Another Battery Question

[Alan de Enfield]

7 minutes ago, Nick D said:

Yes, it is ‘Waeco’ and yes, it does have a thermostat. I don’t know the draw so will have to dig out the book but if my night time usage is between 2/3 amps then presumably it would suggest that this might not be the culprit?

I was thinking of the MOBICOOL range which are peltier and the manual warns not to leave it 'plugged in' without the engine running.

 

Maybe your model is (as you say) thermostatically controlled - I'm sure it will be in the manual.

 

From the MOBICOOL manual :

 

NOTICE!
 Check that the voltage specification on the type plate
corresponds to that of the energy supply.
 Only connect the cooling device to a DC power supply in the
vehicle with the DC cable.
 Never pull the plug out of the socket by the cable.
 Disconnect the cooling device and other power consuming
devices from the battery before connecting a quick charging
device.
 Disconnect the cooling device or switch it off when you turn off
the engine. Otherwise you may discharge the battery.

 

 

Technical description
The cooler is portable. It can cool items and keep them cool or heat items and
keep them warm (with the additional heating feature) to max. 65 °C.
Its cooling system is a non-wearing Peltier cooling, the heat is discharged by
a fan.
When the cooler is connected to the DC socket, the cooling capacity cannot
be adjusted. In this case the cooler cools maximal.

[nicknorman]

36 minutes ago, mrsmelly said:

My cheapos last two years if I am off mains but I charge religiously every day if not cruising or otherwise cruise several hours.

Ah so that explains it. Bringing god into it will surely make the difference. Blessed be your batteries. No doubt they have holy water added to the electrolyte, instead of the usual distilled stuff everyone else uses.

 

Or it could be that you are too pissed on the Communion wine to notice that the lights have gone dim!

[MtB]

44 minutes ago, Nick D said:

I suspect we might have el cheapo batteries although they weren’t actually cheap as they were fitted in an emergency and I didn’t have any choice!

 

Do tell more about this. When was it? How old were the old set when they needed replacing in an emergency?

 

I suspect you have something fundemental wrong with your electrical system killing your batts. Your new ones are heading the same way as your old ones.  3A is an unusually a high current draw to always be there when everything is turned OFF. And too low for a Waeco cool box. My cool box used to draw about 7A for not very much cooling before I threw it away.

 

 

[Nick D]

I’m pretty sure it’s not MOBICOOL and it definitely isn’t portable.  However, I think folks are losing sight of the original point of the post.  Regardless of whether I have a cooler or not, the point is that - on the same approximate daily usage - the batteries are losing charge quicker as the days go on.  It would appear that I am charging them to as full as can be expected so I suspect Nickorman may be correct when he says that it could be the quality of the batteries. We have another 18 days or so left and in that time hope to ‘top up’ on a shoreline overnight so we shall see.

[Guest]

3 minutes ago, nicknorman said:

Ah so that explains it. Bringing god into it will surely make the difference. Blessed be your batteries. No doubt they have holy water added to the electrolyte, instead of the usual distilled stuff everyone else uses.

 

Or it could be that you are too pissed on the Communion wine to notice that the lights have gone dim!

My first NB was blessed by the local vicar, but it still sunk when future owners neglected it.

[Nick D]

1 minute ago, Mike the Boilerman said:

 

Do tell more about this. When was it? How old were the old set when they needed replacing in an emergency?

 

I suspect you have something fundemental wrong with your electrical system killing your batts. Your new ones are heading the same way as your old ones.  3A is an unusually a high current draw to always be there when everything is turned OFF. And too low for a Waeco cool box. My cool box used to draw about 7A for not very much cooling before I threw it away.

 

 

When we first got the boat, I knew even less about battery management than I do now, and thanks to loads of advice from this forum I now know a lot more.  Without going into a massive story, I am pretty sure that the previous problem is not related to this one.  There is never a time when everything is turned off. The fridge and cooler are always on as in the inverter (in sleep mode) and the internet router.  If you are saying that, bearing this in mind, 3A is still high then that does me cause for concern.  Can you clarify this for me?

[MtB]

1 minute ago, Nick D said:

When we first got the boat, I knew even less about battery management than I do now, and thanks to loads of advice from this forum I now know a lot more.  Without going into a massive story, I am pretty sure that the previous problem is not related to this one.  There is never a time when everything is turned off. The fridge and cooler are always on as in the inverter (in sleep mode) and the internet router.  If you are saying that, bearing this in mind, 3A is still high then that does me cause for concern.  Can you clarify this for me?

 

Ok I misunderstood. I thought in the night with no loads on you saw 3A all the time. 

 

Something still doesn't stack up. The fridge, a cooler and an inverter all added together would normally draw about 10A. Even with the fridge off on its thermostat I'd expect perhaps 5A-6A+ from the cool box and the inverter in sleep mode. I'm wondering if not all the discharge current is going through the BMV shunt. This would certainly explain all your symptoms. Something fairly hefty is drawing current without the BMV seeing it, I suspect. Just a guess but would explain everything. 

[Nick D]

19 minutes ago, Mike the Boilerman said:

 

6 minutes ago, Mike the Boilerman said:

 

Ok I misunderstood. I thought in the night with no loads on you saw 3A all the time. 

 

Something still doesn't stack up. The fridge, a cooler and an inverter all added together would normally draw about 10A. Even with the fridge off on its thermostat I'd expect perhaps 5A-6A+ from the cool box and the inverter in sleep mode. I'm wondering if not all the discharge current is going through the BMV shunt. This would certainly explain all your symptoms. Something fairly hefty is drawing current without the BMV seeing it, I suspect. Just a guess but would explain everything. 

Thanks, tbh it varies overnight between 3-6amps so maybe it’s a bit on the low side. I will check with the guys who fitted it.

Edited July 3, 2019 by Nick D

[TheBiscuits]

 

1 hour ago, catweasel said:

 I told my wife to buy some new ones; it was our wedding anniversary so I said she could treat me.

There's nothing celebrates a marriage quite like a great lump of lead and a gallon of acid! 

Edited July 3, 2019 by TheBiscuits

[cuthound]

1 hour ago, catweasel said:

My first NB was blessed by the local vicar, but it still sunk when future owners neglected it.

 

I had my boat cursed at by a certain Reverend... ?

[ditchcrawler]

33 minutes ago, cuthound said:

 

I had my boat cursed at by a certain Reverend... ?

He cursed most he met.

[TheBiscuits]

Just now, ditchcrawler said:

He cursed most he met.

Cursed them to hotel?

 

[Bod]

When was the fluid level last checked in the batteries?

 

Bod

[mrsmelly]

11 hours ago, Nick D said:

Thanks, tbh it varies overnight between 3-6amps so maybe it’s a bit on the low side. I will check with the guys who fitted it.

It could well be your inverter even on standby taking 3 amps without the fridge compressor or owt else running? I had the misfortune on one boat for a short time till I disposed of it of having a stirling combi that sat drawing 4 amps whilst powering nowt. A good inverter sits at around one amp. My present combi sits at 0.3 of an amp until instantly firing up when asked by the fridge or somett. I never turn my combi off and always buy mains stuff. This boat had a 12 volt fridge and a 12 volt freezer fitted on purchase, both working well and now both doing good work on other forum members boats as I replaced with new mains units,  they use less leccy and are bigger and mooooooooooooooooooooooooooocho cheaper to buy. You will find the first twenty years of living aboard are a learning curb re all things living aboard. We found the last ten much better so far as its all fallen into place ?

[Nick D]

1 hour ago, Bod said:

When was the fluid level last checked in the batteries?

 

Bod

They are sealed batteries, so can’t be checked unfortunately 

17 minutes ago, mrsmelly said:

It could well be your inverter even on standby taking 3 amps without the fridge compressor or owt else running? I had the misfortune on one boat for a short time till I disposed of it of having a stirling combi that sat drawing 4 amps whilst powering nowt. A good inverter sits at around one amp. My present combi sits at 0.3 of an amp until instantly firing up when asked by the fridge or somett. I never turn my combi off and always buy mains stuff. This boat had a 12 volt fridge and a 12 volt freezer fitted on purchase, both working well and now both doing good work on other forum members boats as I replaced with new mains units,  they use less leccy and are bigger and mooooooooooooooooooooooooooocho cheaper to buy. You will find the first twenty years of living aboard are a learning curb re all things living aboard. We found the last ten much better so far as its all fallen into place ?

I did wonder if that was the case but have tried it with the inverter off overnight and it makes no difference.  The problem is not so much how much electricity is being consumed but the fact that each day the batteries are draining quicker

[Alan de Enfield]

10 minutes ago, Nick D said:

The problem is not so much how much electricity is being consumed but the fact that each day the batteries are draining quicker

That is typical of batteries reaching the end of their life.

Sulphation gradually increases reducing the capacity of the batteries so they hold less and less, you take 'out' the same number of Ah but it empties the battery sooner.

 

Comparison.

 

You have a 5 litre bucket, fill it with water and it holds 5 litres.

Put 1 litre of mud in the bottom, it is still a 5 litre bucket but now only holds 4 litres of water

Next month add another 1 litre of mud in the bottom, it is still a 5 litre bucket but now only holds 3 litres of water

 

You can see the trend ………………...

 

Every time a battery is not recharged fully (ideally a battery should be recharged immediately after use - which is why starter batteries last for years) and left for 'a few days, or even hours' in a partially dis-charged state sulphation is formed and you have the 'bucket scenario'.

 

If you really do have a 3 amp drain with nothing switched on then that is 72Ah per day which is (effectively) almost requiring 2x 100Ah batteries taken down to ~60% state of charge.

 

If you do have this drain then you should try and find it, if it is the inverter then maybe replace it with a more efficient one.

 

My inverter draws 0.75A simply switched on with nothing plugged into it, some models can be 4 amps.

 

My Waeco fridge is 28-30Ah per day (depends on ambient temperature and how many times you open the door) It runs approximately 15-20 minutes per hour but was running almost continuously when first installed. This was due to undersize cables and the volt drop causing it to keep trying to get down to temperature. Replaced the cable with 'proper sized ones' and now it all fine.

[Nick D]

Thanks Alan, I did wonder if they are reaching the end of their life although they are only a year old and I think I have managed them appropriately I.e always on a shore line/charger when in the marina, and charged fully each day when we are out.  

 

I don't have a 3a drain when nothing switched on. Overnight, with the inverter, fridge and cooler on it varies between 3-6amps.

[mrsmelly]

9 minutes ago, Nick D said:

Thanks Alan, I did wonder if they are reaching the end of their life although they are only a year old and I think I have managed them appropriately I.e always on a shore line/charger when in the marina, and charged fully each day when we are out.  

 

I don't have a 3a drain when nothing switched on. Overnight, with the inverter, fridge and cooler on it varies between 3-6amps.

As Alan says it will prob be yer batts then. At least with new ones you can start from day one with knowledge on how to make them last a little longer 

[Dr Bob]

 

I agree with Alan that the most likely cause is sulphated batteries but it is interesting that the capacity has decreased significantly from the first few days of your 10 day trip to now. 12.4V down to 12.1V IF you used approx the same power is a big change. Be interesting to hear the battery experts view on how this is happening. Is the sulphation that has built up over the year (ie before you got your BMV!) being 'reversed/masked/suspended' when on shore power but then coming back in a few days when back to cycling?

Then again, it would be better to have a more accurate understanding of what the voltages and current draw are. I dont go with the 3-6A overnight. The inverter/router/sundries are likely to be 2A ish. Add 3A each for the fridge/cooler when their compressors come on and you are talking 2-8A.

The OP mentioned 12.18V this morning which is almost 10% more capacity vs 12.10V so is this just about looking at the voltage at rest? – WITH A KNOWN AMPS DRAW. I assume no solar as the voltages would be far different. I always reckoned on a 2A draw knocking 0.1V off what would be the rested voltage. An 8A draw? Maybe that is the difference or a big part of it? Then you have the effect of something wired outside the shunt – ie one of the fridges to ensure least voltage drop. An awful lot of ebersparky thingies are wired direct for voltage drop reasons.

To be accurate and understand your power, why not spend £60 and be able to produce one of these graphs.

 

You can track V's and A's on line (on the Victron server) if you have a BMV. Look at the time between 11pm and 1am. That's our fridge coming on and upping the Amps out from 2 to 5. You can easily diagnose problems such as this and get a record of your data. Any change in voltage without a change in current (on pure discharge) can be seen easily.

[Nick D]

This looks interesting. Didn’t know it was available as all I can see on the Victron App is similar graph for  Watts/amp but only for the last minute. How do I get this extra information?

[Dr Bob]

18 minutes ago, Nick D said:

This looks interesting. Didn’t know it was available as all I can see on the Victron App is similar graph for  Watts/amp but only for the last minute. How do I get this extra information?

Ah, you have to be clever to work this one out.

The graphical output is from the Victron energy portal. Victron sell a Venus GX and a Colour Control GX box which are £300 and £450 (ish when last looked a year ago). Far too expensive. However, Victron have made the code that runs on  the venus GX freely available which just happens to run on a Raspberry Pi. Therefore, buy yourself a Pi 3plus (£38), load the software onto a micro SD card (software ex victron) and plug the Pi into you BMV via a £20 cable. Connect your Pi to your router and then register at the VRM.victronenergy.com site.

Basically, all the data from you BMV is fed to Victon's site and you can pick it up where ever you are over the internet.

@Robbo is the expert. You dont need any specialist knowledge to set it up and you dont need to know how to programme a Pi but some experience helps. I got stuck on the mac address but finally worked it out myself. Mine been connected and working fine since early Feb.

Well worth spending £60 and you can leave it connected when in the marina and watch the power status......so you know when the shore power goes off and comes back on.

[Johny London]

I was going to say that a fridge, an inverter and a cooler on all night would easily be enough to drain batteries, but it's already been said and also you have tried turning things off overnight. But my other point is, when you say "overnight" is that including an evening dose of tv/microwave/pc etc etc - or from bedtime?

You don't mention if you have any solar? If you are presumably going to replace the batteries (as general consensus seems to conclude they are goosed) then having a way to recharge them easily would be important. You literally can't have too much solar - it's not about how much it produces at peak, but what you can get even on poorer days. I reckon even I could avoid wrecking a set of l/a's in the summer now that I have 600w of solar.

 

Some of the apparent discharge might be due to reading the "surface charge" of the batteries to start with.

[Nick D]

Surely most boaters have this sort of stuff without too many battery problems (cooler excepted)?  We don’t have a microwave.  Generally we are consuming c100ah from about 4pm when we stop until we wake up in the morning. This includes the normal tv etc. but we only charge phones etc when cruising and I don’t think we are wasteful with electricity.  We don’t have solar.  I started a thread on here a few months ago about having solar and the general consensus was that it wouldn’t be worth it for our cruising pattern.

 

By chance, we passed a marina today which is part of our home marina group where we can stay overnight for free.  I’ve hooked up the shoreline tonight so it will be interesting to see what happens when we go back off grid over the next few days.

Edited July 4, 2019 by Nick D

[Nick D]

2 hours ago, Dr Bob said:

Ah, you have to be clever to work this one out.

The graphical output is from the Victron energy portal. Victron sell a Venus GX and a Colour Control GX box which are £300 and £450 (ish when last looked a year ago). Far too expensive. However, Victron have made the code that runs on  the venus GX freely available which just happens to run on a Raspberry Pi. Therefore, buy yourself a Pi 3plus (£38), load the software onto a micro SD card (software ex victron) and plug the Pi into you BMV via a £20 cable. Connect your Pi to your router and then register at the VRM.victronenergy.com site.

Basically, all the data from you BMV is fed to Victon's site and you can pick it up where ever you are over the internet.

@Robbo is the expert. You dont need any specialist knowledge to set it up and you dont need to know how to programme a Pi but some experience helps. I got stuck on the mac address but finally worked it out myself. Mine been connected and working fine since early Feb.

Well worth spending £60 and you can leave it connected when in the marina and watch the power status......so you know when the shore power goes off and comes back on.

Thanks. Sounds a bit convoluted but if I’m still having problems will certainly consider it. Might be back on here for help tho!

[mrsmelly]

3 minutes ago, Nick D said:

Surely most boaters have this sort of stuff without too many battery problems (cooler excepted)?  We don’t have a microwave.  Generally we are consuming c100ah from about 4pm when we stop until we wake up in the morning. This includes the normal tv etc. but we only charge phones etc when cruising and I don’t think we are wasteful with electricity.  We don’t have solar.  I started a thread on here a few months ago about having solar and the general consensus was that it wouldn’t be worth it for our cruising pattern.

Correct. You have deffo something of a problem. For instance we left mooring last week and went offline for 3 nights. We have four 110 a/h batteries. Our inverter is NEVER turned off neither is our fridge, or seperate freezer. We go out around 6pm with fully charged batts and next morning depending on what we did when we returned later in the evening our batts are somewhere between 12.2 and 12.4 at 8 am. These are mains units so superior to tinny 12 volt stuff. Fit new batteries and keep em charged I reckon.

2 hours ago, Dr Bob said:

Ah, you have to be clever to work this one out.

The graphical output is from the Victron energy portal. Victron sell a Venus GX and a Colour Control GX box which are £300 and £450 (ish when last looked a year ago). Far too expensive. However, Victron have made the code that runs on  the venus GX freely available which just happens to run on a Raspberry Pi. Therefore, buy yourself a Pi 3plus (£38), load the software onto a micro SD card (software ex victron) and plug the Pi into you BMV via a £20 cable. Connect your Pi to your router and then register at the VRM.victronenergy.com site.

Basically, all the data from you BMV is fed to Victon's site and you can pick it up where ever you are over the internet.

@Robbo is the expert. You dont need any specialist knowledge to set it up and you dont need to know how to programme a Pi but some experience helps. I got stuck on the mac address but finally worked it out myself. Mine been connected and working fine since early Feb.

Well worth spending £60 and you can leave it connected when in the marina and watch the power status......so you know when the shore power goes off and comes back on.