UK Fiat Scudo ( Mini Van ) system.

[BigGElmo]

Hi , this is my ongoing Solar LiFePO4 system installed in my 2008 Fiat Scudo van.
The spec is....
150w monocrystalline panel.
Renogy Rover 12v 20a MPPT charge controller.
PV Isolator
12v 90ah VariCore self build battery in a plastic case.
Xiaoxiang 100a smart BMS.

 

[mikefitz]

Comments.

The inverter you have fitted costs in the UK £37 Inc taxes and delivery , about $50. I have serious doubts regarding its performance.

The 300 amp breaker is not a reliable type. Replace with a fuse at the battery end of the feed cable.

You need fuses at the battery for any red wires connected to the positive terminal.
No way can the BMS power the inverter at its rated 3000 watts. Typical continious current from a cell is 1C, 90 amps. Consider a smaller inverter or if there is a need for one at all for your style of camping.

If you can identify what you need to power in the van we may be able to advise a more efficient technique than a 3000 watt Inverter.

Mike

 

[downhiller]

I don't know nearly as much as mr fitz, but I second his comments, that inverter is garbage, and reviews of those breakers suggest they tend to trip over 100A.

mike, do you know of any similar breakers in the UK that ARE reliable/accurate, or would you always use fuses instead? (And do fuses vary hugely in their reliability as well, or can you pretty much count on a 300A fuse to work as advertised, wherever they're bought from?)

Thanks!

 

[BigGElmo]

Thanks for the comments guys, the old inverter has gone and been replaced with a 1000w pure sine wave inverter, the breaker has been down rated to an 80amp one and this has been tested and trips at 88amps.

 

[BigGElmo]

The 1kw pure sine wave inverter is a great addition and is used to power a 650w travel kettle and a small George Foreman grille which draws 800w 62a for 5 mins to reach maximum cooking temperature from a cold start.......obviously these are not used at the same time.

 

[dirt diggler]

I swapped my resetable type breakers for fuses on anything solar cos i managed to melt 3 of those cheap breakers in 2 months, they seem to work OK on anything else though ? wierd , i hade one refuse to reset after a manual trip (to work on the system), and 2 that refused to trip when tested and had melted the contacts (which are way too small for the loads they are sposed to carry IMHO) , all the other breakers i upgraded to bussmann breakers (usually sold under the Bluesea brand) made in ireland but strangly one came from ireland one come from the US ???

 

[MattiFin]

I don't know nearly as much as mr fitz, but I second his comments, that inverter is garbage, and reviews of those breakers suggest they tend to trip over 100A.

mike, do you know of any similar breakers in the UK that ARE reliable/accurate, or would you always use fuses instead? (And do fuses vary hugely in their reliability as well, or can you pretty much count on a 300A fuse to work as advertised, wherever they're bought from?)

Thanks!

Fuses are not created equal, some struggle to extinquish the internal arc with high currents and/or explode. 12 volt systems are more forgiving than 24 or 48v but there is still some risks involved with the huge current capacity of lithium batteries.

NH fuses are cheap and plentifull in Europe and have good breaking capacity. Downside is that they are sort of bulky.

 

[mikefitz]

Ideally class T fuses should be used as the main 'master' fuse at the battery. Perhaps acceptable is a MRBF fuse at 12v. Use a Bluesea MRBF fuse and holder. Quality DC breakers are not easy to find in the UK, Bluesea, (Bussman) can be found but are expensive.

 

[downhiller]

I don't really know where to find anything that either of you just said ?

Are these suitable: https://www.12voltplanet.co.uk/mega-link-fuses.html

 

[MattiFin]

Ideally class T fuses should be used as the main 'master' fuse at the battery. Perhaps acceptable is a MRBF fuse at 12v. Use a Bluesea MRBF fuse and holder. Quality DC breakers are not easy to find in the UK, Bluesea, (Bussman) can be found but are expensive.

NH fuse is like class T on steroids and easily available in Europe from almost any electrical distributor.
Siba NH1 440v dc 25kA breaking capacity vs class T 125v dc 20kA

 

[downhiller]

440V... 125V... Surely the volts are important aren't they? I'm looking for 12V fuses, am I not?

 

[mikefitz]

A lithium battery can deliver, ( if the BMS fails), huge current, several thousand amps into a fault. This will melt cable and is a fire risk.
The fuse must be designed to break the arc. When a fuse fails you have molten metal, with high current possibility the arc is maintained, ( as in arc welding). The better fuse designes supress this and ensures the current flow is broken.
An automotive 'midi/mega' fuse has a 2000 amp withstand, a MRBF 10000 amps at 12v, and a class T or equivalent , 20000 amps.

NH fuse types

NH Fuses Explained

Swe-Check sell NH fuses from size 000 to size 4A. Available in all speeds; gL, gG, aM, gR, aR, gS & gPV. We also sell NH fuse extractors - fuse pullers. Low prices. Fast service.

www.swe-check.com.au

MRBF fuse with holder,

Blue Sea Terminal Fuse Block 1 Stud (8-25191)

Free Delivery | Low Prices | Great Range. Blue Sea Terminal Fuse Block 1 Stud

www.cactusnav.com

MI,E