Good Sam Club Open Roads Forum: Amp draw vs battery bank & solar array = totally confused!
Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Tech Issues

Open Roads Forum  >  Tech Issues

 > Amp draw vs battery bank & solar array = totally confused!

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 4  
Prev  |  Next
Gdetrailer

PA

Senior Member

Joined: 01/05/2007

View Profile



Posted: 12/27/21 02:01pm Link  |  Quote  |  Print  |  Notify Moderator

For some reason the anti robot anti spam filter keeps flagging my posts with more than one link [emoticon]

So, I will add..

For laptops, you can buy a "universal" laptop charger which can operate directly for 12V battery and some offer both 120V and 12V capability. The ouptut is universal meaning by just changing the tip to one that fits your laptop the voltage and amperage is set correctly for your laptop. Looks like this..

[image]

That is the one my DD has been using on a Dell two in one laptop with a i7 processor, has worked well on 120v and 12V.

Can be found HERE

The more low power items you can run directly from the battery the better off you are, running those items through any 120V inverter then back to 5V or 18-19V for laptop wastes a lot of your RV battery capacity.

Some items, just cannot avoid using an inverter, most TVs the 120V power supplies are built into the device as well as sat receivers.

As far as trying to figure out your power needs from the wattage listed on devices goes, you most likely will way over estimate your power needs. Electrical devices in order to get certifications from UL or CSA they must list the absolute max power draw rating. Most devices will draw considerably less than what the name plate says.

Because of this, to get a more accurate reading one must monitor the actual power draw. One such device is called a "Kill-O-watt"..

valhalla360

No paticular place.

Senior Member

Joined: 08/19/2009

View Profile



Good Sam RV Club Member


Posted: 12/27/21 06:18pm Link  |  Quote  |  Print  |  Notify Moderator

Itinerant1 wrote:

Prepare for long generator run times to care for the batteries if longevity might be a concern. Solar will help but won't do much on cloudy/ rainy days or the shoulder seasons.


A moderately sized solar system with generator can address this.

Lead Acid batteries can take a fairly large bulk charge up to around 80-90%...it's that last 10-20% that are slow...so...

Run the generator in the morning to bulk charge quickly to 80-90%, then let the solar top up the batteries slowly over the rest of the day.

Yes, occasionally, the solar won't do the top up but as long as it's not all the time, the batteries should remain happy.


Tammy & Mike
Ford F250 V10
2021 Gray Wolf
Gemini Catamaran 34'
Full Time spliting time between boat and RV


Itinerant1

Itinerant

Senior Member

Joined: 05/23/2017

View Profile



Posted: 12/29/21 09:05am Link  |  Quote  |  Print  |  Notify Moderator

The OP has mentioned they want to go fulltime and mostly away from hookups. Obviously they are very new to understanding battery power with different draws from items in the trailer, then add solar into the mix and it might be a little more confusing to them during this time of the year with caviar power wants.

Having 1,280w of solar might be considered moderate amount by some. Unless you don't mind dragging out the generator and listening to it for long periods of time then there shouldn't be no issues at all.

I personally don't like listening to them even mine and it's only eu2200i so it gets run only when necessary and try to use it for the least amount of time. Over the past 40 days boondocking traveling out of CO, UT, NV and AZ now. Shorter daylight hours, overcast and rainy days and one location was no option than pointing the trailer west which is just horrible for my solar production potential. Batteries living in the PSOC (bouncing between 25%-95%) using whatever is needed at anytime during this period of time with the daily use of 200-250ah. Decided yesterday to do a full charge using the generator, it was another overcast/ drizzle day and at 1:45pm (47% SOC) with solar production of only 50ah total for the entire day. The batteries needed 265ah (53%) taking 2 3/4 hours to fill the batteries completely charging to 14.1v at 100a.

If the OP can afford them LiFePO4 batteries can have alot of benefits over dead lead. Weight is major factor when living fulltime and traveling. My entire system solar panels, inverter/ charger, solar controller, batteries and misc wiring was 500# total. Just food for thought.


12v 500ah (5,120Wh usable), 20 cells_ 4s5p (GBS LFMP battery system). 8 CTI 160 watt panels (1,280 watts)2s4p,Panels mounted flat. Magnum PT100 SCC, Magnum 3012 hybrid inverter, ME-ARC 50. Installed 4/2016 been on 24/7/365, daily 35-45% DOD 2,000+ cycles.

pianotuna

Regina, SK, Canada

Senior Member

Joined: 12/18/2004

View Profile


Offline
Posted: 12/29/21 11:46am Link  |  Quote  |  Print  |  Notify Moderator

valhalla360 wrote:


Lead Acid batteries can take a fairly large bulk charge up to around 80-90%...it's that last 10-20% that are slow...so...

Run the generator in the morning to bulk charge quickly to 80-90%, then let the solar top up the batteries slowly over the rest of the day.

Yes, occasionally, the solar won't do the top up but as long as it's not all the time, the batteries should remain happy.


That's a great plan Valhalla360.

Unfortunately Lead acid do want to get to 100% as often as possible. My favorite battery doesn't require that, except once every 30 cycles.


Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.

valhalla360

No paticular place.

Senior Member

Joined: 08/19/2009

View Profile



Good Sam RV Club Member


Posted: 12/29/21 10:51pm Link  |  Quote  |  Print  |  Notify Moderator

pianotuna wrote:

valhalla360 wrote:


Lead Acid batteries can take a fairly large bulk charge up to around 80-90%...it's that last 10-20% that are slow...so...

Run the generator in the morning to bulk charge quickly to 80-90%, then let the solar top up the batteries slowly over the rest of the day.

Yes, occasionally, the solar won't do the top up but as long as it's not all the time, the batteries should remain happy.


That's a great plan Valhalla360.

Unfortunately Lead acid do want to get to 100% as often as possible. My favorite battery doesn't require that, except once every 30 cycles.


We need specifics and to run a few numbers if we want to be sure but in general terms, you can get 80-90% in 1-2hours with a generator and then a modest solar array should be able to top up the final 10-20%...this will get you up to 100% most days and you can expect a nice long life out of the battery bank.

PS: do you have a franchise for your "favorite battery"...you seem to be pushing them really hard on multiple threads.

pianotuna

Regina, SK, Canada

Senior Member

Joined: 12/18/2004

View Profile


Offline
Posted: 12/29/21 10:56pm Link  |  Quote  |  Print  |  Notify Moderator

Valhalla,

Nope.

I push hard on balanced wiring, solar, and a few other topics, too.

What drives me crazy is folks who run non vented combustion heaters--especially catalytic.

* This post was last edited 01/01/22 12:08am by pianotuna *   View edit history

OkieGene

oklahoma city

Senior Member

Joined: 01/06/2004

View Profile



Posted: 12/29/21 11:28pm Link  |  Quote  |  Print  |  Notify Moderator

I'll 2nd the suggestion of getting a Kill-a-watt meter.

StirCrazy

Kamloops, BC, Canada

Senior Member

Joined: 07/16/2003

View Profile



Posted: 12/30/21 06:14am Link  |  Quote  |  Print  |  Notify Moderator

Itinerant1 wrote:

Batteries living in the PSOC (bouncing between 25%-95%) using whatever is needed at anytime during this period of time with the daily use of 200-250ah. Decided yesterday to do a full charge using the generator, it was another overcast/ drizzle day and at 1:45pm (47% SOC) with solar production of only 50ah total for the entire day.


wow 50AH a day is my daily use in the camper on a cold evening with the furnace running a bit during the day and all night. in the summer I only use about 20 to 25AH.

Steve


2014 F350 6.7 Platinum
2016 Cougar 330RBK
1991 Slumberqueen WS100

Itinerant1

Itinerant

Senior Member

Joined: 05/23/2017

View Profile



Posted: 12/30/21 08:00am Link  |  Quote  |  Print  |  Notify Moderator

StirCrazy wrote:

Itinerant1 wrote:

Batteries living in the PSOC (bouncing between 25%-95%) using whatever is needed at anytime during this period of time with the daily use of 200-250ah. Decided yesterday to do a full charge using the generator, it was another overcast/ drizzle day and at 1:45pm (47% SOC) with solar production of only 50ah total for the entire day.


wow 50AH a day is my daily use in the camper on a cold evening with the furnace running a bit during the day and all night. in the summer I only use about 20 to 25AH.

Steve


The inverter alone is 48ah daily. Like I said I live like on hookups. December is the roughest month power production/ use with shorter daylight hours, if I can get the nose of the 5th wheel facing the sunrise solar production is usually good throughout the day with little needed help from the generator with an hour charge boost on occasion. This is the 6th winter on the system using it like this.

Gdetrailer

PA

Senior Member

Joined: 01/05/2007

View Profile



Posted: 12/30/21 09:33am Link  |  Quote  |  Print  |  Notify Moderator

Itinerant1 wrote:

StirCrazy wrote:

Itinerant1 wrote:

Batteries living in the PSOC (bouncing between 25%-95%) using whatever is needed at anytime during this period of time with the daily use of 200-250ah. Decided yesterday to do a full charge using the generator, it was another overcast/ drizzle day and at 1:45pm (47% SOC) with solar production of only 50ah total for the entire day.


wow 50AH a day is my daily use in the camper on a cold evening with the furnace running a bit during the day and all night. in the summer I only use about 20 to 25AH.

Steve


The inverter alone is 48ah daily. Like I said I live like on hookups. December is the roughest month power production/ use with shorter daylight hours, if I can get the nose of the 5th wheel facing the sunrise solar production is usually good throughout the day with little needed help from the generator with an hour charge boost on occasion. This is the 6th winter on the system using it like this.


If you have 120V devices that do not need to be powered 24/7 you could use an inverter which has a power save or load sense setting. That will easily slash your wasted power via the inverter running with no load by half.

The inverter I used for my home fridge conversion has that capability, I set it so a 9W load will trigger the inverter on. When no 120V load is detected the inverter goes into a deep sleep. Load detection is nearly instant on, just a slight delay when I open the fridge door and the 120V light turns on.. Granted that may not work well for say your TV, but for myself it is enough savings that it beats having to drag an extra pair of GC2 batteries around.

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 4  
Prev  |  Next

Open Roads Forum  >  Tech Issues

 > Amp draw vs battery bank & solar array = totally confused!
Search:   Advanced Search

Search only in Tech Issues


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:




© 2022 CWI, Inc. © 2022 Good Sam Enterprises, LLC. All Rights Reserved.