Has this happened to anyone: batteries die fast

[John61CT]

Yes voltage is only a very rough indicator of SoC.

Too rough to be useful for diagnosis in this sort of situation.

And I'm skeptical of this battery monitor, would like to see someone with FLA correlate its readings with a hydrometer.

To be honest I'm also wary of the solar controller, there are a dozen different units out there knowledgeable people have raved about.

Is the Renogy SC programmable for length of Absorption cycle?

 

[J.mcculloch]

This morning with nothing on or connected the monitor reads
Panels.    Batteries.    Load
20V.        13.9V.         14.0
0.2 A.      0.2A.            0.0

After turning on the refrig it reads
19.1V.      13.9V          13.9V
3.6A.         0.3A.           5.0A

 

[IGBT]

What did the batteries read before the sun came up?  For them to be 13.9V in the morning they must have been getting a little solar charge before you woke up.

Wake up earlier.

 

[highdesertranger]

the Renogy monitor is not really a battery monitor. but more of a controller monitor. also do you have the refer connected to the Load on the controller? by your numbers it appears so. the refer should be connected straight to the battery, with a fuse inline of course. highdesertranger

 

[Weight]

It is difficult to fully charge AGM batteries using solar alone. Try getting a good charge using a grid tied charger, then see if the solar can keep up with the fridge. Duracell batteries are of good quality, but how were they treated by the dealer and how long were they "on shelf"? as posted above.

 

[John61CT]

Duracell batteries are of good quality

Yes but only the 6V GC2 are (close to) true deep cycling.

Every 12V batt sold in consumer retail is just a starter type. Any "deep cycle" or "marine" marketing is flat-out fraudulent.

Note I'm not saying anything about quality of manufacturing there, Mercedes has excellent QA processes building the Smart Fortwo, but I wouldn't recommend it for towing.

 

[Sabatical]

Yes but only the 6V GC2 are (close to) true deep cycling.

Every 12V batt sold in consumer retail is just a starter type. Any "deep cycle" or "marine" marketing is flat-out fraudulent.

Note I'm not saying anything about quality of manufacturing there, Mercedes has excellent QA processes building the Smart Fortwo, but I wouldn't recommend it for towing.

Great analogy!!

Sent from my SCH-I435 using Tapatalk

 

[J.mcculloch]

the Renogy monitor is not really a battery monitor.  but more of a controller monitor.  also do you have the refer connected to the Load on the controller?  by your numbers it appears so.  the refer should be connected straight to the battery,  with a fuse inline of course.  highdesertranger

Thanks, Yes the refrigerator is connected to the  batteries via a fusebox

 

[J.mcculloch]

What did the batteries read before the sun came up?  For them to be 13.9V in the morning they must have been getting a little solar charge before you woke up.

Wake up earlier.

Yes I will have to get up before 9am,  :blush:

 

[frater secessus]

Hmm, so how does it know how much juice is left in your batteries?

It doesn't, hence the squirrelly random graphic confusing the OP.

Limitations like this are part of the tradeoff for paying several hundred dollars less for a charge controller. A quick glance at prices shows a $450 dollar difference between the two.

 

[frater secessus]

And I'm skeptical of this battery monitor, would like to see someone with FLA correlate its readings with a hydrometer.

To be honest I'm also wary of the solar controller, there are a dozen different units out there knowledgeable people have raved about.

Is the Renogy SC programmable for length of Absorption cycle?

The monitor is a remote display for the controller, showing more info and allowing for easier configuration.  The Renogy MPPT CCs are rebranded Tracers (epsolar/epever).  Not going to win any beauty or status trophies but they work well and are inexpensive. [edit - looks like one of the new modular Tracers (without the center module) covered by a front plate).]

They are configurable for Absorption duration.  There is also free PC software for it if you want to access historical data, draw charts, graphs, config from the keyboard, etc.

 

[John61CT]

So bottom line if you want to do right by your AGM bank, you need a good Battery Monitor and a better controller.

Renogy, panels are great, but avoid the rest, Victron 75/15 is under $100. . .

Whereas with a FLA bank, you can make do with a hydrometer, and coddling is less critical.

 

[frater secessus]

The reason I brought voltage up is it would us discern if the monitor was confused/confusing (it is), or whether the batteries were really heavily discharged. Based on the 9am 13.9v reading it seems either the solar install is doing great harvesting power and/or the batteries were not as deeply discharged as the monitor suggests. Based on experience with this line of chargers and monitors I put my money on the latter.

HDR: the Renogy 300w is currently sold with a 40A cc. I wouldn't think it would be a problem to run a fridge off the LOAD outputs. It would also allow OP to run the fridge without concern of taking the batteries past LVD (once set to a sane value).

 

[frater secessus]

So bottom line if you want to do right by your AGM bank, you need a good Battery Monitor and a better controller.

I disagree.  I think the OP's system is probably working fine and the display's battery icon is just misleading.

Small loads like the ones OP are imposing will not distort voltage readings much at night.  So if we just had to make a change I think OP would be better off configuring the controller according to AGM manufacturer specs including a reasonable LVD,  and max (120min) the Absorption duration.  Run all the loads through LOAD output and trust the system.  

In either case alternator or shore charging would really help give the AGM bank a SternWakian jolt from time to time.  I think he says every 8-10 cycles.

 

[Trebor English]

This morning with nothing on or connected the monitor reads
Panels.    Batteries.    Load
20V.        13.9V.         14.0
0.2 A.      0.2A.            0.0

After turning on the refrig it reads
19.1V.      13.9V          13.9V
3.6A.         0.3A.           5.0A

The photo you posted shows the panel producing .7 amps and the battery draining at 3.6 amps.  At that time were the panels in the sun?  

That was approximately 9 am this morning.  What is it now?  

The fridge should use substantial current, 5 amps on and off as it cycles is reasonable.  The battery should charge at 10 to 15 amps until it gets to 14.8 volts.  For the panel current to be only .7 amps with the fridge running and the battery not full is not right.  There may be a bad connection in the panel to controller area.

Are the 3 panels connected in parallel or series?

Several posters here have expressed their preference for different equipment.
However, 300 watt panels and 300 amp hours of battery with the controller you have should be adequate to run your fridge.  There seems to be something wrong that needs to be fixed.

 

[KathyC]

Just had a similar issue with my Dometic CFX shutting off prematurely. Turned out, the low voltage cut-off was set for "high" (which for mine is 12.6 V). This might be fine if it were connected to my starter battery, but it's not. Issue is solved by changing to "low" or "med" cut-off voltage.

 

[highdesertranger]

frater the reason I said not to hook it to the load is because that is what the directions on my Engel said. highdesertranger

 

[John61CT]

maybe because they already have a built-in LVD

 

[frater secessus]

What was the final outcome, J.mcculloch? Would love to know what was happening with your system; it can help others troubleshoot their systems.

 

[J.mcculloch]

What was the final outcome, J.mcculloch?   Would love to know what was happening with your system;  it can help others troubleshoot their systems.

Thannk You for checking Frater,

Still not sure. Icon on the MT50 monitor shows a graphic of the battery getting lower and lower with use of refrigerator or even endless breeze or fantastic fans. However, monitor also shows 0ver 12V. Amps are low at all times.

I end up turning the system off about 4 hours after sunset just to play it safe on a trip this week. Primarily due to the low battery icon. Idiot light still state charged battery however.

After reading all the replies, I am pretty much more confused not than I was prior to the original post.

I will bring it to someone who can assist and explain better to me when I have the time and 
$$$. No going fulltime till next spring, will surely have it figured out by then