Battery Drain - 240 V Central Heating pump

[sirweste]

 

Idle mode means switched off. It'll never be switched off if you want to use the pump.

 

yer understood. I realised this bit didn't make sense after I wrote it.

Basically want the inverter working as it should and then see how much is drawn from the batteries to run the CH pump

[Geo]

Nope last night was not a typical usage night at all, I do washing once every couple of weeks and hoovering varies but lets say about the same though it's largely irrelevant. And as per earlier posts I'm presently without the genny screaming away so I'm not on my usual charging either.

 

I'm fairly convinced the batteries are poorly, been saying it for a few posts now, yes an equalisation and proper charge is still the plan. Following genny repair and mastervolt set-up tweak.

 

I think there are a couple of things that maybe you have missed and that is understandable.

 

1. Yes you have a very efficient pump and at 7 watts on a supply that was doing the conversion from 12V DC to 230V AC at 100% efficiency that would be fine and the battery usage would be of the order of 0.6A and over 10 hours running 6Ah which is order of 1% of your SoC. However you have missed the inverter overhead which I seem to remember on your inverter is 4A from the battery and that 4A is drawn and used to run the inverter no matter how small or high the power is being drawn from the inverter. So you usage overnight with just the CH pump running the draw on the battery is 0.6A for the pump and 4A for the inverter overhead giving over 10 hours 46Ah which is the order of 7% of the full SoC.

 

2. At the moment your batteries are undercharged and their capacity is down. To what level is an unknown, but lets say for discussion to 75% of the original. Unfortunately the smartgauge readjusts itself to the available capacity of the battery so today 100% SoC on the smartgauge is shown about an hour after charging stops, when your batteries are fully charged to their present 75% of the original capacity, say 675 x 0.75 = 506Ah. Now that means the overnight draw from the batteries is still 46Ah but that is 9% of the available SoC.

 

I hope that is no too convoluted

 

My thoughts

 

Your solution is to get those batteries fully charged and equalised and try to recover them. It will have to be done repeatedly probably maybe even 5 or 6 times just to show any sign of recovery. What would be interesting is the battery SGs as they will give a reasonable idea of how bad the sulphation is. This is urgent every day those batteries are left the harder the sulphate gets and the more difficult it is to remove, there comes a stage when it cannot be removed and they will not be recoverable. However you can hold the present capacity by regular, daily to start with fully charging them as defined by the battery's SG, not the smartgauge.

 

Long term it is a balance between £250 for a 12V pump or the cost of putting back into the battery the extra used by the inverter in overhead draw running the AC CH pump.

 

Think you might have got there while I have been writing

Edited December 6, 2016 by Geo

[sirweste]

Cheers for the post. Yer understood. Interesting the 4 A that you quote, if it's that much then there'll be a fancy 12 V pump on order tomorrow!

 

Didn't know that about sulphation hardening, cheers. Got the genny in the van to do some more multimeter probing. Think I have identified the problem, so hopefully can have it up and screaming (to the delight of all around) soon.

 

Also following the mastervolt tweak monday next week I have organised to breast up to a friends boat to borrow their shoreline for a weekend.

 

If not, I'll chuck the batteries away and start ruining some new ones!

[Geo]

Well you can check the inverter overhead easily by turning everything off except the CH pump and measuring the current into the inverter from the batteries. That will give you the answer to whether to order a 12V pump and some decent cable to run a 12V feed to it.

 

Yes unfortunately sulphate hardens and once it has it is not removable using a charger once it has. Hopefully you can recover a good bit of the capacity. If you take the batteries SG reading when the battery is charged until the SG stops increasing over an hour, the SG reading will give a good idea of the remaining capacity.

 

Good idea to use your friend's shore line. I would suggest if you can, if it is not already, you get the charger side of the combi set to order of bulk 14.8V and the equalisation set to 15.5/16V. Then when on the shoreline run your charge until the battery SG tells you by not increasing for an hour that the battery has taken all it can, then switch to equalisation. Think the recommended equalisation current for the Trojans is 5 Amps and keep repeating the equalisation. It is the equalisation that removes laid down sulphate. Normal bulk will only remove the very soft stuff from a normal charge.

 

Good luck

Edited December 6, 2016 by Geo

[WotEver]

Once Keith has configured your MV, if you don't want to have to keep pulling acid out of the batteries then a simpler solution to determinine when to switch to equalisation will be to watch the charging current and see that it has stopped dropping over a period of 45 minutes. So after a few hours of charging if for instance it's reading 8A at 14.8V and 45 minutes later it's still reading 8A at 14.8V then you're nearasdammit fully charged and can perform the first equalisation.

 

When you've performed 3 full charges and 3 equalisations it would then be a good time to check the relative density and see how the readings compare to a new, fully charged battery. That will give you an estimation of how sulphated the batteries are.

 

Good luck,

Tony

[Geo]

Looking at the Mass Combi 12/2200-100 (230 V) spec

Max. efficiency ≥ 90 %

Continuous power at 25 °C / 77 °F, cos phi 1 2150 W

So that could be an overhead of 215W @ 12V that would be order of 18A

[WotEver]

 

Looking at the Mass Combi 12/2200-100 (230 V) spec

Max. efficiency ≥ 90 %

Continuous power at 25 °C / 77 °F, cos phi 1 2150 W

So that could be an overhead of 215W @ 12V that would be order of 18A

 

But the no-load consumption is 9W. So with the efficiency being no worse than 90% then with a 7W load it should only be drawing 16.7W which is exactly what OP measured it as.

[sirweste]

Yes, the overhead measured last night first time was - 2.3 A and second, third and forth time was 1.3 A. I stress, these readings show that the inverter is not functioning correctly, it should have been in idle and was not. Need to change the dip switches tonight to see if that affects the standby overhead draw from the batts.

 

Yer, thats the plan for the mastervolt on monday, bulk setting from 14.40 V to 14.82 V, float to 13.50 V and Eq to 16.20 V. As per the T-105 DS. Or as close to these settings as the software of the mastervolt will allow.

 

The Mastervolt charger is supposed to go into float once the batteries are full, but I will continually take mass readings too, good advice. I will also do equalisation half a dozen times too, cheers.

[Geo]

Once Keith has configured your MV, if you don't want to have to keep pulling acid out of the batteries then a simpler solution to determinine when to switch to equalisation will be to watch the charging current and see that it has stopped dropping over a period of 45 minutes. So after a few hours of charging if for instance it's reading 8A at 14.8V and 45 minutes later it's still reading 8A at 14.8V then you're nearasdammit fully charged and can perform the first equalisation.

 

When you've performed 3 full charges and 3 equalisations it would then be a good time to check the relative density and see how the readings compare to a new, fully charged battery. That will give you an estimation of how sulphated the batteries are.

 

Good luck,

Tony

 

As you are using a loop sensor be careful as position etc can affect the reading. So to be sure if you measure tail current as suggested by wotever that the loop sensor is not moved between readings as you are looking for 0.1A change at the end of the day.

 

I would suggest that in your case while you are on the shoreline you need to push the batteries as hard as possible and as full as possible and SG is the best measure to a true max charge the battery will take.

 

BTW do keep an eye on electrolyte levels. Top up when the batteries are fully charged is the Trojan recommendation.

[WotEver]

 

As you are using a loop sensor be careful as position etc can affect the reading. So to be sure if you measure tail current as suggested by wotever that the loop sensor is not moved between readings as you are looking for 0.1A change at the end of the day.

 

Surely he'd be using the Mastervolt to determine the charge current? All he has to do is to ensure that everything is switched off when noting the readings.

 

Yes, the overhead measured last night first time was - 2.3 A and second, third and forth time was 1.3 A. I stress, these readings show that the inverter is not functioning correctly, it should have been in idle and was not. Need to change the dip switches tonight to see if that affects the standby overhead draw from the batts.

 

Yer, thats the plan for the mastervolt on monday, bulk setting from 14.40 V to 14.82 V, float to 13.50 V and Eq to 16.20 V. As per the T-105 DS. Or as close to these settings as the software of the mastervolt will allow.

 

The Mastervolt charger is supposed to go into float once the batteries are full, but I will continually take mass readings too, good advice. I will also do equalisation half a dozen times too, cheers.

You don't ever want to use a low float voltage when off-grid.

See this article: http://thunderboat.boards.net/thread/817/battery-charging-primer

 

Edited to put some para spacings in.

I'd suggest making the float voltage 14.8V for Trojans as per the above article.

Edited December 6, 2016 by WotEver

[Geo]

 

But the no-load consumption is 9W. So with the efficiency being no worse than 90% then with a 7W load it should only be drawing 16.7W which is exactly what OP measured it as.

 

9W is a no load spec not the spec with a load so is not a guaranteed figure and could change quite a lot just with a small draw.

 

I am not sure where you get 16.7W from and I am not traipsing through 8 pages looking, as if it was derived from a DC input current to the inverter that would depend on the voltage being supplied by the batteries at that time. I would have expected a current reading not a wattage.

[Geo]

 

Surely he'd be using the Mastervolt to determine the charge current? All he has to do is to ensure that everything is switched off when noting the readings.

 

 

If he does how are you going to account for other loads being used by the boat. Any other load will change the output of the charger and thus the current output of the charger will change and its ammeter will change as it compensates for the total load, batteries + boat loads, being asked of it. The only place that a tail current can be guaranteed is the current that is flowing through the main battery cable from the charger at the battery.

Yes, the overhead measured last night first time was - 2.3 A and second, third and forth time was 1.3 A. I stress, these readings show that the inverter is not functioning correctly, it should have been in idle and was not. Need to change the dip switches tonight to see if that affects the standby overhead draw from the batts.

 

Yer, thats the plan for the mastervolt on monday, bulk setting from 14.40 V to 14.82 V, float to 13.50 V and Eq to 16.20 V. As per the T-105 DS. Or as close to these settings as the software of the mastervolt will allow.

 

The Mastervolt charger is supposed to go into float once the batteries are full, but I will continually take mass readings too, good advice. I will also do equalisation half a dozen times too, cheers.

 

Do not rely on the ammeter on the Mass use your meter and measure at the battery. Better measure the SG

 

If it drops into float, switch the charger off for about 5 minutes and then switch it on, it will restart its charging cycle and should go back into bulk which will give you the best charging capability.

Edited December 6, 2016 by Geo

[WotEver]

I am not sure where you get 16.7W from...

But you'll argue anyway.

 

Okay Geo, carry on, I'm out.

[Geo]

But you'll argue anyway.

 

Okay Geo, carry on, I'm out.

 

Well f your figure was based on the readings quoted in #133, which i had seen, they were not on load overheads. They were readings taken when the inverter was supposed to be in idle and for some reason it was not. Yes I would have

 

My guess is they were the 133 reading

[ditchcrawler]

Again - just for comparison purposes - this a 'high quality' Mastervolt inverter & it is using 56Ah per day just sat switched on and 'doing nothing'.

 

That is the same consumption as two (2) 12 volt fridges (such as 'Waeco')

 

It is all 'fine & dandy' having 220v appliances but you MUST have the infrastructure (and understanding) to support them.

My Mastervolt uses nowhere near that amount, maybe its faulty or there is a hidden ac load somewhere. I think I would disconnect the AC output and then measure the DC current.

[sirweste]

My Mastervolt uses nowhere near that amount, maybe its faulty or there is a hidden ac load somewhere. I think I would disconnect the AC output and then measure the DC current.

 

This is obvious, should have thought of it. On the list for tonight

[Chewbacka]

My inverter wakes up from sleep at about 3W and I know these things below will keep the inverter awake -

TV in standby

Microwave - door shut and light off

Phone charger

 

So even if these are not enough to wake the inverter, if the inverter is awake they will consume power.

[Redeye]

Been down this road, inverters and 240v c/h pumps don't mix. The power factor is low on this type of motor,and inverters don't like reactive loads. Burnt out several pumps and a couple of inverters, even the sine wave ones don't like reactive loads. Go for a brushless dc pump instead. They use far less energy. Inverters are rated at their resistive loads, manufacturers are pretty coy about the reactive load ratings.

 

My Harworth Heating PJ boiler is fitted with A Wilo pump that is super efficient (as little as 3 watts) this has worked just fine on a victron inverter for the last 4 years, it has never missed a beat.

 

Andrew

[Chewbacka]

 

My Harworth Heating PJ boiler is fitted with A Wilo pump that is super efficient (as little as 3 watts) this has worked just fine on a victron inverter for the last 4 years, it has never missed a beat.

 

Andrew

The reason people are unhappy with running an efficient pump from a big inverter is that the inverter when running will itself consume 15W (give or take) so to run a 3W pump will be an 18W load on the batteries.

[WotEver]

The reason people are unhappy with running an efficient pump from a big inverter is that the inverter when running will itself consume 15W (give or take) so to run a 3W pump will be an 18W load on the batteries.

Which of course isn't a problem if you are already using the inverter for a 230V fridge, TV, chargers etc but is a problem if you only need the inverter on to run the pump.

[ditchcrawler]

The reason people are unhappy with running an efficient pump from a big inverter is that the inverter when running will itself consume 15W (give or take) so to run a 3W pump will be an 18W load on the batteries.

My inverter is specified as 5 Watts on with no load.

[Chewbacka]

Which of course isn't a problem if you are already using the inverter for a 230V fridge, TV, chargers etc but is a problem if you only need the inverter on to run the pump.

Agreed - I use my inverter to power my fridge, but it does have a sleep mode so at night the inverter is probably asleep for half the time.

400W of solar has the batteries full by lunch time or so for much of the year.

But in winter I would not use the inverter to run a small pump for 12~24Hrs per day.

My inverter is specified as 5 Watts on with no load.

That is very good.

Mine is a 2kW continuous and is 1.2W asleep and 16W running with zero load.

[WotEver]

But in winter I would not use the inverter to run a small pump for 12~24Hrs per day.

Quite

 

Hence why it's been said several times that OP would be best off with a DC pump.

[ditchcrawler]

Quite

 

Hence why it's been said several times that OP would be best off with a DC pump.

Can you suggest a decent DC pump, I have a Johnson and its mounted in the bathroom cupboard bit its far from silent like a mains central heating pump. Also most can't be hard plumbed in and need rubber hoses and clips.

[WotEver]

I have no personal experience with one so I'll leave others to recommend one. However, the Jabsco gets mentioned positively often. It has variable flow rate and can be properly plumbed in. But it's not cheap. https://www.elyboatchandlers.com/12v-central-heating-pumps/jabsco-eco-circ-12v-central-heating-pump