Alex, did you use this out in Moab this year?
Help me pick a charge controller for my solar install (2 Viewers)
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- #22
I did. I'm not sure i "really" needed it, but it turned out that the group I was with all ended up using my power inverter to charge stuff each night. So, when we would get to camp, i would usually have about 2 hours of daylight left. I would pop the hood, hook up the power inverter, start charging everything and at the same time hook up the solar panel.
One day in particular the charge controller was showing my battery level to be getting low. I hooked up the panel and within an hour it was back to full.
So the answer is yes i did use it, it was very nice to have, was it necessary on this trip.... maybe not.
One day in particular the charge controller was showing my battery level to be getting low. I hooked up the panel and within an hour it was back to full.
So the answer is yes i did use it, it was very nice to have, was it necessary on this trip.... maybe not.
LFD2037
TEXAS LEXUS!
Which controller did you end up going with and are you happy with it? Thanks.
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- #24
I ended up getting the sunsaver that i linked in the first post. I like it a lot so far. I really like the LED light on the front, green for full battery, yellow for kinda low and needs the panel plugged up and then red for really low, plug up or start the truck.
www.solarblvd.com has some great prices.
www.solarblvd.com has some great prices.
That's strange. I have that controller with a Renogy 100w panel on my truck and it makes better than 5A nearly all day - in NEW YORK! Even on cloudy days. Never less than 4A except near sunset, say after 7PM.
LAMBCRUSHER
SILVER Star
MPPT is the way to go... morningstar is making a great product, next to Schneider and Outback that is. the mppt will allow one to charge a battery of lower voltage that the array is capable of supplying, so a 32/48/60+volt panel can charge a 12 volt system...
ntsqd
technerd
In looking at charge controllers for our camper's system I wasn't convinced that I'd reap enough benefits from an MPPT controller to justify doubling the expense. After installing a PWM controller I'm still not convinced that it would be the right choice for that system used the way that it is used. If I ever find that I want/need to significantly increase the panel wattage then I'm sure that an MPPT will make sense.
Were our exposure times more limited and our latitudes higher I can see one being worth the additional expense.
Were our exposure times more limited and our latitudes higher I can see one being worth the additional expense.
TrickyT
Hate that mud...
Any decent charge controller should be able to charge a battery that's lower voltage than the panel. Where MPPT is especially useful is when you have an array of panels in series-parallel combination.
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Yeah, but a real MPPT charger will perform a DC : DC conversion of a higher voltage panel. So, a typical ~18V panel to 12V is ok with both a PWM or MPPT (MPPT is still better), but once you get into the 20V+ range and certainly 24 or 36V panel setups then the MPPT with DC : DC conversion will yield much higher efficiency and higher charge currents into the battery.
It's all a case of what you can afford and whether to put the $ into a larger panel with a PWM controller or smaller panel and MPPT controller. I have a chinese TRUE MPPT controller with DC : DC conversion and it works great and price was in the $100 range.
cheers,
george.
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- #30
So far for my small needs, the charge controller i picked works great with the panel. I plan on really testing it fully on my next two trips since I will be camped in one place for over 4 days running the fridge, music, charging mobile devices, and other items, so i'll be reporting back.
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It should work fine, just keep an eye (meter) the battery feeding all your accessories. It'll give you something to do if you get bored. Just make sure to give the fridge (BEER) top priority 
More likely your 60W panel will be more the limiting factor versus your charge controller. You have a big battery so with solar topping up every day you should be able to 'survive'.
I run an 80W panel in oz and it works quite well with an old school Engel (must be close to 30yrs old) though it can be marginal in very hot weather (higher fridge cycle times). I'll likely pick up an ARB this upcoming trip back since they are much more efficient while holding more beer
cheers,
george.
More likely your 60W panel will be more the limiting factor versus your charge controller. You have a big battery so with solar topping up every day you should be able to 'survive'.
I run an 80W panel in oz and it works quite well with an old school Engel (must be close to 30yrs old) though it can be marginal in very hot weather (higher fridge cycle times). I'll likely pick up an ARB this upcoming trip back since they are much more efficient while holding more beer
cheers,
george.
TrickyT
Hate that mud...
I heard the new ARB's use traditional Danfoss-style compressors, while the the older ARB's and Engel's used solenoid-style "swing" compressors, which were known for their low startup draw. But I have no idea about overall power usage between the two. With the advances in materials in recent recent years I've no doubt that insulation is much better in new refrigs, so that may be the biggest advantage right there....I'll likely pick up an ARB this upcoming trip back since they are much more efficient while holding more beer
cheers,
george.
I recently picked up one of these watt meters off of ebay figuring to monitor refrig power use in different conditions, but so far I've only used it while my old-style ARB was running in freezer mode across Nevada and Idaho, so the numbers weren't representative of that required for
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Yeah, the newer ARB's have the danfoss compressor. I have a couple of friends back in oz with new ARBs and I measured under 3A with the compressor running. My 30 yr old Engel draws closer to 4.5A while running. Of course cycle time is the key and as you say, the insulation is more likely the important factor for 24 hour use and given what I've seen of their ARBs in use, it should outperform my ancient Engel by a large margin while holding more beer
We'll be out bush for about 2 weeks+ so the fridge & solar system will be in full use when we stop/camp. The patrol has dual batteries (both in the 90AHr range) so it could easily handle a couple+ days even without charging the secondary but I like to keep things topped up and you never know if you'll find the perfect spot to camp for several days.
My MPPT unit has an LCD that monitors various parameters including amp.hours put into the battery, so I'll be doing some nerding on the trip
cheers,
george.
We'll be out bush for about 2 weeks+ so the fridge & solar system will be in full use when we stop/camp. The patrol has dual batteries (both in the 90AHr range) so it could easily handle a couple+ days even without charging the secondary but I like to keep things topped up and you never know if you'll find the perfect spot to camp for several days.
My MPPT unit has an LCD that monitors various parameters including amp.hours put into the battery, so I'll be doing some nerding on the trip
cheers,
george.
TrickyT
Hate that mud...
Well please post up some data after your trip. I'll also collect data on my old ARB, although it'll be a while before I get to do any off-roading trips. Gotta go catch salmon in Alaska first.
TrickyT
Hate that mud...
OK, let me at least post up something quantitative to get the ball rolling (and so I can just refer to this thread in the future when I want the data).
This data is not ideal because I didn't differentiate freezer mode from fridge mode as I should have done. My "old style" (circa 2005) ARB fridge ran for 3 days in freezer mode and then 3 days in refrigerator mode. I should have recorded this as two separate "events" but I screwed up and let my wattmeter just run continuously over the 6 days. The ambient temp varied a bunch, from SF Bay Area of ~60* overcast, to Nevada desert of ~105* bright sun/hot pavement, to Montana mountains of ~70*. So over those 6 days (144hrs) my ARB ran a total of 72:06 hrs. It consumed 3192.9Wh of power, or 318.3Ah @ 10.03Vavg. Peak amps were 7.36A and peak watts were 97.6W, although I have no idea what caused these peak conditions and suggest we all just ignore them.
So what numbers do newer style ARB's give?
This data is not ideal because I didn't differentiate freezer mode from fridge mode as I should have done. My "old style" (circa 2005) ARB fridge ran for 3 days in freezer mode and then 3 days in refrigerator mode. I should have recorded this as two separate "events" but I screwed up and let my wattmeter just run continuously over the 6 days. The ambient temp varied a bunch, from SF Bay Area of ~60* overcast, to Nevada desert of ~105* bright sun/hot pavement, to Montana mountains of ~70*. So over those 6 days (144hrs) my ARB ran a total of 72:06 hrs. It consumed 3192.9Wh of power, or 318.3Ah @ 10.03Vavg. Peak amps were 7.36A and peak watts were 97.6W, although I have no idea what caused these peak conditions and suggest we all just ignore them.
So what numbers do newer style ARB's give?
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- #37
Well, like a forgetful dummy, i forgot my volt meter on this last trip. So i can't give any actual numbers. I can give you experience though.
Went camping at a music festival. Truck sat from Thursday around noon to Monday morning around 8:00 AM. The weather was extremely hot (around 90 degrees during the day and 73 at night) for the first three days which caused the fridge to run almost non stop. I did everything i could to use sun shades in the front windows and try to put white towels over the side windows (i think i may cut up some sun shades to rig up and sit in the side windows) in an effort to keep interior temps down.
The sun was out and not hardly a cloud in the sky, so the panel was getting ample sun. After three days i noticed that the charge controller had gone from green, to yellow, to red first thing in the morning indicating a very low battery. I decided to test it and not start the truck but let the solar panel recharge from the previous nights power usage by the fridge. I guess it worked because by that evening the charge controller was back to yellow.... still not green.
This morning when i left, the truck would not start. The charge controller was indicating red and so i was wondering what would happen. Also, it should be noted that that on Sunday it was very cloudy and so the panel did not get saturated with sun.
What i gathered from this is that my 60W panel is enough to keep up with the fridge, but not much more. It would not "recharge" the battery at the end of the day. I need to do some thinking about upgrading to a larger panel. I think if it was cool outside and the fridge was not running so much it can keep up, but i want to plan for all weather conditions.
Luckily there were about 25,000 people there to get a jump start from, so that was good.
In a couple of weeks i'll do another trip, this time to the beach, and i will be parked for 3 days. I will try to remember to bring the volt meter so i can see what kind of actual numbers the panel is putting out.
Went camping at a music festival. Truck sat from Thursday around noon to Monday morning around 8:00 AM. The weather was extremely hot (around 90 degrees during the day and 73 at night) for the first three days which caused the fridge to run almost non stop. I did everything i could to use sun shades in the front windows and try to put white towels over the side windows (i think i may cut up some sun shades to rig up and sit in the side windows) in an effort to keep interior temps down.
The sun was out and not hardly a cloud in the sky, so the panel was getting ample sun. After three days i noticed that the charge controller had gone from green, to yellow, to red first thing in the morning indicating a very low battery. I decided to test it and not start the truck but let the solar panel recharge from the previous nights power usage by the fridge. I guess it worked because by that evening the charge controller was back to yellow.... still not green.
This morning when i left, the truck would not start. The charge controller was indicating red and so i was wondering what would happen. Also, it should be noted that that on Sunday it was very cloudy and so the panel did not get saturated with sun.
What i gathered from this is that my 60W panel is enough to keep up with the fridge, but not much more. It would not "recharge" the battery at the end of the day. I need to do some thinking about upgrading to a larger panel. I think if it was cool outside and the fridge was not running so much it can keep up, but i want to plan for all weather conditions.
Luckily there were about 25,000 people there to get a jump start from, so that was good.
In a couple of weeks i'll do another trip, this time to the beach, and i will be parked for 3 days. I will try to remember to bring the volt meter so i can see what kind of actual numbers the panel is putting out.
Well, it's not too surprising that you observed 60W and PWM to be marginal.
Here is an earlier discussion of sizing. I'm sure there are many more.
https://forum.ih8mud.com/threads/quick-question-about-sizing-solar-panels.681992/
A voltmeter isn't going to tell you a lot. A Wattmeter would be better. I have one like the pic above. Very useful. Was (much?) less than $50 IIRC.
Here is an earlier discussion of sizing. I'm sure there are many more.
https://forum.ih8mud.com/threads/quick-question-about-sizing-solar-panels.681992/
A voltmeter isn't going to tell you a lot. A Wattmeter would be better. I have one like the pic above. Very useful. Was (much?) less than $50 IIRC.
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ntsqd
technerd
IF the SOC of the battery was the same when you tried to start it as it was when you parked it, then I'd say that your panel is keeping up with the fridge. Since the battery was nearly dead I don't think that it is keeping up. The fridge is drawing down the battery on top of what the panel can supply. I'd take a friend in their own rig or a second, fully charged battery to the beach.
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- #40
The problem is at night, not during the day. During the day the panel keeps up, but it's not really "adding" to the battery. So in the evening if it's still hot out and the fridge is still running pretty strong, plus listening to music or charging phones then that's when the battery is going low.
The last day i was at the event, it was cloudy, so i ASSume that the night before drew it down, then the panel couldn't really keep the fridge running since it was pretty cloudy. That means it basically probably did nothing for about 24 hours except just have the fridge and devices run directly off the battery.
The last day i was at the event, it was cloudy, so i ASSume that the night before drew it down, then the panel couldn't really keep the fridge running since it was pretty cloudy. That means it basically probably did nothing for about 24 hours except just have the fridge and devices run directly off the battery.
