How accurate is my Smartgauge?

[rusty69]

15 minutes ago, Mike the Boilerman said:

Remember, when I first posted about my new battery problems, the advice here was "complain to the Yuasa". Now it's looking like its a Smartgauge problem, along with a gap in my own understanding of battery characteristics, or a combination of all three.

I thought the problem was you simply aren't charging your batteries to achieve their maximum lifespan

[MtB]

On 10/04/2017 at 10:15, rusty69 said:

I thought the problem was you simply aren't charging your batteries to achieve their maximum lifespan

Well obviously. But how was I measuring my charging? 

Answers on a postcard

[rusty69]

21 minutes ago, nicknorman said:

If everyone who got an out of calibration Smartgauge sent it back, not for a refund, but for one correctly calibrated, repeat as required, they'd soon get the message. Cactus would complain to Merlin who would complain to whoever was doing the assembly and calibration. And then we would be back to the earlier days of the Smartgauge where it worked properly!

The trouble is the Smartgauge is seen to be a "fuel gauge" type two wire installation device that any idiot can fit(I know, as I've got one). To check it's accuracy would require further equipment and knowledge. 

7 minutes ago, Mike the Boilerman said:

Well obviously. But how was I measuring my charging? 

Answers on a postcard

I would have thought tail current! 

Sorry run out of stamps. 

Edited April 10, 2017 by rusty69

[tomsk]

Out of interest what be SG's view of anyone opening the case to calibrate one and does anyone actually know how to calibrate one?

[rusty69]

1 minute ago, tomsk said:

Out of interest what be SG's view of anyone opening the case to calibrate one and does anyone actually know how to calibrate one?

I guess it would void any warranty that may be in place. If not, and you know how, you ain't got much to loose. 

[WotEver]

19 minutes ago, Mike the Boilerman said:

Besides, WotEver says he is keeping Merlin up to speed on the situation.

Which may or may not have any effect on future production. Whether it does or not it won't fix either of yours, nor the recent one that's 0.5V out. The only way to get them fixed and to ram home the point to Merlin is to send them back for calibration. 

[MtB]

On 10/04/2017 at 10:34, WotEver said:

Which may or may not have any effect on future production. Whether it does or not it won't fix either of yours, nor the recent one that's 0.5V out. The only way to get them fixed and to ram home the point to Merlin is to send them back for calibration. 

 

Frankly, and being somewhat selfish I'm not that bothered if Merlin can't supply accurately calibrated units. I'm not going to put myself to considerable inconvenience to educate them. Any company worth its salt will have effective quality controls in place and the dribble of incorrect Smargauges turning up on this board illustrates they don't have any effective quality monitoring. 

Given WotEver is telling them, whether they are listening or not is up to them. The message shouldn't need 'ramming home', as you put it.

[Sea Dog]

12 minutes ago, rusty69 said:

I guess it would void any warranty that may be in place. If not, and you know how, you ain't got much to loose. 

What good is preserving the warranty on an item if one has already accepted an inaccuracy that cripples it? It needs to go back under warranty for that issue alone otherwise one may as well disregard the warranty and get amongst it.

[rusty69]

4 minutes ago, Sea Dog said:

What good is preserving the warranty on an item if one has already accepted an inaccuracy that cripples it? It needs to go back under warranty for that issue alone otherwise one may as well disregard the warranty and get amongst it.

I agree. Was just answering a question 

 

Edited April 10, 2017 by rusty69

[WotEver]

I think it's a shame that a previously reliable and unique product is becoming useless due to what appears to be poor QC. 

I'm finding myself reluctant to recommend it these days where in the past I would have had no such reservations. 

1 minute ago, Sea Dog said:

What good is preserving the warranty on an item if one has already accepted an inaccuracy that cripples it? It needs to go back under warranty for that issue alone otherwise one may as well disregard the warranty and get amongst it.

+1

[dmr]

9 hours ago, Tom and Bex said:

There does seem to be a run of badly calibrated smartgauges at the moment. The new one I've just installed is reading 0.5v high. That's compared to my digital multimeter and the tracer solar controller. Need to borrow a calibrated meter to check, but find it highly unlikely they would both be that far out and the smartgauge accurate!

Maybe that's why Cactus Navigation sell the smartgauge cheaper than anyone else - they get all the rejects to sell!

If anyone knows how to calibrate the smartgauge let me know - might be easier than getting an accurate one to start with. 

Tom 

The forum is getting a bit bogged down with this calibrated volt meter thing and, in my opinion, giving misleading advice.

I believe that calibrated instruments are only needed for doing formal or legislative work for clients, not for everyday domestic use. Digital voltmeters are accurate and stable instruments. If you buy a 0.5% meter it will likely be better than 0.5%, certainly no worse (unless its really cheap rubbish or broken).

A calibrated 0.5% meter will be NO more accurate, you will just have a piece of paper saying that it really is 0.5% accurate.

If you buy a 0.5% meter you can be maybe 99.5% sure that its its 0.5% accurate 

If you buy two 0.5% meters from different manufacturers and they agree, or compare yours with your mates, then its probably 99.99% sure they are ok.

I recently compared 5 quite old instruments and they all gave a very similar reading.

0.5% is good enough for boat use. 0.1% meters are expensive

..............Dave

[Robbo]

4 minutes ago, dmr said:

The forum is getting a bit bogged down with this calibrated volt meter thing and, in my opinion, giving misleading advice.

I believe that calibrated instruments are only needed for doing formal or legislative work for clients, not for everyday domestic use. Digital voltmeters are accurate and stable instruments. If you buy a 0.5% meter it will likely be better than 0.5%, certainly no worse (unless its really cheap rubbish or broken).

A calibrated 0.5% meter will be NO more accurate, you will just have a piece of paper saying that it really is 0.5% accurate.

If you buy a 0.5% meter you can be maybe 99.5% sure that its its 0.5% accurate 

If you buy two 0.5% meters from different manufacturers and they agree, or compare yours with your mates, then its probably 99.99% sure they are ok.

I recently compared 5 quite old instruments and they all gave a very similar reading.

0.5% is good enough for boat use. 0.1% meters are expensive

..............Dave

0.5 volt inaccuracy for a 12volt system is 4% not 0.5%.  Half a volt is the different between 50% and 100% if taking the reading to measure the SOC on battery.  It's a big inaccuracy!

Edited April 10, 2017 by Robbo

[rusty69]

16 minutes ago, dmr said:

If you buy a 0.5% meter you can be maybe 99.5% sure that its its 0.5% accurate 

Does that make it 99.5% inaccurate? 

Edited April 10, 2017 by rusty69
Forgot Smiley face

[bizzard]

Not makee China is tlouble. China smart, China makee gauge ploper.

Edited April 10, 2017 by bizzard