Review on Long-Lasting EBL 9V Lithium Rechargeable Batteries With USB 5400MWh Capacity (Pack Of 2) by Mario Beats

First, about the "5400mWh". Oddly, this battery is measured in miliwatts. This is marketing bs so people see large number and jump on it. Usually small batteries are measured in "mAh". This means that if converted from watts to amperes (5400/9=600). So these batteries are actually 600mAh which is actually nothing special for Li-Ion batteries. So if you think you getting a ridiculously high capacity battery. Not really. It is a nice capacity still comparing to disposables or NiMh batteries which are more of a 200mAh. So the value for the money is pretty good steel, just a little less car salesman sleaziness would be nice.Now about my specific application. I bought these to put in my Peavey Grind Bass Guitar modified with VFL4 active pickups (those who cares, would know). Returning because of the obscene amount of hissing noise the guitar outputs while with these batteries. Comparing to regular disposable batteries, the same bass has no obvious hissing noise at all. So definitely the deal with the batteries. The batteries measure 9V just like the disposable. On the my multi-meter battery tester mode, they show just over "9" the same as disposable. When connected to the guitar, I measure the same power consumption as with the disposable batteries. However, the hissing noise is insane. actually the noise is louder that the actual notes being played. Yes, the bass guitar works and with these batteries and the volume of the played notes is the same as with disposable batteries, but unfortunately with these, fully charged, EBL Orange/Black 5400mWh batteries, the amount of hiss is unbearable.