Mid Point Fusing

[Samro]

I have a question on Mid Point Fusing.

I have changed my plans to include a second lithium battery under the passengers seat to beef up the capacity/reduce battery load. This is due to a large inverter in the specification together with other normal loads.

What are peoples views on whether or not it is necessary to fuse the battery at the mid point (In red) with half of the rating of the main fuse (in green).

Usually paralleled batteries would live in a dedicated battery compartment directly next to one another and not two batteries under two separate seats, so this seems necessary but each battery is a Renogy 100A Smart battery, each with a continuous supply capacity of 100A with an integrated BMS. I am guessing that the BMS would cut power in in the event of a problem, but unsure on how much this can be relied upon?

I'd like to limit the fuses as much as possible without compromising on safety, but to my mind these are required. Views please?

 

[Dellmassive]

They need to both be fused.

If there is ANY chance of a short to ground then the fuse is the last safety device.

Both battery POS terminals need fusing.... So both sides of the interlink.

This is to act as a protective device in the event of a catastrophic failure... Ie Road traffic collision..

So yes... Fuse both sides of the interlink.

 

[Samro]

They need to both be fused.

If there is ANY chance of a short to ground then the fuse is the last safety device.

Both battery POS terminals need fusing.... So both sides of the interlink.

This is to act as a protective device in the event of a catastrophic failure... Ie Road traffic collision..

So yes... Fuse both sides of the interlink.

Thanks @Dellmassive.

I think I have just simplified my install by ordering this monster to live under the passenger seat:

12V 170Ah Lithium-Iron Phosphate Battery

The Renogy 12V 170AH Lithium-Iron Phosphate Battery is perfect for deep-cycle applications including cabins, solar/wind energy systems, UPS battery backups, telecommunication systems, medical equipment, and more.

uk.renogy.com

This will allow me to be much more organised by locating the power source under the passenger seat and everything else under the drivers seat. It will hopefully be so much neater. Hope it will fit. My CAD model says it will but hope that is right!

Just keeping fingers crossed that a new vehicle will rock up to fit this kit in very soon!

 

[Dellmassive]

good man . .

Renogy 10% discount for you.


I can get you a discount at Renogy United Kingdom


.

 

[Samro]

Oh no! Now you say!!!!!

 

[Dellmassive]

two months ago . . .

Various Discounts Go Here:

I find Amazon prices bouncing up and down all the time. I think it has something to do with stock levels vs demand and other mind boggling algorithms. eg. bought some mcguard locking bolts recently for £35 with stock showing 11. Went back to the page immediately after purchase and they'd jumped...

www.t6forum.com

.

 

[Chris.couldery]

Hi, @Samro - Sorry to bump an old thread. Did you manage to fit the 170ah Renogy under the passenger seat? I'd like to do the same thing and the dimensions look very tight!

 

[drinfinity]

Hi, @Samro - Sorry to bump an old thread. Did you manage to fit the 170ah Renogy under the passenger seat? I'd like to do the same thing and the dimensions look very tight!

I don’t know on this particular battery, but I know the seat base (bench seat style) can be precisely realigned to get a few mm. It is possible to push the big ‘dent’ at the back out slightly (not so much that it reduces the rigidity of the base).

 

[Samro]

Hi, @Samro - Sorry to bump an old thread. Did you manage to fit the 170ah Renogy under the passenger seat? I'd like to do the same thing and the dimensions look very tight!

It fits absolutey perfectly, but I had to use the higher of the two swivel bases that are made by Sportscraft:

SPORTSCRAFT VW Transporter T5/T6 Pass Single Seat Swivel

SPORTSCRAFT VW Transporter T5/T6 swivels are a great addition to your vehicle which allow you to rotate your seat to face the rear of the vehicle.

www.jennings-seats.co.uk

This swivel base has the big nut above the swivel plate and allows sufficient room to fit the battery.
I am very pleased with this base as it has no rock 'n roll and the increase in seat height is minimal.

I easily fitted the DC-DC charger in front, but if I were doing this job again I'd opt for an alternative charger, as I don't rate the Victron.

Note that the LED module and Trailer Assist module needed relocating to the base back in order to accommodate.

Here are some pics of the battery:

 

[Chris.couldery]

@Samro I really appreciate you taking the time to respond and including the pictures, looks just the job!