---
product_id: 11065144
title: "Cap18 - 18 Farad Car Capacitor For Energy Storage To Enhance Bass Demand From Audio System, Audible Warning Tone For Reverse Polarity, Voltage Overload Low Battery Voltage Led"
brand: "boss audio systems"
price: "209557CFA"
currency: XOF
in_stock: true
reviews_count: 8
category: "Boss Audio Systems"
url: https://www.desertcart.sn/products/11065144-cap18-18-farad-car-capacitor-for-energy-storage-to-enhance
store_origin: SN
region: Senegal
---

# Precision ±0.1V LED voltage meter 18 Farad ultra-capacitance Audible multi-condition warning Cap18 - 18 Farad Car Capacitor For Energy Storage To Enhance Bass Demand From Audio System, Audible Warning Tone For Reverse Polarity, Voltage Overload Low Battery Voltage Led

**Brand:** boss audio systems
**Price:** 209557CFA
**Availability:** ✅ In Stock

## Summary

> 🔊 Power Your Bass, Protect Your Ride — Stay Loud, Stay Smart!

## Quick Answers

- **What is this?** Cap18 - 18 Farad Car Capacitor For Energy Storage To Enhance Bass Demand From Audio System, Audible Warning Tone For Reverse Polarity, Voltage Overload Low Battery Voltage Led by boss audio systems
- **How much does it cost?** 209557CFA with free shipping
- **Is it available?** Yes, in stock and ready to ship
- **Where can I buy it?** [www.desertcart.sn](https://www.desertcart.sn/products/11065144-cap18-18-farad-car-capacitor-for-energy-storage-to-enhance)

## Best For

- boss audio systems enthusiasts

## Why This Product

- Trusted boss audio systems brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Safety First, Always:** Audible alerts for reverse polarity, over-voltage, and low battery protect your investment and sound system integrity.
- • **Sleek, Durable Design:** Compact, lightweight with platinum-plated terminals for secure mounting and long-lasting performance under the hood.
- • **Smart Voltage Insight:** Bright blue LED display with ±0.1V accuracy keeps you informed of your system’s exact power status in real-time.
- • **Energy Efficient Auto-Sleep:** Automatically enters sleep mode when volume is low or voltage is stable, preserving battery life and system health.
- • **Power on Demand, No Compromise:** Stores and delivers 18 Farads of rapid energy to keep your bass booming without voltage dips.

## Overview

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.

## Description

View larger Wiring ConnectionsView largerWhat Is A Capacitor?A capacitor is a passive (it consumes but does not produce energy) two terminal electrical component. In building a sound system for your car, you would want to use a capacitor for a couple of different reasons.Why Do I Need One?The main reason a capacitor is recommended is for power reserve. The capacitor stores energy and releases it very quickly to the amplifier(s). How does this help? Music is dynamic, no matter what type you listen to. The dynamics in musical content can vary from soft voices to thundering bass notes. These moments are when the benefit of having a capacitor is heard. The amplifier requires a constant amount of steady power to function efficiently and power the speakers. A capacitor will keep the power going to the amplifier consistent and stabilized, which means a better sounding system. Important: The remote output of the head unit is connected to the remote turn on of the capacitor. The capacitor will not function if the remote wire is not connected to your head unit.FeaturesThree-digit, super bright blue LED voltage meterVoltage measurement accurate to +/- 0.1VDCBlue illuminated window with light following playing musicAutomatic sleep status when volume is low or there is no voltage variation presentWarning tones for the following detected conditions: Reverse polarity connection, over-voltage limit (above 17VDC), and low battery voltage (below 10VDC) SpecificationsCapacitance, microfarads: 18,000,000Working voltage: 16VCDSurge voltage: 20VCDESR (equivalent series resistance): <0.0015 Ohm @ 120Hz/25ºCCapacitance tolerance: +/- 10%Dimensions: 9-1/4 W x 11 L x 3-1/4 H

Review: 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!!****
Review: 100% Satisfaction! - Works like a charm keeps my head lights from flashing and gives my amps that kick when needed

## Features

- Audible Warning Tone For Reverse Polarity - Warning tones for the following detected conditions: over-voltage limit and low battery voltage a capacitor will keep the power going to the amplifier consistent & stabilized, with a better sounding system
- Voltage Measurement - Voltage Overload / Low Battery Automatic sleep status when volume is low or no voltage variation is present. Amplifiers require constant power to function efficiently to power the speaker. Accurate to + / - 0.1 VDC
- Bright Blue LED Voltage Meter - A digital LED readout indicates the unit’s unique working voltage to the decimal point. It comes outfitted with sturdy bolt-down fashion platinum plated terminal w/c makes certain a secure and stable network
- Working Voltage Sufficiency - Preserves and stabilizes energy going to amplifier for better sounding system. The amplifier requires a constant quantity of normal electricity to function efficiently and energize the speaker. Working Voltage: 16 VDC
- Power Capacitor - Elegant outlook of this capacitor makes it the excellent inclusion for the vehicle indoors with excessive superb built. Easy to mount & lightweight. Automatic Sleep Status When Volume Is Low Or There Is No Voltage Variation Present
- Capacitance: 18,000,000 ¬F (18 Farad), Blue Illuminated Display
- Low E.S.R (Equivalent Series Resistance): <0.004¬
- Rated Voltage: 12 VDC, Max Voltage: 16 VDC
- BOSS Audio Systems a 1 year Platinum Online Dealer Warranty so long as the purchase is made through desertcart.com. We strongly encourage professional installation of this product to ensure proper and safe functionality

## Technical Specifications

| Specification | Value |
|---------------|-------|
| 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 |

## Product Details

- **Brand:** BOSS Audio Systems
- **Capacitance:** 18 Farad
- **Capacitance Tolerance:** 10 %
- **Operating Voltage:** 18 Volts
- **Shape:** Round

## Images

![Cap18 - 18 Farad Car Capacitor For Energy Storage To Enhance Bass Demand From Audio System, Audible Warning Tone For Reverse Polarity, Voltage Overload Low Battery Voltage Led - Image 1](https://m.media-amazon.com/images/I/81wSH+4yQmL.jpg)

## Available Options

This product comes in different **Style** options.

## Questions & Answers

**Q: what all comes with it?**
A: Hello, The CAP8 comes with a 1 Watt/51 ohm Resistor and mounting hardware.

**Q: Does this model flash to the beat?**
A: Hello,
The CAP8 only flashes when it is charging.
Thank you,
Boss Audio

**Q: Does this come with a distribution block and can it power a 4500w amp?**
A: The distribution block is built in. It has a in and a out for the positive and negative.  While the capacitor will help the battery and alternator supply enough power to turn it on it may not be able to supply enough support for those really low tones constantly.  I would recommend running a dual battery setup and if there is enough space to do so upgrade the alternator to as high a amperage as you can get. In my case I am driving a 1980 f350 and I upgraded to a 150 amp alternator and all lighting is led. I also run 2 batteries and am looking at installing a second alternator to supply enough power for my amplifier setup. I am pulling 3500 watts. When you install a larger alternator like I did using a 1 wire alternator you will also have to run a significantly larger wire from the alternator to the battery.

**Q: I have an 4000 watts hifonics amp and i have re audio sx 18 d2 1000 watts do u guys think this capacitor gonna handle my system?**
A: I think 3.5 farad its ok

## Customer Reviews

### ⭐⭐⭐⭐⭐ May be long, but if you need a real review its here!
*by D***R on June 15, 2020*

**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!!****

### ⭐⭐⭐⭐⭐ 100% Satisfaction!
*by F***E on November 20, 2025*

Works like a charm keeps my head lights from flashing and gives my amps that kick when needed

### ⭐⭐⭐⭐⭐ BOSS Audio Systems Cap18 - Power Up Your Car Audio System for Ultimate Bass Performance!
*by D***N on October 14, 2023*

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.

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*Product available on Desertcart Senegal*
*Store origin: SN*
*Last updated: 2026-03-08*