Hot Water off Invertor while driving?

[PlymBob]

Has anyone tried this?

Having the Truma Hot Water running off the Invertor whilst driving?

Theoretically it will take a lot of electricity from the leisure battery, but if that is being charged by the alternator with the engine on, maybe it won't flatten the battery. Presumably once up to temperature the Truma's thermostat will switch off anyway, and just keep the temperature topped up.

Or am I missing something important?

 

[scotjimland]

Theoretically it will take a lot of electricity from the leisure battery,

Indeed it will

Heater wattage .. 850 - 1300 depending on model .. do you know yours ?

850 watt at 12v = 71 amps

1300 watt at 12v = 108 amps

 

[pappajohn]

The inverter will draw around 110amps from the battery while heating.
You'll need a B2B to get anywhere near that from the alternator.
If you have solar to the battery that will help as well

 

[scotjimland]

Just a thought..

the electricity from the alternator isn't free, and there will be losses using the inverter..

An alternator typically takes about 1 HP (horse power) for every 25 amps of power generated.

So, a 100 amp alternator will require about 4 HP at full output.

do the sums add up.. is this cheaper than LPG ..?

 

[Guigsy]

A more efficient system is to loop the engine coolant through a heat exchanger to warm your water. I know some vans do this. I'm not sure how useful it is though.

Generally I don't need hot water shortly after driving.

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[Bessy765]

We have a 2019 Burstner on the Fiat 2.3 150 hp. On long runs we use our Victron 12/2000/80 inverter charger to heat the hot water on the lower 240 volt setting. We have 2 x 100 amp Transporter lithium batteries and 700 watts of solar. No smart alternator and no B2B. Have done this for over four years and not noticed any increase in fuel consumption.

 

[L' Hobo]

Has anyone tried this?

Having the Truma Hot Water running off the Invertor whilst driving?

Theoretically it will take a lot of electricity from the leisure battery, but if that is being charged by the alternator with the engine on, maybe it won't flatten the battery. Presumably once up to temperature the Truma's thermostat will switch off anyway, and just keep the temperature topped up.

Or am I missing something important?

Buy a Murvi, my habitation water is heated by the engine heat while travelling so after an hour, perhaps less, I have a full tank of hot water.
If they can do it, I'm sure so can others.
Can't understand why others don't?

 

[1967bowesj]

Sure the alde heater in our pilote does just that of engine, at least it does the radiators so presume it does hot water

 

[L' Hobo]

A more efficient system is to loop the engine coolant through a heat exchanger to warm your water. I know some vans do this. I'm not sure how useful it is though.

Generally I don't need hot water shortly after driving.

It is useful because, with a my well lagged tank, the hot water lasts, unless disturbed, for a number of hours.

 

[scotjimland]

We have a 2019 Burstner on the Fiat 2.3 150 hp. On long runs we use our Victron 12/2000/80 inverter charger to heat the hot water on the lower 240 volt setting. We have 2 x 100 amp Transporter lithium batteries and 700 watts of solar. No smart alternator and no B2B. Have done this for over four years and not noticed any increase in fuel consumption.

if that is the case then your solar must be providing most the the heating power..

the energy to do this has to come from somewhere.. so it's either sunshine or diesel ..

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[donkey]

It is useful because, with a my well lagged tank, the hot water lasts, unless disturbed, for a number of hours.

The problem with Truma 4E or 6E is the fact there is little or no insulation for the hot water reservoir. I know ours is vertually cold after being turned off for a couple of hours.

Geoff

 

[Bessy765]

if that is the case then your solar must be providing most the the heating power..

the energy to do this has to come from somewhere.. so it's either sunshine or diesel ..

True nothing in life is free, if climbing hard or bad weather results in lights wipers demister. We turn it of but. Cannot say the mpg alters much.

 

[PlymBob]

2 x 100 A/h Lithiums and 220 W Solar. Truma Combi E has 900W setting. Also B2B.

I ask because I have a gas leak and may turn off the gas till return to UK in a week or so.

 

[cyberyacht]

The problem with Truma 4E or 6E is the fact there is little or no insulation for the hot water reservoir. I know ours is vertually cold after being turned off for a couple of hours.

Geoff

Yes, irritating isn't it. You'd think there'd be some degree of insulation designed into it. The only upside is that it provides a bit of habitation warmth through the vented panel that hides it. Not really wanted when it's 33C outside though.

 

[donkey]

2 x 100 A/h Lithiums and 220 W Solar. Truma Combi E has 900W setting. Also B2B.

I ask because I have a gas leak and may turn off the gas till return to UK in a week or so.

"I have a gas leak and MAY turn off the gas"

A bit of advice, Turn it off now!

Geoff

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[PlymBob]

"I have a gas leak and MAY turn off the gas"

A bit of advice, Turn it off now!

Geoff

Obviously I already have turned gas off, but still hoping I can fix problem. If not I am seeking advice about Plan B (above).

 

[Cush]

How long does it take to heat your boiler to temp on 240? Might not need the full 71 (or more) amps if less than an hour. What out put is your b2b? It’s sounds theoretically possible.

 

[Guigsy]

In my experience with a Truma 6E, the electric takes forever to get to temperature. And it's not powerful enough to sustain that temperature. It's ok for one water saving ship shower. But if I'm really muddy after a mountain bike ride and I need a longer wet or rinse, I switch it to gas or I'll have a cold shower by the end. Or if me and the wife both have a shower in the morning, I'm first and she gets a cold one (damn, I forgot to switch to gas, sorry love. ).