Balmar SG-200 Battery Monitor

[lateral]

Originally Posted by rgleason

I am guessing that the SG200 when woken up needs to figure out what has happened when asleep. So initially SOH%100 and SOC%100.


Do you know if, when the system has been quiet a long time with no charger attached, what the measured amp drawdown is?

Does it go to sleep. Or just the screen?
Mine has similar numbers; Low SOC for voltage /SG readings.
I'm not that interested until its got a history to work off.
Sayes me doing sg readings...haha.

[transmitterdan]

Originally Posted by rgleason

I am guessing that the SG200 when woken up needs to figure out what has happened when asleep. So initially SOH%100 and SOC%100.


Do you know if, when the system has been quiet a long time with no charger attached, what the measured amp drawdown is?

I would guess the SG200 is periodically checking current draw and voltage. That doesn’t take hardly any power. The screen is what eats power. I feel confident the important stuff doesn’t go to sleep.

[Wood]

Originally Posted by rgleason

I am guessing that the SG200 when woken up needs to figure out what has happened when asleep. So initially SOH%100 and SOC%100.


Do you know if, when the system has been quiet a long time with no charger attached, what the measured amp drawdown is?

I will know that answer tomorrow.

[Wood]

Everything switched off for 5 days. Clamped the SG200 feed wire and read 0.027 amps. Battery negative pre-shunt read 0.032 amps.

Bilge pump circuits only bypass switches. That would account for the bleed.

Woke up SG200 and read 0.00 amps,. 12.6 volts, 0 percent SOC,. 100 percent SOH.

SG200 awake feed wire clamped reads 0.042 amps.

With switches and chargers on SG200 reads the same.

House bank bulk charge to 14.8 started at 14 amps and quickly reached absorption. Then dropped to float at 6.3 amps acceptance

SG200 still showed 0 percent SOC.& 100 percent SOH.

[sailinglegend]

Originally Posted by Wood

Everything switched off for 5 days. Clamped the SG200 feed wire and read 0.027 amps. Battery negative pre-shunt read 0.032 amps..

I don't understand any of this.

The SG200 must be permanently connected and will only take a very small amount of power. This is the only way it can calculate the SoC of the battery. It cannot be switched on and off, or switched to a different bank.

[lateral]

"Everything switched off for 5 days."
But not the SG200?
Thats weird you have a zero% SOC.
Mine has been slowly coming down from 100% SOC as it figgers out where 100% is.
Unfortunately I have been doing split cycles with no big draw down.
SOH is still 100% which its not, obviously.
Have you checked your inputs?

[transmitterdan]

Guys, clamp DC meters are terribly inaccurate at very low DC current. You can only measure current draw of the SG200 using a direct connection 300mA meter like a good Fluke. With a typical DC clamp the reading is just a random number. Maybe if you have a $1,000.00 DC clamp rated for 10A it might be within a few hundred % of the correct reading. But the typical 200A clamp meter that sells for around $100.00 is not able to read within an amp of the actual value.

[Delfin]

Originally Posted by Wood

Everything switched off for 5 days. Clamped the SG200 feed wire and read 0.027 amps. Battery negative pre-shunt read 0.032 amps.

Bilge pump circuits only bypass switches. That would account for the bleed.

Woke up SG200 and read 0.00 amps,. 12.6 volts, 0 percent SOC,. 100 percent SOH.

SG200 awake feed wire clamped reads 0.042 amps.

With switches and chargers on SG200 reads the same.

House bank bulk charge to 14.8 started at 14 amps and quickly reached absorption. Then dropped to float at 6.3 amps acceptance

SG200 still showed 0 percent SOC.& 100 percent SOH.

Had a similar situation with the SoC being dead wrong after 4 cycles. In discussion with Balmar, larger banks like yours or mine may take longer to become accurate. I brain wiped mine, set charge voltage higher than the default, and have only been through one cycle, but after a draw down it was nuts on the correct SoC. I'm going to run a few more cycles before drawing any conclusions, but I suspect the lower default setting for the charge voltage value may be an issue.

[sailah]

Launched boat today, motored out to mooring for maybe 45 min total. Batteries were already fully charged.

Noticed the same phantom draw of -0.3Amps per SG200 as someone else when i had no loads on and battery switch off.

Checking voltage on both banks they were 13V since just getting topped off by alternator so i assume ACR was connecting both banks. Amperage could have come from between banks? I didn't stick around to see if it dropped to 0 after banks reach 12.75V at which point ACR.

Will check when i get on again.

Im seeing consistent 100% SoC which i expect, SoH is still at 90%

[rgleason]

Originally Posted by transmitterdan

Guys, clamp DC meters are terribly inaccurate at very low DC current. You can only measure current draw of the SG200 using a direct connection 300mA meter like a good Fluke. With a typical DC clamp the reading is just a random number.....

Sorry, I guess I started this by measuring with a clamp meter....
Best not to do so! It's not a good value.

[Wood]

Originally Posted by sailinglegend

I don't understand any of this.

The SG200 must be permanently connected and will only take a very small amount of power. This is the only way it can calculate the SoC of the battery. It cannot be switched on and off, or switched to a different bank.

Batteries disconnected from potential loads. SG200, as you know, is not switched.

[lateral]

Can I play too....
For comparison my SG200:
*Reads zero A with all loads off but feed to DC sw/board on.
* Fluke clamp meter read zero A too. Accurate to nearest 50mA.
* SOC is still a little wonky. Catches up from 88% to 100% with only 1hr
charging.
*SOH definitely wonky as batteries 4yrs old. Still reading 100%.
* I am not going to expect any real sense until I,ve done at least 4 50% DOD's
and recharges.

[lateral]

Tonite I checked config and it was not what I set it??
As soon as I corrected it numbers started falling into line.
SOC 100% at tail amps 4.2 (approx 0.01C)
SOH 90%. (4yro FLA's)
0.3A unknown draw.

[sailah]

Originally Posted by lateral

Tonite I checked config and it was not what I set it??
As soon as I corrected it numbers started falling into line.
SOC 100% at tail amps 4.2 (approx 0.01C)
SOH 90%. (4yro FLA's)
0.3A unknown draw.

Do you have an ACR between banks? I now have exact same scenario as you do. When i was on hard and charging thru battery charger i would not get the 0.3A draw. Now that I'm in water im seeing it. Only thing i can think of is battery are coming off an alternator charge, ACR is still closed due to batt voltage being above 12.75.

I'll check it out today but i was very careful when i recently rewired boat to not have any unswitched loads other than stereo memory and bilge pumps but i don't see either consuming 0.3A

[lateral]

Yes . Blue seas ACR.
Haven't had time to figger where the parasitic draw is from.