just pointing out that the quality control on these is poor, so I won't expect them to last very long. br>br>For others who require a reliable power source, these may be a questionable choice, despite the fact that they are an excellent price for rechargeable batteries, especially with the micro USB charging port; however, since I'm prototyping something, this isn't an issue. br>br>It's just strange because they connect to the other brand of battery more tightly. More evidence that they're only a fraction of an inch off. Even at these low voltages, and especially with the poor quality control, it would be dangerous to connect them without squeezing the larger connectors; such a loose connection could cause a spark and cause them to heat up.

Brooklyn Li

| Jul 15, 2021

meters. I have an Oden, and it has a lithium 9V battery that can be recharged using a standard micro USB cell phone cable. It's a brand-name Lithium 9V battery that's been around for over a decade and is still going strong. I only charge it once every few years, so I know these lithium 9V batteries will last a long time. br>br>Also, this DMM does not have an auto-off feature. off, as is the case with many MM's, which is a shame because it invariably results in dead 9V batteries. Now all you have to do is re-charge the battery! In this case, I purchased a four-pack so that I can simply swap. Also, NO ACID LEAKAGE! br>br> After a few years, traditional 9v batteries leak and destroy the device - When you need to replace the device, that's a pricey battery!br>br>Keeping this 15-year-old multi-device device running costs a lot of money! Keep your meter out of the trash!.

Donovan Rios

| Mar 06, 2021

I was looking for a nine-piece set. I didn't want to buy a new charger just for this style of battery, so I went with volt batteries that could be recharged. I already had an 18650 battery with a micro-USB port. I was curious if a 9V version of USB charging was available. I found these, but I was concerned about their size, and whether they would fit in the same compartment as my alkaline 9V batteries. So I posed a question here, and I received a positive response. So I placed an order for them. I'm very happy with how things have turned out. They are compatible with alkaline 9V batteries and can be stored in the same compartment. I can't speak for capacity, but they do the job for which I purchased them, so I'm happy.

Dayana Copeland

| Mar 20, 2021

I have a Walmart Hyper Tough flashlight, which is an LED flashlight that runs on two 9-volt batteries. It has two brightness settings, bright and brighter, and while it is bright, it consumes 9 volt batteries like a teenager at a cookout, even when the flashlight is turned off. I'm happy to report that these batteries are still performing admirably after all this time, from delivery to today, March 24, 2021. So I'm going to put the extras I bought into my home's smoke detectors. If only these guys could make car batteries, they'd have a winner.

Khalil Frank

| Aug 29, 2021