55 replies to this topic

[EnviroProf]

I owe everyone an updated. I don't have any pics yet and I'll give a better description soon, but I've been running my 180 watt panel for a few weeks now and it just cranks out the juice! We typically would use 15 - 25 amps in a 24 hour period.  I can be at 96% SOC (according to the trimetric when I back out of the shop to load up. I don't pre-chill the Engel 45qt fridge and crank it on and the fantastic fan on low and the panel is still making around 2 amps positive.  I currently have completely disconnected the camper from the truck so no alternator charging. By the time we drive an hour or two to our destination, the batteries are at 100%. We stay at 100% until the sun goes down (running the Engel, fantastic fan, and lights).  Overniight, we might get down to 94% SOC including running the furnace for 10 minutes (even in record breaking 95+ degree heat here in MT, the mountains can get down to 40 degrees in the morning).  By 10 or 11 am, we are back up to 100% SOC.  

 

If anyone is interested, I did work up the correct Trimeteric 2030/Solar controller (SC2030) parameters from a chart on the Exide website. Note, these only apply if you are running the FWC factory Flat Plate AGM Exide batteries. If you run other batteries, that manufacturer should be consulted with to get the correct parameters for that specific battery set.  I also exchanged emails with a helpful Senior Engineer at Exide confirming all parameters. I'll post them up in the next few days.  

 

Will have some photos of the mount as well. It was simple using the factory roof tracks and a few pieces of 1/4" aluminum bar. 

 

 

I have also been looking at the Solar Blvd. 180 Watt panel priced at $200 (w shipping).

https://www.solarblv...lar-panel-copy/

 

AM Solar also has a 180 watt panel for $270 (w shipping). http://amsolar.com/r...els/solar-sf180

 

They are close to the same size and I think that both would fit between the vents on a Fleet and would span the Yakima tracks. The key difference (besides cost) is the weight. The AM Solar 180 is listed at 24.5 lbs., while the Solar Blvd. 18 is listed at 33 lbs. 

 

Chadx, sounds like you are happy with your panel. Any issues with the weight and lifting the roof?

Edited by EnviroProf, 25 August 2017 - 10:03 PM.

[Chadx]

EnviroProf, I've not had any issues lifting with the panel on top. I'll note that we ordered our shell with the heavier-rated lift struts (40 lb?) since we knew we'd be adding solar within the year. The front is the harder of the two ends, but it's really that first 2" to get it started, then it is very easy. The last half of the lift, it practically goes up by itself.

Still amazed what this panel will do. I was at the gas station the other day under the canopy in total shade and was making almost an amp. I usually don't bother prechilling the Engel on AC power because the solar makes so much there is no need. Very nice.

I've noticed the trimetric says the percentage full drains faster now that the solar and controller are hooked up. It used to drain 1% in 24 hours parked inside and now it is 2% and sometimes 3%. Anyone have the same experience? This with the main camper power switch off so only thing hooked up is controller. Maybe the controller led lights? Seems strange. But as soon as I pull out in the sun, it charges so fast I'm not too concerned. What drain do others have when camper is sitting (with no light on solar panel and not hooked up to charger)?

As mentioned before, the solar controller is programmed with parameters specifically for the Exide AGM batteries (parameters directly from an Exide engineer). It seems to charge the batteries way better than my battery tender as it knows it needs to replace X amount of juice plus extra. Where the battery tender runs it up to a certain voltage then goes into float. For example, my trimetric said I was at 96%. I plugged in the battery tender and it charges through it's various stages overnight and went to float. But the trimetric says I'm at 98% full rather than 100%. Unplug the tender, plug it back in, goes through it's cycles and goes to float in a few minutes as it brings the voltage up immediately. As soon as I back out into the sun, the solar chargers to it's specs and brings it up to 100%. Yes, battery tender is hooked up to go through the shunt, as is everything. Trimetric sees the input amps from the tender. It is just that the tender can only read and make decisions off of voltage where the trimetric "knows" more input output history so the controller can more thoroughly charge.

...or, for some reason, my trimetric is reporting more battery drain than is really occurring. I have it programmed for my 100/100 shunt and with various loads, it seems to report accurate amp draw.

My main interest is the trimetric reporting battery drop over time. I know flooded batteries do lose charge when sitting, but that is internal to a battery and not being drawn so the shunt shouldn't know about it. Is there an algorithm built into the trimetric to assume some battery loss over time and it reports that as a percentage drop? And now with the controller and temp gauge tied to the trimetric, maybe it is doing the same but adjusted for temp since the higher the temp, the faster a sitting flooded battery loses charge? And these last few months have been very hot in my shop so maybe the algorithm reports more loss? I guess I'll contact Bogart and ask these questions.

But any comments or thoughts?

Edited by Chadx, 26 August 2017 - 03:02 PM.

[Squatch]

Everything sounds normal. Simple fact is the Trimetric is more precise than most AC smart chargers! Especially when set up for a specific battery.

 

I've been very tempted to buy a 2nd Trimetric and sc2030. And them make a portable charger for my folding 120 watt suitcase panels. Then use that to charge my boat batteries.

 

My system seems to have a .1 draw most of the time with nothing on. It may be less than that but with 500 amp shunt I only read .0 not .00. It's not an issue at all for me.

 

Yep it doesn't take much time in bright sun and the 160 watt panel fills the battery lickety split. In good weather the battery is charged to 100% by mid morning with my fridge always on at 34*.

 

I've found the 2 biggest factors with low batteries are several days with little sun. Or very hot days where the camper is closed up and the fridge has to work hard.

 

I added a small LED light in my camper that draws .1 amp. That's about all I use most of the time for lighting. I haven't converted the stock incandescent ceiling lights. Last night I was showing the camper to an old friend who hadn't seen it yet. I turned on both lights in one fixture. Amp draw was 2.8-9 amps. That's more than either my furnace or fridge on ECO!

Edited by Squatch, 26 August 2017 - 03:12 PM.

[rando]

One issue with all integrating current monitor type battery monitor is that these small loads and errors can lead to big errors over time.   For instance a 0.09A load would likely not be measured by a 0.1A resolution current meter.  However, if you have 0.09A load over a day, that is 2Ah out of your battery, over a week it is 14Ah, or ~20% of your battery capacity.    It is important to get the highest current resolution you can, and to charge to 100% so your battery monitor can 'synchronize' fairly often.   This is one of the great advantages of always on solar - when just sitting, the battery should get fully charged every day, which should reset the battery monitor to 100% and reset these integrated errors. 

 

From what your saying it sounds like your monitor has some accumulated error or some sort of offset.  Any battery that has been on float for more than 24 hours should be fully charged.

[Chadx]

From what your saying it sounds like your monitor has some accumulated error or some sort of offset.  Any battery that has been on float for more than 24 hours should be fully charged.

Thanks for your insight. My shunt is 100/100 so my amp reading is down to .01 rather than .1 like the 500s. Was really just trying to figure out if the 2%+ discharge over a day when parked in the shop is normal.

To clarify, when the solar charges the batteries, it hits 100% easily and quickly. When the battery tender charges, it goes to float before the trimetric says 100% full. Before i had the solar panel and controller, I had the trimetric attached and the tender was my only source of chargimg. If I recall correctly, the trimetric would report 100 charge if the tender was left on for 24+ hours so the tender float must slowly/eventually get it up there. But yesterday was the first time I even bothered with the tender since I installed solar and it was out of curiosity not necessity. And it was interesting, and really just a side observation, that when the tender went into float overnight (Maybe 8 hours on the charger), the tender thought the battery was full (based on it's only way to tell; voltage) and the trimetric thought the amount of current the battery received was enough to get the battery only up to 98% at that point. Again, just an interesting point and I agree that getting the trimetric up to the 100% charged starting point daily is the best way to keep the numbers as close to accurate as possible.

So sounds like everything is normal including the daily drop when no charging is taking place. I was just surprised in how much the daily drop was with zero draw and curious how a shunt and/or monitor would know about or calculate battery percentage discharge over time (with no draw) and if that was built into the trimetric or controller or if the controller/panel were somehow drawing current when not actively charging and parked indoors.

[buckland]

being mostly electrically ignorant... can one explain (basically) what a shunt does in this application. (I understand that a shunt redirects electricity).... is it a spliced-in wire? 

[Squatch]

Reality is the .1 reading on my Trimetric is probably less than ,1. I think the Trimetric senses any loss and rounds up to .1.

 

Different batteries drop at different rates when not being charged. AGM's tend to maybe lose a little more than my Sealed Lead Acid true deep cycle. The manufacturer usually lists a discharge graph online.

 

The Bogart stuff actually data logs for several days whether you are set to watch it or not. The manual states that it's normal for the charger to replace whatever is lost at 110% return charge to compensate. So I think .1 resolution is not an issue at all. We're just charging fridge batteries here. Not keeping an Apollo capsule and it's occupants alive in space.

 

I agree on the always on solar. Most of the time my batteries are at 100% daily. That's what the battery wants to see for best life span. Though they do need to get a 1/2 deep discharge from time to time. A few cloudy days will take care of that. best of both worlds. I do check my monitor most days. if I do get down in the 70%'s or rarely in the high 60%'s I will break out the add on portable 120 watt panel to get things back to 100%. It's rarely needed and mostly because I was parked in shade for several days. With both panels in the sun I have 280 watts. Things charge fast!

Edited by Squatch, 26 August 2017 - 05:14 PM.

[Squatch]

being mostly electrically ignorant... can one explain (basically) what a shunt does in this application. (I understand that a shunt redirects electricity).... is it a spliced-in wire? 

A shunt is a very precise high amperage resistor. Precise enough that it allows measurement instruments to read the difference between one side and the other when current flows across it. Without it you would not be able to monitor current flow only battery voltage. The resistance is extremely low. Almost non existent.

 

 

Brass item in center is my Shunt.

 

Switchable circuit breaker on left.

 

Intermittent circuit breaker on top.

 

On right is Bogart SC2030 charge controller.

 

Taken before items installed.

Edited by Squatch, 26 August 2017 - 05:36 PM.

[rando]

Reality is the .1 reading on my Trimetric is probably less than ,1. I think the Trimetric senses any loss and rounds up to .1.

 

Different batteries drop at different rates when not being charged. AGM's tend to maybe lose a little more than my Sealed Lead Acid true deep cycle. The manufacturer usually lists a discharge graph online.

 

The Bogart stuff actually data logs for several days whether you are set to watch it or not. The manual states that it's normal for the charger to replace whatever is lost at 110% return charge to compensate. So I think .1 resolution is not an issue at all. We're just charging fridge batteries here. Not keeping an Apollo capsule and it's occupants alive in space.

 

I agree on the always on solar. Most of the time my batteries are at 100% daily. That's what the battery wants to see for best life span. Though they do need to get a 1/2 deep discharge from time to time. A few cloudy days will take care of that. best of both worlds. I do check my monitor most days. if I do get down in the 70%'s or rarely in the high 60%'s I will break out the add on portable 120 watt panel to get things back to 100%. It's rarely needed and mostly because I was parked in shade for several days. With both panels in the sun I have 280 watts. Things charge fast!

 

 

All very true.    Any battery monitor only has a certain precision.   If you are good to 10%, you are doing pretty well. 

[buckland]

Thanks Squatch, 

Appreciate the Electric 101 explanation as I still struggle with the basics. Trouble with catching up learning is that there are huge holes in the knowledge. I am pretty confident that I am missing something whenever I delve into an electrical project.