Off Grid

[dmr]

6 minutes ago, ditchcrawler said:

I have 24 volts DC and 230 volts AC via  a Mastervolt 1500 True sine inverter, the inverter is on 24/7 but as I said in another post, we cruise every day.

I thought we cruised a lot but you beat us hands down.

[DaveP]

Here's my electricity consumption on a 60ft cc'ing narrowboat.

 

Raspberry Pi/Battery Monitor/Router/4g modem - continuous 7w (14Ah)

1800w inverter - idle 8w (16Ah)

Fridgefreezer - 80w 25% time (40Ah)

TV/hifi etc - 40w 4hr/day (15Ah)

Laptop/Tablet/phone charging - 8Ah

Water pump - 50w 30min/day (2Ah)

Lighting - 10w 5hr/day (4Ah)

 

Total approx 95-100Ah/day

 

I've got 200Ah of lithium batteries and 600w of solar, so at the moment I'm using an electric kettle (4Ah/brew) and toaster (6Ah/2slices) which total another 20Ah/day.  And the heater in the washing machine will pull another 30Ah/wash (plus the 10Ah for the motor) once or twice a week.

 

In a month or so with the decreasing daylight, I'll pull the other 600w of panels out from underneath the decking of the roof veg garden.  This will support 100Ah/day until the end of November with properly chosen mooring spots.  Then the fridge goes off (and the inverter) pulling the consumption down to 40-50Ah/day.  The stove is lit for food, brews and heat.  Then at the end of January the electric consumption can be ramped back up, and panels stowed for the veg to bloom again....

 

 

 

[ditchcrawler]

1 hour ago, dmr said:

I thought we cruised a lot but you beat us hands down.

But mine gets left in a marina for over half the year

[Osh]

Thank you all for the replies.  Helps a lot 🙃

[David Mack]

On 23/08/2022 at 21:12, agg221 said:

I suspect you may have a less power-hungry (aka more efficient) starter set-up than us. Ours has a 5" CAV starter which draws some phenomenal current to start the Kelvin. It hasn't got that many starts in it from a freshly charged battery and can't even spin the engine on full compression from cold. In reality, if I did the energy audit properly that is probably not a good thing, but I can convince myself that once the hand start is reinstated it won't really count..!

 

Alec

If the starter struggles to spin the engine from cold, why do you think you will be able to when the hand start is reinstated?

[Tony Brooks]

On 23/08/2022 at 21:12, agg221 said:

I suspect you may have a less power-hungry (aka more efficient) starter set-up than us. Ours has a 5" CAV starter which draws some phenomenal current to start the Kelvin. It hasn't got that many starts in it from a freshly charged battery and can't even spin the engine on full compression from cold. In reality, if I did the energy audit properly that is probably not a good thing, but I can convince myself that once the hand start is reinstated it won't really count..!

 

Alec

 

That suggests something is very wrong. Undersized start batter/bank, sulphated start battery, badly undersized starter wiring (do the wires get warm?), something wrong inside the starter like shorting armature or field coils, one pair of brushes worn out, or maybe an ill matched flywheel and pinion.

[Jen-in-Wellies]

1 hour ago, Tony Brooks said:

 

That suggests something is very wrong. Undersized start batter/bank, sulphated start battery, badly undersized starter wiring (do the wires get warm?), something wrong inside the starter like shorting armature or field coils, one pair of brushes worn out, or maybe an ill matched flywheel and pinion.

Needs refurbishing, with new, younger hamsters inside the starter motor, or the ones in there already haven't been fed properly. The battery and electrics are just to give them a jolt and make them run around the wheel that's connected to the pinion. 😀 🐹

Edited August 25, 2022 by Jen-in-Wellies

[agg221]

Hi David and Tony,

 

I’m very aware of and value your experience so my reply below is not intended to be patronising - I have written it this way because I anticipate that some readers (including the OP) are probably less familiar with the idiosyncrasies of vintage diesels so the detail may be more useful. In this case it is a c.1948 Kelvin J2 with original fit starter motor.

 

To address your comments, I do not believe anything is wrong. No components are faulty- the battery is quite new and has not been abused, the cables are new, thick and short and do not get hot. The starter motor was overhauled fairly recently and engages and spins up fine. Everything is per original specification around pinions etc.

 

What you have is a combination of a very early diesel design (1928 on a Ricardo patent) with a similar age of starter motor design. The engine relies on mass for evenness - a big, heavy, slow-running lump. This means the starter motor is not very efficient and has relatively low torque, so it simply can’t get the engine up to a high enough speed within a single turn for the momentum to carry it over compression. This is how it has always been so there are two ways to address it.

 

The first is fairly standard - open decompression levers to remove the compression force from that necessary to turn the engine, allow it to get up to speed over several rotations and then flick them over, the momentum of the engine carrying it through the compression stroke so it fires and is then away. With an engine that only needs one cylinder to run on, if you have separate levers you only need to compress one cylinder but in practice once whichever cylinder reaches compression first fires, that should create far more force than spinning it over on the starter or by hand and bring the other cylinders into play. In practice, whilst my engine will start hot like this, the diesel venturi on the top is not of a shape which allows cold starting on diesel (later ones were but I am not sure of the date). Therefore an alternative is needed.

 

The alternative in my case is to open an upper chamber which increases the volume above the piston, reducing the compression ratio. The chamber also includes a spark plug, the spark being generated by a magneto. You now have an early type simple petrol engine. Firstly, the lower compression ratio means the starter motor has enough power to swing the engine over compression (and I can do it by hand) and secondly the generation of a spark is not speed-dependent so with the magneto in good condition it will fire on the first stroke at any rotational speed. In practice it often isn’t quite that quick as the engine is manually primed and sometimes needs a bit of extra air to get to a firing mix, but it takes a lot less rotation time and battery to fire up than on diesel.

 

Jen, good point on the hamsters. Maybe they didn’t enjoy the disturbance of the BCN Challenge and have failed to breed, or maybe the small colony has got too incestuous and some new blood is needed.

 

Cheers

 

Alec

[Tony Brooks]

4 minutes ago, agg221 said:

Hi David and Tony,

 

I’m very aware of and value your experience so my reply below is not intended to be patronising - I have written it this way because I anticipate that some readers (including the OP) are probably less familiar with the idiosyncrasies of vintage diesels so the detail may be more useful. In this case it is a c.1948 Kelvin J2 with original fit starter motor.

 

To address your comments, I do not believe anything is wrong. No components are faulty- the battery is quite new and has not been abused, the cables are new, thick and short and do not get hot. The starter motor was overhauled fairly recently and engages and spins up fine. Everything is per original specification around pinions etc.

 

What you have is a combination of a very early diesel design (1928 on a Ricardo patent) with a similar age of starter motor design. The engine relies on mass for evenness - a big, heavy, slow-running lump. This means the starter motor is not very efficient and has relatively low torque, so it simply can’t get the engine up to a high enough speed within a single turn for the momentum to carry it over compression. This is how it has always been so there are two ways to address it.

 

The first is fairly standard - open decompression levers to remove the compression force from that necessary to turn the engine, allow it to get up to speed over several rotations and then flick them over, the momentum of the engine carrying it through the compression stroke so it fires and is then away. With an engine that only needs one cylinder to run on, if you have separate levers you only need to compress one cylinder but in practice once whichever cylinder reaches compression first fires, that should create far more force than spinning it over on the starter or by hand and bring the other cylinders into play. In practice, whilst my engine will start hot like this, the diesel venturi on the top is not of a shape which allows cold starting on diesel (later ones were but I am not sure of the date). Therefore an alternative is needed.

 

The alternative in my case is to open an upper chamber which increases the volume above the piston, reducing the compression ratio. The chamber also includes a spark plug, the spark being generated by a magneto. You now have an early type simple petrol engine. Firstly, the lower compression ratio means the starter motor has enough power to swing the engine over compression (and I can do it by hand) and secondly the generation of a spark is not speed-dependent so with the magneto in good condition it will fire on the first stroke at any rotational speed. In practice it often isn’t quite that quick as the engine is manually primed and sometimes needs a bit of extra air to get to a firing mix, but it takes a lot less rotation time and battery to fire up than on diesel.

 

Jen, good point on the hamsters. Maybe they didn’t enjoy the disturbance of the BCN Challenge and have failed to breed, or maybe the small colony has got too incestuous and some new blood is needed.

 

Cheers

 

Alec

 

Fair enough, but I find it difficult to believe that a reputable manufacturer of the time would not take steps to ensure fairly easy starting. Do you have data on the battery size Kelvin recommended, because we don't hear much about difficult starting. Accepting they are not that common.

Edited August 25, 2022 by Tony Brooks