A cheap battery monitor

Available directly from China..

I'm always wary of these devices because you don't really know if they are tested to any real standard, but it is cheap, even if only used as a voltmeter and 200A digital ammeter.

It will only read from one battery bank.

If anybody tries it out, perhaps they would put a review up.
 
Thoughts:

1. It's cheap from China.
2. You probably can't input parameters like Peukerts and the charging efficiency - so with AGMs it's Ah count could be inaccurate.
3. It won't tell you the State of Charge of your battery because you probably can't input your bank capacity either.
4. It doesn't seem to have alarms which are very useful for high/low volts or high Ah discharges. Alarms are a very useful feature.
4. It will only measure one bank's voltage. Most other more expensive ones allow you to measure the volts on three battery banks.

Having said all that it's Volts/Amps count might be accurate enough. Better to buy one of these if you can't afford £150 or more for a proper one.

At least you will be monitoring your system much better than without it.
 
Or, throwing an alternative into the pot,

I was thinking of trying one of the following types, which are all less than £15 each. Their visual simplicity and programmability (applies to 3 of the four) suits my need. I know they are not the same as the full monitor but they provide a lot of detail in a small space and do not need a shunt. (Why put a potential 'single point of failure' in circuit? - a basic that derives from my days designing satellites) .

eBay items
190752720351
150479033981
150481419848
160763116221 (with alarm)

Regards
Bob
 
RIBW said:
Or, throwing an alternative into the pot,

I was thinking of trying one of the following types, which are all less than £15 each. Their visual simplicity and programmability (applies to 3 of the four) suits my need. I know they are not the same as the full monitor but they provide a lot of detail in a small space and do not need a shunt. (Why put a potential 'single point of failure' in circuit? - a basic that derives from my days designing satellites) .

eBay items
190752720351
150479033981
150481419848
160763116221 (with alarm)

Regards
Bob
Click to expand...



Better than nothing maybe.

Id not fancy the 3 led one much, apart from for its compactness.

The 6 LED ones better perhaps.

Its the 12 LED one that I like most.

I'd like more info in the charging voltage range. From say 13 to 15 volts and less detail in the lower part of their ranges.


Better , but more expensive, than the 6LED ones that Aldi and Lidl have fromtime to time


A simple digital volts display would be the most useful IMHO.
 
The 'fuel level' Peukerts etc functions are nice in theory. Does anyone find them usefully accurate in daily/yearly use as in '20% AH left, that's plenty for TV tonight and a cert. crank over in the morning'?

If it's just a general indication for us all who are obsessed with battery usage, why not this one (with the correct shunt for you)

http://www.ebay.co.uk/itm/330853516179?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649
(no connection..)

I'm thinking about swapping my BEP for this- no menus, no programming.

Nick
 
NickRobinson said:
The 'fuel level' Peukerts etc functions are nice in theory. Does anyone find them usefully accurate in daily/yearly use as in '20% AH left, that's plenty for TV tonight and a cert. crank over in the morning'?
Click to expand...

I don't use the % left indication at all, but Peukert is important in computing the Ah going in and out of the battery, so that the charge level is reasonably accurate.
 
I have one of the 120v 500amp ones on order
http://www.ebay.co.uk/itm/DC-120V-5...-Discharge-Indicator-With-Shunt-/170901504188
IMO it will be as accurate as a BM1 but not as accurate as a Smartgauge.
And certainly cheaper than both. If I get it together I may do a report once its been upand running for a while.
I have had vm and am from this company before and they do what they say on the box.

If you want the muts you need to wait for the new Smartgauge which is in development.
 
Magnette said:
I have one of the 120v 500amp ones on order
http://www.ebay.co.uk/itm/DC-120V-5...-Discharge-Indicator-With-Shunt-/170901504188
IMO it will be as accurate as a BM1 but not as accurate as a Smartgauge.
And certainly cheaper than both. If I get it together I may do a report once its been upand running for a while.
I have had vm and am from this company before and they do what they say on the box.

If you want the muts you need to wait for the new Smartgauge which is in development.
Click to expand...

Hi Magnette, please do if you can. I'm sure people will be interested even if its just something basic, I.e it's fairly accurate or not.

Thanks all for the info, I've got nothing to monitor at the moment other than a multimeter that I check with. So my thoughts are 1, I've done ok so far and 2 something is better than nothing for now anyway. I would rather spend the money on a new battery as mine is getting on.

Thanks again,
Mat
 
RIBW said:
... and do not need a shunt. (Why put a potential 'single point of failure' in circuit? ...
Click to expand...
They don't need a shunt because they don't measure current. You can't do so without one, so that's why.

[Later] It seems my reply offended the quoted party. No offence intended, just offering clarification to any readers who had not picked this up.
 
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Amp Hour meter

I think this device as linked by OP would be ideal for what it does.
It measures amp hours in and out for any period.
So if you are on board overnight anchored you can measure exactly how many amp hours were used by checking in the morning. Now run the engine or rely on solar panels or even battery charger to measure how much you put into the batteries. If you can replace what was taken out by an engine run for instance then you know you can do the same thing next night.
The actual battery charge will be an estimate based on starting from a charged battery but really the BM-1 etc can not do much better because the actual battery capacity diminishes with age.
One of our forum members "Yapp" has described and sent to me details of construction of such a cumulative AH gauge but I decided it was a bit beyond me. I seen before but could never find again something simiular. I am tempted to buy even though I really don't need one.I love it. olewill
 
Well i decided to get one and it arrived in a couple of weeks. What i would say is that you need to calibrate it so if you are looking for something to work straight out the box then don't buy. Volts wise it seems good, Amps it needs a little bit of messing about with to get an accurate reading. The other features like the AH counter works on you telling it the capacity of your battery and then simply counts them out and back in. It doesn't appear to have any intelligence in it for that. Mine also tends to bounce around a little when it has no load on it, not been able to sort that out just yet.

William_H also got one and has found the same.

So is it worth it? For me it was, i had nothing to start with and now have something. If i find i need much more accuracy then i might invest in something better but this may just do the trick for me.

Hope thats useful for someone,
 
NickRobinson said:
The 'fuel level' Peukerts etc functions are nice in theory. Does anyone find them usefully accurate in daily/yearly use as in '20% AH left, that's plenty for TV tonight and a cert. crank over in the morning'?
Click to expand...


For any battery monitor to be even somewhat close to accurate it needs to calculate for Peukert and allow for the user to input the batteries Peukert value as supplied by the battery manufacturer. Cheap battery monitors simply count amps and ignore Peukert. This is simply lazy engineering or a complete lack of "engineering" that will lead to errors...... Some actually choose a Peukert value for you and again these will be off the mark and counting errors will only continue to worsen if you are not manually resetting it very often when the bank is known "full"...

Here's an example of two different battery banks I install..

We are assuming both banks have an "average draw" of about 8A.

500Ah bank Peukert 1.11 average load 8A - Peukert corrected bank size = 566Ah

500Ah bank Peukert 1.50 average load 8A - Peukert corrected bank size = 884Ah

Without programming the Peukert number how on earth does a battery monitor account for these variances under that particular load.

Any typical Coulomb counter/Ah counter that does not allow for at least the batteries Peukert value to be programmed is going to be an inaccurate counter..

The Chinese battery monitor in the original post DOES NOT allow for programing of the Peukert value....

For grins lets look at those same banks with high loads. In this case, without Peukert correction, you would be over drawing your bank if just looking at the Ah's consumed screen. Percent / %charged, corrected for Peukert, is the only way these tools even come close to being accurate.


500Ah bank Peukert 1.11 average load 80A - Peukert corrected bank size = 439Ah

500Ah bank Peukert 1.50 average load 80A - Peukert corrected bank size = 280Ah
 
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Maine Sail said:
For any battery monitor to be even somewhat close to accurate it need to calculate for Peukert and allow for the user to input the batteries Peukert value. Cheap battery monitors choose a "general" Peukert for you which is often quite off the mark.

Here's an example of two different battery banks I install..

We are assuming both banks have an "average draw" of about 8A.

500Ah bank Peukert 1.11 average load 8A - Peukert corrected bank size = 566Ah

500Ah bank Peukert 1.50 average load 8A - Peukert corrected bank size = 884Ah

Without programming the Peukert number how on earth does a battery monitor account for these variances under that particular load.

Any typical Coulomb counter/Ah counter that does not allow for at least the batteries Peukert value to be programmed is going to be an inaccurate counter over time..

The Chinese battery monitor in the original post DOES NOT allow for programing of the Peukert value....

For grins lets look at those same banks with high loads. In this case, without Peukert correction, you would be over drawing your bank if just looking at the Ah's consumed screen. Percent / %charged, corrected for Peukert, is the only way these tools even come close to being accurate.


500Ah bank Peukert 1.11 average load 80A - Peukert corrected bank size = 439Ah

500Ah bank Peukert 1.50 average load 80A - Peukert corrected bank size = 280Ah
Click to expand...

In fact, the thing in the original post doesn't include any Peukert calculation, so it's pretty much useless except as a voltmeter.
 
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