Dry camping, battery idea?
We're scheduled to pick up our brand new Keystone Premier Bullet 19FBPR in early May. I'm pretty excited, but we'll be dry camping for two weeks and I have a couple questions regarding battery life. ...
Forum Discussion
Charging batteries from solar panels follows the same RULES OF CHARGING that plugging into Shore Power or Generators does.
If you want to expect to charge your batteries in a quick three hours of time then you will need 14.4VDC@15-20AMPS to re-charge each battery in your battery bank in a three hour time span. Two battery setup system will require 30-40AMPS of usable DC current.
If your solar panels can handle this then this is what will happen. A typical 120WATT SOLAR PANEL will only produce around 6AMPS of usable power when in the HIGH SUN. If your single battery is discharged below 12.0VDC (50% charge state) it will NOT re-charge your battery in a three hour time span.
If you only have 13.6VDC@15-20AMPS of charge voltage to charge up a single battery that has been discharged to 12.0VDC (50% charge state) it will take 12 hours of time to re-charge a single battery to its 90% charge state.
If you have 13.2VDC@15-20AMPS of charge voltage to charge up a single battery that has been discharged to 12.0VDC (50%charge state) it will take 60 hours to return the battery to the 90% charge state.
These are deep cycle battery charging laws not just Uncle Roy Ken yapping away.
Here is a test ran by PROGRESSIVE DYNAMICS on this subject:
"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."
We have been camping off the power grid for around five years with our 255AH capacity battery bank and do almost the same style of camping we would do at regular camp grounds that have electric power available with the exception of not using the air conditioning or high wattage microwave. Running the high DC current associated with the propane furnace is not included in any of this.
My daily routine is running around 20-25AMPS of DC Current from my battery bank between 8PM to 11PM each night running the home entertainment items and few appliances from both an Inverter for the 120VAC items and direct connected to the batteries for the 12VDC items. Included in this will be the 24/7 parasitic drains from the direct connections to the battery bank. My 255AH battery bank will then drop down to around 12.0VDC by 8AM the next morning which is when I connect the trailer shore power cable to my 2KW generator and can re-charge the 255AH battery bank back up to its 90% charge state in as little as three hours time. Now I can do this all over again for the next day/night battery run.
What I want to do now knowing what all we want to run when camping off the power grid is to supplement my re-charging times using some solar panels. In our case it seems the solar panels will not generator more than around 15-18AMPS of usable DC current for around 6-8 hours (120-144AHs) during the one high SUN DAY. In my setup this will NOT replenish my batteries enough to get them back up to their required 90% charge state so we will have to run our generator for the first two hours of the high current charge period and then allow the solar panels to "finish off" the final more lower level of charging to get them back up to their 90% charge state. When running my trailer off my 2KW Generator my DC Battery Monitor Panel shows 52-53 AMPS being consumed by the 255AH Battery Banks in the first 15-20 minutes of the initial 14.4VDC BOOST Charge cycle then it starts dropping back ending around 8AMPS in the two hour BOOST charge cycle.
I will not start any battery consumption in my setup if the battery bank is NOT at the 90% charge state. Otherwise it will get dark on us around 10-11PM at night when the less re-charged battery banks will drop to the 12.0VDC level. i.e. being less charged up they will not make it to 8AM the next morning unless they start out at 90% charge state. When my battery banks drops to 12.0VDC I will shut them down to keep from doing damage to them.
In our method of camping with installed Solar Panels we would use the generator method first to complete the initial high current charge time period and then allow the solar panels to finish up the remaining 90% charge state before the high SUN goes away on us. Also keep in mind you may have some days with NO HIGH SUN at all which will require the use the generator to meet your 90% battery charge state. For us having the generator is MUST HAVE situation.
This is the way we would approach this situation of camping off the power grid just using the generator method and are very successful about it now. It is all second nature for us now.. The three hour charge time usually fits in just fine for those camp ground places we visit here on the East side of the US that have generator run time restrictions in place.
Since we have all of these modern day things now with our trailer setup might as well use them is our way of thinking.
We only think of having solar panels supplemental to keeping our batteries re-charges maybe requiring less runs with the generator. My POPUP trailer roof will only support around three 120WATT solar panels and these would not work well for our style of camping with only producing 15-18AMPS total of usable DC Current in a 8 hour high SUN DAY. The panels can only supplement our use of the generator to be successful every camping day off the power grid with our 255AH capacity battery bank.
You can see others on here have alternate ways of using their solar panels with their installed batteries. This is only my way of thinking and the major thought for me is to continue to be successful for EVERY camping trip.
If I get get better performance with the added solar panels that is just more power to use I didn't have before installing the panels. My saving grace PLAN B will always be having the generator along with us on our trips.
Just me thinking
Roy Ken
If you want to expect to charge your batteries in a quick three hours of time then you will need 14.4VDC@15-20AMPS to re-charge each battery in your battery bank in a three hour time span. Two battery setup system will require 30-40AMPS of usable DC current.
If your solar panels can handle this then this is what will happen. A typical 120WATT SOLAR PANEL will only produce around 6AMPS of usable power when in the HIGH SUN. If your single battery is discharged below 12.0VDC (50% charge state) it will NOT re-charge your battery in a three hour time span.
If you only have 13.6VDC@15-20AMPS of charge voltage to charge up a single battery that has been discharged to 12.0VDC (50% charge state) it will take 12 hours of time to re-charge a single battery to its 90% charge state.
If you have 13.2VDC@15-20AMPS of charge voltage to charge up a single battery that has been discharged to 12.0VDC (50%charge state) it will take 60 hours to return the battery to the 90% charge state.
These are deep cycle battery charging laws not just Uncle Roy Ken yapping away.
Here is a test ran by PROGRESSIVE DYNAMICS on this subject:
"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."
We have been camping off the power grid for around five years with our 255AH capacity battery bank and do almost the same style of camping we would do at regular camp grounds that have electric power available with the exception of not using the air conditioning or high wattage microwave. Running the high DC current associated with the propane furnace is not included in any of this.
My daily routine is running around 20-25AMPS of DC Current from my battery bank between 8PM to 11PM each night running the home entertainment items and few appliances from both an Inverter for the 120VAC items and direct connected to the batteries for the 12VDC items. Included in this will be the 24/7 parasitic drains from the direct connections to the battery bank. My 255AH battery bank will then drop down to around 12.0VDC by 8AM the next morning which is when I connect the trailer shore power cable to my 2KW generator and can re-charge the 255AH battery bank back up to its 90% charge state in as little as three hours time. Now I can do this all over again for the next day/night battery run.
What I want to do now knowing what all we want to run when camping off the power grid is to supplement my re-charging times using some solar panels. In our case it seems the solar panels will not generator more than around 15-18AMPS of usable DC current for around 6-8 hours (120-144AHs) during the one high SUN DAY. In my setup this will NOT replenish my batteries enough to get them back up to their required 90% charge state so we will have to run our generator for the first two hours of the high current charge period and then allow the solar panels to "finish off" the final more lower level of charging to get them back up to their 90% charge state. When running my trailer off my 2KW Generator my DC Battery Monitor Panel shows 52-53 AMPS being consumed by the 255AH Battery Banks in the first 15-20 minutes of the initial 14.4VDC BOOST Charge cycle then it starts dropping back ending around 8AMPS in the two hour BOOST charge cycle.
I will not start any battery consumption in my setup if the battery bank is NOT at the 90% charge state. Otherwise it will get dark on us around 10-11PM at night when the less re-charged battery banks will drop to the 12.0VDC level. i.e. being less charged up they will not make it to 8AM the next morning unless they start out at 90% charge state. When my battery banks drops to 12.0VDC I will shut them down to keep from doing damage to them.
In our method of camping with installed Solar Panels we would use the generator method first to complete the initial high current charge time period and then allow the solar panels to finish up the remaining 90% charge state before the high SUN goes away on us. Also keep in mind you may have some days with NO HIGH SUN at all which will require the use the generator to meet your 90% battery charge state. For us having the generator is MUST HAVE situation.
This is the way we would approach this situation of camping off the power grid just using the generator method and are very successful about it now. It is all second nature for us now.. The three hour charge time usually fits in just fine for those camp ground places we visit here on the East side of the US that have generator run time restrictions in place.
Since we have all of these modern day things now with our trailer setup might as well use them is our way of thinking.
We only think of having solar panels supplemental to keeping our batteries re-charges maybe requiring less runs with the generator. My POPUP trailer roof will only support around three 120WATT solar panels and these would not work well for our style of camping with only producing 15-18AMPS total of usable DC Current in a 8 hour high SUN DAY. The panels can only supplement our use of the generator to be successful every camping day off the power grid with our 255AH capacity battery bank.
You can see others on here have alternate ways of using their solar panels with their installed batteries. This is only my way of thinking and the major thought for me is to continue to be successful for EVERY camping trip.
If I get get better performance with the added solar panels that is just more power to use I didn't have before installing the panels. My saving grace PLAN B will always be having the generator along with us on our trips.
Just me thinking
Roy Ken
