Feedback on this solar kit?
Hello, I see Harbor Freight has this kit on sale for $140. Yes, I know it's probably the cheapest cheesiest thing I could probably buy because it's from HF, but it's my first endeavor into solar charg...
Forum Discussion
The problem with the small solar panels is they only put out of course just a trickle charge into your battery. Then while you are using it to run a lamp or some small device then you want the solar panel to put that back into your battery right away. If you don't replace it then your battery gets weaker and weaker and when it gets down to around 50% charge state which is appx 12.0VDC then the battery will start its internal self-destruct mode if not re-charged back up in a timely manner.
The 45WATT panel will take many days to bring your battery back up to its 90% SOC and before that happens you have probably already used the batteries again for some more low wattage things... It just never catches up.
If this was tractor sitting in the yard for a week or so then the 45WATT panel would re-charge that battery back up to at least its 90% SOC before you used it again.
The deep cycle battery rules says you can get 99% of its performance if you can get it back to its 90% charge state if you want to use it again. This is why everyone wants to use the smart mode battery chargers run by a generator as they will get your deep cycle battery back up to its 90% charge state in a short three hours time... This is not magic - it is deep cycle battery science...
This is exactly what I do when camping off the power grid. I have smart mode charging on-board and beefed up batteries to run all of the 120VAC items we want to have running from an inverter and all the 12VDC items from being direct connected to the batteries. This is planned to run off my increased battery bank until the next morning when it drops down to 12.0VDC. Then I connect my trailer to the 2KW generator and using the smart mode charging converter can re-charge the batteries back up to their 90% charge state so that we can do this all over again for the next day/night run off the batteries. We are very successful doing this... My deep cycle battery bank is only 255AH capacity
If I had a solar panel large enough to recharge my batteries in a four-five hour time frame during the day than I would not need the generator. The solar panels would have to develop around 20AMPS to be able to do this in that short of time however. 20AMPS relates to probably four 120WATT Solar panels as you can only get around 5-6 usable AMPS from a single 120WATT panel. Actually I would probably need more power than 20AMPS as i have three deep cycle batteries in my setup. The rule of thumb is usually 15-20AMPS available per battery to get the quick three hour re-charge time done.
just passing along to describe what some of us have to go thru camping off the power grid successfully every time. Not many short cuts available to you.
This brochure statement from Progressive Dynamics sort of sums it up... This is true for using your generator or your solar panels for power source...
"Progressive Dynamics ran this test on the amount of time it took a PD9155 (55-amp) converter/charger set to three different output voltages to recharge a 125 AH (Amp Hour) battery after it was fully discharged to 10.5-volts.
14.4-VOLTS (Boost Mode) – Returned the battery to 90% of full charge in approximately 3-hours. The battery reached full charge in approximately 11 hours.
13.6-VOLTS (Normal Mode) – Required 40-hours to return the battery to 90% of full charge and 78-hours to reach full charge.
13.2-VOLTS (Storage Mode) – Required 60-hours to return the battery to 90% of full charge and 100-hours to reach full charge."
There isn't any free lunch...
Roy Ken
The 45WATT panel will take many days to bring your battery back up to its 90% SOC and before that happens you have probably already used the batteries again for some more low wattage things... It just never catches up.
If this was tractor sitting in the yard for a week or so then the 45WATT panel would re-charge that battery back up to at least its 90% SOC before you used it again.
The deep cycle battery rules says you can get 99% of its performance if you can get it back to its 90% charge state if you want to use it again. This is why everyone wants to use the smart mode battery chargers run by a generator as they will get your deep cycle battery back up to its 90% charge state in a short three hours time... This is not magic - it is deep cycle battery science...
This is exactly what I do when camping off the power grid. I have smart mode charging on-board and beefed up batteries to run all of the 120VAC items we want to have running from an inverter and all the 12VDC items from being direct connected to the batteries. This is planned to run off my increased battery bank until the next morning when it drops down to 12.0VDC. Then I connect my trailer to the 2KW generator and using the smart mode charging converter can re-charge the batteries back up to their 90% charge state so that we can do this all over again for the next day/night run off the batteries. We are very successful doing this... My deep cycle battery bank is only 255AH capacity
If I had a solar panel large enough to recharge my batteries in a four-five hour time frame during the day than I would not need the generator. The solar panels would have to develop around 20AMPS to be able to do this in that short of time however. 20AMPS relates to probably four 120WATT Solar panels as you can only get around 5-6 usable AMPS from a single 120WATT panel. Actually I would probably need more power than 20AMPS as i have three deep cycle batteries in my setup. The rule of thumb is usually 15-20AMPS available per battery to get the quick three hour re-charge time done.
just passing along to describe what some of us have to go thru camping off the power grid successfully every time. Not many short cuts available to you.
This brochure statement from Progressive Dynamics sort of sums it up... This is true for using your generator or your solar panels for power source...
"Progressive Dynamics ran this test on the amount of time it took a PD9155 (55-amp) converter/charger set to three different output voltages to recharge a 125 AH (Amp Hour) battery after it was fully discharged to 10.5-volts.
14.4-VOLTS (Boost Mode) – Returned the battery to 90% of full charge in approximately 3-hours. The battery reached full charge in approximately 11 hours.
13.6-VOLTS (Normal Mode) – Required 40-hours to return the battery to 90% of full charge and 78-hours to reach full charge.
13.2-VOLTS (Storage Mode) – Required 60-hours to return the battery to 90% of full charge and 100-hours to reach full charge."
There isn't any free lunch...
Roy Ken
