Tell me no

[nayther]

Been surfing, reading, poking, etc. for a 300 watt solar system for my Wildcat. I've been convinced that MPPT controller with bluetooth is the way to go, don't need a remote panel, can mount controller near batteries, etc.

Currently have 2 6 volt GC Costco batteries and 2,000 watt inverter with separate auto transfer switch. 3000 watt Honda for back up (2000 Predator in the near future for short trips when A/C not needed)

So why shouldn't I buy this:
https://www.ebay.com/itm/ECO-300W-So...t/123816042129

[david_reaves]

I pieced together a system for my daughter's teardrop. It uses a single 150 panel to charge their deep-cycle 12V (120 A/hour) battery. Does a full charge from 50% in about 5 hours of sun/partly cloudy. All their lighting is LCD. The highest single power consumer is the exhaust fan, IF it is turned on high, which is about 5 amps. Next highest is USB chargers at 2.1 amps. They can actually run their camper for about 3 days with no charging needed.

The question from me is, for your dual 6 volt system, do you need really 300 Watts for charging? Assuming you have the 210 Amp-hour Costco 6V, you could drain to 50% and recharge in around 6 hours with the 300 watt system (which appears to be limited to 20 amps-- 5 amps below the theoretical amperage for 300 watts). Are you planning to use that much electricity? Of course, with the 2000 watt inverter, you could completely drain your batteries-- to zero, in about 75 minutes. So it might be necessary. I'd think that with judicious use your 210 amp-hour system should be good for a couple of days. It will never run the A/C, but could be used for microwave or hair dryer for a few minutes. An LCD TV of RV size is probably going to use about 80-90 watts or 7-8 amp/hours. Are you going to be watching TV when you are boondocking? Have you done the math to figure out what you will actually be using?

Finally, a lot of people that use solar chargers don't use MPPT since the extra efficiency is expensive and frequently not necessary. Also, why bluetooth? That seems to be an extra complication that can break and also uses extra power. If your phone breaks have you lost the ability to access the charge controller? A 30 or 40 watt Pulse Width Modulating (PWM) controller with an onboard display would be way less expensive than MPPT. Prices on the panels themselves are a bit higher for monocrystal vs polycrystal, but there is an advantage on efficiency and size. For a 2 panel system, neither efficiency nor size is likely to be a major factor. The one concern is that you can't tell from the E-bay listing who makes the panel. The quality of the panel is probably the key factor in the whole equation.

Overall, you'd probably do well with the system shown. You might be able to do as well, though, spending a bit less money too.

[rk06382]

Originally Posted by nayther

Been surfing, reading, poking, etc. for a 300 watt solar system for my Wildcat. I've been convinced that MPPT controller with bluetooth is the way to go, don't need a remote panel, can mount controller near batteries, etc.

Currently have 2 6 volt GC Costco batteries and 2,000 watt inverter with separate auto transfer switch. 3000 watt Honda for back up (2000 Predator in the near future for short trips when A/C not needed)

So why shouldn't I buy this:
https://www.ebay.com/itm/ECO-300W-So...t/123816042129

Do not buy a 'solar system'. They will put the cheapest parts in the system.

I pieced together my system with Amazon free shipping. I measured my roof & solar panel & calculated how many panels I could get on the roof. I then settled on Renogy slim solar panels. I started with six 100 watt panels. I started with a 40 amp MPPT controller from China and had problems.

Two months later I upgraded to a Victon 50 amp MPPT controller and a Victron BMV-712 battery monitor. They talk to each other.

I park my FR3 in my driveway & can read the bluetooth from my house.

[LTDunltd]

Scratch built 300 watts solar system $629.79

3 ea DOKIO 100W 12V Monocrystalline Solar Panel $97.99 ea.
1 ea Victron Energy SmartSolar MPPT 100/30 Charge Controller $226.10
1 pr WindyNation 10 Gauge 10 AWG One Pair 20 Feet Black + 20 Feet Red Solar Panel Extension Cable Wire MC4 Connector $28.99
1 pr uxcell 1Pair MC4 Y Branch Solar Panel Adaptor Cable Connector 30A MMMF FFFM Set Wire T Splitter $14.09
1 ea Bussmann CB185-30 Surface-Mount Circuit Breakers, 30 Amps. $35.67
1 ea Victron BMV-712 Battery Monitor with Battery Temperature Sensor $226.95

I had already upgraded to a Battle Born 100 Ah LiFePO4 battery.
With the Victron app, I can monitor both units for SOC and amp usage.

[nayther]

Well nobody said "NO" but seems as thought he charge controller would be suspect. Maybe piecing it is a better option since my trailer is "solar ready" with a port on the roof and wiring from there to the pass through.

[nayther]

Originally Posted by LTDunltd

Attachment 208614
Scratch built 300 watts solar system $629.79

3 ea DOKIO 100W 12V Monocrystalline Solar Panel $97.99 ea.
1 ea Victron Energy SmartSolar MPPT 100/30 Charge Controller $226.10
1 pr WindyNation 10 Gauge 10 AWG One Pair 20 Feet Black + 20 Feet Red Solar Panel Extension Cable Wire MC4 Connector $28.99
1 pr uxcell 1Pair MC4 Y Branch Solar Panel Adaptor Cable Connector 30A MMMF FFFM Set Wire T Splitter $14.09
1 ea Bussmann CB185-30 Surface-Mount Circuit Breakers, 30 Amps. $35.67
1 ea Victron BMV-712 Battery Monitor with Battery Temperature Sensor $226.95

I had already upgraded to a Battle Born 100 Ah LiFePO4 battery.
With the Victron app, I can monitor both units for SOC and amp usage.

All of that on a pop up? What kind of loads to you have?

[Flybob]

I would not figure in your "solar Ready" portion as most of the ones I have seen are not designed for a 300w system as the wires are too small. The key to a good system is the controller. I would go to a good US supplier and purchase panels, controller and wiring/connectors. I have tried some of the inexpensive MC4 connectors and they do not hold up. If you are going to attach this to your RV I suggest you use good components and not have to replace things in a year or two.

[LTDunltd]

Originally Posted by nayther

All of that on a pop up? What kind of loads to you have?

I do mostly boondocking, and living in Oregon, we can go months with out seeing the sun. So I went overkill on the solar set-up to insure that I keep the battery charge.