Free 7 Day Trial RV GPS App RV Trip Planner Campground Reviews RV Maintenance Free 7 Day Trial ×


Reply
 
Thread Tools Display Modes
Old 01-13-2016, 01:21 PM   #21
Senior Member
 
Join Date: Sep 2015
Posts: 155
Charging

I inherited a little 2hp generator that drives a 12 volt alternator via a v belt. No 110 but puts out over 20 amps of 12 and I installed a 7 pin plug so I can just plug the trailer connector in and charge away. Not sure were my father got it but he was cheap so I doubt it cost much and since it's only 2hp it's quiet and cheap to run.
DocRob is offline   Reply With Quote
Old 01-13-2016, 01:41 PM   #22
Senior Member
 
NorSnrub's Avatar
 
Join Date: Aug 2012
Posts: 331
I run generator and put a harbor freight big charger on that has 3 modes 1 trickle 2 10 a and one that could start your car.
NorSnrub is offline   Reply With Quote
Old 01-13-2016, 02:58 PM   #23
Senior Member
 
Join Date: Mar 2014
Posts: 2,608
If it weren't for the CPAP, you would find it considerably cheaper, a lot quieter, and less fuss and mess to just add battery capacity for a one week dry camp/boondock. The trick in calculating battery capacity is to know your daily usage in AH.


If you can drive your daily usage down to 30AH or less, just carrying a battery bank of 450 (225 useable) AH will take care of you. Four 6V 232AH golf cart batteries from Costco cost $300 (including tax), and gives you 464AH.


A caution - water and holding tank capacities, as well as food storage, may also limit your boondocking endurance.


just a thought in a different direction
Fred W
2104 Rockwood A122 A-frame with two 6V 232AH Costco golf cart batteries - 4 nights dry camping with heater running 50% during night.
pgandw is offline   Reply With Quote
Old 01-13-2016, 03:12 PM   #24
Senior Member
 
camaraderie's Avatar
 
Join Date: Feb 2014
Posts: 2,646
If you have a pair of 12V batteries ...they are usually group 24, 27 or 31...and the largest (31) will typically provide around 110 amp hours...so you have at most 220 amp hours in your batteries and around 160 with the group 24's.
You can PUT BACK in bulk charge around 20% of the rated amp hours of the bank.... so between 32 and 44 amps is the MAX charger size you need...having a bigger one will not charge you faster....but having a smaller one WILL make you run the genny a lot longer.
Now...you never want to go beyond about 50% discharge so you will need to charge and replenish between 80 and 110 amp hours when you recharge.
Using a 45 amp charger and a need to replenish 110 amp hours in a group 31 battery would seen to take around 2.5 hours then ....except it doesn't. It will take about twice as long to fully recharge the battery than you would calculate due to increased charge resistance as the battery gets over 80% charged.

So hopefully you already have a charger that supplies the optimum amps for your battery bank. just plug your coach power into your generator 110V socket and let the charger do its' work ... remembering that it will be very unusual if your batteries can be fully recharged in less than about 4-6 hours of run time daily AND that if you don't fully recharge and you discharge below 50% regularly you will be cutting your battery life cycles way short.
If you are planning on doing a lot of boondocking then you really should get a true battery monitor that can tell you EACH of the things above...amp hours used, amp hours remaining, amp hours replenished and actual state of charge...and more. These run around $150 bucks and pay for themselves...Trimetric and Victron make em and if you search for those names here...you'll see a bunch more stuff.
Good luck.
__________________
________
Cam
2015 Georgetown 280DS
2019 Vespa Primavera 150's (pair)
camaraderie is offline   Reply With Quote
Old 01-13-2016, 03:51 PM   #25
Senior Member
 
Too Tall's Avatar
 
Join Date: Mar 2014
Posts: 862
Thanks for all the info. I'm going to do a little of both recommendations, I think, Increase my battery bank to 3 or possibly 4 batteries. Purchase a 2K generator for coffee, microwave and charging.

Any suggestions on generators, I saw Northern Powerhouse today for about $600. It's 52 db and seems pretty nice, any thoughts on this one? Or bite the bullet and get the Honda.
__________________
Rockwood 2104S, 2014 Ram 2500 Diesel.
USMC 68 -70
Too Tall is offline   Reply With Quote
Old 01-13-2016, 04:50 PM   #26
Senior Member
 
Join Date: Mar 2014
Location: Mountain Foothills of Southern Alberta
Posts: 1,471
It is hard to beat the quailty of a Champion 2000 for the price.
__________________

2007 Surveyor SV230
- 200 Watts Solar/MPPT Controller - 230 AH Battery Bank (Two-GC2) - 600 watt PSW Inverter - (2) 2000 watt Inverter Generators - LED Lighting
2009 F150 - 5.4 Litre - Tow Package
Boon Docking 99% of the time.
boondocking is online now   Reply With Quote
Old 01-13-2016, 05:08 PM   #27
Senior Member
 
Join Date: Sep 2010
Posts: 358
charging while boondocking

So far you are getting great advice regarding charging using a generator. Everyone I know in our annual Elk Camp (5 RV's, 30 day stretch, no close water or dumps) uses a generator, usually the larger Hondas, or the two small Hondas running in parallel.
I use a 3500 generator, so I can run the microwave, charge the batteries and heat up water, all at the same time. We never watch TV out there, so that is not an issue. I can run the wife's hair dryer, but only it with the water heater off.
We also have solar panels, that we don't have mounted, but store in the basement. I put them on top of the roof, and take them down when we pack up. I also clean them once a week with a soft cloth and Windex, since it is quite dusty. If I didn't have to run the hair dryer once in a while, I could avoid using the generator at all. Really. Depending on what unit you buy, you can put enough amps into the batteries with three panels every single day to take you through the night. They start charging as soon as you get enough light.
Once when I was stuck in the lot of a dealer, for two nights, the panels took light from the lot lighting, and charged all night! They have a one-way diode to prevent the batteries from discharging into the panels at night.
You can get cheap panel systems from Harbor Freight, or you can pay more.
Do a little homework before you buy, and you may be pleasantly surprised.
hankpac is offline   Reply With Quote
Old 01-13-2016, 07:07 PM   #28
Senior Member
 
Too Tall's Avatar
 
Join Date: Mar 2014
Posts: 862
Quote:
Originally Posted by camaraderie View Post
If you have a pair of 12V batteries ...they are usually group 24, 27 or 31...and the largest (31) will typically provide around 110 amp hours...so you have at most 220 amp hours in your batteries and around 160 with the group 24's.
You can PUT BACK in bulk charge around 20% of the rated amp hours of the bank.... so between 32 and 44 amps is the MAX charger size you need...having a bigger one will not charge you faster....but having a smaller one WILL make you run the genny a lot longer.
Now...you never want to go beyond about 50% discharge so you will need to charge and replenish between 80 and 110 amp hours when you recharge.
Using a 45 amp charger and a need to replenish 110 amp hours in a group 31 battery would seen to take around 2.5 hours then ....except it doesn't. It will take about twice as long to fully recharge the battery than you would calculate due to increased charge resistance as the battery gets over 80% charged.

So hopefully you already have a charger that supplies the optimum amps for your battery bank. just plug your coach power into your generator 110V socket and let the charger do its' work ... remembering that it will be very unusual if your batteries can be fully recharged in less than about 4-6 hours of run time daily AND that if you don't fully recharge and you discharge below 50% regularly you will be cutting your battery life cycles way short.
If you are planning on doing a lot of boondocking then you really should get a true battery monitor that can tell you EACH of the things above...amp hours used, amp hours remaining, amp hours replenished and actual state of charge...and more. These run around $150 bucks and pay for themselves...Trimetric and Victron make em and if you search for those names here...you'll see a bunch more stuff.
Good luck.
I looked at the panel today, the RV charger says 55 amps output so I assume most of that would go to charging the batteries if no other major draw from other stuff.
__________________
Rockwood 2104S, 2014 Ram 2500 Diesel.
USMC 68 -70
Too Tall is offline   Reply With Quote
Old 01-13-2016, 07:09 PM   #29
Senior Member
 
Too Tall's Avatar
 
Join Date: Mar 2014
Posts: 862
Quote:
Originally Posted by hankpac View Post
So far you are getting great advice regarding charging using a generator. Everyone I know in our annual Elk Camp (5 RV's, 30 day stretch, no close water or dumps) uses a generator, usually the larger Hondas, or the two small Hondas running in parallel.
I use a 3500 generator, so I can run the microwave, charge the batteries and heat up water, all at the same time. We never watch TV out there, so that is not an issue. I can run the wife's hair dryer, but only it with the water heater off.
We also have solar panels, that we don't have mounted, but store in the basement. I put them on top of the roof, and take them down when we pack up. I also clean them once a week with a soft cloth and Windex, since it is quite dusty. If I didn't have to run the hair dryer once in a while, I could avoid using the generator at all. Really. Depending on what unit you buy, you can put enough amps into the batteries with three panels every single day to take you through the night. They start charging as soon as you get enough light.
Once when I was stuck in the lot of a dealer, for two nights, the panels took light from the lot lighting, and charged all night! They have a one-way diode to prevent the batteries from discharging into the panels at night.
You can get cheap panel systems from Harbor Freight, or you can pay more.
Do a little homework before you buy, and you may be pleasantly surprised.
thanks for the info. Will your 3500 genset run the AC? Also, do you know what watt is your solar panels? thanks a lot.
__________________
Rockwood 2104S, 2014 Ram 2500 Diesel.
USMC 68 -70
Too Tall is offline   Reply With Quote
Old 01-13-2016, 07:27 PM   #30
Junior Member
 
Join Date: Jul 2015
Posts: 16
Too Tall: Charging flooded cell lead-acid batteries is a multi-faceted challenge. There is not a good single answer. The 12V Converter on your camper is not a particularly good battery charger and it will take days or weeks to fully charge your two batteries. If you are determined to charge you batteries with a genset, then you should by a quality 3-stage battery charger to go along with it. The absolute best dissertation on RV battery charging can be viewed at this website. https://handybobsolar.wordpress.com/...ging-puzzle-2/

Happy Camping,
Jamnut
Jamnut is offline   Reply With Quote
Old 01-13-2016, 09:44 PM   #31
Senior Member
 
camaraderie's Avatar
 
Join Date: Feb 2014
Posts: 2,646
Quote:
Originally Posted by Too Tall View Post
I looked at the panel today, the RV charger says 55 amps output so I assume most of that would go to charging the batteries if no other major draw from other stuff.
Yep..sorta mostly...the limiting factor is the wire gauge/length used to send the charge to the batts which is typically undersized...but I think you'll be just fine.
The battery monitor will let you know how many amp hours you use daily so you can figure out how long each day you need to crank the genny....you can also do other stuff while charging since 55amps at 12V is 600 watts or so ...so you can watch TV & do your 120V charging chores for cell phones etc. at the same time.
Since it takes so much time to get the last 20% of charge into the batteries...I prefer to deplete the battery to 50% before charging. If you don't use that many amp hours in a day...you can delay the genny running till you really need it and then be more efficient in how you charge.
Good luck with it all.
__________________
________
Cam
2015 Georgetown 280DS
2019 Vespa Primavera 150's (pair)
camaraderie is offline   Reply With Quote
Old 01-13-2016, 09:45 PM   #32
Senior Member
 
Too Tall's Avatar
 
Join Date: Mar 2014
Posts: 862
Quote:
Originally Posted by Jamnut View Post
Too Tall: Charging flooded cell lead-acid batteries is a multi-faceted challenge. There is not a good single answer. The 12V Converter on your camper is not a particularly good battery charger and it will take days or weeks to fully charge your two batteries. If you are determined to charge you batteries with a genset, then you should by a quality 3-stage battery charger to go along with it. The absolute best dissertation on RV battery charging can be viewed at this website. https://handybobsolar.wordpress.com/...ging-puzzle-2/

Happy Camping,
Jamnut
When charging the batteries via an external charger, should I disconnect the battery cable from the RV to prevent any kind of back feed to the charger in the RV?
__________________
Rockwood 2104S, 2014 Ram 2500 Diesel.
USMC 68 -70
Too Tall is offline   Reply With Quote
Old 01-13-2016, 10:11 PM   #33
Senior Member
 
Join Date: Mar 2014
Location: Mountain Foothills of Southern Alberta
Posts: 1,471
Quote:
Originally Posted by Too Tall View Post
When charging the batteries via an external charger, should I disconnect the battery cable from the RV to prevent any kind of back feed to the charger in the RV?
If you have a 55 amp converter/"RV charger" in your trailer (as you say) then there is no need to use an external charger. Your converter will work just fine to charge your batterys and it will not take weeks as mentioned earlier.
__________________

2007 Surveyor SV230
- 200 Watts Solar/MPPT Controller - 230 AH Battery Bank (Two-GC2) - 600 watt PSW Inverter - (2) 2000 watt Inverter Generators - LED Lighting
2009 F150 - 5.4 Litre - Tow Package
Boon Docking 99% of the time.
boondocking is online now   Reply With Quote
Old 01-13-2016, 10:13 PM   #34
Site Team
 
bikendan's Avatar
 
Join Date: Jan 2007
Location: Camano Island, Washington
Posts: 25,214
Quote:
Originally Posted by boondocking View Post
If you have a 55 amp converter/"RV charger" in your trailer (as you say) then there is no need to use an external charger. Your converter will work just fine to charge your batterys and it will not take weeks as mentioned earlier.
x2
__________________
Dan-Retired California Firefighter/EMT
Shawn-Musician/Entrepreneur/Wine Expert
and Zoe the Wonder Dog(R.I.P.)
2016 PrimeTime TracerAIR 255, pushing a 2014 Ford F150 SCREW XTR 4x4 3.5 Ecoboost w/Max Tow Package
4pt Equal-i-zer WDH and 1828lbs of payload capacity
bikendan is online now   Reply With Quote
Old 01-13-2016, 10:26 PM   #35
Senior Member
 
camaraderie's Avatar
 
Join Date: Feb 2014
Posts: 2,646
Quote:
Originally Posted by Jamnut View Post
Too Tall: Charging flooded cell lead-acid batteries is a multi-faceted challenge. There is not a good single answer. The 12V Converter on your camper is not a particularly good battery charger and it will take days or weeks to fully charge your two batteries. If you are determined to charge you batteries with a genset, then you should by a quality 3-stage battery charger to go along with it. The absolute best dissertation on RV battery charging can be viewed at this website. https://handybobsolar.wordpress.com/...ging-puzzle-2/

Happy Camping,
Jamnut
Lots of good info there but he is dead wrong on acheiving 100% charge. While the mfr. recommendation of 14.8 or 14.7 bulk may be ideal under controlled circumstances...it is beyond ridiculous to suggest that a 100% charge will never be acheived with less. The Progressive line supplies 14.4V bulk and 13.6V finish and 13.2V float. Iota provides...14.8/14.2 and 13.2 respectively. Both of these will fully charge a bank of batteries of up to around 220amp hours as quickly as possible... and fully charge banks of about twice that size if time is not of a concern. (i.e plugged in at the park or house.). Those of us who occasionally check SOC with a hydrometer have seen this time and time again.
The advice to keep 12V wire from chargers short and thick is excellent ...however you don't want the charger in the same compartment as the batts due to off gassing and spark danger in a sealed space...if yours is not enclosed then no problem.
__________________
________
Cam
2015 Georgetown 280DS
2019 Vespa Primavera 150's (pair)
camaraderie is offline   Reply With Quote
Old 01-13-2016, 10:40 PM   #36
Senior Member
 
camaraderie's Avatar
 
Join Date: Feb 2014
Posts: 2,646
Quote:
Originally Posted by Too Tall View Post
When charging the batteries via an external charger, should I disconnect the battery cable from the RV to prevent any kind of back feed to the charger in the RV?
Ditto on NO need for an external charger if you have the internal one.

BUT...if you do for some reason want to use an external charger...yes...remove the leads from the other charger.
__________________
________
Cam
2015 Georgetown 280DS
2019 Vespa Primavera 150's (pair)
camaraderie is offline   Reply With Quote
Old 01-13-2016, 10:59 PM   #37
Senior Member
 
Too Tall's Avatar
 
Join Date: Mar 2014
Posts: 862
Quote:
Originally Posted by camaraderie View Post
Ditto on NO need for an external charger if you have the internal one.

BUT...if you do for some reason want to use an external charger...yes...remove the leads from the other charger.
Thanks, I'd prefer to just plug the genset into the power cable and fiddle around for a few hours during the day while around the campsite then secure the genset for the night. I assume once voltage reaches 12.7 (off the charger) that's a full charge?
__________________
Rockwood 2104S, 2014 Ram 2500 Diesel.
USMC 68 -70
Too Tall is offline   Reply With Quote
Old 01-14-2016, 12:03 AM   #38
Senior Member
 
camaraderie's Avatar
 
Join Date: Feb 2014
Posts: 2,646
Quote:
Originally Posted by Too Tall View Post
I assume once voltage reaches 12.7 (off the charger) that's a full charge?
Absolutely NOT... 12.7V is NOT full if the batteries are connected to the coach and less than 24 hours has passed since you last charged or used them. THIS assumption is what kills batteries. This is why you need a true battery monitor.
12.7 could quitel literally mean a battery half full if because the surface charge (not real) put on the battery by charging takes 24 hours at rest to dissapate. Rather inconvenient if you boondock. LOL
Absent a real battery monitor the ONLY way to know when you are 100% when you stop charging is using a hydrometer and testing at least a few cells in each battery.... pain in the ass but accurate. Read the link to avoid the pitfalls in mesurement that are possible & simple to avoid.
Using the Battery Hydrometer

You will definitely be surprised and how many HOURS it will be before you get a full charge. But if you are short term boondocking ( less than a week) you don't necessarily have to get all the way to 100% as long as you don't fall below 50% and can cycle between 50 and 80-90% until you can get home and plug in for an overnight charge to 100%. (This is only for wet cells....agms' are much more sensitive about needing a full charge.)
__________________
________
Cam
2015 Georgetown 280DS
2019 Vespa Primavera 150's (pair)
camaraderie is offline   Reply With Quote
Old 01-14-2016, 12:23 AM   #39
Senior Member
 
Join Date: Mar 2014
Location: Mountain Foothills of Southern Alberta
Posts: 1,471
Quote:
Originally Posted by Too Tall View Post
Thanks for all the info. I'm going to do a little of both recommendations, I think, Increase my battery bank to 3 or possibly 4 batteries. Purchase a 2K generator for coffee, microwave and charging.
You're welcome !
__________________

2007 Surveyor SV230
- 200 Watts Solar/MPPT Controller - 230 AH Battery Bank (Two-GC2) - 600 watt PSW Inverter - (2) 2000 watt Inverter Generators - LED Lighting
2009 F150 - 5.4 Litre - Tow Package
Boon Docking 99% of the time.
boondocking is online now   Reply With Quote
Old 01-14-2016, 06:40 AM   #40
Senior Member
 
Witch Doctor's Avatar
 
Join Date: Feb 2012
Location: Clarksville Va.
Posts: 10,363
Quote:
Originally Posted by Flybob View Post
Many of the larger TVs have high current alternator systems, the problem is the length of the wiring from the alternator, through the TV and the TT will cause enough voltage drop that you will have limited charging capability. Also even large alternator equipped TVs have limited charging capacity at idle.
You can correct me if I'm wrong, Makes no difference in the size of the TV alternator. It is the size of the wire that matters that runs to the plug. At best a TV will only put out the a trickle charge even if it's a 200 amp alternator. They just are not designed to charge TT batteries, at best just to keep them charged while driving. If you the OP is planning on alot of boondocking then invest in a good honda that do your loads. If you are just doing it to try it out you would be off renting one, then figure out what you really want to do. Just my 2 cents....Main thing JUST HAVE FUN....
__________________
Coachmen M/H
Concord
2018 / 300 DSC

Witch Doctor is offline   Reply With Quote
Reply

Tags
battery, camping, charging, dry camping

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Forest River, Inc. or any of its affiliates. This is an independent, unofficial site.



All times are GMT -5. The time now is 06:49 PM.