Battery drainage, urgent problem

[skipmac]

The economy regulators are usually simple pwm with no microprocessor - they connect the panel to the battery by a transistor switch. The on time (switch closed) is large when the battery is low, and very short when the battery approaches the float setting and off when float is reached. Hence there is a drop across the switch when its open - open circuit panel volts on one side and battery volts on the other. The resting time will be short - the regulator will periodically close the switch as soon as the battery drops below 13.6 to maintain it off load at 13.6.
True, the battery would not remain at 13.6v for long, but maybe the OP measured it with no load. If he had kept monitoring the panel volts he would have seen it drop to battery volts, especially when a load was applied. His regulator could of course be faulty.

When I switch off my charger the voltage drop to 13V or less shows on the meter almost instantaneously if the load is a few amps to a few seconds if the load is under an amp.

Have not watched closely to see how long it takes with no load at all but I'm getting ready to go out to the boat and will try it to see. The batteries should be 95% or better so should be good conditions for the test.

 

[steveghoward]

Hi all,

Firstly, thanks to everyone who has taken the time to respond, once again this forum has shown that there are truly helpful and considerate sailing folk out there.

So, latest news, yesterday 1st thing we switched off everything we could on the boat and just left the battery to charge via the panels. It cut to floating at approx 10.30 am and sat all day with the charge on the battery terminals showing between 13.4 and 13.6. Last night after the sun had gone down it settled to 12.6 volts.

When I woke this morning before dawn and checked, the regulator lights were showing green and the battery 12.4 so it appears there is not drainage thru the night to any significant degree.

We have now switched the fridge back on and it is chilling down and has been on for some two hours.

The battery is now reading 13.3 and the regulator 16.01. Bright sunshine no shadows.

I will leave it in this mode all day and see whether the battery drains as quickly this night when the sun goes down. Watch this space!

Conclusions so far.

I have probably been a bit blasé about battery management thinking big panels, large batteries, no worries. This has xhan

 

[steveghoward]

Cont'd. . . . . .
This has changed and I am back to being more vigilant.

The regulator definitely is not right for the job. It came as part of the solar panel kit and appears to be the most basic modelavailable. As I bought two panel kits I have a spare sitting in a locker as well.

I am booked into IBA for comprehensive electric checks next week and will discuss further upgrading the regulator.

Also I think the fridge could probably do with a service as well which may well cut down on operation time saving energy.

Speaking of which, can anyone answer this query?

The control knob for the fridge runs from 0 (ambient) to 7 (coldest) .

If I have reduced the temp down to,say, 6 and it then stays there slowly warming to 5 when the compressor kicks in and takes it back to 6, will this use more or the same energy than if the fridge is on 3 ,reducing to 2 and kicking back in to get to 3.

If the answer is the same amount of energy used, I might as well leave it on 6 permanently instead for constant cold beers instead of turning it to 3 at night cos I think it is reducing energy use?

 

[RAI]

The higher your fridge setting the colder the compressor tries to keep the interior. It is the temperature difference between inside and outside that determines the energy used. So your fridge will use less power if set at 3 than it will at 6. It will probably be a square law relationship, so setting 3 might use a quarter of the power of 6.

 

[ianj99]

Cont'd. . . . . .
This has changed and I am back to being more vigilant.

The regulator definitely is not right for the job. It came as part of the solar panel kit and appears to be the most basic modelavailable. As I bought two panel kits I have a spare sitting in a locker as well.

Get a pro quality (ie a lot more expensive) regulator and your problems should be over and the lesson is - for battery charging, as opposed to real time solar power and fully charged battery maintaining, you need more than a £10 regulator.

 

[vyv_cox]

I would still like to know the level of acid in the single battery. With good quality regulator, lower output panels and 330 Ah battery bank we need to top up with water periodically.

 

[macd]

Get a pro quality (ie a lot more expensive) regulator and your problems should be over and the lesson is - for battery charging, as opposed to real time solar power and fully charged battery maintaining, you need more than a £10 regulator.

+1

 

[ex-Gladys]

Hi

So, latest news, yesterday 1st thing we switched off everything we could on the boat and just left the battery to charge via the panels. It cut to floating at approx 10.30 am and sat all day with the charge on the battery terminals showing between 13.4 and 13.6. Last night after the sun had gone down it settled to 12.6 volts.

When I woke this morning before dawn and checked, the regulator lights were showing green and the battery 12.4 so it appears there is not drainage thru the night to any significant degree.



The battery is now reading 13.3 and the regulator 16.01. Bright sunshine no shadows.

I think your battery is in trouble as Viv suggested. Over the last couple of months we've spent a number of days aboard, running our compressor Waeco coolbox, Tacktick hull and NMEA transmitters, cabin lights (LED's). At no point first thing in the morning did the batteries show less than 12.7v. In the day a combination of the panels and variable amounts of motoring charged the batteries but we only ever take mains to run a mains kettle and toaster. Admittedly we have 330AH (2years old) and 90W of panels, but even so 12.4 is low IMHO,

 

[ianj99]

I think your battery is in trouble as Viv suggested. Over the last couple of months we've spent a number of days aboard, running our compressor Waeco coolbox, Tacktick hull and NMEA transmitters, cabin lights (LED's). At no point first thing in the morning did the batteries show less than 12.7v. In the day a combination of the panels and variable amounts of motoring charged the batteries but we only ever take mains to run a mains kettle and toaster. Admittedly we have 330AH (2years old) and 90W of panels, but even so 12.4 is low IMHO,

So your advice is for him to buy new batteries? 12.4v represents the true state of charge of the battery which is low precisely because the solar regulator is not upto the job. It never allows the batteries to exceed 13.6v which is not high enough to charge them above about 80% - ie ~12.4v after resting.
Unless you can see 14 to 14.4v at the battery terminals during charging you are wasting upto 20% of your expensive batteries capacity and also shortening their life.

Why is it so hard for this simple concept to be grasped? No wonder there are so many threads on here about battery charging, batteries not lasting, not accepting charge, not supplying the expected ampere hours! The answer is not larger batteries or newer ones* - its the charging & battery management that needs looking into and yes, you do need to keep an eye on the electrolyte level, which will drop more quickly when trying to get as close to 100% charge into the battery.

* unless poor charging regime is to blame.

 

[vyv_cox]

B

So your advice is for him to buy new batteries? 12.4v represents the true state of charge of the battery which is low precisely because the solar regulator is not upto the job. It never allows the batteries to exceed 13.6v which is not high enough to charge them above about 80% - ie ~12.4v after resting.
Unless you can see 14 to 14.4v at the battery terminals during charging you are wasting upto 20% of your expensive batteries capacity and also shortening their life.

Why is it so hard for this simple concept to be grasped? No wonder there are so many threads on here about battery charging, batteries not lasting, not accepting charge, not supplying the expected ampere hours! The answer is not larger batteries or newer ones* - its the charging & battery management that needs looking into and yes, you do need to keep an eye on the electrolyte level, which will drop more quickly when trying to get as close to 100% charge into the battery.

* unless poor charging regime is to blame.

Since Gladys was supporting my comment I feel impelled to reply. Over the past ten years on several occasions we have suffered a marked deterioration in battery storage capacity very similar to the OP's. On almost every one we have found the cause to be that electrolyte level in the cells had reduced to a marked extent. This is perfectly normal with open cell batteries, even those that do not reach 14.4 or more charging voltage. There have been times when I suspect some cells were almost dry as the volume of water needed to top up has amounted to close on a litre per battery.

I also think that the OP is expecting an awful lot from a single 150 Ah battery. We run our fridge full time but there are few other users. We had 2 x 110ah batteries but upgraded to 3 x 110ah a few years ago. The difference was remarkable, overnight voltages improving from less than 12.0 to 12.4.

 

[ianj99]

B

Since Gladys was supporting my comment I feel impelled to reply. Over the past ten years on several occasions we have suffered a marked deterioration in battery storage capacity very similar to the OP's. On almost every one we have found the cause to be that electrolyte level in the cells had reduced to a marked extent. This is perfectly normal with open cell batteries, even those that do not reach 14.4 or more charging voltage. There have been times when I suspect some cells were almost dry as the volume of water needed to top up has amounted to close on a litre per battery.

I also think that the OP is expecting an awful lot from a single 150 Ah battery. We run our fridge full time but there are few other users. We had 2 x 110ah batteries but upgraded to 3 x 110ah a few years ago. The difference was remarkable, overnight voltages improving from less than 12.0 to 12.4.

I was agreeing, not disagreeing - if he has let the cells run dry he will have damaged the battery but we've yet to hear what the levels were.

Electrolyte loss is a sign of effective charging (or overcharging - though this seems unlikely in this case). Charles Sterling makes a point that after fitting one of his digital alternator regulators, that the electrolyte level must be checked as loss is only to be expected and is also a case for not using sealed LA batteries. (high ambient temperature will also contribute to loss through simple evaporation)

I also agree that he is working the battery hard: I wonder how many deep discharge cycles the Vetus batteries are rated at?
A better regulator and more capacity would be the ideal solution and prolong battery life as well.

 

[skipmac]

Hi all,

Firstly, thanks to everyone who has taken the time to respond, once again this forum has shown that there are truly helpful and considerate sailing folk out there.

So, latest news, yesterday 1st thing we switched off everything we could on the boat and just left the battery to charge via the panels. It cut to floating at approx 10.30 am and sat all day with the charge on the battery terminals showing between 13.4 and 13.6. Last night after the sun had gone down it settled to 12.6 volts.

When I woke this morning before dawn and checked, the regulator lights were showing green and the battery 12.4 so it appears there is not drainage thru the night to any significant degree.

We have now switched the fridge back on and it is chilling down and has been on for some two hours.

The battery is now reading 13.3 and the regulator 16.01. Bright sunshine no shadows.

I will leave it in this mode all day and see whether the battery drains as quickly this night when the sun goes down. Watch this space!

Conclusions so far.

I have probably been a bit blasé about battery management thinking big panels, large batteries, no worries. This has xhan

Hi Steve,

Could you clarify one point. Where are you reading 16.01 at the regulator? Is it at the input IE the panel side or output to the batteries?

I would respectfully disagree with the statement "large batteries". The load from your fridge is a lot for the capacity you have. Have to second the recommendation from ianj99. Come replacement time you should really upgrade from a leisure battery to a true deep cycle and a better regulator. (We are quite free with spending your money for you, as you can see.)

 

[steve123]

If the OPs Vetus batteries are like the ones I have then they are sealed 'maintenance free' and cannot be topped up. Like these:
http://www.vetus.com/electricity-on-board/batteries/vetus-maintenance-free-battery-105-ah.html

 

[ianj99]

If the OPs Vetus batteries are like the ones I have then they are sealed 'maintenance free' and cannot be topped up. Like these:
http://www.vetus.com/electricity-on-board/batteries/vetus-maintenance-free-battery-105-ah.html

They are not a good choice for the OP's use. Trojan are the batteries of choice for deep cycle, rapid charging, with regular checks on the electrolyte level.

A pair of series connected T105s would be ideal. https://www.tayna.co.uk/T-105-Trojan-Battery-Deep-Cycle-T105-P7253.html

I was thinking about what I would use in the OP's position and came up with:

Three 180w panels ~ £700 30amp max output
One pair of Trojan T105s £200 Max recommended charging current is 10-13% of C20 ah rating (10% of 225 = 22amps, 13% = 30amps)
One 25amp 3stage controller £300 eg Victron

Total ~ £1200.

Life expectancy say 5years (panels will be longer) so cost per year = £235 which is acceptable to run a fridge.

I added a third panel as I forgot to allow for powering the fridge AND charging the battery during the day. When the fridge compressor switches off, the max current from the 3panels of 30amps is still within the recommended battery charging current.

 

[Chris_Robb]

I noted that the person who posted in post no. 8. You had removed an alternator charge controller and the alternator now charges at 14.5V. Does the alternator have a multistage charge controller in it? If it doesn't and you motor for 20 hours, you may well overcharge the batteries.

I stand corrected, but that is the point of an advanced alternator regulator, to boost the charge to 14.4 V until it is deemed full, then go on to float. However if the alternator's own regulator is set to 14.5V, then the Advanced regulator is effectively being overruled by the alternator all the time. So I don't understand why the alternator controller "impeded" the charging voltage. (other than bad connections).

 

[steveghoward]

Hi all,

Sorry about the delay in updating everyone, but we have been waiting for the electric techno for the last few days.

He arrived yesterday and metered everything that has any relevance to the battery charging.

As I suspected, the second battery is also on its way out and is holding less and less charge and, without a doubt, along with the other battery we had, is defo faulty. Cue what I feel is going to be a long and protracted discussion with Vetus, the manufacturers. Their first comment on their website is that any warranty problems should be discussed with the retail outlet which, as previously mentioned is going to be difficult as the units were bought in the south of France and we are now in Greece. However, I am sure this will be ongoing and I will keep all informed of progress (or otherwise!) regarding this.

In the meantime, I have replaced the faulty battery with twin Varta 180. amp hour batteries which, coincidentally, are the same size as the previous 140 ah units.

Also, I have had the fridge compressor cleaned, serviced and re gassed which has transformed its operation. It is almost embarrassing how much more efficient it is operating, with the subsequent reduction in energy use.

The only thing I still have reservations about is the techie seemed to think that the regulator in place is perfectly adequate for the task in hand. I shall be watching the whole operation like a hawk and if there is any doubt I will get it swapped. I may do anyway, ha'poth of tar etc.

anyway, the problem appears to have been solved for the moment (apart from the warranty issue) and I would like to thank all of you who took the time and effort to give support and suggestions over the last few weeks.

It is much appreciated.

Regards

Steve and Jan

Yacht Serenite.

 

[lpdsn]

In the meantime, I have replaced the faulty battery with twin Varta 180. amp hour batteries which, coincidentally, are the same size as the previous 140 ah units.

I'd be suspicious of that, especially if they are roughly the same weight (which basically means same Pb content). Means one sellers Ah isn't as good as the other's Ah.

 

[ianj99]

Hi all,The only thing I still have reservations about is the techie seemed to think that the regulator in place is perfectly adequate for the task in hand. I shall be watching the whole operation like a hawk and if there is any doubt I will get it swapped. I may do anyway, ha'poth of tar etc.

anyway, the problem appears to have been solved for the moment (apart from the warranty issue) and I would like to thank all of you who took the time and effort to give support and suggestions over the last few weeks.

It is much appreciated.
Yacht Serenite.

I would definitely fit a multi stage regulator, even if there isn't time to use equalization mode to reach 100%, it will probably maintain the charging current at a higher level and therefore put more AHs back than the cheap regulator which maybe tapering off the charging current too much as float voltage is reached.

I am surprised at the problems with the Vetus batteries and if it was the battery management which caused their premature demise, you don't want a repeat with the new batteries.

 

[Chris_Robb]

Hi all,


The only thing I still have reservations about is the techie seemed to think that the regulator in place is perfectly adequate for the task in hand. I shall be watching the whole operation like a hawk and if there is any doubt I will get it swapped. I may do anyway, ha'poth of tar etc.

/QUOTE]

Lets just do a final audit of your system. ( may have missed some info in the posts- sorry if I have)

1. Do you have a battery monitor such as a Nasa BM1? - Purpose - Monitor voltage on house batteries and most important - see the level of charge coming into the house batteries from solar and engine.

2. On the alternator, do you have a charge controller such as the Sterling? Raises the output voltage to 14.4V to get a proper charge. (under 14V charging is a waste of time unless you live in a marina)

3. Confirm voltages when engine charging. should be 14.4V

From you description of the solar regulator, it is not fit for purpose. You should see the same voltage on the solar regulator as at the battery. If not, it must be disconnecting and not charging the batteries at all. I have a basic STeco 30amp controller, and I will see over 14V on it when the fridge/freezer is not running (draws 8 amps).


So all your testing really runs from having a decent monitor on the batteries - analogue voltmeters are just not accurate enough for the job. So the crucial question is what amps are going in to the battery and from the different sources. Without this knowledge you can have no idea what your system (solar and engine) is doing.

Are the techies right? I recently had 4 new batteries put in. The installer wanted to lower the charge rate to under 14 V - he said the batteries would last longer - well I suppose he was used to boats which are marina based who plug in everyday! The only way is to understand it yourself - plenty on the internet, and more than enough knowledge on this site.

 

[ianj99]

Lets just do a final audit of your system. ( may have missed some info in the posts- sorry if I have)

1. Do you have a battery monitor such as a Nasa BM1? - Purpose - Monitor voltage on house batteries and most important - see the level of charge coming into the house batteries from solar and engine.

2. On the alternator, do you have a charge controller such as the Sterling? Raises the output voltage to 14.4V to get a proper charge. (under 14V charging is a waste of time unless you live in a marina)

3. Confirm voltages when engine charging. should be 14.4V
From you description of the solar regulator, it is not fit for purpose. You should see the same voltage on the solar regulator as at the battery. If not, it must be disconnecting and not charging the batteries at all. I have a basic STeco 30amp controller, and I will see over 14V on it when the fridge/freezer is not running (draws 8 amps).
So all your testing really runs from having a decent monitor on the batteries - analogue voltmeters are just not accurate enough for the job. So the crucial question is what amps are going in to the battery and from the different sources. Without this knowledge you can have no idea what your system (solar and engine) is doing.

Are the techies right? I recently had 4 new batteries put in. The installer wanted to lower the charge rate to under 14 V - he said the batteries would last longer - well I suppose he was used to boats which are marina based who plug in everyday! The only way is to understand it yourself - plenty on the internet, and more than enough knowledge on this site.

I only wish the message would get through! We can only keep hammering away promoting correct battery management.
Sadly, as demonstrated by posts on a nearby thread, a head in the sand attitude seems to prevail - ie if I don't have battery problems (for now) my charging regime must be fine.

The Golden rules:
Avoid discharging below 40% for maximum battery life (about 11.95v no load on a rested battery)
Never leave a battery partially discharged
Keep a check on the electrolyte level of non sealed batteries, especially if rapid charging is practiced.
Use multi stage charging for ALL charging
Remember that without a multi stage regulator, the battery is unlikely to get above 85% charge, so the useable capacity is 85 - 40 = 45% of the rated AH capacity. In other words, if you use 50AH between recharges, you need to fit a 100ah battery and the charger needs to be able to put about 60AH back in the available charging time.
Fit a digital battery monitor such as the Nasa BM1 - if you never see over 14v even with the load removed, then you are undercharging.