Electrics / Leisure battery problem

[Fazerloz]

Our coffee unit give batteries a hard life. The battery when new will easily work a 10 hour day. Depending on the make of battery they will last from as little as 6 weeks up to what we use now Trojans 12mnths. When knackered and only lasting 4hrs the volt meter will be reading 12.5v and when put under load will drop into the low 10s which would be below your fridge requirements causing it to fault. When taken off load the battery voltage rapidly returns back to 12.5/12.4v which would make you think the battery was good. But it can't supply required amount of power.
Do not forget with a 110ah battery you will only in reality have a usable 60/70ah without doing damage dependant on the quality of the battery. If so you are doing well to get your 5 days without ehu.
At this moment I am having the same problem with the comp fridge in the MH as you and for some reason I am back peddling from buying new batteries when I know it would sort it. Suppose it could have something to do with spending £400 on new batteries.

 

[Fazerloz]

Thanks, I could try that last idea in conjunction with borrowing another battery to try. Not sure if ATS will be very forthcoming re the warranty though. It doesn't seem to matter what anyone else says, just what their check says.

Warranties on batteries may as well be written on toilet paper as there are that many get outs. [how deep its been discharged, for how long , how its charged, how many cycles its done etc ,etc.].

 

[harrow]

Our coffee unit give batteries a hard life. The battery when new will easily work a 10 hour day. Depending on the make of battery they will last from as little as 6 weeks up to what we use now Trojans 12mnths. When knackered and only lasting 4hrs the volt meter will be reading 12.5v and when put under load will drop into the low 10s which would be below your fridge requirements causing it to fault. When taken off load the battery voltage rapidly returns back to 12.5/12.4v which would make you think the battery was good. But it can't supply required amount of power.
Do not forget with a 110ah battery you will only in reality have a usable 60/70ah without doing damage dependant on the quality of the battery. If so you are doing well to get your 5 days without ehu.
At this moment I am having the same problem with the comp fridge in the MH as you and for some reason I am back peddling from buying new batteries when I know it would sort it. Suppose it could have something to do with spending £400 on new batteries.

I know.

I feel real pain when I spend money.

Have I told you that I am retired now, only another six years till I get my state pension !

:wacko::wacko::wacko:

 

[Fazerloz]

I know.

I feel real pain when I spend money.

Have I told you that I am retired now, only another six years till I get my state pension !

:wacko::wacko::wacko:

A very similar boat to me. Paddles and creeks. But keep your chin up.

 

[molly 2]

The op state's the fridge uses 5 amph ,I was leads to believe they use 2 amph when running ,much less when the thermastat turns off .sterling do a fridge comparison test on U tube, worth a look .

 

[Deleted member 5816]

I believe they draw 5 amp but as there is the thermostat to regulate the temperature they reckon an average of 2 amps, with possible battery damage and the fridge working overtime in the warm weather it looks more than likely a faulty battery most people don't recognize the damage by allowing a battery to go flat ( the op may not have done this) but without all the details it's difficult to give a definitive answer to his problems

Alf

The op state's the fridge uses 5 amph ,I was leads to believe they use 2 amph when running ,much less when the thermastat turns off .sterling do a fridge comparison test on U tube, worth a look .

 

[Conroy]

Our coffee unit give batteries a hard life. The battery when new will easily work a 10 hour day. Depending on the make of battery they will last from as little as 6 weeks up to what we use now Trojans 12mnths. When knackered and only lasting 4hrs the volt meter will be reading 12.5v and when put under load will drop into the low 10s which would be below your fridge requirements causing it to fault. When taken off load the battery voltage rapidly returns back to 12.5/12.4v which would make you think the battery was good. But it can't supply required amount of power.
Do not forget with a 110ah battery you will only in reality have a usable 60/70ah without doing damage dependant on the quality of the battery. If so you are doing well to get your 5 days without ehu.
At this moment I am having the same problem with the comp fridge in the MH as you and for some reason I am back peddling from buying new batteries when I know it would sort it. Suppose it could have something to do with spending £400 on new batteries.

Been and done a check of the battery like you refer to, with my multimeter. With fridge off it read 13.25; switched fridge on and it read 12.90; switched fridge off again and it read 13.25. Does this imply the battery is in fact ok? I was beginning to hope it was a faulty battery, it would be more expense to buy a new one (on top of what I've already spent trying to sort this) but at least it would get it sorted, hopefully.

 

[Conroy]

I believe they draw 5 amp but as there is the thermostat to regulate the temperature they reckon an average of 2 amps, with possible battery damage and the fridge working overtime in the warm weather it looks more than likely a faulty battery most people don't recognize the damage by allowing a battery to go flat ( the op may not have done this) but without all the details it's difficult to give a definitive answer to his problems

Alf

My understanding is that you divide the wattage of the appliance by 12 to get the amps usage. So a wattage of 60 would give amps usage of 5 per hour. I've just googled my fridge and it appears to be 45 watt, so the usage should be 3.75 per hour. Taking into account the thermostat operation I can see how 2 amps per hour could be right. If a battery only ever gets to say 70% of full charge, which would be 77 amps for a 110 amp battery, then surely it should still last nearly 2 days, taking into account the additional trickle in from the solar panel. But it's actually running out in less than 10 hours.

I may not be technical but I'm not bad at maths, which is why I take dispute with the auto electrician's comment about it all being a matter of maths. I get that but the figures don't seem to add up.

 

[pgandt]

As a matter of interest whats the nake and model of the fridge. I dont know your type of motorhome but can you run it on LPG?


Also lesuire batteries whilst having in your case 110amp capcity they will not give you all of that to use. Once they get to approx 80% of capcity they basically cannot supply enough power at the ampage you need to run in this case your fridge. Consequently the fridge will stop working on 12v

Ps i am not an expert in any way but the above is my understanding about battery capcities etc

 

[Conroy]

As a matter of interest whats the nake and model of the fridge. I dont know your type of motorhome but can you run it on LPG?


Also lesuire batteries whilst having in your case 110amp capcity they will not give you all of that to use. Once they get to approx 80% of capcity they basically cannot supply enough power at the ampage you need to run in this case your fridge. Consequently the fridge will stop working on 12v

Ps i am not an expert in any way but the above is my understanding about battery capcities etc

It's a Waeco MDC65 compressor fridge that doesn't work off gas.

My understanding too, from what I've read previously, in my last reply to Alf I actually assumed 70% as maximum capacity, so if 80% is more the case it should last even longer.

Now I understand the maths, I don't really know how we managed 5 days in the past without hook-up or driving, but if I could get back to 2 to 3 days I'd be pleased.

 

[harrow]

It's a Waeco MDC65 compressor fridge that doesn't work off gas.

My understanding too, from what I've read previously, in my last reply to Alf I actually assumed 70% as maximum capacity, so if 80% is more the case it should last even longer.

Now I understand the maths, I don't really know how we managed 5 days in the past without hook-up or driving, but if I could get back to 2 to 3 days I'd be pleased.

IF nothing else has changed then it has to be the battery.

As long as nothing has changed and the leisure battery still receives the same amount of charge current.

:wave::wave::wave:

 

[Deleted member 5816]

If you did get the times you stated originally, and the fridge is ok then the only other thing is the charge by the solar panels an you test the charge from them. If they are not charging adequately then this looks like the problem. You state 13.25 no fridge 12.90. With fridge.


Alf

It's a Waeco MDC65 compressor fridge that doesn't work off gas.

My understanding too, from what I've read previously, in my last reply to Alf I actually assumed 70% as maximum capacity, so if 80% is more the case it should last even longer.

Now I understand the maths, I don't really know how we managed 5 days in the past without hook-up or driving, but if I could get back to 2 to 3 days I'd be pleased.

 

[molly 2]

I believe they draw 5 amp but as there is the thermostat to regulate the temperature they reckon an average of 2 amps, with possible battery damage and the fridge working overtime in the warm weather it looks more than likely a faulty battery most people don't recognize the damage by allowing a battery to go flat ( the op may not have done this) but without all the details it's difficult to give a definitive answer to his problems

Alf

makes sense Alf, the dometic 3 way fridge takes 10 amps constant, mine causes lots of problems for my uero 5 smart alternator . another member runs a similar compressor fridge no problem he has a large battery bank and a 400 w solar panel .I am beginning to think the op battery has hard a life and is well below the original capacity .

 

[Chris356]

We had a waeco in our t5 think the cut off voltage is 10.5 volts so if you're fridge is cutting off after 8 hours then your battery is goosed

 

[Fazerloz]

Been and done a check of the battery like you refer to, with my multimeter. With fridge off it read 13.25; switched fridge on and it read 12.90; switched fridge off again and it read 13.25. Does this imply the battery is in fact ok? I was beginning to hope it was a faulty battery, it would be more expense to buy a new one (on top of what I've already spent trying to sort this) but at least it would get it sorted, hopefully.

I take it these figures are taken during the day with the solar panel still connected to the battery. If so not a true reflection of the battery voltage. See what the readings are at night when you have no input from panel.

 

[Deleted member 5816]

By my reconning it will be a Renault 2.5 Euro 4 engine

Alf

Oh dear. I just re-read your original post. If your van is 54 reg, it could be Euro 6 and will be Euro 5.

What I'm writing here applies to Euro 6, but also can apply to Euro 5. You may find out whether it affects your van by reading the manual, or by connecting a multimeter to the battery with the engine running, but I fear you do have this setup, which may be the root of your problem.

One of the ways that vehicle makers got past increasingly stringent pollution limits was to install "Smart Alternators". Basically these reduce fuel use by generating a lot of power when decelerating and braking, and stuffing it into the battery.

For this to work, they need to have some spare capacity in the battery. So all the rest of the time, they leave the battery partly empty. Typically they charge the battery to about 12.4v or so instead of the 14.54v that normal AGM batteries are charged to

Yup, they deliberately don't fill the battery up. This is fine for starter batteries. And it does reduce pollution, save fuel and is an all-round good thing.

However, if you have a split charge relay fitted, your leisure battery is also being kept part empty as well. The relay simply joins the batteries together when the engine is running. In fact, it is quite likely that the leisure battery will be discharging as you drive, topping up the starter battery from the power the solar panels put in.

This is a well-defined issue but the industry is hoping you won't notice, because the fix is not cheap. Basically, you need a device that will take the 12.4v supply from the engine battery/alternator and convert it to a 14.54v supply for your leisure batteries. And that will also protect your leisure battery from the 15.5v surge when you brake.

The good news is that these are readily available off-the-shelf (as far as I know). The bad news is that they cost over £300 plus fitting (which is not specially difficult) Although other cheaper makes are available, I would buy one made by Sterling Power Products.

One other alternative is to fit a voltage-sensing split charge relay, which will leave the batteries separate unless the voltage rises. But this means you'd get very little charge when driving. It is possible that this is what is fitted already. You will need to ask someone who knows your van's specifications (not me!)

 

[molly 2]

Problem I have with my uero 5 smart alternator is after a few days on hookup the engine battery is charged by the on board charger ,so the engine battery is overcharged to about 12 .7 volts this shuts the alternator down until battery drops to about 12.2 volts so no charge is going to either battery , the fridge On 12 v volts flatterns the leisure battery until the engine battery drops to 12.2 v then it charges the engine battery up to about 12.4 not enough to charge leisure battery .I have a voltmeter connected to sig lighter socket it shows anything from 12.2 to 15 v if I drive with fridge off the leisure holds its charge .I have considered the sterling B toB but have concerns about it conflicting with the CBE 200 electronics .I contacted sterling they said could not comment on my system but think it should be ok ?. So no comeback on them if it frys my electronics,,.I have fitted a 100w solar panel which is a big help .as Charles sterling says on you tube videos. Not fit for purpose.

 

[Canalsman]

I believe you're incorrect about the fridge when operated on 12 volts.

Three way fridges are always wired so that the 12 volt feed is provided directly by the vehicle alternator ...

 

[Conroy]

I take it these figures are taken during the day with the solar panel still connected to the battery. If so not a true reflection of the battery voltage. See what the readings are at night when you have no input from panel.

Did another check late last night as you suggested. First reading with fridge off was 12.92; then 12.45 with fridge on; then 12.67 with fridge off again. I'm guessing that the fact it was not much lower with the fridge on indicates the battery may be OK after all. OR DOES IT? Maybe that's too simplistic. As I've already said, I'm not very technical.

I'd love the battery to be the problem, as I assume replacing it would be the simplest solution. I'm worried though that I might incur the expense and it makes no difference. A couple of people have mentioned that a battery can possibly seem ok when tested but still be faulty, by discharging too quickly. Maybe I need to pursue that, maybe even have a chat with the manager at ATS about it.

We're taking off at the end of August for several weeks, to Croatia and some of the Balkan countries, so I really hope I can get this problem sorted before then.

 

[Conroy]

By my reconning it will be a Renault 2.5 Euro 4 engine

Alf

The van is a Renault Master 2.5, 54 reg. Didn't know about the Euro rating so googled it and it seems it's Euro 3, as registered before 1 January 2005. Don't know if this makes any difference.