Tracer BN, low charging current/power

[dison4linux]

Greetings, I just replaced a cheap PWM charge controller with a Tracer 1215BN. I have the BlueTooth box so I can monitor the stats on my phone.
At the brightest hottest part of the day I'm seeing 0.05A / 1.1W charging current and the panel voltage being 21.5V which is near open circuit voltage for that panel.
The mode shown is currently "Boost" I've never seen it go into "Bulk" charging which I think it should be because the battery voltage is 12.2V (flooded).
I have tried using the "default" settings for the controller (Sealed) and also changed the setting to "flooded" which is where it is currently.
Are there any other settings I can change to get it to pull in more juice from the solar panel? I've tested the short circuit current of the panel and I can get over 0.6A in full sun... more than 10X greater than the current I'm pulling in from it now, and almost 8X greater power.

I have heard others say that a 10W panel isn't enough for this controller to act correctly but I want to confirm that is true before I drop $100 bucks on a bigger panel, as I don't really need any more than 10W to keep this battery topped off.

In the current state, the battery self-discharges faster than the controller is charging it. I'll upload a screenshot from the App.

Thanks,
Jon

 

[Brewman]

Is the battery charged?

 

[MisterSandals]

say that a 10W panel isn't enough for this controller to act correctly

With just 10W, the controller is waiting for more power to start up. Does the controller show a "night time" indicator or anything?

And even if the controller did power up, it would likely need at least 10W itself to function let alone apply charge to a battery(s).

 

[dison4linux]

Is the battery charged?

Hello Brewman,
In my opinion, no the battery is not completely charged. My understanding for flooded lead acid batteries is that 100% SoC would be around 12.6V open circuit at the terminals. Both the App and a multi-meter report the battery voltage at around 12.2V currently, but it has dipped down as low as 12.0V while being connected to the controller and panel, and there was no change in power usage from the panel. The voltage is up around 12.4V today because I charged the battery a little the old fashioned way yesterday to keep the battery healthy.

 

[dison4linux]

With just 10W, the controller is waiting for more power to start up. Does the controller show a "night time" indicator or anything?

And even if the controller did power up, it would likely need at least 10W itself to function let alone apply charge to a battery(s).

No it shows "daytime" (I edited the first post to include a screenshot from the controller)
If it were using close to 10W and not having luck with that, I could understand that, but its using only around 1.0W sometimes even less from the panel.

 

[Brewman]

I agree with the above, the SCC is using all the power from the panel to run itself.

 

[dison4linux]

I agree with the above, the SCC is using all the power from the panel to run itself.

I agree that 10W may not be enough for this SCC to act correctly, but to say it is "using" all of the 10W before any can be sent to the battery is simply incorrect. Measuring the across the panel terminals on the SCC with a multi-meter shows 20-22V. Measuring in-line with the panel with multi-meter shows less than 50mA. If the SCC were "using" 10W, the panel voltage would be dropped down further from open circuit voltage and I would be able to measure the current that the SCC was "using" coming from the panel, and it would show something well over 50mA. Right now the panel is barely being used.

 

[Brewman]

The manual says it uses 60ma self consumption. That would be 7.2W.

 

[dison4linux]

The manual says it uses 60ma self consumption. That would be 7.2W.

That would be 0.72W
12V X 0.060A = 0.72W

 

[Deleted member 165]

What is the amp hour rating of your battery? If it's of any decent size, 10 watts will struggle to ever charge it anyway, so you might as well get a bigger panel and try that first.

 

[Brewman]

My bad, put the decimal in the wrong place.

 

[Deleted member 165]

That would be 0.72W
12V X 0.060A = 0.72W

Add the potential voltage drop through the wires from the controller to the battery.

 

[dison4linux]

What is the amp hour rating of your battery? If it's of any decent size, 10 watts will struggle to ever charge it anyway, so you might as well get a bigger panel and try that first.

It is a group 24 RV/Marine Deep Cycle Battery... I think that's somewhere in the 75AH range.
I agree with you 100% on the math, 10W ~ 0.75A let's say conservatively, so 75AH would take 100 hours to charge in ideal circumstances...
But the battery is already fully charged, I'm just trying to keep it that way, but instead no energy is being pulled in from the panel and the battery is slowly discharging.

 

[Brewman]

Add the potential voltage drop through the wires from the controller to the battery.

And the actual wattage coming from the panel.

 

[Brewman]

Might be that the SCC can't lock into the power point with such a low wattage coming in.

 

[Deleted member 165]

12.2 is closer to empty than charged. 10 watts is simply not big enough.

 

[dison4linux]

Add the potential voltage drop through the wires from the controller to the battery.

Voltage drop is a factor of current. So if there's only 0.060A travelling from the battery to the controller. 14AWG wire is about 2.5 ohms per 1000 feet, and I have 10 feet, that's 10/1000*2.5=0.025 ohms
0.025 ohms X 0.060 A = 0.0015 Volts dropped across the wires between the controller and the battery.... pretty negligible in my opinion.

 

[dison4linux]

12.2 is closer to empty than charged. 10 watts is simply not big enough.

Even if I start it at fully charged ... 12.8V or so open circuit after rest... The voltage just slowly declines.
10W should be enough to keep it charged, It was way more than enough to keep it charged with the old PWM controller I replaced with the Tracer.
I agree its not enough to charge it.

 

[Deleted member 165]

It is probably losing more self-discharging at night than you are adding during the day. MPPT needs more juice to get things started than pwm. If you wont get a bigger panel, go baxk to the PWM.

 

[dison4linux]

And the actual wattage coming from the panel.

That's the whole point of this thread.

there aint' no watts comin' from the panel, 'cause the controller ain't drawin' any

When I hook up the old PWM controller, it draws about 7.5W from the panel and charges/keeps the battery charged just fine.
Swap out controllers, panel voltage is near open circuit, and current is near zero and battery slowly discharges.