New some help with buying Batteries guys.

[Loafer]

GL2, don't run your microwave unless the engine is running! That sort of current draw is almost certainly a battery killer!

[IanM]

GL2, don't run your microwave unless the engine is running! That sort of current draw is almost certainly a battery killer!

 

I was going to say something similar. We ditched ours very quickly.

[Greylady2]

Thanks Tony/Loafer/Nick and Ian,

 

I will take all your advice and laminate a sign letting mum n dad know not to use the Microwave and Slow Cooker unless on shore power. (We dont need to anyway really)

 

much appreciated.

 

EDIT : ive noticed a huge difference in the amount of Amps needed to get to 4 % since yesterdays massive engine charge and ive altered the tail end charge to 1 %.

 

cant thank everyone enough.

Edited June 29, 2016 by Greylady2

[MtB]

I will take all your advice and laminate a sign letting mum n dad know not to use the Microwave and Slow Cooker unless on shore power. (We dont need to anyway really)

 

 

Slow cookers draw FAR less power than microwaves. Still not great to have one on battery power but not in the same league as a micowave at battery killing.

 

 

 

EDIT : ive noticed a huge difference in the amount of Amps needed to get to 4 % since yesterdays massive engine charge and ive altered the tail end charge to 1 %.

 

 

Que?!

[Greylady2]

Slow cookers draw FAR less power than microwaves. Still not great to have one on battery power but not in the same league as a micowave at battery killing.

 

 

 

 

 

 

Que?!

 

Mike what do you mean Que ?

 

Bit confused sorry lol

[MtB]

Mike what do you mean Que ?

 

Bit confused sorry lol

 

 

Spanish for "Do what, mate?"

 

(Quoting Manuel from Faulty Towers.)

[Greylady2]

Spanish for "Do what, mate?"

 

(Quoting Manuel from Faulty Towers.)

Its been a long day Mike. Lol

[Tony Brooks]

Just tried to google the power of slow cookers but as usual very little technical detail provided for those I looked at. A Lakeland one quoted three heat settings and 120W another fancy one 700W.

 

Now. If that 120W was quoted at the high heat setting that's about 12 amps at 12 volts the the lower settings would average less. 12 amps for (say) an hour to bring the contents to the boil and then maybe 4 amps for the rest of the day should make minimal difference to the battery charging I would have thought as long as the engine was running all the time - that is you are cruising. Any 60 amp plus alternator should easily cover it and charge the batteries.

 

Anyway after the first (say) hour the alternator will have spare output because the batteries are limiting what they will accept so the slow cooker would be running on alternator power, not the batteries.

 

Lots of ifs and unknowns there but if slow cooking is your thing I suggest that by selecting the right slow cooker and only using it when the engine is running makes perfect sense.

Edited June 30, 2016 by Tony Brooks

[Sea Dog]

I will take all your advice and laminate a sign letting mum n dad know not to use the Microwave and Slow Cooker unless on shore power.

Also make another one saying "Don't use the laminator unless on shore power"!

[Greylady2]

Also make another one saying "Don't use the laminator unless on shore power"!

Lol I did tut tut. ?

Just tried to google the power of slow cookers but as usual very little technical detail provided for those I looked at. A Lakeland one quoted three heat settings and 120W another fancy one 700W.

 

Now. If that 120W was quoted at the high heat setting that's about 12 amps at 12 volts the the lower settings would average less. 12 amps for (say) an hour to bring the contents to the boil and then maybe 4 amps for the rest of the day should make minimal difference to the battery charging I would have thought as long as the engine was running all the time - that is you are cruising. Any 60 amp plus alternator should easily cover it and charge the batteries.

 

Anyway after the first (say) hour the alternator will have spare output because the batteries are limiting what they will accept so the slow cooker would be running on alternator power, not the batteries.

 

Lots of ifs and unknowns there but if slow cooking is your thing I suggest that by selecting the right slow cooker and only using it when the engine is running makes perfect sense.

Good information thanks Tony.

 

I just checked ours and it says 210w, crock pot a crock a ----. ?

[MtB]

Lol I did tut tut.

 

Good information thanks Tony.

 

I just checked ours and it says 210w, crock pot a crock a ----.

 

 

With the crock pot having a simple electric element in it as the heater, one can repuy on that 210w as being the draw it takes from the power supply.

 

Not so with a microwave. Even if a microwave has a 'low' setting of 120W into the food, in my experience of them the lower settings still run at full power, but only for a proportion of the time. So the 'low' setting on a 700W microwave achieves 120W heat into the food by running the 700W magnatron for ten seconds then resting for about 50 seconds.

 

If yours does this (and all those I've ever used do), then running it at a lower power still hammers the batteries but for less time, rather than drawing a lower current in the firdt place. Whether the batteries still suffer I'm not so sure. The inverter probably doesn't like it much either!

[Greylady2]

 

 

With the crock pot having a simple electric element in it as the heater, one can repuy on that 210w as being the draw it takes from the power supply.

 

Not so with a microwave. Even if a microwave has a 'low' setting of 120W into the food, in my experience of them the lower settings still run at full power, but only for a proportion of the time. So the 'low' setting on a 700W microwave achieves 120W heat into the food by running the 700W magnatron for ten seconds then resting for about 50 seconds.

 

If yours does this (and all those I've ever used do), then running it at a lower power still hammers the batteries but for less time, rather than drawing a lower current in the firdt place. Whether the batteries still suffer I'm not so sure. The inverter probably doesn't like it much either!

I will stick a Pan of beans in a pan and use the gas then, on a serious note I think we will limit items with heating elements and microwave to shore power only.

 

Cheers Mike I hope your arm sockets have recovered from you know what. ?

Edited June 30, 2016 by Greylady2

[nicknorman]

Yes a microwave's magnetron is "all or nothing" but not sure I go along with the anti-microwave arguments. Is it bad for batteries to have to deliver high current for a short time? If so, it's funny how starter batteries seem to survive so long with a single 110AH battery delivering 2 or 3 hundred amps during a start, every day.

 

To my mind it's more about the overall energy drain. Of course the two cooking methods are quite different but a microwave produces very little extraneous heat - most of the electrical energy goes to heating the food. Whilst a slow cooker is of course much lower power, it is on for hours and hours and a fair bit of the heat energy is lost to the outside.

 

But as I said, they are different types of cooking. If you want a nice stew, the slow cooker is the thing to use (although a gas oven or stove top would obviously use less electricity!) but if you want to heat your too-cool cup of coffee, heat up a ready meal, soup etc, then I don't see why a microwave should be on the hate list.

 

I see no reason not to use a microwave for short periods especially if the engine is running.

Edited June 30, 2016 by nicknorman

[MtB]

I see no reason not to use a microwave for short periods especially if the engine is running.

 

 

Won't all that constant switching on and off wear out the inverter?

[nicknorman]

 

 

Won't all that constant switching on and off wear out the inverter?

 

No. But you knew that anyway!

[MtB]

True, I just asked for the benefit of the OP (obvs), who might be wondering such a thing

Edited June 30, 2016 by Mike the Boilerman

[Paul C]

I don't think you can put down the microwave based simply on its instantaneous power consumption. The reason being, that power requirement isn't "excessive" once spread over 4 batteries - yes there is an additional effect due to the high current draw (Peukeurt's Law) but unless you understand this you can't legitimately say not to run it. Also, both ditchcrawler and MtB's estimation of actual (electrical) power draw are wrong (this is based on myself using a microwave and measuring its current draw).

 

It comes to one of the basics of boat electricity - POWER AUDIT.

 

Put it another way, you need to know how much comes out, to know how much to put in.

[ditchcrawler]

Just tried to google the power of slow cookers but as usual very little technical detail provided for those I looked at. A Lakeland one quoted three heat settings and 120W another fancy one 700W.

 

Now. If that 120W was quoted at the high heat setting that's about 12 amps at 12 volts the the lower settings would average less. 12 amps for (say) an hour to bring the contents to the boil and then maybe 4 amps for the rest of the day should make minimal difference to the battery charging I would have thought as long as the engine was running all the time - that is you are cruising. Any 60 amp plus alternator should easily cover it and charge the batteries.

 

Anyway after the first (say) hour the alternator will have spare output because the batteries are limiting what they will accept so the slow cooker would be running on alternator power, not the batteries.

 

Lots of ifs and unknowns there but if slow cooking is your thing I suggest that by selecting the right slow cooker and only using it when the engine is running makes perfect sense.

We have one and although by household standards they are low power they are very inefficient. The outer case gets as hot as the cooking pot as the only heat insulation is at the bottom to stop it cooking the worktop and cable. We run ours when the engine is running only so its not a problem, but would never consider running one just from the battery. I did take it home for the winter to see it I could insulate it but Diana kept on using it at home. I have Googled for cool to the touch ones without any luck. Ours is 200/240 Watts and 3 heat control, on our 24 volt system it draws 2 Amps on Warm, 6 Amps on low and 8 Amps on high. I am not sure how the heat control works as it looks to be a single element and I was expecting twin elements with a series parallel switch like the old solid hotplates use to use.

[Greylady2]

We needed and now have 4 new 110ah leasure batterys, how low do I need to go on the amp read whilst running to make sure they are full charged and I am able to reset the SOC ?

 

I've been running the engine for a while it read 12.4 amps and now it's 4.63 amps

 

 

Does it need to be 2 or 4 amps ?

 

Sorry you be a mithering swine.

True, I just asked for the benefit of the OP (obvs), who might be wondering such a thing

I given up wondering it's easier to ask someone who knows lol

Edited June 30, 2016 by Greylady2

[Jess--]

4 x 110AH batteries = 440AH

 

4.63 A on charge is just a touch over the 1% rate that has been mentioned

 

I would say they are fully charged

Edited June 30, 2016 by Jess--

[Greylady2]

4 x 110AH batteries = 440AH

 

4.63 A on charge is just a touch over the 1% rate that has been mentioned

 

I would say they are fully charged

 

 

Sorted thanks all, much appreciate all your help and advice.

Edited June 30, 2016 by Greylady2

[Tony Brooks]

A minute ago the above reply said that the amps jumped to 6.something when the engine was turned off but that bit has gone now.

 

I do not see how that can happen, engine turned off, alternator shuts down so no amps flowing.

 

Many be it was -6.x (minus 6.x amps) in which case it was measuring the current being drawn from the batteries by the domestic equipment. just before turning off the charge was probably 10 or 11 amps so 6. something never got to the batteries leaving the 4.63 amps of charge for the batteries.

 

If so it still indicates they are as close to fully charges as it is reasonable to get.

[nicknorman]

We needed and now have 4 new 110ah leasure batterys, how low do I need to go on the amp read whilst running to make sure they are full charged and I am able to reset the SOC ?

I've been running the engine for a while it read 12.4 amps and now it's 4.63 amps

Does it need to be 2 or 4 amps ?

Sorry you be a mithering swine.

 

I given up wondering it's easier to ask someone who knows lol

Yes 4.x Amps can be considered fully charged. However it's a bit of a moot point because there isn't really such a thing as "fully charged" since the batteries will go on taking less and less current, but over a very long time. So if you ran the engine overnight and all day tomorrow you might get below 1A but only after burning a lot of fuel and driving yourself and everybody else mad!

 

So 1% is good, even 2% is probably adequate. 4% is too high IMO. Of course the caveat to all that is that we don't know what the capacity of the batteries actually is now, so when we say 1% is 4.4A that presumes 440AH capacity which they probably don't have any more.

 

But anyway, 1% of new capacity might be 2% of actual capacity which is still OK!

[Loafer]

What batteries are they, GL2?

[Loafer]

Another thing worth noting, GL2, is the RATE of charge current decay, towards the end of your charge.

 

You won't know how much your battery bank capacity is decreasing with age, but your ammeter will tell you that, if you observe it carefully.

 

Get used to seeing how the charge current reduces, on your Victron gauge. (the 'I' display, just below 'V') As you reach fully charged NO MATTER WHAT the capacity is, you will note that the charging current changes more slowly. It would eventually come to a halt.

 

So as an example, if you see that the charge current hasn't reduced much in the last half-hour, then they're full. I'm not sure of the numbers, I just use a 'feeling' brought about by observation.

 

Try observing, GL, and absorb what you see!