

🔌 Power up with confidence—safety that’s always visible, reliable, and built to last!
Blue Sea Systems Terminal Fuses deliver industry-leading 200 Amp current protection at up to 58V DC, featuring a visible blown fuse indicator and a 10,000 AIC rating that meets ABYC standards. Ignition protected and IP66 rated, these fuses are engineered for marine and high-demand battery bank applications, ensuring unmatched safety and peace of mind when paired with compatible Blue Sea fuse blocks.





| AC Adapter Current | 200 Amps |
| ASIN | B001E4F3J4 |
| Best Sellers Rank | #3,868 in Automotive ( See Top 100 in Automotive ) #23 in Automotive Fuses #186 in Fuses |
| Brand | Blue Sea Systems |
| Brand Name | Blue Sea Systems |
| Color | blue/sea |
| Current Rating | 200 Amps |
| Customer Reviews | 4.8 4.8 out of 5 stars (1,259) |
| Date First Available | October 1, 2001 |
| Fishing Technique | Any |
| Included Components | Fuse |
| Item Dimensions LxWxH | 4 x 3 x 1 inches |
| Item Package Dimensions L x W x H | 3.11 x 1.46 x 0.87 inches |
| Item Weight | 0.05 Pounds |
| Item dimensions L x W x H | 4 x 3 x 1 inches |
| Manufacturer | Blue Sea Systems |
| Material | Plastic |
| Model Name | MRBF |
| Mounting Type | Through-Hole Mount |
| Number of Items | 1 |
| Package Weight | 0.28 Kilograms |
| Part Number | 5187 |
| Size | 200 Amp |
| Specification Met | Abyc |
| Style | 200a |
| Suggested Users | mens |
| UPC | 632085051877 |
| Unit Count | 1.0 Count |
| Voltage | 58 Volts |
| Warranty Description | Manufacturer Limited |
B**L
Blew within seconds! Good quality
Worked great. Blew the fuse while I was installing it!
F**D
DIYers for lithium battery builds remember it’s all about the AIC!!
This is a great product. Many complain about the price. But it’s a critical safety measure for life and property safety so is $80 for a fuse and holder worth getting versus some cheap Chinese thing that if the absolute worst happens (internal battery failure/ thermal runaway conditions) you want to bet your life and/or home on? Yes we have other safety devices, BMSs etc…but if you don’t plan for the worst (highly unlikely) scenario then you’re a gambler. IMHO Remember the AIC rating is super important in fuses. That’s what going to prevent an arc from forming and allowing massive current to flow not to mention it can act as an ignition source for the hydrogen gas LifePo4 batteries vent. No arc less chance of fire. With these terminal fuses keep in mind the AIC drops as your pack voltage goes up from 12v to 24/48v. I build both. The picture is of a 16s 48v LFP pack. The terminal fuse is 3rd or 4th in line of safety measures right from the start. It doesn’t have the AIC @48v to handle a serious failure, hence it’s just a part of the safety system. #1 a must - class T fuse with an AIC rating of at least 20k connected directly to the battery main positive. If you can find a 50K AIC even better. #2 BMS - great when they work but even the highest quality ones can fail you. Not something to depend on solely. #3 DC breaker - this is a cheap junk Chinese breaker that I have zero trust in. For me it’s merely a cutoff switch to the terminals. It came as part of the metal enclosure kit. I can’t find a quality breaker that fits in there unfortunately. #4 These terminal fuses. Fan to vent gas from the case with a VOC sensor I built to alert me if hydrogen gas is being vented. Also added temperature sensors on various parts of the metal case to alert me (also connected to a microcontroller I built). I changed the default settings on the BMS for short circuit amps to a much much lower numbers same with temperature settings. Since my packs pull very minuscule amount of power I’ll never come close to the 100a the bms/pack is rated for. From there it’s again a series of disconnect switches, class T fuses to the inverter. For my “worst case scenario nothing stopped an internal failure” I have CellBlockEX pellets to pour on top of the box. I also have a Lifepo4 designed fire extinguisher (yes they are different due to the LFP chemistry and the ability of LFP batteries to self ignite since they produce all the elements needed for fire on their own. I also have canisters of Stat-X First Responder Aerosol Fire Suppression to toss at a fire and run away. Is this all overkill many would say yes. I would ask that same question to them if they skimped out on parts and lost property or god forbid life. I bet I would get a different answer then. Be safe folks. While super rare, you better have measures in place to deal with the super rare possibilities. Or like I said maybe you’re a gambler. Up to you what you need to feel safe and sleep at night. Class T fuses need to be in place sometimes a lot depends on your setup. Blue sea systems gets an A+ from me. I know you are paying more for the name but I’m ok with it. YMMV! Happy DIYing! Free energy from the sun!!
U**C
Quality you can depend on.
It meets the expectations on both quality of manufacturing and functionality. Its a Bussmann. Enough said .
J**S
The Best Option For RV Batteries
The best way to keep your battery safe is to buy this style of fuse. Just say'n.
A**R
Worth The Extra $
Top quality fuses. Since you can't test a fuse without destroying it, I always buy those from made by reputable companies rather than taking chances on unknown brands. It is worth paying for quality.
R**S
Lintimed to 14V
Looks like good quality fuse. Hope it works.
D**E
Exactly as described. Very courteous. Highly recommended seller.
Exactly as described. Very courteous. Highly recommended seller.
N**V
Nice
Good job
P**.
Lo ocupo para la línea de ventilador eléctrico de mersedez benz lo único que costó modificar poco por que viene un poco más grande de tamaño pero todo bien
K**S
Still going strong
T**E
Quality fuse, received as described. Thank you.
M**Y
Tested out 280ah battery with 2000w inverter. No issues with Mrbf fuse.
M**T
Neat arrangement having fuse mounted directly to battery terminal - pity about the price , but then again what price against short circuit or fire.
Trustpilot
Hace 2 semanas
Hace 2 semanas