FORM Fusion 10X4 4-Bank Marine Battery Charger, 40A Total (10A per Bank), 12V Smart Onboard Boat Charger for Lithium (LiFePO4), AGM, and Deep Cycle Batteries - Waterproof with Force Start
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Availability:
In Stock.
Arrives
Tuesday, Oct 28
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Features
- SET IT & FORGET IT MAINTENANCE MODE Enjoy worry-free charging with our automatic maintenance mode. Once your boat batteries are fully charged, this marine battery maintainer seamlessly switches to trickle modekeeping your lithium marine batteries topped off. Ideal for use as a marine battery tender or battery trickle charger for boat setups.
- ADVANCED WEATHERSHIELD WATERPROOF COATING Built to endure tough marine environments. Our onboard marine battery charger features WeatherShield Internal Coating and IP67 waterproofing, making it the perfect boat charger for saltwater, rain, or high-humidity conditions.
- IMPROVED BATTERY SENSING TECHNOLOGY Multi-bank charger optimized to enhance the lifespan & performance of your Lead Acid, AGM, Lithium or LiFeP04 Batteries. This 4 bank marine battery charger adjusts voltage and current automatically for safe, efficient charging. Use as a 12 volt marine lithium battery charger or multi-bank battery tender to extend battery life and avoid overcharging.
- UNMATCHED CUSTOMER SUPPORT FROM A FAMILY-RUN SMALL BUSINESS Backed by a 24-month warranty and USA-based tech support. Whether you're installing a 4 bank battery tender on a fishing boat or using this as an on board charger for boat storage, were here to help. Includes step-by-step videos and guides. Trusted by over 75,000 boaters who rely on our marine battery chargers for safety and peace of mind.
- FORCE START MODE FOR DEAD BATTERIES Recharge low-voltage or sleep-mode lithium marine batteries with a timed low-amp boost. Force Start mode safely revives dead cells and then switches to full charging automatically. Great for seasonal boats and as a trickle charger for boat battery or emergency marine battery trickle charger.
Brand: FORM
Color: Black
Product Dimensions: 9.8"D x 10.9"W x 2.4"H
Output Voltage: 12 Volts (DC)
Specification Met: CEC, DOE, FCC
Product Dimensions: 9.8 x 10.9 x 2.4 inches
Item Weight: 16.94 pounds
Date First Available: December 30, 2024
Manufacturer: FORM
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Tuesday, Oct 28
Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Top Amazon Reviews
Works great
Reviewed in the United States on July 22, 2025 by William Bush
I think the FORM Fusion 10X4 is a highly specific and capable piece of equipment designed for complex power systems. The core function I appreciate is its ability to deliver 40A total charging power, split across four distinct banks at 10A each. This architecture is vital because it allows me to charge four separate 12V batteries individually, even if they are wired in series to create a higher voltage system, such as 48V for a golf cart. This individual bank control ensures a custom charge for each battery, preventing charging issues that arise from one weak battery in a series. I like that the unit is built to be resilient. It features a weather-resistant design that makes it a solid choice for onboard marine installation in salty environments. Furthermore, once a battery reaches a full charge, the unit automatically transitions into a trickle mode, which means I don't have to manually monitor the process. I also like the inclusion of a "Force Start" mode, intended to revive batteries that have dipped too low, although it is important to know that it will fail to initiate on batteries with extremely low voltage, such as 1V. A few technical facts stand out about this charger. It is built quite heavily; I understand the unit weighs approximately 15 pounds 15.6 ounces. The premium cost reflects its specialized features and robust construction. I observe that the charger supports multiple battery types, including lithium, AGM, and deep cycle. It is reassuring to know that the unit comes with a generous 5 year warranty. Like someone else said, I found that simply unplugging and re-plugging the unit can reset it and restore full charging function across all four banks if you have any issues. In other words, use the most basic form of troubleshooting in existence, unplug it and plug it back in. Installing it is about as easy as installing any battery charger. There's really nothing that would make installation all that difficult or complicated. I've been using it for about 3 months now, and it is still working the same as the day I took it out of the box.
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Reviewed in the United States on October 9, 2025 by C
I installed this FORM Fusion 10X4 charger aboard my boat, and it’s been a solid upgrade. The fact that it charges four batteries individually (10A each, for a total of 40A) is incredibly convenient. It keeps everything charged and healthy without needing bulky external gear. Plus, once each battery hits full, this unit automatically switches to trickle mode, so you don’t have to babysit your batteries. Another thing I really like is how it’s built for salty environments. The weather-resistant design feels trustworthy when I’m out on the water. And “Force Start” mode? A lifesaver when a battery dips too low, so you basically give it a quick boost to get things rolling again. That said, it’s not exactly cheap and it’s definitely a premium marine charger. Also, while I get peace of mind knowing it’s waterproof and smart enough to handle multiple battery types (lithium, AGM, deep cycle), some of this might be overkill for casual use or smaller setups. Bottom Line: If you’re running a bigger rig or marine system and need a reliable, onboard charger that’s smart and weather-ready, this is a great choice, but just expect to invest a bit more for those features.
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Reviewed in the United States on September 9, 2025 by Cassablanca
This has been the perfect solution to my golf cart charging issues. My Yamaha GC is all electric 48VDC. I did not want to put in one of those all-in-one 48v lifepo4 batteries that cost over a thousand dollars, I wanted to use my four 12vdc 100 amp lithium batteries I had. This charger is exactly what is needed if you want to use separate 12v batteries, especially lithium batteries in series to get up to 48 volts. This FORM Fusion 10X4 4-Bank Marine Battery Charger, 40A Total (10A per Bank) lets you keep all four batteries wired in series, yet charge each battery individually for that custom charge each battery needs. Over the past month, this charger has performed really well keeping my Golf Cart ready to go at any given moment! I have never trusted the 48v chargers with separate batteries because they can not compensate for one bad battery which can lead to disastrous results with charging. This charger is quite heavy, so I'm hoping that's because it's filled with good quality copper wiring and not just a weighted steel plate at the bottom. Form & function is wonderful and it was easily mounted for quick connections!
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Reviewed in the United States on August 26, 2025 by John J.
Really nice charger that can withstand the elements. Fully sealed against water and dust intrusion yet it can dissipate about 100 watts of heat (claimed 84% efficiency or better at the max 600 watt rating) without resorting to cooling fins/ridges on the outside of the case. Each of the four connections is individually controlled for both battery chemistry and charge status. Each connection even has its own button to control the functions so it's really easy to use and you're never confused about which output is selected. It is quite big and heavy, coming in at over 12lbs just for the unit itself and then another couple of pounds for all of the cables. Unfortunately none of the cables are able to be disconnected. There's definitely secure waterproof power connectors out there, so I do wish they'd made that upgrade to the unit for people that might not need all 4 connections all the time. Cables are really nice though, with inline fuse holders with 15amp automotive blade fuses on both the positive and negative wires about 6 inches from each connector. Functions well to deliver a good charge to even mixed and matched battery banks.
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Reviewed in the United States on July 31, 2025 by Dave