Monitoring Battery Discharge

[FlyingScot]

Originally Posted by rgleason

I'd suggest checking your facts first before attacking. There is a Bluetooth App being prepared.


http://www.cruisersforum.com/forums/...ml#post2786208

Check mirror, then let us know what you see.

For additional flexibility, purchase the optional Bluetooth® Gateway and download Balmar’s Smartphone App


Optional Smartphone/Bluetooth® Gateway
Free iOS and Android Apps (Requires Bluetooth® Gateway PN SG2-0300

SG200 Battery Monitor | Balmar

I don't have one but this clearly says PURCHASE & OPTIONAL.

EDIT: For the record I said should include. Hardly an attack. Optional is definitely not included. Another $60-75 plus having to mount one more item. I much prefer fully integrated.

[john61ct]

Should be optional

[Cheechako]

Many devices have a built in voltmeter now days. VHF, Depth Sounder, GPS etc. My experience with "amp counters" has not been pleasant, easy or reliable. Your's may be better. In the end, what you need to know is simple.
For the KISS minded:

[Delfin]

Originally Posted by john61ct

Problem is programmatically defining "a cycle" for cases when energy flows both ways without necessarily hitting a benchmark high or low point.

I think that need may be better served with a cheap little AH counter, ideally rigged with big "zero reset" button.

Hardly.

All that is required is a running totalizer that resets when the Ah consumed value reached zero. Just like the Link 20.

[AedanC]

Originally Posted by Cheechako

Many devices have a built in voltmeter now days. VHF, Depth Sounder, GPS etc. My experience with "amp counters" has not been pleasant, easy or reliable. Your's may be better. In the end, what you need to know is simple.
For the KISS minded:

Unfortunately that method only gives a reliable result when the batteries have been unloaded for a long time, somewhere between 12 and 24 hours. Of course once you turn on that depth sounder, VHF or GPS then it’s no longer unloaded anyway......

[rgleason]

I would second that suggestion, and if it is difficult to add to the device screens, it should be added to the bluetooth app.

Also I would like to have a screen with all the info needed to do a discharge test and take timed photos of the values as it goes down.

But even better would be a full history as a graph and table in the bluetooth app, based on "snapshots" taken at a user defined interval so we can do 20hr tests, or test loads etc.

Then be able to export the data.

[FlyingScot]

Balmar makes good products from what I have read. But is it worth almost double the cost of a Victron BMV-712. This happens to be $178 on Amazon right now.
The SG-200 + BT dongle is over $300.

Estimated SOH is one difference I see. Of course if you have Victron smart MPPT's you'll want the Victron.

[john61ct]

Originally Posted by Delfin

All that is required is a running totalizer that resets when the Ah consumed value reached zero. Just like the Link 20.

Why would a meter showing zero need to be reset?

How would the user determine where to set that zero point for a bank that never gets to Full?

Sincerely not being argumentative, I just do not understand the basis of the algorithm you're proposing.

And do not see how basing decisions off AH would be better or even different from a known-accurate SoC %.

[john61ct]

Originally Posted by AedanC

Unfortunately that method only gives a reliable result when the batteries have been unloaded for a long time, somewhere between 12 and 24 hours. Of course once you turn on that depth sounder, VHF or GPS then it’s no longer unloaded anyway......

Plus the correspondence table is different for different model batts.

And changes with aging.

But many simply think accuracy is unnecessary, happy to save money, get by with "good enough".

[smac999]

Originally Posted by Cheechako

Many devices have a built in voltmeter now days. VHF, Depth Sounder, GPS etc. My experience with "amp counters" has not been pleasant, easy or reliable. Your's may be better. In the end, what you need to know is simple.
For the KISS minded:

all of those show unit voltage which is not the same as battery voltage. battery voltage is measured directly at the battery. all of those will show lower voltages from wiring, switches, fuse blocks etc.

amp counters are awesome for 99% of the boats out there. that are plugged into shore power ~360 days a year. for the 1%'s that never plug in and never get a bank full, and never properly reset them when full. you likely have issues.

[Delfin]

Originally Posted by rgleason

I would second that suggestion, and if it is difficult to add to the device screens, it should be added to the bluetooth app.

Also I would like to have a screen with all the info needed to do a discharge test and take timed photos of the values as it goes down.

But even better would be a full history as a graph and table in the bluetooth app, based on "snapshots" taken at a user defined interval so we can do 20hr tests, or test loads etc.

Then be able to export the data.

The behavior I would be looking for is the behavior of the Link 20 coulomb counter. When current acceptance drops to a certain point, the Ah used resets to zero. As long as a current source is there and the count of Amps used is positive, the display is 0 Ah used. Turn off charging sources, or take more out than you are taking in and the counter goes negative.

Sitting at anchor on the house bank, the Ah count increases as a negative number. When the target withdrawal is reached, you start charging.

And since we're designing Balmar's equipment for them, they should also store a running total of all negative Ahs used. This would give a lifetime to date value for how much energy has been stored and released by the bank.

You know more about capacity testing than I do, but it seems to me that if I have an accurate SoH, and that value is a percentage of initial capacity, don't you have a capacity test as valuable as a 20 hour?

[thereefgeek]

Have the Victron 700 w/Bluetooth on our boat and it works great.
Marinehowto-dot-com has a lot of great info on install and programming it for accuracy.

[FlyingScot]

Originally Posted by Delfin

And since we're designing Balmar's equipment for them, they should also store a running total of all negative Ahs used. This would give a lifetime to date value for how much energy has been stored and released by the bank.

I suspect their app will show this. I know the Victron app shows "history" and under "energy" is lists total discharged and charged in KWh. Easy to see how much extra you put in compared to how much you take out.

[john61ct]

Maybe make that functionality manifest as an option, for those with lead banks who strive for endAmps.

It just does not apply to IMO properly managed LFP.

[john61ct]

Originally Posted by Delfin

You know more about capacity testing than I do, but it seems to me that if I have an accurate SoH, and that value is a percentage of initial capacity, don't you have a capacity test as valuable as a 20 hour?

If you don't objectively know AH capacity (usually via a load test), it is not possible for the SoC% to be accurate.

That's why a meter that accurately "knows" SoH without a load test is revolutionary.