I bought this kit for my VW Jetta TDI. I'm still on the stock alternator and deleted the under-hood battery. My sound system is about 3K watts RMS.

I was running the stock lead-acid battery before with a small LiFePO4 motorcycle battery, and at idle on the heavy bass and rebassed stuff I was dropping to about 13.0V and 13.2V while driving.

Now with the Gushen kit at full tilt at idle I'm dropping to only 13.5V and staying steady at 13.8V to 14.2V while driving.

I charge at 14.0V so slightly lower than typical for a stock alternator and 13.8V was typical on the old battery before without running the stereo. Looks like I can finally upgrade my system!

Will be buying from them again

I ordered this for my sound system. Its 8krms. 1 taramps hd 3k and 1 taramps big boss 5k. 1 skar rp75.4. 325a singer alt. This replaced 3 xs975 agms. No comparison from the agm. My voltage drop is only .3v at idle with 3/4 volume. Full tilt is 1 volt at idle. At 1200 engine rpm . 3v drop. Running the alt at 14.3 to 14.4 volt. Only time will tell. So far so good though. Will update in a few months. This is in a toyota yaris btw