🔊 Power Your Bass, Protect Your Ride — Stay Loud, Stay Smart!
The BOSS Audio Systems CAP18 is an 18 Farad car audio capacitor engineered to stabilize and enhance amplifier power delivery for superior bass performance. Featuring a precision LED voltage meter, audible warnings for electrical faults, and an automatic sleep mode, it ensures consistent sound quality while protecting your vehicle’s electrical system. Compact and easy to mount, it’s the professional choice for millennial audiophiles seeking reliable, high-impact car audio upgrades backed by a 1-year warranty.



| ASIN | B001DXDAAA |
| Best Sellers Rank | #7 in Car Amplifier Capacitors |
| Brand | BOSS Audio Systems |
| Brand Name | BOSS Audio Systems |
| Capacitance | 18 Farad |
| Capacitance Tolerance | 10 % |
| Customer Reviews | 4.4 out of 5 stars 3,066 Reviews |
| Global Trade Identification Number | 00583082324023, 00791489108980 |
| Included Components | Capacitor |
| Item Dimensions W x H | 7.75"W x 11"H |
| Item Height | 3.2 inches |
| Item Shape | Round |
| Item Type Name | BOSS Audio Systems CAP18 Car Capacitor - 18 Farad, Energy Storage, Enhance Bass From Stereo, Warning Reverse Polarity Tone, Voltage Overload Low Battery Voltage Led |
| Item Weight | 5 Pounds |
| Manufacturer | BOSS Audio Systems |
| Maximum Voltage | 16 Volts |
| Mounting Type | Rack Mount |
| Operating Voltage | 18 Volts |
| Shape | Round |
| UPC | 583082324023 791489108980 |
| Warranty Description | 1 YEAR WARRANTY |
D**R
May be long, but if you need a real review its here!
**UPDATE** - Here we are almost 2 years later. (Normally with the PCX models, they would have FAILED, into permanent circuit protect by 6mo to 1yr)... NOT THESE... I bought a 2nd one for backup, and it's been collecting dust in my attic, cuz THIS CAP IS THE TRUTH! I honestly have more voltage, 14.7 , than when I first installed it. NO strain on my alternator, and only 1 battery replacement in this 2yr period! Caps will usually KILL a battery unless isolated by a relay, and stress your Alt. NOT HERE.. battery had a dead cell... alternator tested just as strong as a new one! Can I give this 6 stars?? This company should have me do a video for them, cuz I see nothing but PRAISE deserved for them. I could NOT be happier thanks to them! If this is available still, stop thinking and BUY IT! Of the 100+ Caps I have EVER owned, this has been the BEST performing, longest lasting, and TOUGHEST one hands down.** (Oh yeah I almost forgot..Never ONCE been into "protection mode!" --- God of Caps under $200!)** Let me start by stating, ive ALWAYS provided an honest and unbiased review here and everywhere i post a product review! So heres my analysis of this Boss 18cap, 18 farad capacitor. Overall? A+ ... NOW... lemme point you to a few indisputable facts about this product. #1. Any novice or pro level car audio or electrical consumer will realize this is NOT 18 farads... in reality its closer to between 5-8 farads. You can test it with whatever meter you want, but the way these are built (Hybrid Capacitors) is a combination of a standard 2-5 farad stiffening cap tied down to an additional circuit board with 8 separate high voltage rail caps much like those found in the Brazillian amps these days. Im not an engineer but the basic expl. Is that the board allows the main cap to exceed its normal storage capacitance by having these smaller caps recharge it much faster and thus creating a virtual bank of reserve power in a loop. #2. Dont be fooled... if you have owned the Power Acoustik pcx30, Planet Audio 20f, or several others that "Resemble" this (look at the connections, not the outside case) then you are correct, YOU DID OWN THIS! its the same cookie cutter design including the pcb board and voltage display. The one thing that sets this apart from the others is that THIS ONE the 18cap uses MUCH LARGER stiffening caps than ALL the rest! That 1 factor makes this SUPERIOR to the other clones. These caps themselves are nearly the same as the 4.4 and 5 farad Rockford caps which were phenomenal. So theres 2 of those to drive the build. Now for power. I am a pro builder and have been for 20 years. Capacitors have their place in audio IF USED CORRECTLY!. *NOTE: If you are trying to make a stock Acura Integra run a true 5k watt amp with 4 15's (eye roll) please leave this page and find your local alternator shop and get your electrical upgraded to a 300a or higher alt., get your Big 3 done, and load a couple XS batteries behind a relay! This will not help you!* **NOW.... if you are in my boat, (ex.) I have a 2020 Honda Crv which is under a spectacular warranty, and ANY modification to stock electrical will VOID my whole warranty, unless honda installs it. I can ADD anything i want but i cant remove anything. The honda CRV comes with a stock 90-120a alternator, but the electrical is maintained by less than 1/3 of that. I am running 2 Rockford T2d212, (1000 rms each) and a Brazilian 3k amp (tested at 3375 rms @ 2 ohms) plus an active EQ and Crossover. Ive got big 3 done, and all OFC 0 gauge run to the back. My voltage sat resting at 12.4 and 14.4 driving. Without the cap, i could hit some mid bass notes (the ones that drain voltage 45-55hz) and if at a light, i could nearly shut the car off if i was at 1/2 tilt. That said, an alternator was not an option (warranty void). Ive tested several of these hybrid caps and out of the ones mentioned above and some others... THIS ONE is the only one that proved helpful!. With this, my resting voltage is 14.5 and my driving voltage is 14.7. I can be sitting at a stop light with headlights on, AC blasting, system at 1/2 tilt, bass knob cranked, windows THROBBING and every car around me PISSED and my voltage MIGHT touch 13... never below 12 unless i am near blowing my subs. Final thought. WE HAVE A WINNER. Excellent design.. small footprint... supplements the variable juice needed to carry my system without invading my warranty commitment. Dont look further... start here.. you will not be disappointed. ***MAKE SURE U CHARGE THE CAP FIRST!!****
F**E
100% Satisfaction!
Works like a charm keeps my head lights from flashing and gives my amps that kick when needed
D**N
BOSS Audio Systems Cap18 - Power Up Your Car Audio System for Ultimate Bass Performance!
Rating: ⭐⭐⭐⭐⭐ The BOSS Audio Systems Cap18 is a high-capacity car audio capacitor designed to supercharge your car’s audio system and ensure that your bass demands are met with precision. Pros: 1. Enhanced Bass Performance: This 18 Farad car capacitor provides a significant surge of energy when your audio system demands it, resulting in enhanced bass performance that’s particularly crucial for music enthusiasts. 2. Audible Warning Tone: The built-in audible warning tone acts as a safeguard, alerting you in the event of reverse polarity, voltage overload, or low battery voltage, helping prevent damage to your car’s electrical system. 3. Low Battery Voltage LED: The integrated LED indicator displays your battery voltage, ensuring you’re always aware of your car’s electrical status. 4. Easy Installation: Setting up the Cap18 is straightforward, and it’s compatible with a wide range of car audio systems. 5. High-Capacity Design: With its 18 Farad capacity, this capacitor can handle substantial power demands, ensuring your audio system operates at peak performance. Cons: 1. Size: The Cap18 is relatively large, so it’s important to ensure you have enough space in your vehicle for installation. In summary, the BOSS Audio Systems Cap18 is an outstanding choice for car audio enthusiasts seeking to optimize their system’s bass performance. Its high-capacity design, complete with safety features like the audible warning tone and low battery voltage LED, ensures your system runs smoothly and avoids potential electrical issues. While it may be on the larger side, its performance benefits are well worth the space it occupies. If you’re serious about achieving powerful bass and high-quality audio in your car, the Cap18 is a must-have accessory to supercharge your car audio experience. Highly recommended for audio aficionados looking to elevate their car audio setup.
O**R
So far these subs sound great. I have them set up for 2 ohms ...
I have had the system installed with 2) NEW Kenwood KFC-W3016PS 12" subs being pushed by the kenwood KAC-9106D 2000 Watt mono block class D amp and thus cap (boss audio cap8 farad). So far these subs sound great. I have them set up for 2 ohms and No issues thus far. Made sure everything was installed to specs and made sure all adjustments were within both the amps and the subs specs. I have the settings moderately low but when turned up it really hits. I installed with a zero gage power cable 4 gage ground cable and 12 inch speaker wires. I also have a custom enclosed fiberglass box with about 1 1/2 to 2 cubic feet in it. If I new how to post pics I would but I don't, so I wont. The cap came with instructions and west very easy to charge and install. The blue lights in the center look great. I still have a little dimming of the interior lights when amp is turned up and system is blasting at its max but not during normal music play at a moderate level. Ovarian all I'm happy with the cap.
J**1
Great quality and power for the price! Not just some knockoff brand!
Great price for such a high Farad Capacitor! 8 Farad provides a lot of wattage protection for your vehicle charge system. Installed in my 2018 Ford F-150 which has a 1000 watt JBL 5 channel amp and a Mono Kicker 400 watt amp for my subwoofers. Was super easy to install and first Charge with included resistor, has well made +/- hookup posts for the cables, and a very accurate voltage display to see the Capacitors voltage charge state. For being an 8 Farad Cap, it’s not very big whatsoever! Nice design as well. Even though truck has a strong AGM battery and powerful DC Alternator, I still wanted to protect all the high tech electrical systems in my truck. Not only does it prevent any light flickering/dimming when playing music loud. It also provides extra boost of power to my amps making my audio system sound even more powerful then it did without the Capacitor. My truck has a big 8” touch screen interactive radio display so I didn’t want to cause any damage to the system. I can crank up my system extremely loud and not worry about any headlight dimming or audio degrading. When purchasing a Capacitor you really have to do your research since there’s so many cheap no name brands on the market that really don’t do anything positive but it only hurt your audio equipment.! If your not careful, you really can damage your equipment doing more harm then good. For the price you can’t go wrong, and a good tip is to always over size the caps Farad rating so your helping your audio equipment and not hurting it.
☠**☠
Definitely recommend 👌
Good. 😎👍it helped my little system, now the sound & bass is much crisp. 🔊🎵🎶 Just follow the instructions for the installation & all will go well. Definitely recommend👌 ⚡Discharge Car Battery ⚡
K**C
Good cap and not over priced.
Great item,good price , easy install and it makes any system look . Does its job , no dimming of lights and it’s by far the best cap I’ve had .
E**Y
Lug
Since first installing this I have had nothing but problems. I followed the instructions to precharge the capacitor; I received No digital display readout. The digital readout only started once I hooked up the positive wire running from the battery (last hookup). For whatever reason the digital readout has only worked sporadically ever since. Twice, I went to start my car and found that my 1-year old car battery was completely dead. I learned that the capacitor continued to drain my car batter after the car and stereo and everything was off, and off for HOURS. I then rewired the recommended setup of the remote cable to run straight to my amp and then double over to the capacitor. That seemed to somewhat solve the problem for about 3 months. Additionally, when my car has a lot of electrical circuits all working at once--defrost, heated seat, rear defog, headlights, or windshield wipers, and stereo on low--I notice that my headlights are dimming or my turn signal is weak like the capacitor isn't doing it's job. Ironically, that is WHY we buy the capacitor in the first place--to solve this issue! So, again, further evidence that my capacitor wasn't working properly from the beginning. Finally, periodically, I go to start my car and it starts really hard and low and slow like the battery is near dead. But, luckily it still starts, and because this only occurs periodically I ignore the problem. Well, yesterday, I went to start my car and my car battery was dead AGAIN, for the 3rd time since installing this capacitor 4 months ago. I jump-started my car and immediately unhooked this complete P.O.S. capacitor and my car seems to start and run just fine again. Ironic. Point is, this capacitor is nothing but a useless lug and succubus of the energy of your poor car battery. Unfortunately, it took me 4 months to figure this out. Now, I am past the point of 90-day return. This is a cheaply made product intended to fail, and thus a terrible investment. Don't buy it. Please.
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