Victron Multiplus and MPII Feedback Request

[MAX Burner]

What a fantastic upgrade!  We'll be doing this over the fall in prep for our JAN Q-site outing....  Excited to see how this shakes out, @jd1923!

Will you disable the PD converter/charger function and use the MPII charger function?  Just curious...

Edited July 25 by MAX Burner

[katanapilot]

1 hour ago, MAX Burner said:

What a fantastic upgrade!  We'll be doing this over the fall in prep for our JAN Q-site outing....  Excited to see how this shakes out, @jd1923!

Will you disable the PD converter/charger function and use the MPII charger function?  Just curious...

Why would you not just remove the PD charger completely?  The Victron is so much more capable.  For example - you can limit/inhibit charging based on battery temperature.  So if you have lithium batteries with no heater blankets, you can prevent charging at low temperatures. 

[Mike and Carol]

3 hours ago, katanapilot said:

Why would you not just remove the PD charger completely?  The Victron is so much more capable.  For example - you can limit/inhibit charging based on battery temperature.  So if you have lithium batteries with no heater blankets, you can prevent charging at low temperatures. 

Seems like it would be easiest to just turn the PD charger off.  Mine is off most of the time, solar charging  has been enough in most cases.

[jd1923]

5 hours ago, MAX Burner said:

What a fantastic upgrade!  We'll be doing this over the fall in prep for our JAN Q-site outing....  Excited to see how this shakes out, @jd1923!

Will you disable the PD converter/charger function and use the MPII charger function?  Just curious...

I will disconnect for sure. It is designed for lead-acid and to run LiFePO4 you need the upgraded model as Chris @Wayfinder had installed. I will use that end fuse for the microwave, now our Emeril Air Fryer, to separate it from all the 110V outlets.

Wondering if it's worth just leaving there as a backup, in case of Victron MP2 failure. Charging with a LA pattern is better than nothing. But with solar, I will likely pull it to save 2 LBS! That spot then becomes a vent. 🤣  

[jd1923]

Oh, it finally got here! I've done a lot of prep work but could not start many tasks until I could see it in person. It does have the dual DC terminals, so no extra buses for me. Each will have 12VDC in from the batteries and 12VDC out to the Oliver buses, not extra complications.

The beast is heavy and VERY much top heavy. The center of weight is 8" from the top on a 22.5" chassis. I need to work my mounting platform accordingly. I also received the VE.Bus Smart Dongle which is the Bluetooth control interface. No Cerbo and no screen display for me, at least for now.

I'm working this week and next, so this will take a while. Like I mentioned before, I will start a build thread after I get a bit done. It's going to be fun!  

[jd1923]

@rideadeuce Hey Mike, what did you use as a fuse or circuit breaker for connecting the positive battery cable to your MP2?

I believe a 300A DC fuse is required. I bought a breaker, but it looks like junk and so do all the ones I see online. Thank you.

Edited August 4 by jd1923

[rideadeuce]

3 hours ago, jd1923 said:

@rideadeuce Hey Mike, what did you use as a fuse or circuit breaker for connecting the positive battery cable to your MP2?

I believe a 300A DC fuse is required. I bought a breaker, but it looks like junk and so do all the ones I see online. Thank you.

 

The Epoch 460 marine battery I have has a 500amp built in T-fuse plus my OEM build had a 300amp T-fuse directly outside the battery bay so I called it good. I did buy some 180 amp MRBF fuses for the terminal but ended up returning them. If you need any kind of fuses, I recommend Blueseas. 

Excerpt from Panbo.com

“ Let’s get one exciting thing out early. These batteries contain a 500 amp fuse under the cover of the battery, just before the positive post of the battery. The fuse Epoch uses is from the EV market and carries an amp interrupt capability (AIC) of 50,000 amps. That rating means that with up to 50,000 amps flowing through the fuse, it will still successfully trip to an open and safe condition.

ABYC’s electrical safety standards require a fuse with a 20,000 amp AIC. Before disassembling this battery, I’d never seen a class T rated above 20ka AIC. Thus far the only gripes I have about the fuse are that it appears difficult to source a replacement — which I’m hoping Epoch can help with by selling replacements — and I think Epoch should label the outside of the battery to warn there’s a fuse inside. That way, a boat owner won’t find themselves stumped if they accidentally trip the fuse.

But, make no mistake this fuse is a really big deal and a really good thing. By placing a high AIC fuse inside the battery, installers are now relieved of the obligation to place a physically large class T fuse as close to the batteries as possible. The combination of fuse holder size and thick cables can make this a challenge. Knowing the fuse is inside the battery, an MRBF post-top fuse holder can now be safely used. Thus, the entire system is protected via the internal fuse, and the wire off the battery is protected by an appropriately sized MRBF on the positive terminal.”

Cheers, 

Mike

 

 

 

[jd1923]

5 hours ago, rideadeuce said:

Thus far the only gripes I have about the fuse are that it appears difficult to source a replacement

I wanted a breaker at the batteries so I could have the dual-purpose of an ON/OFF switch but believe I will source a Class T fuse instead. It is the safest for our new expensive HW. I'll go back to disconnecting ground when I need the batteries disconnected, like I have all my life! (only when servicing) We don't store ours and I'm working to minimize connections/buses on my design.

I found a Blue Seas holder. Not seeing a waterproof model though, which is hard to understand from Blue Seas, and I want mine right on top of the batteries. They all have a plastic snap-fit case with open ends for the cables.

They sell Class-T fuses made in Mexico. I found this company South Bend Components. You should be able to buy any Class T fuse though before your pic, I have not seen a 500A fuse. Amazon.com: South Bend Components 300A Class T Fast Blow Fuse (2-pack) : Automotive

OTT installed a 250A Blue Seas ANL fuse in our hull for the 2KW Xantrex inverter. You would need a 500A fuse for the rate 5500W peak power of the MP2 but who would ever hit that number inn normal use. Good to have a backup for sure. I'll buy a 2-pack. The 300A handles 3000W with 20% margin and for the same money they have 350A and a 400A for $5 less. Maybe I should get the 400A since it can hold up to 4800W. Not positive on all the logic here.

You should have a backup for the OTT installed 300A Class T fuse as this will blow first and likely the built-in 500A fuses would never, unless the 300A fuse fails closed which it should not at the 20,000 amp AIC rating.

[rideadeuce]

I agree with everything you said above. My batteries have an on the battery ON/OFF switch and through the comm port extended remotely installed in the pantry. If you wanted a cutoff switch I would use a Blueseas switch next to the ANL fuse you already have installed. 

Amazon link:  https://a.co/d/3ahngGe

 

Edited August 5 by rideadeuce

[jd1923]

Thanks Mike! Not using the OEM fuse holder, given it’s ANL and mounted in a ridiculous  location!

Just checked the MP2 manual and it states using a 400A fuse. Just purchase this fuse: https://a.co/d/4D4H2ok and this holder: https://a.co/d/0015iEi

I went with the “ignition protected” unit, not that an Oliver has an ignition but for $20 more you get a snap-closing case and heavy weight terminals.

@rideadeuce given my research, you should get a 400A Class T fuse as a backup if your 300A ever blows. The 500s in the Epoch batteries will never blow given a lower rated fuse closer to the load. Thx

[Ronbrink]

On 7/24/2024 at 3:23 PM, jd1923 said:

The Florida company Inverter Supply

Which model did you get?  I see two at $997, models ending in 110 and 120.

[jd1923]

5 hours ago, Ronbrink said:

Which model did you get?  I see two at $997, models ending in 110 and 120.

Correct, I had the same question. A member of the Victron Community Forum posted, 110 is manufactured in Malaysia, the 120 from India, otherwise the same model. I purchased the 120 and it does state made in India.

[rideadeuce]

On 8/4/2024 at 12:22 PM, jd1923 said:

Maybe I should get the 400A since it can hold up to 4800W.

The problem with that is, I believe, the 4/0 cabling is only rated to about 250 amp. I was mistaken about mine being a 300 amp ANL it is 250 amp from the factory. So I think I should stick with the lower amp fuse but definitely may look into changing from ANL to T class for the higher AIC. Not sure about beefing up the cables. 

[jd1923]

2 hours ago, rideadeuce said:

The problem with that is, I believe, the 4/0 cabling is only rated to about 250 amp.

I'm not seeing 250A for this application. Keep in mind the 4/0 welding cable is rated at 600V and of course we're at 12V. OTT had installed a 250 ANL fuse in ours for the 2KW Xantrex and I think you would blow the 250 soon enough running the MP2 at capacity.

I was going with a 300A until I found this. See PDF page 16 of the Victron MP2 manual (where they have written a spec for a 400A fuse on 1/0 cable for short runs):

There is much confusing and differing information out there! You got me thinking 300A would have been a better choice (but why does Victron write 400A for the12V model?).

See this from What Is The Ampacity Of 4/0 Welding Cable? (nassaunationalcable.com) where they state: "According to IEWC, the ampacity of 4/0 welding cable for 600-volt in-line applications is 315 Amps when the copper temperature is 60 C, and the ambient temperature is 40 C." They do not state for how many feet of cable.

Also, tables like this are everywhere online, stating the 4/0 Welding cables handles 600A:

Also, does the Victron table mean running two (2) 1/0 cables, doubling up the cable? Why would they do that? BTW the cross-sectional area of two (2) 1/0 cables is basically the same as a 4/0 cable. 

Edited August 13 by jd1923

[rideadeuce]

That is reassuring. Great research, as always! I think I will order a 400 amp ANL for now and maybe switch to T class when I catch up a little. I do wish I had more of an electrical education. Learning as I go, thanks to the forum members many times. Thanks! Enjoy seeing your take on the install. 

Edited August 13 by rideadeuce

[mossemi]

9 hours ago, jd1923 said:

Also, does the Victron table mean running two (2) 1/0 cables, doubling up the cable? Why would they do that? BTW the cross-sectional area of two (2) 1/0 cables is basically the same as a 4/0 cable. 

I think a lot of Victron's thinking is based upon their marine market.  I don’t remember if Overland used 2 x 1/0 or 2 x 2/0 cables with the first MP 3000 installation in a LE2, but I’m sure he doubled the cables.  He installed the MP under the front dinette seat so the cable run was a little longer and it was easier to run below the floor.

Mossey

[jd1923]

10 hours ago, rideadeuce said:

😂I think I will order a 400 amp ANL for now and maybe switch to T class when I catch up a little.

Thank you, Mike! Or perhaps consider a 350A ANL fuse if you want to error on the side of caution (350Ax12V=4200W). I'm not sure why they spec a 400A fuse (4800W)! This is actually double the stated 2400W continuous power output of the MP2. Peak at 2x continuous seems high to me but Victron engineers should know. Certainly, a 250A fuse is not enough for the power needs of the MP2! I also wonder if the Class-T is needed in our application? You already have Class-T built into your batteries which is the most expensive component of your installation.

I took a couple courses in electrical engineering, but like y'all, I learned what I know from doing, decades working on old cars, RVs and homes. And we all learn from forums and the OTT Forum has amazing members, helpful, knowledgeable and super responsive! When researching online, I often add the word 'forum' to the end of a keyword search. I join a new forum every time I purchase a new project vehicle!

I learned most of this subject from another online forum, when building a from scratch solar/inverter setup in a Bigfoot RV. On the BOCI forum, I became friends with an EE who worked his installation prior to mine and was there to help, every step of the way!

Our AZ home came with one 200A panel. Over the years, I've added 4 subpanels! The first was 60A for the spa, running 100' cable from garage through the attic and down. Then 100A in an outbuilding for 220V compressor and woodworking tools. 60A for the kitchen with separate 20A breakers for fridge and extra oven (while running natural gas there for a new cooktop). I removed the electric cooktop, so I thought to use the original 8-3 cabling for having a better powered kitchen! Chris loves it, as she can run two ovens and the microwave without worries and the fridge does not overheat in the summer months anymore (with a 10 AWG feed vs 14 AWG wiring on a 15A circuit along with other wall outlets). Most recently we added a 60A panel for a new (used) Tuff Shed with 30A RV outlet. We trenched the side yard and ran 125 FT of 8-3 direct burial cable. Just some ideas to consider! 🤣

Restoration and enhancement projects have been my lifelong hobby, as I can tell so many here have as well. We have a huge amount of collective tacit knowledge in the regulars here. I've been often asked, "How do you know how to do that?" My usual answer is, "I don't know, but I will when I'm finished."

I was able to work a quick effective project here, starting from 3 Oliver owners who came before and posted. I posted my project in great detail for those who sooner or later will have this on their Wishlist. I did not have this on my radar at all, thinking the LiFePO4 investment was too much $$$, until you Mike made it look reasonable and relatively simple! Thank you for that. 

And thank you @mossemi for your insight here and often! I can see how running 1/0 cables, even doubled, would be an easier installation in boat hulls then the bulky 4/0. Perhaps also cheaper when puchasing large spools.