SKU: 27914633282

Dual Pro SS4 Auto 4 Bank Battery Charger w/2 Bank B.O.S. [SS4AUTO/BOS12V2]

$423.45 $470.50
Save 10%
No.2 Bestseller on watersyst.com >

Pay in installments of $117.62 with ShopPay, AfterPay and Klarna

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Aug 13 - Aug 18

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

Description

Dual Pro SS4 Auto 4 Bank Battery Charger w/2 Bank B.O.S. [SS4AUTO/BOS12V2]SS4 Auto 4 Bank Battery Charger with 2 Bank B. O. S. This kit includes Dual Pros B. O. S. Battery Optimization System 12V 2 Bank (PN: BOS12V2) and Dual Pros SS4 Auto 40A 4 Bank Lithium AGM Battery Charger (PN: SS4AUTO). B. O. S. Battery Optimization System 12V 2 Bank B. O. S. actively shuttles energy between batteries to keep the pack balanced, increasing battery strength and longevity. Batteries in a pack will become out of balance and the pack is

SS4 Auto 4 Bank Battery Charger with 2 Bank B.O.S.

This kit includes Dual Pro’s B.O.S. Battery Optimization System - 12V - 2-Bank (PN: BOS12V2) and Dual Pro’s SS4 Auto 40A - 4-Bank Lithium/AGM Battery Charger (PN: SS4AUTO).

B.O.S. Battery Optimization System - 12V - 2-Bank

B.O.S. actively shuttles energy between batteries to keep “the pack” balanced, increasing battery strength and longevity.

Batteries in a pack will become “out of balance” and the pack is only as good as its “weakest link”. In watercraft applications, this is further compounded when the trolling motor battery is used for peripherals and/or to assist the cranking battery.

B.O.S. actively shuttles energy as needed between batteries wired in series to ensure equal voltage before, during, and after charging.

B.O.S. keeps packs balanced, enabling maximum performance, and quadruple run time on the water.

Premature battery failure due to an unbalanced pack has been, unfortunately, accepted as the ‘norm’ for decades. The B.O.S. answers this call with a BSAP-24 algorithm that can accurately predict and select the battery that needs additional energy to match the other batteries within the pack. This simultaneously and successfully extends the life of each battery in the pack, as well as increasing run times.

Features:

  • Available in 6V, 8V, and 12V configuration
  • Up to six batteries in a series
  • Battery Selection and Prediction (BSAP-24) algorithm
  • Less than 1mA sleep mode
  • Transfer rate up to 7.5A
  • Self-powered
  • Any type of battery chemistry

Used in Any Application Where Batteries Are in Series:

  • Marine
  • Golf
  • Industrial
  • Aerial Equipment
  • Solar Power
  • Electrical Vehicles
  • Communications
  • Defense/Military

SS4 Auto 40A - 4-Bank Lithium/AGM Battery Charger

Latest Technology:

  • Detects if a battery is Lithium or AGM
  • Automatically charges both Lithium and AGM batteries for optimal performance
  • Fully automatic. Completely and safely charges both Lithium and AGM batteries
  • Algorithms designed and validated with battery manufacturers for a 100% charge
  • The startup feature will wake up batteries that have turned off due to low-voltage protection
  • Auto return to charging feature
  • Quickest charge times in its class
  • Unbeatable performance, reliability, safety, and quality delivered by DUAL PRO®

Features:

  • Waterproof - Use on land and in fresh and saltwater
  • TROUBLE-FREE—Just Plug It In and Forget It!
  • Independent outputs
  • Fully automatic/multi-stage charging
  • On-board diagnostic codes
  • FCC 15 Parts A & B interference compliant
  • Approved and meets ISO 8846 Marine standards
  • Ignition protected (US Coast Guard 33 CFR 183.410)
  • 3-Year Warranty

AutoProfile Intuitive Charging Technology Lithium/AGM

Professional and Sportsman Series chargers have set the standard in the marine industry for more than two decades, known as the safest, most reliable, and best performing chargers in the industry.

AutoProfile Intuitive Charging Technology provides flexibility for the charging system, ready for the ever-changing lithium battery technologies. No matter if users choose Lithium or AGM batteries for the boat, Dual Pro is ready to keep a boat on the water longer, enhancing battery performance and extending battery life.

Specifications:

  • Charger Input - Voltage: 120v
  • Charger Output - Amps: 40a
  • Charger Output Voltage: 12/24/36/48v
  • Charging Banks: 4
  • Portable: No
  • Box Dimensions: 3"H x 6"W x 9"L WT: 25.4 lbs

Quick Guide (pdf)
Owner's Manual (pdf)
Brochure (pdf)
Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 27914633282

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.8 ★★★★★
Based on 21 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
A
Verified Purchase
Amazon Customer
Whiting, US
★★★★★ 5
All-around thumbs up!
Size: 934W-Z, Color: Black
So far, so awesome. Easy to assemble, comfortable, arrived quickly and is exactly what I was looking for. I have a tall work bench in my new studio so I needed a chair that we could allow me to sit higher than a regular office chair and allow me to get off my feet after standing on the concrete floor. Plus its a nice looking chair that I am sure will last a long time. I love the flip-up arms and the lumbar support. This is just right!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 8, 2026
D
Verified Purchase
Danielle Chen
Massapequa, US
★★★★★ 5
Perfect Balance of Comfort, Support, and Style!
Size: 934-Z, Color: Black, Size: 934-Z, Color: Black
I’ve been using this chair for a few weeks now, and I’m genuinely impressed with how much of a difference it’s made in my workspace. The mesh back is one of my favorite features—it offers excellent breathability and prevents that sticky, overheated feeling you sometimes get with solid-back chairs, even after sitting for hours. The seat cushion is firm enough to give proper support but still has enough give to keep me comfortable through long workdays. It feels like the perfect middle ground between soft and supportive. The adjustable foot ring has been a complete game changer for me. I use a taller desk setup, and having somewhere to rest my feet makes a huge difference in posture and overall comfort. Whether I’m sitting upright for focused work or leaning back to read, it’s always at the right height. The flip-up armrests are another smart design choice. When I’m typing, I like to have them down for support, but when I’m done, I can flip them up and push the chair neatly under my desk—saving space and keeping things tidy. The casters roll smoothly on both hardwood and rugs, so I can move around easily without scraping the floor or getting stuck. The overall build quality feels solid and sturdy, with no wobbles or creaks. Assembly was surprisingly quick—everything was clearly labeled, the parts felt durable, and it only took me about 20 minutes from opening the box to sitting in the chair. The sleek, modern look is another big plus—it blends in perfectly with my home office décor without feeling bulky or taking up too much visual space. If you’re looking for a chair that combines comfort, ergonomic support, durability, and style, I can’t recommend this one enough. It’s equally great for work, studying, or just relaxing at your desk, and it’s definitely been worth every penny.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on August 12, 2025
S
Verified Purchase
sleepywan
Birmingham, US
★★★★★ 3
OK for the price, but overall comfort is avergae
Size: 934-Z, Color: Mustard
Easy to put together, color (mustard) accurate to images, and while I understand this is not a high-end chair, I feel like it still needs to be rated for its quality. Pros: the seat cushions are fairly comfortable and it rolls well. Adjustable footrest is easy enough and mostly sturdy. Cons: For a tall office chair, it doesn't go up high enough. I actually had to lower my standing desk to sit at it, which then isn't where I want it when I'm standing now. It's also a bit wobbly. The seat area's attachment to the post isn't as solid as it should be for a tall chair, so while sitting, it does tend to lean/slope forward and wobble side to side. The lumbar support is not adjustable, so I'm not even really sure what it does. And the armrests are not very comfortable to use. Since they are hard plastic, they are just a bit too rigid to rely on for any comfort. They are basically there to hold on to when you're getting out of the chair.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 29, 2026
M
Verified Purchase
Mel
Waukegan, US
★★★★★ 4
Good Value for a Tall Chair
Size: 934W-Z, Color: White
I have received this chair just today and would like to give my first impressions of it. Height is super adjustable as well as the foot rest. My desk is very tall (~34 inches vs standard ~29 inches) and does not suit a standard height chair. This chair's height is enough to sit comfortably at mybut also still having adjustment to be even higher. Lumbar support is a manual adjustment that can be adjusted by sliding the lumbar piece up or down and it seems it can be tiled as well. No reclining feature or slight backrest tilt adjustment. I'm used to my chairs reclining so it feels a little awkward siting in a flat base and straight backrest. I feel like I'm sitting too forward or leaning forward slightly but is probably something I can get use to. Easy to put together and feels very sturdy. Plastic parts of chair are made from a really sturdy plastic, like playhouse plastic materials. Wheels roll around carpet easily. Mesh seems to be a strong material, though the mesh feels kind itchy on bare skin. Overall, I think this is a good chair to get if you're needing a tall chair for a good value and can sacrifice no backrest tilt.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 3, 2025
T
Verified Purchase
Tram
New York, US
★★★★★ 5
Excellent value for money!
Size: 934W-Z, Color: Black, Size: 934W-Z, Color: Black
I absolutely love this office chair! I needed a chair that could support my standing desk without sacrificing comfort, and this one completely exceeded my expectations. It's incredibly sturdy and durable, well-made, and the height adjustment is super convenient, making it easy to find the perfect fit. Even during long hours of work, the seat is comfortable, and the ergonomic design effectively reduces pressure on my back and legs. I love its clean, modern look—it fits my home office perfectly. Assembly was quick and easy, and for this price, the quality is absolutely fantastic!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on February 24, 2026

recommand products

the animals Ark poster
11.00
the war on drugs LIVE DRUGS poster
11.95
u2 No Line On The Horizon poster
11.95
kings of convenience Peace Or Love poster
14.00
incubus 8 poster
11.95