Audiobahn ACAP7J

The Audiobahn ACAP7J (UPC: 651718015710) is touted as a one-of-a-kind 24 Volt rated, 30 Volt surge device, but it doesn't work at all with my 24 Volt system.

Audiobahn responded to my email about this issue, after 5 calendar days (= 3 working days) later and informed me that the matter had been referred to their engineering department. But after waiting 7 more calendar days (= 5 working days) without a response, I escalated the matter to Amazon.com (where I purchased the product) for a quick return of the item and a refund.

I charged the capacitor, through the supplied resistor, on my 24 Volt battery, and was surprised to still see a spark-jump when I connected the positive wire (although a spark-jump does not damage a car audio capacitor).

The ACAP7J capacitor showed no signs of life at all, even when I later tested it on a 12 Volt battery.

It may be possible that I was, somehow, supplied with a mislabeled 12 Volt rated, 24 Volt surge capacitor: The internal circuit board number reads: 220419. The circuit board also contained a relay that was clearly rated @ 14VDC. The Amazon.com photo (as well as the Audiobahn website photo) shows a 24 volt capable 4-digit digital display on the device, but the capacitor I received is not a true 4-Digit Digital Display (19.99 volt maximum display). The outside of the capacitor clearly reads: "2 farad ACAP7J"

Also, the retail box originally had a UPC: 651718015710 printed on it, but was covered by a label with a barcode that read: B004W36NR0 (256147). The reason I am pointing this out is that, upon further scrutiny, there are numerous photos of the Audiobahn ACAP7J, throughout the internet, featuring 4-digit digital displays with a 19.99 volt maximum display. So you are advised to use caution here.

On closer inspection, the internal capacitor is a standard 2 farad, 60VDC aluminum cylinder capacitor, 3" diameter x 8.5" tall(76mm diameter x 216.5mm tall), housed in a boxy-shaped 3.156" x 3.156" x 8.75" (80mm x 80mm x 222mm) chromed plastic exterior.

I bench tested the 2 farad, 60VDC capacitor, by switching the Audiobahn circuit board with a typical 12 Volt rated, 24 Volt surge circuit board, and the capacitor tested just fine on a 12 volt system.

But there are definitely quality control issues with this product:

- Both of the aluminum "+" and "-" terminals of the internal cylinder capacitor were deformed, such that the circuit board, when screwed tight on one of the terminals, was 1/16" (1.5mm) above the other capacitor terminal. And to screw-tighten down the other terminal would have put unacceptable stress on the circuit board and damage its components. So I had to do a quick re-surface of the aluminum "+" and "-" terminals of the cylinder capacitor until they were on the same plane, before I could bench test the capacitor.

- There was an insulated yellow wire, on the underside of the Audiobahn circuit board, that was completely mashed flat, between the "-" connecting surface of the circuit board, and the "-" terminal of the cylinder capacitor. But the Audiobahn circuit board still did not function when I re-routed the wire.

Final Note:
I have to confess that this is not the outcome I really wanted for this device. I expected to have some dialog with the Audiobahn engineering department and they could have easily gotten off the hook by simply mailing me the correct 24 Volt rated, 30 Volt surge circuit board, and I would have installed it myself -if indeed there even is a 24 Volt rated, 30 Volt surge circuit board in existence.

I ordered an Audiobahn ACAP7J, and it proved to be very leaky, so Sonic replaced it with another, which also was very leaky; it was unusable. These caps do not meet their nominal specs, as far as I could tell, and I would not recommend them.