I've found a source for 70v Mega fuses in the UK 50A to 500A

[Ron-ski]

I'm updating my Victron install, and wanted to use 58v or 70v Mega fuses (I have T Class on the battery rack), which are very hard to find or rather expensive for Victron ones, when I came across some fuses on CPC Farnell, a company I've used from time to time over the years. The good thing is anybody can buy from them, and postage was free for the 7 fuses I purchased.

You may well need to filter the results to 70v on the left, as the link doesn't seem to quite work as expected.

https://cpc.farnell.com/c/electronic-electrical-components/fuses-circuit-protection/fuses-fuse-accessories/fuses/automotive-fuses?voltage-rating-vdc=70v

Here's a direct link to the 50a version.

https://cpc.farnell.com/multicomp-pro/mp011370/automotive-fuse-50a-70v-dc/dp/FF03538

There isn't a data sheet, or at least I couldn't find one. The fuses are marked Adler which appears to be a German fuse manufacture.

Data sheet is on page 42 of the catalogue here. The fuses range from 40A to 500A, all rated at 70V DC with a breaking capacity of 2.5kA

The QR code scans as 10.AEY.3100900.00,AD230331D080100355

It'd be interesting to know peoples thoughts on them.

 

[SeaGal]

Good find. I've used 70V mega fuses from Bimble Solar in the past, either Littelfuse or generic ones...

https://www.bimblesolar.com/extras/dc-breakers-fuses/dc-maxi-maxi

But the Farnell price is half that of the Bimble ones

It'd be interesting to know peoples thoughts on them.

Having said that, I have migrated to using NH class fuses in place of the Mega ones, which have similar high breaking rating as class T, but more readily available in UK (& europe) - and these Mersen ones cost only a pound more than the mega fuses.
https://www.bimblesolar.com/extras/dc-breakers-fuses/dc-fuse-disconnect/DC-fuse-50A-NH00

 

[Suijkerbuijk]

I use block fuce direct on the battery it self
Reason the arc of it go wrong.

The t-fuses fuce are the best.
But thare are some other solutions you can use.
In my case i use block fuse its a standard that is use on boats ( i use a boat)
It can easy find those fuse to replace.
And my systeem use only 12 volt .

Good info about fuse and wy you will not go for a mega fuse on lifepo4.

 

[Ron-ski]

I have a battery rack, each battery on the rack has a T Class fuse, and a large Zbeny circuit breaker, each battery feeds out to a busbar on the side of the rack, this busbar then feeds through another higher rated T class, and a higher rated breaker, the 120mm2 cables then connect to the Lynx Shunt, which then has two power in's connected to it which are converted to take fuses.

The Lynx Power in and the Lynx Distributor only take mega fuses, and in my case I only have the inverter and the MPPT SCC's connected to the Lynx Power In, the heavy duty battery protection is taken care by the T Class fuses on the battery rack.

In my opinion nobody should be fusing 48v LifoPO4 batteries with mega fuses, they simply don't have the breaking capacity (AIC rating).

 

[SeaGal]

I like your bus-bars with the extra connection for the balance leads - where did you get those from?

 

[Ron-ski]

The busbars are the flexible laminated copper type, I got them from Aliexpress.

The balance leads are actually connected to a separate component, I cut the original busbars in half and tapped a small thread into them. I've noticed recently on Andy's Off Grid Garage that some of the laminated busbars now come with a suitable thread already in them.

 

[Suijkerbuijk]

I have a battery rack, each battery on the rack has a T Class fuse, and a large Zbeny circuit breaker, each battery feeds out to a busbar on the side of the rack, this busbar then feeds through another higher rated T class, and a higher rated breaker, the 120mm2 cables then connect to the Lynx Shunt, which then has two power in's connected to it which are converted to take fuses.

The Lynx Power in and the Lynx Distributor only take mega fuses, and in my case I only have the inverter and the MPPT SCC's connected to the Lynx Power In, the heavy duty battery protection is taken care by the T Class fuses on the battery rack.

In my opinion nobody should be fusing 48v LifoPO4 batteries with mega fuses.

View attachment 228429

I agree .

If you have set like that with a diy systeem .
But if you have battery from a store and its just 12/24 volt systeem.
A t-fuses really over do it .
Well a block fuse is a lot cheaper and easy from a store .
And it can handel a big ark spark after burning the fuse.
Its more save than a mega fuse wat al lot of people use.

Mrbf fuse (Cube Fuse) can handel icc of 10.000a on 14 volt
5000a on 32 volts .

T-fuses do on icc 20.000a on 125 volts .

Mega fuse do only 2000a on 32volts.(So bad )

Nh00 Fuse are icc 120.000a on 250vdc (you have ac and dc model)
Really the best you can have for big systeems.

The mrbf fuse (Cube Fuse) are set direct on the battery terminal.
So even if you have 12/24 /48 battery pack made from battery from a store (not diy)
You can set one by one battery its own mrbf fuse .
If its blow that battery is disconnect from all the other ones.

Just my 2 cents about it.

 

[Brucey]

I have a battery rack, each battery on the rack has a T Class fuse, and a large Zbeny circuit breaker, each battery feeds out to a busbar on the side of the rack, this busbar then feeds through another higher rated T class, and a higher rated breaker, the 120mm2 cables then connect to the Lynx Shunt, which then has two power in's connected to it which are converted to take fuses.

The Lynx Power in and the Lynx Distributor only take mega fuses, and in my case I only have the inverter and the MPPT SCC's connected to the Lynx Power In, the heavy duty battery protection is taken care by the T Class fuses on the battery rack.

In my opinion nobody should be fusing 48v LifoPO4 batteries with mega fuses, they simply don't have the breaking capacity (AIC rating).

View attachment 228429

Very cool. So each battery drawer can slide out on the rails for maintenance?

 

[Luk88]

I agree .

If you have set like that with a diy systeem .
But if you have battery from a store and its just 12/24 volt systeem.
A t-fuses really over do it .
Well a block fuse is a lot cheaper and easy from a store .
And it can handel a big ark spark after burning the fuse.
Its more save than a mega fuse wat al lot of people use.

I'm not sure I understand the difference between a DIY and a store bought battery. Perhaps store-bought has more internal DC resistance therefore its capable of less short circuit current?

A fuse, regardles which you choose is only a small fraction of the cost of the system. Fuses is the last thing I'd try to save on. IMO Unless your battery is under 100AH in the EU NH is the only way (US equivalent is T-class I guess?).

With my 280Ah and 300Ah batteries I use 400A NH2 fuses that are capable if interrupting 25kA of DC short circuit (or 120kA AC).

View attachment 228429

Very nice setup, do you have a build thread with more pictures. I love to look for inspiration in systems like this.

 

[Suijkerbuijk]

I'm not sure I understand the difference between a DIY and a store bought battery. Perhaps store-bought has more internal DC resistance therefore its capable of less short circuit current?

A fuse, regardles which you choose is only a small fraction of the cost of the system. Fuses is the last thing I'd try to save on. IMO Unless your battery is under 100AH in the EU NH is the only way (US equivalent is T-class I guess?).

With my 280Ah and 300Ah batteries I use 400A NH2 fuses that are capable if interrupting 25kA of DC short circuit (or 120kA AC).



Very nice setup, do you have a build thread with more pictures. I love to look for inspiration in systems like this.

More like
Multi use 12 volt battery in series from a store.
Yes thare are 48volt battery from a store .
But the cheap one are more expensive than just thake a lot of 12volt models with high amps.

Sorry that i was not clear about it.

 

[NC_hydro]

The Lynx Power in and the Lynx Distributor only take mega fuses, and in my case I only have the inverter and the MPPT SCC's connected to the Lynx Power In, the heavy duty battery protection is taken care by the T Class fuses on the battery rack.

In my opinion nobody should be fusing 48v LifoPO4 batteries with mega fuses, they simply don't have the breaking capacity

Victron makes a Lynx Class T power in designed for class T fuses.

 

[Ron-ski]

Very cool. So each battery drawer can slide out on the rails for maintenance?

Yes they do, runners are good for 100KG, which as you can guess is about the weight of the battery. I designed and built the entire rack, welded it all together etc. It was designed for four batteries, currently I only have two, don't think I need more.

Very nice setup, do you have a build thread with more pictures. I love to look for inspiration in systems like this.

Yes, on another forum.

Ronski's Solar & battery DIY build with whole house backup

We already have 4kw of solar on our house roof, which was installed in December 2015, this is comprised of 16 panels witha Solaredge inverter and optimisers, and uses the best two roof's of the house. As some of you might be aware on the solar thread I've been looking into getting an additional...

forums.overclockers.co.uk

Victron makes a Lynx Class T power in designed for class T fuses.

They do indeed, but when I started designing and building my system in August 2022 they didn't (it went live in February 2023). If I did it now, knowing what I now know, I would do it differently, and would highly likely use DIY battery boxes as well.