Fusing Of A Different Sort: MRBF Fuses

The Audi required a compact fusing solution under the hood. I didn't want to deal with trying to run a 0AWG lug and cable at a 90 degree bend so I looked to the marine industry for a MRBF fuse terminal.
This video goes over what it is and how it works.
MRBF Fuse holder: www.amazon.com...
MRBF Fuses: www.amazon.com...

[@WizzRacing]

I use these all the time. As you can stack them..You can buy 2 of the Two Pole versions. Stack them and run 4 separate fuse types from one connection point. No 4 point connection buss bars that cost $100.00+ each. And if you have an issue. You know where to look. Not to mention they take up very little space. All that is needed. Is to install a Disconnect. If you need to service the system...

[@pooladdict2472]

Thanks for the video! I just put a dual one of these in my current build, one for alt and for amp power, looks so clean and neat! Expensive but anything blue sea is, marine grade isn’t cheap.

[@BatdogGarage]

No problem, man. If it helps me I’m sure it’ll help others.

[@Mike-01234]

Thanks for the video I got one of these off Amazon and showed up in a bag with no instructions. This is perfect for my off grid solar project in my shed.

[@cwarren83]

Welp, if I ever need a compact fuse I know what I'm going with now!!!

[@Jukebox_Janie]

Thank goodness 😅 I thought I’d never find a video explaining this fuse, great job at explaining this

[@wadehensley5005]

Looks like it also makes routing cable a bit easier since you don't have to account for the bulky anl holders. Very nice

[@BatdogGarage]

For sure. That's a tight area and it's difficult to package an ANL (or mini ANL) fuse holder in there in a way that the fuse is easy to replace. This is compact, allows for much nicer cable routing, and is easy to service.

[@sbrownproductions]

I want to use these - but my battery terminal is all 5/16 stud, not 3/8 - tempted to try a large washer and see if it works…

[@scose]

you can use the M8 size of the Littelfuse ZCASE SMZ. It's a similar idea, but the fuses are not compatible.

[@SeriousSchitt]

I've just spent hundreds of dollars buying up all those other fuse types, circuit breakers etc, only to discover these. I love they way the fuse is right on your terminal, however, I'm just questioning if only one holder with one 300A is the way to go? This means you'd have to have one hell of a thick cable from your battery terminal to your 'next' fuse terminal block (which would probably be a Blue Sea Standard Blade ATO/ATC Fuse Block) and that's only rated at 100 amps which would mean if you were wire up 10, 15A circuits in it, you'd overload it! Would it not be better to run several of these at lesser amps (100A a piece) in my case, one to feed the fuse block (100A) one to feed the electric hydraulic tipper trailer (100A) one to, perhaps, feed another fuse block (100A) etc? Thanks.

[@BatdogGarage]

There's a run of 0AWG that goes to the back of the car and feeds a fused power distribution panel with mini ANL fuses. This was the perfect solution for the application where it was used. Your application may require a different setup.

[@SeriousSchitt]

@@BatdogGarage After a bit more research and some thought it actually sounds like the ticket, I’m going to do something similar myself. Thanks for the video.

[@JoshuaCorley]

I love these fuses been using them on bus bars running bus bar on top of the fuse so complete protection

[@BatdogGarage]

They really are handy. I figured I'd share them because they're not car audio specific products and many people in the car audio world don't know about them.

[@JoshuaCorley]

@@BatdogGarage good work mate

[@extrememiami]

I use these fuses the most of any BUT they have less time to deal with voltage spikes than an ANL fuse. These are fast blow. They still can deal with a split second of higher voltage but they blow faster than a slow blow or T timed or TT fuse. For reference 2ga wire would be 150A fuse, 0 ga for 300 Amps. If it's for a starter only wire I go with a bit higher fuse to deal with starting ingress voltage spike. Most people say you don't fuse a starting wire but in my location for new build boats they now require the cable to be fuses. That's why I watched this video. Trying to see if 300A terminal fuse will still blow starting. I see people say 200-250A for ANL fuses but they blow slower than these. I have 225A fuses so I'll use them for now and carry some spare 300 Amp blocks too. A starter can draw 550 amps for a fraction of a second sometimes, I guess I'll find out if the fuse blows from that quick of a surge or now. Anyone else use these for starter cable? Or main engine line w starter on it?

[@Mastermindyoung14]

Can the starter wire handle 500a continuous? If not, I wouldn't fuse it higher

[@extrememiami]

@Mastermindyoung14 no wire in any car ever build would handle 500a. I don't even know if the powerline to my house can handle 500 amps. I was asking about fusing a starter because no manufacturer fuses the starter cable. They are a unique senerio where they receive 200 Amps for like 1 microsecond so you'd want to put in a fuse that has a break time of over that period and they time frames for these block fuses are not listed or we'll known, just that it's faster than ANL fuses. Starters aren't fused because the amperage they produce for that first microsecond is inconsistent and depends on a huge number of factors like engine piston size, current battery level, alternator size, compression ratio, gearing, current temperature outside, fuel injection type, etc. It's not a simple answer like fuse it for 500 amps. The block fuses only even go up to 300 I think. My question really was will this fuse type allow a 2 microsecond spike or is it super fast.

[@BioSteve]

Ive been running them for the last 4-5 years and i love them. Somewhat pricey though compared to ANL fuses. You can also use bolts made out of plastic or special nuts that are made out of plastic if you are running a metal bolt. In germany we call them CF8 or Littelfuse.

[@someusername121]

I've tried running plastic bolts (actually fiberglass) and my experience is they're not strong enough to properly clamp down a big crimp on connector. They'll loosen and stretch. My strategy was to use a plastic washer to isolate the head of the bolt and then put some headshrink around the shank of the bolt where it passes through the bus bar. The bolt and nut then become fused.

[@yenyeoh735]

Thanks for the video. I’m learning about the electrical system for my up coming van conversion build and your video was very informative. 1 Question 🙋🏻‍♀️ however, if the terminal size on the battery is 1/2” M14, how would you make it fit?

[@BatdogGarage]

Drill the opening. I had to trim the tab on this unit when I installed it in the Audi.

[@John-yb2xp]

Cuz I was inverted 😂 ✈️🔁

[@Rodman8500]

that is pretty slick ,never seen that before .by the way i really like all the videos ,so much information and technique and your approach to car audio is very different from the rest. keep it up!

[@BatdogGarage]

Thanks, man. I sometimes get grief for video length, but I've found that people will skip through a short video just like they will a longer one. The trick is that the short video doesn't help those that need things explained so they're easier to understand. So...I don't cater to those with short attention spans. If you want some in-depth info/how-to I'll typically have that.

[@LivingonBikes]

You are an excellent teacher

[@martehoudesheldt5885]

looks good but what is the volt drop under 3/4 or more? load heating at same load?? will they survive after a full 24 hrs at said load?

[@digitalbilly]

thanks for the video so mrbf and cbbf exact same? just one is made by cooper?

[@andufuse]

The MRBF fuse how to waterproof?