"Advised that my leisure battery is dangerous " (1 Viewer)

[Notski]

hi, have just had a habitation survey on my 2005 CI MIZAR and was told by the engineer that the original CI design having the Leisure battery under the drivers seat is a flaw in the original design. His concern is that in the event of an accident the batteries terminals could make contact with the metal underframe of the seat base. The battery is clamped down appropriately to the chassis but he was still concerned that as the gap is quite small, contact is a possibility. The recommended remedy was to relocate the battery. Would an appropriate solution be to insulate the underneath of the seat frame with thick rubber matting cable tied securely? Was thinking maybe in two halves incase of condensation adding to the problem of creating a circuit. Have also been advised that I need to include an inline fuse to my second battery and have searched previous posts which seem to suggest a 25amp fuse would be suitable? 110amp battery. Any thoughts/advice would be much appreciated!

 

[mustaphapint]

Both my leisure batteries are under the front seats. I have used fairly thick foam matting on top of each battery to try prevent any possible contact with seat base.
I've used 50 amp fuses to protect the connections between the batteries. If you have a high powered inverter even this may not be enough.

 

[Minxy]

I wonder if a previous owner has replaced the leisure battery under the driver's seat with one that is taller than the original? I would have thought, however, that your 'insulating' it with a rubber mat should be sufficient to prevent any 'electrifying' bum problems!

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[Notski]

Hi, I have installed an inverter also so will do a bit more searching on that to make sure I fuse it correctly! Thanks

 

[Notski]

If I started with a 25amp fuse to be cautious and then stepped it up if it was too sensitive, would that be good practice or am I showing myself up as not knowing pretty much anything about this kind of thing? (Imagining people cringing at my response now)

 

[Notski]

I wonder if a previous owner has replaced the leisure battery under the driver's seat with one that is taller than the original? I would have thought, however, that your 'insulating' it with a rubber mat should be sufficient to prevent any 'electrifying' bum problems!

Thanks could be why!, electrifying bum problems..... doesn't bear thinking about

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[mustaphapint]

If I started with a 25amp fuse to be cautious and then stepped it up if it was too sensitive, would that be good practice or am I showing myself up as not knowing pretty much anything about this kind of thing? (Imagining people cringing at my response now)

In the range of fuses I have seen there isn't an alternative 50 amp fuse which would replace a 25 or 30 amp fuse. The inline 50 amp fuses and holders I bought have much heavier duty cables and fittings than the normal range which goes up to 30 amps.
The main thing a fuse between batteries is meant to protect would be a short to earth and I reckon a 50 amp fuse would blow just as quickly as a 25 amp if that should happen.
If you have a 1000 watt inverter you could be drawing 80 amps from the batteries (1000/12.5) so at least 40 amps from each battery.

 

[funflair]

If your batteries are a distance apart they should be fused by two fuses as there would be a battery at either end if there was a short on the cable. What size is your inverter? the cable between the batteries needs to be able to handle at least half the inverter maximum amps or ideally all of it, and suitably fused to protect the cable.

Martin

 

[Boringfrog]

I have these fitted on my under seat batteries.

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[funflair]

I have these fitted on my under seat batteries.View attachment 134763

Might depend on the inverter size.

Martin

 

[Boringfrog]

Might depend on the inverter size.

Martin

500amp rated on Amazon.

 

[funflair]

500amp rated on Amazon.

But to pull 500 amps you would need a big cable and then another one to the second battery and then the habitation feed cables and possibly solar connection and it ain't all going to fit IMO.

Martin

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[Boringfrog]

But to pull 500 amps you would need a big cable and then another one to the second battery and then the habitation feed cables and possibly solar connection and it ain't all going to fit IMO.

Martin

Never said anyone was going to pull 500amps. All I'm saying is I use these under seat, battery to battery.

 

[pappajohn]

500amp rated on Amazon.

I think you mean 500 WATTS.
500 amps equates to a 6000watt (6kW) inverter.
500 WATTS = 41.6 amps max current so an 80amp mega fuse should suffice allowing for a 1000WATTS start-up surge current.

 

[mitzimad]

the crucial point here is whats the clearance between terminal and the closest metal part

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[pappajohn]

To draw 500amps from a 110ah battery means you battery would last for just 11 minutes to 50% discharge.

 

[funflair]

Never said anyone was going to pull 500amps. All I'm saying is I use these under seat, battery to battery.

I understand what you are saying but the OP says that they have two batteries and an inverter, a decent size inverter will need chunkier cables than will go into those battery clamps bearing in mind that it is more than one cable as you have to join the batteries together as well.

If they come back and say it's a 200 watt inverter great, that's why my first comment was it depends on the size of the inverter.

Martin

 

[funflair]

I think you mean 500 WATTS.
500 amps equates to a 6000watt (6kW) inverter.
500 WATTS = 41.6 amps max current so an 80amp mega fuse should suffice allowing for a 1000WATTS start-up surge current.

It's the spec of the battery clamps 500 amps would be a momentary starting load not a prolonged inverter load.

Martin

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[pappajohn]

It's the spec of the battery clamps 500 amps would be a momentary starting load not a prolonged inverter load.

Martin

It can't draw more than its peak load no matter what and a 500w inverter invariably has a 1000w peak load which equates to 82 amps.

 

[Notski]

I have these fitted on my under seat batteries.View attachment 134763

Like the look of those, ideal!

 

[Notski]

Will check my inverter size tonight!

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[jockaneezer]

Like the look of those, ideal!

Just be aware that if your battery terminals are pretty close to the seat underside, there may not be enough room to "flip" up those terminal clamps to fit them.

 

[DuxDeluxe]

When I had the leisure batteries under the seats in my first van, they were both in battery boxes

 

[funflair]

It can't draw more than its peak load no matter what and a 500w inverter invariably has a 1000w peak load which equates to 82 amps.

I dont think we dont know what the inverter size is yet, but what I am trying to say is that the 500 amps was quoted by @Boringfrog as the spec of the clamps (quoted from Amazon), and even if they are OK for a 500 amp starting load they will not be any use for a larger inverter load as there is not room in the clamps to get any decent cables in.

Martin

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[Jaws]

The batteries were under the seats in the Miller
All I did was put a couple of plastic chopping boards on top of them .. But then, there was only about 25mm between the terminals and the seat springing !

 

[gus-lopez]

To draw 500amps from a 110ah battery means you battery would last for just 11 minutes to 50% discharge.

It's the capacity of the clamp, nothing to do with inverter size. Just the amount of current they can handle.

I dont think we dont know what the inverter size is yet, but what I am trying to say is that the 500 amps was quoted by @Boringfrog as the spec of the clamps (quoted from Amazon), and even if they are OK for a 500 amp starting load they will not be any use for a larger inverter load as there is not room in the clamps to get any decent cables in.

Martin

That's why most leisure batteries have 8mm posts as well on both positive & negative for auxiliary connections.