Solar pros and cons?
I'm interested in boondocking techniques, and would appreciate any links to threads concerning the best way to use solar panels to recharge batteries, where to mount them, how to stow them for travel,...
Forum Discussion
AS you will notice when reading the specs of the panels you are looking at most give you the USABLE DC power output current which for a typical 100-120WATT panel is only 5-6AMPS DC CURRENT..
Don't expect this to charge your battery up in a couple of hours...
The battery science is that when you hit a deep cycle battery with 14.4VDC the battery will want to draw a good 15-17AMPS DC Current and if this much power is available the battery will get to its 90% charge state in as quick as a three hour charge time... You will probably run out of sun light before a single 100-120WATT panel will get a single 85-100AH battery charge back up to its 90% charge state when only using 5-6AMPS of current.
In my case my three 85AH Deep Cycle batteries draw around 52-53AMPS when I first start charging them each morning and my PD9260C being run by my 2KW Generator does get the three batteries back up to their 90% charge state with a three hour battery run. I haven't got into the solar panels yet but I suspect I will have to run my generator first for an hour or so to get over the initial large current draw by the batteries then I perhaps can allow my planned two or three 100-120WATTs solar panel to keep the charge going at around 15AMPS or so as the high sun keeps the solar panels going the rest of the SUN DAY. Then perhaps around 4PM or so I will have my three 85AH batteries back up to their 90% charge state so I can use them again the next day/night run off of the batteries.
Just my thoughts on how to address this after discussing all of this among all of the battery/solar experts on here...
My daily use of DC power seems to be around 300WATTs with 1-2 DC AMPS being drawn all day long with my parasitic draw and the 20AMPS or so using an Inverter mainly from 8PM to 11PM each night to run all of our home entertainment items and lights. My 90% charged state battery bank will drop to around 12.0VDC by 8AM each morning doing this when I start my battery bank re-charge using the 2KW Honda Generator connected to the trailer. After my battery drops back from 14.4VDC MODE to 13.6VDC mode then I am pretty sure my solar banks of three 100-120WATT panels or so will get my battery bank back up to the 90% charge state so I can do all of this all over again. This is my plan at any rate hehe... In my case I will have to know around 4PM if my battery bank is back up enough otherwise I run out of time I am usually allowed to run my 2KW generator before generator use time restrictions at most of the places we go expires at 8PM each day. I will not survive the night unless my battery bank starts out at least at 90% charge state.
Just passing all of this on to get your juices going on doing this in a planned and successful way for using solar panels. I don't think you can just stick up a solar panel and run off of it when the sun is out and do anything for your charging your battery bank. Got to look at the long run...
Mother nature would always get after me around 10PM each night when all the lights go out due to battery dropping to zero charge state if I don't start out each evening with at least 90% charge state batteries...
After five or so years now of learning how to do all the things we want to do when camping off the power grid and being successful now of re-charging my battery banks each morning I am just now starting to get in on the solar panel panels.
Takes a bit of planning to be successful about it for me...
Roy Ken
Don't expect this to charge your battery up in a couple of hours...
The battery science is that when you hit a deep cycle battery with 14.4VDC the battery will want to draw a good 15-17AMPS DC Current and if this much power is available the battery will get to its 90% charge state in as quick as a three hour charge time... You will probably run out of sun light before a single 100-120WATT panel will get a single 85-100AH battery charge back up to its 90% charge state when only using 5-6AMPS of current.
In my case my three 85AH Deep Cycle batteries draw around 52-53AMPS when I first start charging them each morning and my PD9260C being run by my 2KW Generator does get the three batteries back up to their 90% charge state with a three hour battery run. I haven't got into the solar panels yet but I suspect I will have to run my generator first for an hour or so to get over the initial large current draw by the batteries then I perhaps can allow my planned two or three 100-120WATTs solar panel to keep the charge going at around 15AMPS or so as the high sun keeps the solar panels going the rest of the SUN DAY. Then perhaps around 4PM or so I will have my three 85AH batteries back up to their 90% charge state so I can use them again the next day/night run off of the batteries.
Just my thoughts on how to address this after discussing all of this among all of the battery/solar experts on here...
My daily use of DC power seems to be around 300WATTs with 1-2 DC AMPS being drawn all day long with my parasitic draw and the 20AMPS or so using an Inverter mainly from 8PM to 11PM each night to run all of our home entertainment items and lights. My 90% charged state battery bank will drop to around 12.0VDC by 8AM each morning doing this when I start my battery bank re-charge using the 2KW Honda Generator connected to the trailer. After my battery drops back from 14.4VDC MODE to 13.6VDC mode then I am pretty sure my solar banks of three 100-120WATT panels or so will get my battery bank back up to the 90% charge state so I can do all of this all over again. This is my plan at any rate hehe... In my case I will have to know around 4PM if my battery bank is back up enough otherwise I run out of time I am usually allowed to run my 2KW generator before generator use time restrictions at most of the places we go expires at 8PM each day. I will not survive the night unless my battery bank starts out at least at 90% charge state.
Just passing all of this on to get your juices going on doing this in a planned and successful way for using solar panels. I don't think you can just stick up a solar panel and run off of it when the sun is out and do anything for your charging your battery bank. Got to look at the long run...
Mother nature would always get after me around 10PM each night when all the lights go out due to battery dropping to zero charge state if I don't start out each evening with at least 90% charge state batteries...
After five or so years now of learning how to do all the things we want to do when camping off the power grid and being successful now of re-charging my battery banks each morning I am just now starting to get in on the solar panel panels.
Takes a bit of planning to be successful about it for me...
Roy Ken
