POWERMASTER, has anyone heard of these?

[cereal tiller]

To expand on Alan's post and picking up on your points, 13.6V is not 'fully charged' it is in fact what is known as the 'surface charge' voltage which can be seen immediately after charging. Think of it as the voltage sitting on the surface of the plates within the battery (that's not what it is but it suffices for an explanation). After a period of several hours of resting that voltage will have had a chance to permeate through the plates and stabilise and only at that time can you read the voltage to determine the true state of charge. 12.7V on a rested battery is fully charged. 12.2V (50% ish) is as low as you should ever take ordinary leisure batteries if you want a long life from them.

 

Obviously, sitting around for hours waiting for the battery voltage to stabilise isn't very convenient. Fortunately there are other methods.

 

The very best way to determine the SoC is to measure the specific gravity (specific density) of the electrolyte using a hydrometer. This however is messy, somewhat dangerous, and can only be done with open wet cell batteries.

 

Another (far more convenient) method of determining when the batteries are fully charged is to look at the charging current on an ammeter. When the current drops to around 1% or 2% of the battery capacity (so 3.3-6.6A for a 330Ah bank) OR when the current hasn't dropped for about an hour then the batteries are fully charged.

 

A SmartGauge can be very useful for the non-technical to monitor their battery usage.

 

Hope that helps,

Tony

I have explained surface charge as the froth on a fizzy drink when it is first poured.

 

CT

[christophert]

It does, thank you all. Tomorrow I'll disconnect the batteries as they will have had an overnight charge. I'll take a reading straight away and then periodically as the day goes on. So the batteries may be damaged even though the green indicators on the batteries themselves show they are healthy? If the batteries check out ok, then there must be something draining them ... a dodgy wire somewhere on the boat maybe

[christophert]

To elaborate on what I said above, the batteries indicators are showing green. If the batteries were damaged, surely this would not be the case?

[stratford4528]

It does sound as if your batteries are faulty. If you put a battery tester on them which simulates a heavy load it will tell you what the volt drop is. There are 110 amp batteries on ebay with 4 years guarantee. I paid £59 each

[christophert]

It does sound as if your batteries are faulty. If you put a battery tester on them which simulates a heavy load it will tell you what the volt drop is. There are 110 amp batteries on ebay with 4 years guarantee. I paid £59 each

Cheers. That's why I'm confused. I had them deep charge tested at a marina, was told they're fine. Also the green indicators on the batteries say they are healthy. I'm thinking something is draining them, but what?

[WotEver]

A load test tells you nothing about the capacity of the battery and I do wish folk who should know better would stop offering it as some kind of 'battery health check'. If you have been consistently under charging them (which I believe you have) especially if you've been consistently over-discharging them (which I KNOW you have) then their capacity will be much reduced. Hence you can charge them up but their capacity is so diminished that they discharge very quickly.

 

Mine and Alan's posts tell you everything you need right now.

 

Yes it is possible that you have some kind of mysterious load but it's unlikely.

 

There's no point in saying 'I don't like electrics' and then spending no time at all in trying to learn some basics - not unless you want to buy new batteries every couple of months.

 

You need some monitoring devices. At the very least an ammeter and based on your knowledge I think it would be best coupled with a SmartGauge.

[christophert]

A load test tells you nothing about the capacity of the battery and I do wish folk who should know better would stop offering it as some kind of 'battery health check'. If you have been consistently under charging them (which I believe you have) especially if you've been consistently over-discharging them (which I KNOW you have) then their capacity will be much reduced. Hence you can charge them up but their capacity is so diminished that they discharge very quickly.

 

Mine and Alan's posts tell you everything you need right now.

 

Yes it is possible that you have some kind of mysterious load but it's unlikely.

 

There's no point in saying 'I don't like electrics' and then spending no time at all in trying to learn some basics - not unless you want to buy new batteries every couple of months.

 

You need some monitoring devices. At the very least an ammeter and based on your knowledge I think it would be best coupled with a SmartGauge.

'There's no point in saying 'I don't like electrics' and then spending no time at all in trying to learn some basics' - To answer, I have been spending a lot of time trying to learn the basics and learning I am.

'especially if you've been consistently over-discharging them (which I KNOW you have)' How do you know? No, I have not been constantly over discharging them. I do not, and never have.

I am not doing or done anything different now to what I did with my old batteries which lasted eight years. The current batteries are two years old. Yes, they may be faulty, and I will explore further, and yes, my battery charger may also be faulty and I'll need to check it out, but no, it's nothing to do with my stupidity or knowledge of electrics

[WotEver]

'especially if you've been consistently over-discharging them (which I KNOW you have)' How do you know? No, I have not been constantly over discharging them. I do not, and never have.

I know from this comment, which shows that you do...

 

... how I monitor the batteries is by inverter letting me know there's not enough in them...

A fully charged battery sits at around 12.7V. A 50% discharged battery (as low as you should take a standard leisure battery) has approximately 12.2V. The inverter will cut out at around 11.9V. That is FLAT. And a leisure battery should never be taken that low.

 

Tony

[WotEver]

'There's no point in saying 'I don't like electrics' and then spending no time at all in trying to learn some basics' - To answer, I have been spending a lot of time trying to learn the basics and learning I am.

Yes, I apologise for that, I was mixing you up with another poster who recently said that he hates electrics and was basically burying his head in the sand. So that was completely uneccessary. Please accept my apology.

 

Edited for auto-incorrect.

Edited October 10, 2016 by WotEver

[WotEver]

It does sound as if your batteries are faulty. If you put a battery tester on them which simulates a heavy load it will tell you what the volt drop is...

... which tells you precisely nothing about their capacity and is about as useful as a chocolate teacup.

 

Further, it can actually damage the plates in a leisure battery.

[christophert]

New batteries may be sensible step. Just concerned if there is a fault causing damage that new batteries will meet the same fate.

Also, not too sure if I can have my battery charger tested, but if not, a new battery charger may be a step in the right direction, The one I have now is eight years old.

[WotEver]

If you fit an ammeter you will know...

 

1. How well your alternator is working.

2. How well your charger is working.

3. When your batteries are fully charged.

4. Whether or not you have a spurious load flattening the batteries.

 

Tony

[christophert]

If you fit an ammeter you will know...

 

1. How well your alternator is working.

2. How well your charger is working.

3. When your batteries are fully charged.

4. Whether or not you have a spurious load flattening the batteries.

 

Tony

Alternator working fine I believe. Will do a parasitic draw test tomorrow - today I had it off shorline to go through electrics and to see if any electrical item was draining the batteries excessively. after a while the 12v led lights in the bedroom began to dim where the other lights throughout were fine. In the past, they have all dimmed together. I will check wiring in bedroom. I agree with what you say, the batteries have gone flat too many times too quickly and most likely kaput

[dor]

And don't take any notice of the little green "magic eye" indicators. I assume they are little floats that drops if the SG drops. but in my experiecne they cheerfully look green on a virtually dead highly sulphated battery and don't really tell you anything about the condition.

[mross]

Please tell us the Ah of each battery and how many batteries you have in your domestic bank. The experts here will find this useful. Also get a good hydrometer. This is a really easy to use one on eBay for £14.

 

http://www.ebay.co.uk/itm/E-Z-Red-SP101-Battery-Hydrometer-original-easy-to-read-/322276243231?hash=item4b0929371f:g:n3cAAOSweW5VbMOf

 

Also on Amazon at £20.

 

https://www.amazon.co.uk/E-Z-Red-EZRS101-Battery-Hydrometer/dp/B000JFHMRU/ref=sr_1_1?ie=UTF8&qid=1476165671&sr=8-1&keywords=E-Z+Red+battery

 

No point buying new batteries until you get to the root cause of your problems.

Edited October 11, 2016 by mross

[mross]

Waeco 1512 is an inverter. Could yours be a 1215? This is a 15A charger - please confirm.

Edited October 11, 2016 by mross

[WotEver]

Please tell us the Ah of each battery and how many batteries you have in your domestic bank. The experts here will find this useful. Also get a good hydrometer. This is a really easy to use one on eBay for £14.

 

http://www.ebay.co.uk/itm/E-Z-Red-SP101-Battery-Hydrometer-original-easy-to-read-/322276243231?hash=item4b0929371f:g:n3cAAOSweW5VbMOf

 

Also on Amazon at £20.

 

https://www.amazon.co.uk/E-Z-Red-EZRS101-Battery-Hydrometer/dp/B000JFHMRU/ref=sr_1_1?ie=UTF8&qid=1476165671&sr=8-1&keywords=E-Z+Red+battery

 

No point buying new batteries until you get to the root cause of your problems.

It will (should) be in the instructions with the hydrometer but it's worth stressing that Specific Density readings must be temperature compensated to give an accurate result.

 

Anyway, I think an ammeter would be if far more use right now. It would instantly show any unexpected load, it would prove the charger is working (or not, of course), it would show when the batteries are fully charged...

[Phil Ambrose]

It does sound as if your batteries are faulty. If you put a battery tester on them which simulates a heavy load it will tell you what the volt drop is. There are 110 amp batteries on ebay with 4 years guarantee. I paid £59 each

Ditto

Phil

[Alan de Enfield]

It does sound as if your batteries are faulty. If you put a battery tester on them which simulates a heavy load it will tell you what the volt drop is. There are 110 amp batteries on ebay with 4 years guarantee. I paid £59 each

 

Guaranteed against what ?

 

You will find that your batteries are (probably) rated for something like 200 cycles to 70% SOC which is soon accumulated when charging / discharging every day on a boat.

 

The guarantee is NOT a guarantee of the batteries 'holding their charge', or a guarantee of the batteries 'holding capacity' for 4 years as you can destroy a battery in a matter of a few days by discharging it too far and then not recharging it correctly.

 

You will find that the 'guarantee' you have is against 'manufacturing defects' such as the case splitting and pouring acid all over your boat - however they will not cover the damage caused - just replace the battery.

 

To the Op - DO NOT buy any more batteries until you have sorted out you electrics - firstly undertake an electrical usage audit, then plan how to replace that used, and monitor your usage so you know when. and how much to replace.

 

Relying on your Inverter telling you the batteries are flat is "not ideal"

[cuthound]

Like WotEver Ever I would recommend d an ammeter.

 

This will allow you to check many things.

 

Tail current - so you know you are fully charging your batteries.

 

Connected load - so you know what equipment is draining your batteries by how much.

 

Capacity - by switching on equipment to loads until you reach 10% of battery capacity (11 amp load for 110 ah battery, and measuring voltage every hour for up to 5 hours. Take the load off and measure the battery voltage every hour. When it reads 12.2 volts the battery has 50% capacity left.

[dor]

Ammeters can tell you a lot if you know what they are saying, especially when used in conjunction with an accurate voltmeter.

 

I've got three ammeters - one on the negative return which tells me the net total going into or out of the batteries, one on the DC panel meter giving the non-inverter current, and therefore by inference the difference gives me the current used by the inverter.

 

The third one is on the supply from the solar panel, after the controller. I think a lot of people would benefit from this - only a few pounds, with shunt, on eBay. There must be a lot of people who haven't got a clue how much their panel is producing, going by the number you see with ropes across them or partially shaded some other way. The cells are in series and increase resistance when shaded, so only a small area needs to be in the shade to significantly drop the output.

 

Sad case that I am, I also have four voltmeters, including one in the saloon so I can watch it all evening.

[christophert]

Hi mross, Waeco 1512 is an inverter. Could yours be a 1215? This is a 15A charger - please confirm.

Just been to double check, 1512 definitely. It's called a WAECO PerfectCharge 1512. It's aprox eight years old. Sending pic

[christophert]

 

Sorry, pic upside down.

[WotEver]

Just been to double check, 1512 definitely. It's called a WAECO PerfectCharge 1512. It's aprox eight years old. Sending pic

 

Yup, here are the manuals: https://www.manualslib.com/products/Waeco-Perfectcharge-Iu1512-4156377.html

 

Tony

[christophert]