((Eagle/Fleet)) - Shell Amateur Build

[RC Pilot Jim]

Vic - truck been sitting in carport since 12 noon on Tuesday - no load. This morning percent of charge - 89%. Voltage 12.9. Having battery load tested Monday.

 

[Vic Harder]

Vic - truck been sitting in carport since 12 noon on Tuesday - no load. This morning percent of charge - 89%. Voltage 12.9. Having battery load tested Monday.

Yup... good call.

 

[RC Pilot Jim]

Vic - had the battery load tested this morning and it passed with flying colors. That's good. This past week sitting in the carport the battery has maintained 99-100% with just the reflected light off my neighbors roof.

Tomorrow we leave for Ocotillo Wells and the four Wheel rally. We will see how it performs the next 4 days

 

[Vic Harder]

OK, but are you not the least bit confused by your earlier numbers?

For comparison, my camper has been sitting outside, snow covered (so no charging going on) and after 5+ days it is still reading 97%

 

[RC Pilot Jim]

yes VicI am confused ???

I was thinking about what changed since my last 7 day, engine off camping trip. Only thing is the size of the Engle fridge 40 quart marine with plastic cover vs the 35 quart with the metal cover and wonder if the insulation on the marine version is less which could cause the fridge to run longer.

Reviewing my notes on the two, the 35 quart (MT35) starts the cycle at 2.7 amps slowly declining to 1.7 amps during its run over the cycle period. The 40 quart (MR040) starts at 2.7 amps slowly declining to 2.0 over its 2 min 45 second run every 30 minutes.

My one 80 amp battery (40 usable amps) using an average of 2 amps per hour in a 24 hour period should last 20 hours. At the latitude I winter camp at we experience 14-15 hours of darkness per day which should give me a 5 hour cushion before needing a charge.

Based on my notes the battery was losing ground over time.

I will see and record how it does next three days. and report next week.

 

[RC Pilot Jim]

Field Report

Returned from Ocotillo yesterday afternoon.

Engine off 3 days. Devices run: Engle fridge and lights.
Battery range full to empty: 95% sundown - 4:40pm to 83% - 6:15 am.
Voltage range 12.9 full sundown - 12.6 sunrise.
Location: 325 miles south of Independence latitude.

Not comparing apples to apples as engine was off only 3 days vs 7 days for the hot springs. Mate just fixed a salad for the potlucks so we did no cooking during that time and all our social was at the "Main Street Event Center".

 

[Vic Harder]

Jim, are you saying that you went from fully charged to 83% after 3 days of no charging?

 

[RC Pilot Jim]

Sorry Vic that was confusing. Suffering from drive/towing lag this morning.

Day 1 100% sunset - 87% morning . Voltage 12.9 sunset - 12.7 sunrise Fridge not running
Day 2 95% sunset - 85% morning - voltage 12.9 sunset - 12.6 sunrise " " "
Day 3 93% sunset - 83% morning - Voltage 12.9 sunset - 12.5 sunrise " " "

 

[Vic Harder]

OK, let's review:

Devices run:
Fridge - 5.5 AH /day
iPad - 1.8 AH/day
Fan - 0.2 AH/day
Lights - 0.2 AH/day (I don't recall seeing how many hours the lights are on for in post #175 above) - this number assumes just one hour

Total = 7.6 AH.

You have a 150W panel, and when the sun is highest in the sky you get about 5A.

The battery bank is a a single 80 amp AGM that has been load tested and found good.

You are using a MorningStar SunSaver 10L solar controller that goes into float mode at 13.6 volts.

And monitoring all this with Trimetric TM2030 and are seeing that the charging volts never exceeded 13.8 volts.

Did I get all that?


Ok, so then I have some more questions and some possible insights:

1) Where is this 150W panel you have? On the roof? Are there any shadows on it? (fan/vent cover popped open and casting a shadow on even just one corner of a single cell can kill your output).
2) Is it a portable and/or are the wires leading to it very small guage? The reason I ask is:

3) At 80% nominal efficiency, you are getting about 120W out of that panel. Your batteries need to see about .5V higher than they are currently resting at in order to charge. So if they are reading 12.9 at sunset, the solar controller needs to give them 12.9 + .5 = 13.6V. You are seeing 13.8. That sounds ok, but..
4) After a few days, the charge seems to stabilize at 85% or so. At that voltage (you said 12.5) the charger needs to only deliver 13V. It seems to be able to do that and keep the battery at 85%. This leads me to suspect a large amount of voltage drop between the panel and your battery so that you really are not seeing 13.8 at the battery.
5) AND, the difference in current at these two voltages is minimal - 120W / 13.4V = 8.96A and 120W / 13V = 9.23; however, you are only seeing 5A. That's not right - see shadow question above.

 

[rando]

I would be shocked if the fridge was only drawing 5.5Ah per day, unless it is super cold out. With ~27C/80F temps even the most efficient fridges will average to about 0.8 - 1A - so more like 20Ah in a day.

A flat mounted solar panel won't generate a huge amount of power at this time of year - the peak solar elevation is only ~40 degrees, even in so cal. 1-cos(90 - 40) = 0.65. So before any other loses, the maximum you can get is 65%, add in the PWM charger losses, dirty panels etc and you are easily down to 50%, which for a 160W panel at 13.5V is pretty close to 5A.

If you stay in one place for a while, you may be a good candidate for a portable solar panel that you can set out facing the sun. Even with a smaller 100W portable panel you could easily double your solar input.

 

[PaulT]

If you stay in one place for a while, you may be a good candidate for a portable solar panel that you can set out facing the sun. Even with a smaller 100W portable panel you could easily double your solar input.

+1 on the portable panel aimed at sun & tilted correctly.

We have a 4 lb 100 watt flexible panel that we used for that purpose before adding a 160 watt tiltable panel to our roof. Many times it was our primary source of charging power in winter or when there was unavoidable shade over the factory roof mounted 100 watt. Setting up the panel first thing in the morning and until we finished breakfast plus again around dinner added significantly to charging. During the day, we could leave it flat on the roof to contribute.

Paul

 

[RC Pilot Jim]

Vic, Rando and Paul,

Per Trimetric:
Fridge draws 2.7 amps at start of cycle declining to 2 amps in about 45 seconds for another 2 minutes (observed with stop watch). Cycles 2min-45seconds every 30 minutes or 5.5 minutes every hour during darkness. I figure it averages 1.6-2 amps per hour (24 hour period) because it cycles 4 times and hour during the day in 85 degree temps.

My panel produces 5.1 amps December 22nd (observed) and 9.1 amp June 22nd (observed) with battery intentionally drained to 70%. It is mounted flat on the roof and probably has some "skim" of dirt after days on the road.

Most of our camping is 3-4 days. We will do one 2-3 week trip in summer (asphalt) with mixture of dry camping and elect/water campsites. Winter so far is two 7 day trips off the grid and two - three 3-day trips with elect hookup.

I have a 60 watt portable (3.5 amps per hour) that I use sometimes in the winter in forested areas . Most of the time its not needed.

I havent asked Stan reason FWC uses 12 gauge wire instead of at least 10 and wonder if the 10 gauge breaks more often when the top is put up and down.

What started this report was my observation that at 26 months on a 24 month guaranteed battery the bat wasn't holding a charge as long as I thought it would.

 

[rando]

It sounds like everything is working as it should!

The wire gauge really doesn't matter (to first order anyway), particularly with a PWM charge controller. The battery is already pulling the ~18 - 20V from your panel down to ~13.5 V. It really doesn't matter if that voltage drop happens at the panel (which would be the case with heavy gauge wire) or in the wires (which would be the case with really skinny wires), as long as you are not dropping 5V in the wire! If you upgrade to an MPPT charge controller, it starts to make a small difference, but that is more than made up for with the higher native efficiency of the MPPT algorithm.

I think it would be pretty easy to perform you own load test on your battery if you wanted to baseline it's performance. Unless they did a 20hr test on the battery at the store, the results of that sort of test are only marginally related to your usage.

 

[RC Pilot Jim]

Thanks all of you for your input.

On the Ocotillo trip we did not bring the iPad so were not drawing ,(point) 8 amps an hour for about 3-4 hours every day.

And I just remembered that at the Springs we were charging friend Terry's starter battery off the 60 watt portable panel and running his Engle "040" fridge at the same time.

Terry's Honda pilot
I made a temporary charge controller and volt meter box to monitor the process. The blue box its mounted in was created with a 3D printer using Solidworks...Pretty neat.

The morning of the second day the volts were 11.8 (Pilot) because the previous afternoon he had left the ignition key on for about 4 hours (big battery drain). Day two I ran both fridges 6 hours during the day and charged my battery. Terry just charged his battery. Day three both fridges 4 hours(Time the sun was highest in the sky).

Day 4-7 just ran my fridge and charged batteries. That may be the reason my panel and single battery were struggling the rest of the week. .

Arriving home the alternator charged battery back to 99% and its held that every day since.

 

[Vic Harder]

Good stuff. As rando pointed out, it was all working as it should. Heaven knows I sometimes over complicate/think things.

 

[RC Pilot Jim]

Yes Vic, the more gauges I have sometimes the more I worry about it all not working well forgetting that I functioned with just a volt meter for years.

 

[RC Pilot Jim]

Field Report

Friend Terry and I just returned from our annual 9 day winter trip to Saline Valley hot springs. Both vehicles solar worked well for the trip.

On reply # 194 reader can view the portable solar controller with voltmeter that we use with my portable 60 watt rigid panel on friend Terry's Honda Pilot charging his car battery. Each morning I viewed the reading before sunup as 12.5 volts

My 150 watt ran everything that I used. Because the weather was cooler the "Trimetric " reported the percentage of full range was between 89%-100% with 13 hours of darkness per day.

Last item was fuel mileage between Olancha and San Marcos - 20.6 mpg driving 65 mph. Traveling south, downhill (4500 feet - 900 feet) . 2013 V6, 4WD Tacoma now has 48,400 miles on it. Best reading in California I've ever had.

 

[Squatch]

Are you "equalizing" your battery from time to time with the Trimetric? If not that may account for some of the perceived degradation over time.

Your system is very similar to mine. But I'm using a very purpose built group 31 Sealed Lead acid storage deep cycle. It's actually made to be ideal for solar storage and such. After almost 2 years I can detect no changes in storage capacity or charging with it. It's supposed to have a 10 year useful life if well cared for.

I want to do similar to what you did. I want to make up a portable charge controller for my portable homemade suitcase. 2 60 watt panels hinged together and wired parallel. That way I could use it to charge trolling motor batteries or whatever else it might be useful for. It's rarely needed to supplement the roof top panel.

 

[RC Pilot Jim]

Hi Squatch,

I re-read the "Trimetric" paragraph on "Equalizing". "...recommended for 'liquid electrolyte batteries' ...(but often not the gel or AGM types). It also refers to "Section 7" which is information on how to NOT kill your batteries.

I re-read that section and believe I understand it and the "absorption charging voltage" is within specs.

The other issue is "what harm, if any?" are we doing to friend Terry's starting battery by charging it with a 60 watt solar panel to run his Engel fridge 18 days per year. Panel and battery did their jobs when we camped engine off for 7 days.

 

[RC Pilot Jim]

I use this Post a a resource so need to add the following:

Field Report:
June 19th, 2018
Resolved Tacoma Front end "popping noise"