Garage
Shop

See all parts that fit your 2015 M3

Boss CAP3.5S (SILVER)

3.5 Farad Digital Capacitor (CAP35S)

Boss
Shop all Boss
Product videos
highlight-star-icon

3.5 Farad Digital Capacitor • Digital voltage level display • Chrome finish terminals • Includes mounting brackets • 20V DC • 24V Surge

Learn more about the cap3-5s

We apologize

This item has been discontinued


Loading...
51KSC404 main

Kicker KSC4 (51KSC404)

300W Peak (150W RMS) 4" KS Series 2 Way Coaxial 4-ohm Speakers

3
-16.67%

$99.99

List price $119.99

Product Highlights


3.5 Farad Digital Capacitor • Digital voltage level display • Chrome finish terminals • Includes mounting brackets • 20V DC • 24V Surge

Description


Boss brand icon

Authorized dealer

When heavy bass notes in your music hit, the current demand on your system greatly increases and could cause voltage drops. This stiffening capacitor acts as a power reservoir, instantaneously supplying added power to keep your system playing strong.
  • 3.5 Farad Digital Capacitor
  • Color: SILVER
  • Digital voltage level display
  • Chrome finish terminals
  • Includes mounting brackets
  • 20V DC
  • 24V Surge
  • Dimensions (without mounting brackets): 11"L x 4"W x 4"H
  • Authorized Internet Dealer
  • 1-year Manufacturer's warranty

Product history:

Boss CAP3.5S thumbnail
(newest, current model)
Boss CAP32C thumbnail
(previous model, replaced by Boss CAP3.5S (SILVER))

Loading...
Club 322F main

JBL Club 322F (SPKCB322FAM)

150W Peak (50W RMS) 3.5" Club Series 2 Way Coaxial 3-ohm Speakers

1
-27.29%

$79.95

List price $109.95

CVP8 main

Cerwin-Vega CVP8 (Sold Individually)

350W Peak (170W RMS) 8" CVPRO Series Pro Full Range 4-ohm Speaker

-16.67%

$49.99

List price $59.99

51KSC3504 main

Kicker KSC35 (51KSC3504)

200W Peak (100W RMS) 3.5" KS Series 2 Way Coaxial 4-ohm Speakers

4
-11.11%

$79.99

List price $89.99

CF-350mt main

JL Audio CF-350mt

70W RMS 3.5" CF Series Custom-Fit Midrange 4-ohm Tweeters

4
No picture

Jensen JS35K

150W Peak (50W RMS) 3.5" Apex Series 2-Way Coaxial 4-ohm Car Speakers

Club 34F main

JBL Club 34F (JBLSPKCB34F)

150W Peak (50W RMS) 3.5" Club Series 2 Way Coaxial 3-ohm Speakers

4
-27.29%

$79.95

List price $109.95

Limited time!
46CSC354 main

Kicker CSC35 (46CSC354)

180W Peak (60W RMS) 3.5” CS Series 2 Way Coaxial 4-ohm Speakers

16
-30.71%

$51.96

List price $74.99

CF-275mt main

JL Audio CF-275mt

60W RMS 2.75" CF Series Custom-Fit Midrange 4-ohm Tweeters

12
V3 main

Cerwin-Vega V3

360W Peak (120W RMS) 3" Vega Series 2025 Edition 2-Way Coaxial 4-ohm Speakers

TS-A1081F main

Pioneer TS-A1081F

460W Peak (100W RMS) 4” A Series 2-way 4-ohm Coaxial Car Speakers

3
-18.18%

$90.00

List price $110.00


Best selling similar products

XCAP10H small

NVX XCAP10H (TRUE 10 FARAD CAPACITANCE)

• For High-Powered systems
• Bright Blue LED Voltage Display
• Improves Bass Response (SPL)

(47)

$299.99

List price $371.99

RFC10HB small

Rockford Fosgate RFC10HB 10 Farad Hybrid Capacitor

• 10 farad Hybrid Digital Capacitor
• Increases quality of sound
• Increases level of bass
• Platinum plated

(46)

$529.99

List price $709.99

SSCap5M small

Stinger SSCap5M

• 5 Farad Digital Capacitor
• Carbon Fiber Design
• 5000 Watt Systems
• Digital Display

(3)

$162.99

List price $349.00

BB1D small

Belva 1.0 Farad Capacitor

• 1.0 Farad Power Capacitor
• Perfect for Systems up to 1000 Watts
• Audible Warning
• Red Voltage Display
• Mounting Brackets Included

(80)

$38.99

List price $79.99

XCAP1F small

NVX XCAP1F

• For Systems Up To 1200 Watts
• Bright Blue LED Voltage Display
• Improves Bass Response (SPL)

(33)

$109.99

List price $131.99

BB2D small

Belva BB2D

• 2.0 Farad Power Capacitor
• Perfect for Systems up to 2000 Watts
• Audible Warning
• Red Voltage Display
• Mounting Brackets Included

(36)

$54.99

List price $89.99

SPC5010 small

Stinger SPC5010

• Digital 10 Farad Capacitor
• Bright Red LED Voltage Display
• Monitor System Voltage
• 12-16 Volt Operation / 18 Volt Surge
• Louder And Cleaner Bass Response

(20)

$339.99

List price $739.00

V8-3DDC small

T-Spec V8-3DDC

• 3.0 Farad Digital Capacitor
• Voltage Meter
• Impact Resistant Polycarbonate Cover
• Simple Mounting System

(28)

$158.99

List price $176.99

SPC505 small

Stinger SPC505

• Digital 5 Farad Capacitor
• Bright Red LED Voltage Display
• Monitor System Voltage
• 12-16 Volt Operation / 18 Volt Surge
• Louder And Cleaner Bass Response

(17)

$274.99

List price $599.00

BT-SA150-975 small

Sundown SA150-975 (SA150)

• Non-digital 150 farads capacitor
• Made for systems up to 1200 watts
• Includes mounting hardware for a secure installation

$299.99

List price $359.99

Specifications & Details


Capacitor Specifications
Capacitance (farads)
3.5 farads
LCD Meter Display
Yes
Maximum Input Gauge Size
Any Gauge with use of Ring Terminal AWG
Maximum Output Gauge Size
Any Gauge with use of Ring Terminal AWG
Built-In Distribution Block
No
Primary Color
Silver
Illumination
Red LED lights
Width
4"
Height
4"
Depth
11"
Warranty and Return Policy
Parts Warranty Duration
1 year
Labor Warranty Duration
1 year
Warranty Provider
Manufacturer

Item Details


Manufacturer:

Model Number:

CAP3.5S

Weight:

6.00lbs

Internal SKU:

cap3-5s

Internal Product ID:

13128

Product and How-to Videos


Customer Ratings & Reviews


Boss CAP3.5S (SILVER) thumbnail image

5 star
55%
4 star
18%
3 star
18%
2 star
9%
1 star
0%



Durability
4.2
Value
4.2
Features
4.1
Design
4.8
Usability
4.7

Customer Reviews

Sort by:

Loading...

great value

Recommended seller because its really good seller, on time and priced really good.

By gony on October 10, 2012

10 found this helpful


Good for the price

Okay first a background on what I use and what is the sound system. I have a Jeep Liberty 2003 sport 3.7L w/ 4WD and I ripped out my stock system entirely (except for in-dash tweeters as the tweeters are good quality). My system is a Kenwood 8105D 1000 watt amp powered with 8 gauge wire, and 2 12" Kenwood subs connected with 10 gauge wire. The capacitor kept gauges and lights from dimming, however seemed even 3.5 farads was not good enough as I listen to bass heavy techno and hip hop and a lot has constant bass. So after a couple minutes at Max or 90% volume, the cap would be drained and cut out to recharge. But that might be more my music selection. It does make the signal cleaner however and more responsive. However I decided to buy the Boss 10 farad capacitor to get more capacitance for my needs and will give this to my buddy who helped me install my system as he only has 2 x 200 watt rockford almost 20 year old amps and 2 10" kicker competition subs that are also almost 20 years old... They were his dads while he was in the USAF and he had them still sealed and never used. So I would recommend this to people with not too powerful systems if you are like me and like songs with constant bass hits like techno commonly does or some hip-hop/rap

By Alon on April 17, 2011

6 found this helpful


This Boss Cap rocks

I have an Alpine 1400 Watt RMS system in a boat connected to an Isolated Kinetic 2400 Battery. I wanted lots of battery time so the boat could just sit and play without worries. Well the boat rocks. I only have a 55 amp alternator and have not upgraded the main battery wiring. Yes I have a monster battery isolated from the main system by manual switch. I have let the boat sit with the stereo cranked full volume for 6+ hours at a time. Frankly I have never yet drained the Kinetic when doing this. I have this Cap inline in the power very close to the Alpine PDX-1.600 that pushes the Alpine Type R sub. The Cap has a volt meter on it that is very useful and a little light that lights every time the Cap is handling the power deficiency. It works great. I have seen this system drop to 11.4 Volts and still pound hard due to this Cap. As my Kinetic battery starts to drop in voltage this cap goes to work and the Sub-Woofer is never even affected by it. The whole set up works beautifully and this Cap does its job perfectly. Very Happy with the results of this system.

By Just-a-Fool on August 5, 2012

4 found this helpful


A++++

Great product!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I would totally purchase from you again. Thank you.

By eman on June 14, 2012

4 found this helpful


Good product

The boss cap was a great buy and I recommend it. I have had it for 6 months now and so far it has functioned great. This cap did not take any dimming away which disappointed me there but I found out it could possibly be my alternator, but I don't think it's exactly that. I did notice it gives your subs more power/bass which is phenomenal.

By JG on May 7, 2012

4 found this helpful


it alright

My 1 farad cap does better than this but its still okay.

By whatever on January 2, 2012

4 found this helpful


Ok product

I bought this product for only a 1200watt amp. I bought it for intended upgrade on amp and subs in a few weeks. It did take care of some of the dimming on my car but not all the way. I know caps cant fix everything but this thing did work and looks good to after a good install. If your looking for a decent cap on a budget go with this one.

By Will Stickle on January 21, 2011

4 found this helpful


Good Product

Ive been installing & sellng car audio for 10 years and I recommend this product. This cap has a great value and works like i'ts supposed to. However if youre running small gauge wire and a high wattage amp, this is only a band aid for your system. If you have a good battery, upgraded wiring and a good alternator you dont really need a capacitor.

By Brad on May 27, 2012

3 found this helpful


ok

Works if your system is under 3000 but not the best and it wines extremely loud with the RPM's of your car.

By Jesse on December 29, 2011

3 found this helpful


Excellent product

I am extremely satisfied with this product. Both the installing technician and other technicians are going gaga about it. Everyone wants to know where did I get it. I would not hesitate to recommend it to anyone.

By Nalda on April 21, 2012

2 found this helpful




MVH-P7300 small

Pioneer MVH-P7300

In-Dash MP3, WMA, ACC Mechless Receiver with 3" Color Display, USB Direct Control for iPod/iPhone

(3)

$259.99

List price $319.99

BMF1514 small

Crossfire BMF1514

15" Dual 2 Ohm BMF Series Car Subwoofer

(2)

$119.95

List price $279.00

DLPKCHG1 small

XpressKit DLPKCHG1

Xpress Kit Door Lock and Alarm Control Interface with Integrated Bypass Module for 1999-2004 Jeep Cherokee

(2)

$32.99

List price $99.99

PA500.4 small

Polk Audio PA500.4

800W Max, 4-Channel Amplifier

(5)

$249.99

List price $429.99

DAX8000S_MRR_S8GM2_R small

Kenwood DAX8000S Direct Fit Digital Receiver Package

for Includes Receiver, Interface Module, Mount Brackets, Harness, iDataLink Maestro ACC-HU-KEN1, Bypass Harness (requires extension) Plug and Play Upgrade Kit

(37)

$1532.97

List price $2159.97

2SV8-GRAY small

Sonic Sub Box: 2SV8 (Gray)

Dual 8" Vented MDF Enclosure

(6)

$49.99

List price $69.99

VTL402HDL small

HD Bar Type License Plate Rear-View Back-up Camera With LED Light

BOYO Vision VTL402HDL

(3)

$84.99

List price $149.99

PKG-RSE3DVD small

Alpine PKG-RSE3DVD

10.2" TFT-LCD Overhead Flip-down Monitor Screen with Built-In DVD player, and 1 set of wireless headphones

(1)

$599.95

List price $700.00

1SA12-GRAY small

Sonic Sub Box: 1SA12 (Gray)

Single 12" Airport MDF Enclosure

(23)

$59.99

List price $99.99

Related Searches


Save up to 10 different vehicles in your garage
Vehicle
Store
Delete

2024 Dodge Durango

2015 BMW M3

2015 Audi RS7

Add vehicle Clear all vehicles
Where to find vehicle info
Are you sure you want to clear your garage?
This action cannot be undone. Confirm
This page was not designed for products.
If you continue, you will be redirected to a category customized for your vehicle. Continue
Loading...
Identify your vehicle and submodel details
  • Owner's manual
  • Vehicle's insurance card
  • Vehicle registration
  • Vehicle produced after 2005: Inside driver's side door
  • Vehicle produced before 2005: Rear passenger doorjamb, glove box, center console, or engine compartment
Car Info Side Door Icon
Vehicle Registration Icon
Vehicle Insurance Icon

Modern vehicles often require specific brackets, wiring harnesses, and mounting solutions. A fit guide ensures:

  • You see only parts engineered for your exact vehicle
  • You avoid incompatible radios, speakers, or wiring
  • Installation is smoother, faster, and frustration-free
  • You get the correct accessories the first time

Whether you're replacing a factory stereo or upgrading your entire audio system, the Fit Finder eliminates uncertainty.