Balmar SG-200 Battery Monitor

[witzgall]

I will add that you should ensure that the SG200 is recognizing that charge termination is taking place. There is a plus sign that shows on the color display's SoC screen. If you are not reaching that, either:

1. The batteries are not being fully charged.
2. The conditions the SG200 uses to mark charge termination is not being met. This is outlined in the manual.

Getting that little plus sign to show up at the end of the charge is really important to the SG200.

Chris

Originally Posted by SVHarmonie

It certainly IS possible, depending on exactly how your battery chargers are deciding to end the absorption phase.

What is your absorption voltage set point? At 82% SOC, a healthy 580 A-hr bank of Firefly batteries should still be able to accept all your chargers can put out not really tapering off until close to 90%SOC...

How many cycles do you have on your SG200 since it was installed or last reset or upgraded? What is your battery capacity set to? How about the charge voltage and taper current?

I would cycle your battery chargers off, and reset them so they start over with bulk. See what happens.

[lateral]

I hoped latest firmware had solved the slow discharge/incorrect SOC thing.
Not so. One week no load discharge, From 100%+.
=12.8V 82% SOC, 100% SOH.

Also, set my tail/taper current to 6A (should be 4.7A for 1%) as 100% was coming up way early.

So, is this going to be the caveat on this device permanently?
That the SOC under low/self discharge load, will not be accurate?

[witzgall]

Did you re-select the chemistry if upgrading from other than the very latest chem?
Have you allowed the battery to be learned after the chem reload?
What size battery?
What is the SoH? A drop that big can mean that the SoH is being reported as higher than it should be, and a drop of this magnitude is showing that.

Chris

Originally Posted by lateral

I hoped latest firmware had solved the slow discharge/incorrect SOC thing.
Not so. One week no load discharge, From 100%+.
=12.8V 82% SOC, 100% SOH.

Also, set my tail/taper current to 6A (should be 4.7A for 1%) as 100% was coming up way early.

So, is this going to be the caveat on this device permanently?
That the SOC under low/self discharge load, will not be accurate?

[lateral]

Originally Posted by witzgall

Did you re-select the chemistry if upgrading from other than the very latest chem?
Have you allowed the battery to be learned after the chem reload?
What size battery?
What is the SoH? A drop that big can mean that the SoH is being reported as higher than it should be, and a drop of this magnitude is showing that.

Chris

Hi Chris,
The only change I made was taper current.
Should I do a factory reset, and configure from scratch?
And, is this required after every FW update?
Thanks.
(5yro FLA 464Ahr factory)

[SVHarmonie]

Originally Posted by lateral

I hoped latest firmware had solved the slow discharge/incorrect SOC thing.
Not so. One week no load discharge, From 100%+.
=12.8V 82% SOC, 100% SOH.

Also, set my tail/taper current to 6A (should be 4.7A for 1%) as 100% was coming up way early.

So, is this going to be the caveat on this device permanently?
That the SOC under low/self discharge load, will not be accurate?

Lateral,

I would suggest that you reconsider changing the taper current from the default suggested by Balmar. Yes, I KNOW your batteries are not FULLY charged until the absorption charge drops down to 4.7A. But that is totally irrelevant to the SG200. If the SG200 was controlling your charger, then what you have done might be a good idea, but that it is not the case.

The fact that the SG200 will then reset itself to 100% SOC when your batteries are actually at 98% or 99% is not at all relevant to how you should be using it. It is NOT designed to tell you in a precise way when the batteries are at exactly 100%, it’s no better at that than a simple amp meter. It’s job is to tell you how much energy you have withdraw from the batteries and when to start recharging them.

By fussing with the taper current you risk upsetting the algorithm that measures the SOC, and getting no real benefit out of the change.

[lateral]

Manual sayes 2-4%, so should I set it at say 14A?
I bought the device for family members to easily
Manage power usage. Thanks for input!

[SVHarmonie]

Originally Posted by lateral

Manual sayes 2-4%, so should I set it at say 14A?
I bought the device for family members to easily
Manage power usage. Thanks for input!

I would use the default setting that is set when you first select the battery chemistry. For Firefly batteries, I believe that is 2% of the entered battery capacity. Not sure about other chemistries.

I am not at all privy to the internal details of how this meter works (the CIA should be so good at keeping secrets!) but it has been emphasized that the transition to "100%+" at the voltage and taper current specified is critical for the instrument to do its job. By setting the taper current lower, there is a significant risk that the charger drops to float before the transition is caught by the SG200.

[Peeew]

I do believe that I am learning here. Thanks for the educated advice. After a good day of charging by solar I still see 82% and 100% SOH. So I turned on the shore power and the two 40 amp chargers. Within a minute or so they went from bulk @14.4 v to float at 13.6v. So that looks like they are charged, no? I went to check the Balmar shunt settings and some seemed off. Type and capacity is right at carbon foam and 580 amphours. But- the taper current was set at 0. So I reset that to 11amps, 2% of capacity. And the max charging voltage was set at 14.4 which is the max they should see. That’s wrong I think, so I set that to 13.6 v which is the max the batteries should show and is float voltage. Still showing 82% but I am planning on leaving on float overnight and then let them run back down again before a recharge cycle.
Now does this seem to make sense? I guess I misread what “max charge voltage” means. Thanks.

[Peeew]

Two more bits of info to add to above. With the shore power chargers on, floating, I see about 1 amp going in to battery bank now. And I have never yet seen a + sign on my monitor. I’m hoping the corrected settings do the trick.

[lateral]

Originally Posted by SVHarmonie

Lateral,
It is NOT designed to tell you in a precise way when the batteries are at exactly 100%, it’s no better at that than a simple amp meter. It’s job is to tell you how much energy you have withdraw from the batteries and when to start recharging them.

By fussing with the taper current you risk upsetting the algorithm that measures the SOC, and getting no real benefit out of the change.

I just find it bizarre that you have to set it at other than your batteries requirement for 100% and that is inherent in the algorithm; With the + sign for good measure! I am aware that 100% is an obscure goal post.
so I can live with bs settings.
Don't really care what counter intuitive settings are required, I just want it to work as advertised, ie most accurate BM todate.
*A close to accurate SOC with no load. (Leaving boat unattended with no charger)
*Close to accurate SOC on normal loads/charging regime to 50% dod.
After 1yr+, can't see it happening.
*I don't use it for ending absorbtion, as I have always used Ammeter.


Last attempt:
Equalize batteries.
Factory reset.
Set to FLA
Set to 3%C for 100% and charge past that with ammeter to ~1%C
Wait for two or three "normal" use cycles.
If I don't get something meaningful, its coming out.

[witzgall]

1. Get the + sign to show up. If it happens within a few AH or full, then you are good to go.
2. If it happens way before, then simply adjust either the charge voltage or taper current, starting with the taper current.

Remember, the SG200 works very differently than all other monitors. The indication of charge termination is used to determine when the batteries are full. We can then use that information as a component to determine what the aged capacity is. That is done without you having to discharge the battery fully, like you would do with a 20/hr discharge test. It does need to see enough discharge, and points of rest, to make the calculations.

If you have aged LA batteries, it can take more than 2-3 cycles. Rodd collins has told me he has seen some LA needing ~10 cycles. We have had too many people calling in that repeatedly are resetting the monitor and not giving it time to learn. If you are getting that + sign, I would leave it alone, and give it time to learn.

Chris

Originally Posted by lateral

I just find it bizarre that you have to set it at other than your batteries requirement for 100% and that is inherent in the algorithm; With the + sign for good measure! I am aware that 100% is an obscure goal post.
so I can live with bs settings.
Don't really care what counter intuitive settings are required, I just want it to work as advertised, ie most accurate BM todate.
*A close to accurate SOC with no load. (Leaving boat unattended with no charger)
*Close to accurate SOC on normal loads/charging regime to 50% dod.
After 1yr+, can't see it happening.
*I don't use it for ending absorbtion, as I have always used Ammeter.


Last attempt:
Equalize batteries.
Factory reset.
Set to FLA
Set to 3%C for 100% and charge past that with ammeter to ~1%C
Wait for two or three "normal" use cycles.
If I don't get something meaningful, its coming out.

[witzgall]

If you set the taper current lower, it will potentially reach charge termination BEFORE it gets to float, the opposite of what you suggest.

Chris

Originally Posted by SVHarmonie

By setting the taper current lower, there is a significant risk that the charger drops to float before the transition is caught by the SG200.

[sailah]

Mine seems to be doing well after the firmware update and that weird cable issue I was having.

Can I ask a dumb question without going through the entire thread?

I have 230AH of 6V GC batteries, brand new last year. What, if any, adjustments should I make to charge current taper? I think it's stock, haven't adjusted it from factory setting.

My boat has been on the dock with solar and no loads so I haven't cycled it at all from firmware update.

I pretty much stay at 100% (+) SOC and SOH at 90% has never really changed even last year. I don't do very deep drains on battery but will this summer with more cruising plans. I did have 1 oopsie with a bilge pump that stuck on last year and saw 2% on the Balmar...

My batteries tend to stay in float on mooring with 80W solar panel.

[witzgall]

Don't mess with the charge settings if you are getting charge termination and it is not happening way before the charger actually switches to float. The stock values are different for each chemistry, and should work well for you.

Chris

Originally Posted by sailah

Mine seems to be doing well after the firmware update and that weird cable issue I was having.

Can I ask a dumb question without going through the entire thread?

I have 230AH of 6V GC batteries, brand new last year. What, if any, adjustments should I make to charge current taper? I think it's stock, haven't adjusted it from factory setting.

My boat has been on the dock with solar and no loads so I haven't cycled it at all from firmware update.

I pretty much stay at 100% (+) SOC and SOH at 90% has never really changed even last year. I don't do very deep drains on battery but will this summer with more cruising plans. I did have 1 oopsie with a bilge pump that stuck on last year and saw 2% on the Balmar...

My batteries tend to stay in float on mooring with 80W solar panel.

[sailah]

Thanks Chris