Battery help please

[MtB]

 

The Smartgauge it turns out, is no help at all if you want to know when your batteries are fully charged. BEWARE.

[WotEver]

1 hour ago, dmr said:

The Smartgage is a very useful device to nicely complement amp-hour type battery monitors.

 

[MtB]

Just now, WotEver said:

Give it a rest, Mike. 

 

Ignore the petulant child, a SmartGauge will sort your problems out. 

 

Just read the manual and you'll see I'm right. 

[WotEver]

Just now, Mike the Boilerman said:

 

The Smartgauge it turns out, is no help at all if you want to know when your batteries are fully charged. BEWARE.

Yet another untruth. You really do like to spread that around, don’t you?

[MtB]

1 minute ago, WotEver said:

Yet another untruth. You really do like to spread that around, don’t you?

 

Just recounting my personal experience of wrongly factory-calibrated Smartgauges. I have two, remember?

[WotEver]

Just now, Mike the Boilerman said:

 

Just recounting my personal experience of wrongly factory-calibrated Smartgauges. I have two, remember?

Yes. I remember. I also remember the tens of thousands that are out there performing their purpose daily with very satisfied users. 

[MtB]

 

Two Smartgauges purchased, two Smartgauges faulty straight from the box. A GREAT product.

 

Not.

 

 

 

[Jeanie920]

2 hours ago, Mike the Boilerman said:

 

This needs examining more closely. The output from a TP is 240Vac, and 240Vac cannot be used to charge lead acid batteries unless a separate mains battery charger is used. 

 

Normally no matter how low a battery bank gets, it will suck up power from the battery charger. The fact that your system won't charge if the indicated SoC of the battery bank falls under 95% tells us there is something really weird going on. 

 

Does a TP also have a DC output for charging batteries perhaps? If not, what extra kit do you have for battery charging? There must be something!

The inverters act as battery chargers 

[WotEver]

3 minutes ago, Mike the Boilerman said:

Two Smartgauges purchased, two Smartgauges faulty straight from the box. 

Yup, you were very unlucky. Good thing the tens of thousands of others weren’t like that because then you might have some justification for your accusations. 

 

Edited June 13, 2018 by WotEver
Typo

[MtB]

Just now, WotEver said:

Yup, you were very unlucky. Good thing the tens of thousands of others weren’t like that because then you might have some justification in your accusations. 

 

Not accusations. Just stating the facts as they happened to me.

 

Readers here can make their own judgements.

 

I still have the inaccurate Smartgauges should anyone want to test/examine them.

[WotEver]

3 minutes ago, Jeanie920 said:

The inverters act as battery chargers 

Instead of reading the percentage charge readout, watch the charging current instead. You’re looking for it to drop to around 1% of the battery capacity (so 6A for a 600Ah bank for instance) at 14.4V (or thereabouts) charging voltage. I think you’ll find that you’re massively undercharging them. 

2 minutes ago, Mike the Boilerman said:

Not accusations. 

Yes, accusations. Whenever a SmartGauge is suggested you jump in and say that they’re rubbish. They’re not. That is false. They are extremely useful gauges for the non-technical. The fact that you bought two, both of which were miscalibrated, is unfortunate, but has no bearing on the effectiveness of the product.  

[MtB]

4 minutes ago, WotEver said:

Yes, accusations. Whenever a SmartGauge is suggested you jump in and say that they’re rubbish.

 

You will not be able to find a post where I say they are rubbish.

 

I recount my experiences and leave the readers to decide.  

[WotEver]

20 minutes ago, Mike the Boilerman said:

I bought into this lie...

No, you never said they were rubbish

[MtB]

10 minutes ago, WotEver said:

No, you never said they were rubbish

 

As I said, I recount my experiences with two of them. I bought one. DISASTER. Wrecked batteries as I trusted the readings.

 

I bought another three months later for a different boat. ANOTHER DISASTER potentially but no wrecked batteries as I checked it on arrival. FAULTY again.

 

I will be buying a third shortly, anonymously. I will be testing its calibration on arrival and I'll report the results here, honestly and truthfully whatever they are. 

 

Edited June 13, 2018 by Mike the Boilerman

[Alan de Enfield]

23 minutes ago, Jeanie920 said:

The inverters act as battery chargers 

May I suggest that you read up a little on the equipment that you have - it will help to understand your problems and will allow folks to make suggestions / help based on some facts.

 

An Inverter does NOT act as a battery charger.

An inverter FLATTENS batteries by taking 12v out of the battery and making it into 230v AC ('mains' electric)

A Battery charger takes 230v AC (mains electric) and changes it to 12 v to charge the batteries.

 

I would suggest that you have a 'combi'. Inside the box are two separate pieces of electronic equipment 

1) An Inverter

2) A battery charger.

 

When you have a mains supply (land line / generator / Travel Power) this will feed into the battery charger and charge the batteries.

When you don't have a 230v mains supply the inverter will take the 12v from the battery and make it into 230v (mains) to run your washing machine, kettle etc

 

You can imagine what would happen if your inverter is taking power from the battery, making 230v (mains) to power the battery charger to charge the batteries - your batteries will get lower and lower and lower until they are totally knackered.

If they don't - you have invented perpetual motion

[David Mack]

6 hours ago, Jeanie920 said:

We switched off the fridge and freezer at night. With the batteries over that level it was fine. I could use the washing machine whilst travelling and cook the dinner as long as thevengine was running. 

 

With the engine running, the travelpower is supplying the cooker, washing machine, fridge and freezer directly, and you don't need any battery capacity at all. That you had to switch the fridge and freezer off overnight demonstrates that you batteries were already reduced to a small fraction of their original capacity.

[rusty69]

6 hours ago, Mike the Boilerman said:

Two Smartgauges purchased, two Smartgauges faulty straight from the box. A GREAT product.

 

Not.

I'll give you a tenner for the two! 

[Dr Bob]

9 hours ago, WotEver said:

Give it a rest, Mike. 

 

Ignore the petulant child, a SmartGauge will sort your problems out. 

The BMV will be just as good as a smart gauge and you have the BMV already. Learn how to use it as per my previous post. Roland's use of a volt meter is an example how you can get 'part way' there. Just understanding voltage will be a big step forward for the OP before considering Ahrs in/out.

[WotEver]

15 minutes ago, Dr Bob said:

The BMV will be just as good as a smart gauge...

No it won’t Bob. What experience do you have of a SmartGauge? They are an excellent companion for a BMV. 

[Dr Bob]

9 hours ago, WotEver said:

Instead of reading the percentage charge readout, watch the charging current instead. You’re looking for it to drop to around 1% of the battery capacity (so 6A for a 600Ah bank for instance) at 14.4V (or thereabouts) charging voltage. I think you’ll find that you’re massively undercharging them. 

Well said Tony. That is the critical thing. Even the non technical need to understand that if they want to not replace batteries all the time.  Also I would add never let you batteries drop below 12.2v at rest. Not a difficult concept to learn.

9 hours ago, WotEver said:

Yes, accusations. Whenever a SmartGauge is suggested you jump in and say that they’re rubbish. They’re not. That is false. They are extremely useful gauges for the non-technical. The fact that you bought two, both of which were miscalibrated, is unfortunate, but has no bearing on the effectiveness of the product.  

Why buy a smartgauge when the BMV tells you all of the above? They are very useful if you don't have a BMV and can't be bothered faffing round fitting a shunt but a smartgauge will not help the OP.

 

eda. Post crossed with yours. I think that answers your question.

Edited June 14, 2018 by Dr Bob

[WotEver]

1 minute ago, Dr Bob said:

a smartgauge will not help the OP.

I disagree entirely. A SmartGauge would show OP that their batteries are sitting at around 30% SoC, not the 95% that they think they are. 

[system 4-50]

Probably a silly question but are all the batteries wired together as one bank or is there a pair for each combi?

[alan_fincher]

12 hours ago, Jeanie920 said:

Yes that’s what was happening. When I had the batteries tested yesterday a couple of them were reading 87% on the printout  but on the others the print out was saying to buy new batteries as they were very low. 

 

11 hours ago, Jeanie920 said:

The man from the Marina workshop brought something to test the batteries.the machine he had produced a printout of the state of each battery. Unfortunately he didn’t give me the printout.  He tested 4 of them. I only discovered the extra battery this evening. The other 2 batteries. 

 

It simply isn't posible to quickly attach some machine that gives a good estimsation of actual battery condition by a single reading at a point in time.

 

The best it can do is estimate at what percentage that battery is of the total charge it could hold, but it can't tell you if it were fully charged, ho much of the original capacity it would now be capable of.

 

Don't be influenced by anybody telling you otherwise, however convincing they sound!

[Dr Bob]

31 minutes ago, WotEver said:

I disagree entirely. A SmartGauge would show OP that their batteries are sitting at around 30% SoC, not the 95% that they think they are. 

The batteries do not think they are a 95%. The BMV does. As I keep saying NEVER look at SoC. The BMV will be showing voltage at rest sub 12.0V. The BMV will be showing voltage at light load sub 12.0V. If you understand that.....which should be information an 'electric only' boat owner knows....then the Smartguage is superflous. Why pay another £100 for kit that is not showing you anymore. Ok, if you dont have a battery monitor then it is a quick and easy way to get information.

As someone who understands how smartguages work, there is another issue. Voltmeters and ammeters work by reading a measured value so are accurate to the limits of accuracy and calibration on that machine. Smartguages measure voltage only -then use that voltage, the rate of change of voltage and likely the rate of change of rate of change of voltage and along with other variables calculate a SoC reading. The calculation is done via a mathematical model likely using multi linear regression. If some of the smarter modeling techniques had been used then Gibbo would have used this in the marketing bumph as Topology, neural networks, sparse data prediction etc etc are seen  by many in the industry as far better ways to predict than multi linear regression. It is difficult to get multi linear regression models to work as a 'global' model. I know. I spent 15 years managing our modelling team for a major petrochems company and sold model based prediction systems for predicting gasoline quality but using Topology. Multi linear regression just didnt hack it. Anyway, lets assume Gibbo has got a global model working .....it still means the smartguage is calculating the SoC which then brings in extra layers of potential error. We seem to understand they are not good at measuring the final stages of charge. I think I saw someone say they are not accurate below 50% which is not surprising as lots and lots of data is needed to build models and I doubt if that many of Gibbo's test data were on batteries less than 50% - so the models may not work that well below this number. Whatever you think, there will be some error and MtB has shown that just a small problem in calibration can give an expensive outcome.

I do believe smartguages are useful as they are easy to fit and no need for faffing around fitting a shunt, but unfortunately they could be expensive if you rely on the SoC output. For the same captial outlay you can buy a decent battery monitor that measures current as well and that means you can do 'your' tail current test and 'my' voltage at rest test and not bother to look at SoC. If you have a bmv already - it is a no brainer. I think all serious boaters (ie liveaboards) should have a basic understanding of how to look after batteries.

[WotEver]

16 minutes ago, Dr Bob said:

The batteries do not think they are a 95%. The BMV does.

Read my sentence again. The subject was the OP.