Review on 5-Pack EBL 9V Rechargeable Lithium Ion Batteries With 600MAh Capacity And 5-Bay Charger For Smoke Alarm Detectors - 2A Input by David Carter

UPDATED 26 October 2018 - Just two days after posting the initial review, I've rechecked the battery charge on each one, and they now range from 8.21 to 8.29 volts - an obvious across the board drop in just 48 hours. Now almost just for review purposes, I think I'll keep them another couple of weeks and see what else I can learn before activating my 30 day full refund guarantee. I keep getting "nice" emails from the manufacturer, but that doesn't change the fact that five out of five batteries have already shown measurable decreases in charge after just 48 hours, and despite the promises of the company, the advertising still does not state that the batteries themselves are NOT 9 volt batteries. They're misrepresenting these batteries as if they were 9 volt when they were never designed to charge to that level by the company's own acknowledgement, and the charger should only be able to charge to 8.4 volts maximum anyway, according to the listed specifications in their advertisement for the charger. There are other various specifications with Delta-this and Delta-that in the top portion of the product listing, including far less important specs, yet they allow uninformed potential purchasers to believe they'll be getting 9 volt rechargeable batteries when they're not even designed to that specification. Let's see what happens over a week's time in a smoke alarm and in a TENS unit. The battery going into the smoke alarm started at 8.28 volts this evening. The battery that went into the TENS unit for ½ hour started out at 8.29 volts. I was able to turn the TENS unit up to 7 on a 0-8 intensity scale before I got to the reasonable maximum level I could tolerate on my neck and shoulders. But in fairness, that's only slightly higher than a brand new Duracell alkaline measuring 9.56 straight out of the package - it got turned up to about 6.5 on the intensity scale to get the same intensity (I have a fairly high tolerance). So at least initially, these compared nicely in a TENS unit. After ½ hour of use the battery measured 8.25 volts - a drop of .04 volts. It will be interesting to see how the battery performs over the next several days with additional ½ hour periods of use.27 October 2018 note - an additional use of the TENS unit dropped the battery to 8.22 volts - and that was with only one side of the TENS unit being used today, not both. Given the fact that these batteries start out more than one volt lower than an alkaline Duracell, and I don't know what the lower limit of the TENS unit is, it's not even worth the effort to wait until near the end of the 30-day return window. And the battery put in the smoke alarm just last night has already also dropped from 8.28 volts to 8.22 volts less than 24 hours later. If that rate of discharge continues at more than .05 volts per day, it will only be a matter of weeks before the smoke alarm battery requires replacing. Unacceptable.Given the initially lower starting voltage of these batteries that the company misleadingly failed to include in their advertising, the number of people that have had to replace batteries very early after purchase, and the relatively useless though outwardly polite responses I keep getting from the company, I've decided to exercise my 30 day refund option. I'll buy a more reliable brand of NiMH rechargeable batteries and probably stick with (unfortunately) non-rechargeable alkalines for the smoke alarm in order to get the "standard" replacement time of once per year.==== Original review from 24 October 2018 follows ====These arrived with an average of 7.25 volts available each (not much variation), and charged overnight to between 8.25 to 8.32 volts each. So we at least know they don't charge to the advertised 9 volts - or even the advertised 8.4 volt output of the charger according to the company's product description. One would expect that a company producing (or at least marketing under their name) both the charger and the batteries designed for that specific charger, would provide a charger that is capable of charging a 9 vote battery to its full capacity. I'm "generously" not giving it a 1-star rating at this point, because I don't know that the batteries won't perform reasonably well even in spite of the questionable construction of the charger, and the batterys' failure to reach the advertised 9 volt capacity. IF they perform in all of my 9v devices and last a reasonable amount of time, I MIGHT upgrade this to a 3-star rating, but that's maximum.The charger construction is not at all adequate. Some of the connections are not properly aligned with the holes through which they protrude. This causes inadequate space between the battery connector and the plastic around the charging connector. In other words (see the accompanying photo), there is a circular cutout in the plastic through which the charger connections protrude. Those connectors are not centered in the middle of the circular cutout, leaving inadequate space between the connector and the plastic frame around them, resulting in a need to force the battery into the charger with considerable pressure. At least three of the batteries were initially standing up at an angle, due to the negative post on the battery not being easily able to fit between the smaller post in the charger and the edge of the plastic hole around that charger post. Forcing the battery into the charger slot finally "popped" it in between the charger post and the narrow space between the post and the plastic case.Look at the accompanying photo, note how the smaller circular connector (the bottom one of the two in the photo, not the 6-sided connector) is offset far to one side of the hole through which it protrudes in the charger. It sits toward the upper left portion of the round hole in the plastic frame. That makes is extremely difficult to get a solid connection with the corresponding 6-sided connector on the battery - it has to be forced in, in order to make a full connection in and around the two connectors for charging. At least two of the five charger stations on the device are exceptionally close (i.e. at least one or two batteries will be affected if more than three are charged at a time).After I have let the batteries that I'm not currently using sit around for a few weeks, I'll test them again for charge and update this review. Obviously, at this early stage I'm unable to rate "durability" or "battery life" as requested in the review.