The C-Brats Forum Index
HomeForumsMy TopicsCalendarEvent SignupsMemberlistOur C-DorysThe Brat MapPhotos

Solar Battery Charger
Goto page 1, 2  Next
 
Post new topic   Reply to topic    The C-Brats Forum Index -> Electrical and Wiring
View previous topic :: View next topic  
Author Message
thechadmiller



Joined: 20 Jan 2018
Posts: 73
City/Region: Portland
State or Province: OR
C-Dory Year: 2017
C-Dory Model: 22 Cruiser
Vessel Name: Agostino
Photos: Agostino
PostPosted: Sun Apr 21, 2019 7:55 pm    Post subject: Solar Battery Charger Reply with quote

Hi everybody. This subject seems too complicated and it kinda makes my head spin.

We are about to go do our SJI trip for 10-15 days out. Never done anything like that before and not sure how charged our house battery will stay since it doesn't seem like we'll be traveling too far every day.

We don't have much stuff to draw the battery down, a small GPS, an iPad, rechargeable speaker and the Wallas for cooking mostly at this time of year. We have a couple of solar lights that seem to be fine for our needs so we don't plan on using the LED hard-wired ones all that much.

Is it super dumb to buy something like this:
https://www.amazon.com/gp/product/B0046DSLFS/ref=ox_sc_act_title_1?smid=A3DSEGSTO8CUC0&psc=1

Just something to have hanging out during the day when we are moored? We don't have shore power to charge when at a dock.

Feel free to just say "save your money" and spend more later on something better or "this should do the trick".

thanks.
Chad
Back to top
View user's profile Send private message
jkidd



Joined: 23 Oct 2006
Posts: 1176
City/Region: Northern, Utah
State or Province: UT
C-Dory Year: 2007
C-Dory Model: 22 Cruiser
Vessel Name: Voyager
Photos: Voyager (JK)
PostPosted: Sun Apr 21, 2019 9:13 pm    Post subject: Reply with quote

That might work ok to maintain a fully charged battery.
_________________
Jody Kidd
KE7WNG
Northern, Utah

Back to top
View user's profile Send private message Send e-mail
BrentB



Joined: 15 Jul 2006
Posts: 4322
City/Region: Greenwood
State or Province: IN
Photos: BrentB
PostPosted: Sun Apr 21, 2019 9:26 pm    Post subject: Reply with quote

I would buy a Honda 2000 generator.

No more worries and lots of capacity

M2cw

_________________
Brent Barrett
Back to top
View user's profile Send private message
thataway



Joined: 02 Nov 2003
Posts: 17007
City/Region: Pensacola
State or Province: FL
C-Dory Year: 2007
C-Dory Model: 25 Cruiser
Vessel Name: thataway
Photos: Thataway
PostPosted: Sun Apr 21, 2019 11:01 pm    Post subject: Reply with quote

First I would say that is expensive for a 20 watt solar panel. Second, with your power demands an hour of the engine a day should more than suffice--or 2 hurst's every other day.

I believe that you have a 2017 Honda 90, which has a 35 amp alternator. This should have at least 20 amps available to the battery

Do you have two batteries? Most of the time the boats come with the smaller group 24 batteries--but that should suffice. These days I carry one of the small jump start kits (Li ion battery)--these can also charge cell phones etc. (we just charge our phones from the 12 volt system in the boat.

Enjoy the trip!

_________________
Bob Austin
Thataway
Thataway (Ex Seaweed) 2007 25 C Dory May 2018
Thisaway 2006 22' CDory November 2011 to May 2018
Caracal 18 140 Suzuki 2007 to present
Thataway TomCat 255 150 Suzukis June 2006 thru August 2011
C Pelican; 1992, 22 Cruiser, 2002 thru 2006
Frequent Sea; 2003 C D 25, 2007 thru 2009
KA6PKB
Home port: Pensacola FL
Back to top
View user's profile Send private message Send e-mail
hardee



Joined: 30 Oct 2006
Posts: 10039
City/Region: Sequim
State or Province: WA
C-Dory Year: 2005
C-Dory Model: 22 Cruiser
Vessel Name: Sleepy-C
Photos: SleepyC
PostPosted: Mon Apr 22, 2019 12:04 am    Post subject: Reply with quote

Chad, What size battery(s) do you have? One or two, Marine/RV Deep Cycle? You may find that you move enough that you don't need that solar. Do you have any way to monitor your battery SOC (State of Charge). I use a simple volt meter that plugs into the Cig lighter. Works, easy and cheap, and I can know when I need to run the OB's. I have found that I only need about a half hour a day, for what I run: Phone charger, small Garmin GPS for anchor watch, HH VHF charger occasionally, and rarely the Wallas. I do use a CPAP at night, about 7.5 hours, (about 5 amps), which is my biggest draw.

I'm with Bob on this one. It seems expensive for what you are getting. Get a way to monitor your battery voltage, and then you can know what you need to do next.

Harvey
SleepyCMoon

_________________
Though in our sleep we are not conscious of our activity or surroundings, we should not, in our wakefulness, be unconscious of our sleep.
Back to top
View user's profile Send private message
ssobol



Joined: 27 Oct 2012
Posts: 1804
City/Region: Leesburg
State or Province: VA
C-Dory Year: 2008
C-Dory Model: 22 Cruiser
Vessel Name: SoBELLE
Photos: SoBelle
PostPosted: Mon Apr 22, 2019 12:09 am    Post subject: Reply with quote

When I need to charge the house battery I just run the motor for awhile. My Honda BF90 can put about 20 amps into the battery at about 1K rpm. When anchored out, I just run the motor for about 20-30 minutes at a time when needed to top up the battery. Usually just takes once in the morning and once in the evening. Depends on whether or not we are using the refrigerator or not.

Unless you need the VAC a generator puts out, the motor alternator will charge the battery(s) a lot better than a small portable generator.

I have a Honda 1000, but only carry it for times we plan on being anchored out and anticipate needing the air conditioner.
Back to top
View user's profile Send private message
journey on



Joined: 03 Mar 2005
Posts: 3254
City/Region: Valley Centre
State or Province: CA
C-Dory Year: 2005
C-Dory Model: 25 Cruiser
Vessel Name: journey on
Photos: Journey On
PostPosted: Mon Apr 22, 2019 9:34 am    Post subject: Reply with quote

I use a 25 watt solar panel to float the truck's battery when it sits for several weeks. I would not ask any more of it, but it does that job well. As I remember, it cost ~$30 from e-bay, so $144 seems excessive.

That said, with your load and our previous experience in moving about in the SJI (San Juan Islands, I presume,) you should be fine, charging by running your motor.

Boris
Back to top
View user's profile Send private message Visit poster's website
Marco Flamingo



Joined: 09 Jul 2015
Posts: 826
City/Region: Seattle
State or Province: WA
C-Dory Year: 2004
C-Dory Model: 16 Cruiser
Vessel Name: Limpet
Photos: Limpet
PostPosted: Mon Apr 22, 2019 10:09 am    Post subject: Reply with quote

Get a little monitor like this and see what your usage is on the SJI trip. You may have to run your motor while at anchor or maybe not. Then you can decide if a solar kit is worthwhile. https://www.amazon.com/LIHAN-Charger-Display-Voltage-Compatible/dp/B01JA627KU/ref=sr_1_4?keywords=cigarette+lighter+battery+monitor&qid=1555944682&s=gateway&sr=8-4

You pay a hefty premium for the convenience of a little kit. Plug and play is nice and you can move it to the best spot for solar gain. But you are paying at least double for the watts that you're getting over doing a setup yourself. What is usually missing in the convenient kit is the solar controller (as an example https://www.amazon.com/Controller-Battery-Paremeter-Adjustable-Regulator/dp/B06W5NP5JR/ref=sr_1_4?keywords=solar+panel+regulator&qid=1555945136&s=gateway&sr=8-4). These little gadgets improve the efficiency of solar charging and tell you much more about your batteries.

The other problem with the little kits is that they work okay for keeping a battery topped off, but if you really drain a battery down (over night for instance), you will be sitting for a while waiting for a 20 watt solar panel to bring the battery back up enough to start an engine. Bigger is better (and faster).

Mark
Back to top
View user's profile Send private message Send e-mail Visit poster's website AIM Address
DavidM



Joined: 24 Dec 2017
Posts: 153
City/Region: Punta Gorda
State or Province: FL
C-Dory Year: 2006
C-Dory Model: 22 Cruiser
PostPosted: Mon Apr 22, 2019 12:54 pm    Post subject: Reply with quote

That is a very expensive package and 20 watts won't do much. If you want a package, look on Amazon for at least 100 watts. Those packages usually come with a very cheap Chinese controller. Look for packages with Renogy products. Those are still Chinese, but Renogy is a big Amazon supplier and they probably aren't going to be selling junk.

You can also put one together yourself for about half the cost and it will include a quality controller.

I gave a talk on solar power at the recent Hontoon gathering. Here is a link to the Trawlerforum library section where you can download an article I passed out: http://www.trawlerforum.com/forums/downloads.php?do=cat&id=2

In this library section it is titled "Solar Panels for Your Boat". In the same section there are two other articles that I wrote: "Sizing a Large Solar Panel System" which talks about the use of a battery monitor to understand your DC loads and "Designing and Installing a Large Solar Panel System" which goes into the mechanics of the installation.

The latter two articles are appropriate for a heavy DC user. Most of you can just install one or two 100 watt panels which should cover your needs.

One thing I learned in the Q&A afterwards at Hontoon is that Victron now has a line of inexpensive MPPT controllers with or without a bluetooth interface. A single 100 watt panel can be installed with their 15A controller which costs about $88 without bluetooth. You will need their 20A unit for two 100 watt panels which is about $157 with bluetooth.

Victron's new products and competitive pricing with PWM controllers makes it worth considering a MPPT controller even for small systems.

David
Back to top
View user's profile Send private message Send e-mail
thechadmiller



Joined: 20 Jan 2018
Posts: 73
City/Region: Portland
State or Province: OR
C-Dory Year: 2017
C-Dory Model: 22 Cruiser
Vessel Name: Agostino
Photos: Agostino
PostPosted: Mon Apr 22, 2019 2:28 pm    Post subject: Reply with quote

Thanks everybody. I ordered a cig lighter voltage monitor.
We have 2 batteries, both marine. Both Group 24 size?
The starter battery says cranking and 800CCA / 1000MCA,
the house is deep cycle and 550CCA / 690MCA / 140 RC.

Just been reading lots of summaries and... yeah. Math. But even if I'm just kinda right, our regular electronics won't pull too much. The main variable would be the Wallas.

Fingers crossed.
Back to top
View user's profile Send private message
DavidM



Joined: 24 Dec 2017
Posts: 153
City/Region: Punta Gorda
State or Province: FL
C-Dory Year: 2006
C-Dory Model: 22 Cruiser
PostPosted: Mon Apr 22, 2019 4:15 pm    Post subject: Reply with quote

thechadmiller wrote:
Thanks everybody. I ordered a cig lighter voltage monitor.
We have 2 batteries, both marine. Both Group 24 size?
The starter battery says cranking and 800CCA / 1000MCA,
the house is deep cycle and 550CCA / 690MCA / 140 RC.

Just been reading lots of summaries and... yeah. Math. But even if I'm just kinda right, our regular electronics won't pull too much. The main variable would be the Wallas.

Fingers crossed.


Not to put too much of a damper on the fun, but if those "deep cycle" batteries don't also give an amp hour spec, they are unlikely to be true deep cycle batteries and won't last as long.

I agree, your Wallas heater will be the power hog.

David
Back to top
View user's profile Send private message Send e-mail
thechadmiller



Joined: 20 Jan 2018
Posts: 73
City/Region: Portland
State or Province: OR
C-Dory Year: 2017
C-Dory Model: 22 Cruiser
Vessel Name: Agostino
Photos: Agostino
PostPosted: Mon Apr 22, 2019 4:33 pm    Post subject: Reply with quote

It's this:
https://www.interstatebatteries.com/products/srm-24

81 amp hours.
Back to top
View user's profile Send private message
Marco Flamingo



Joined: 09 Jul 2015
Posts: 826
City/Region: Seattle
State or Province: WA
C-Dory Year: 2004
C-Dory Model: 16 Cruiser
Vessel Name: Limpet
Photos: Limpet
PostPosted: Mon Apr 22, 2019 5:21 pm    Post subject: Reply with quote

If the Wallas works like my Espar, it is the startup that uses the most electricity. The glow plug is +8 amps and can run for 15 minutes. Once going, it drops down to about .8 amps. Given the tiny amount of fuel my Espar uses, I do most of my temperature regulation at anchor by opening the windows instead of letting the thermostat cause the unit to cycle. Running the batteries down is more likely and a bigger problem than running out of diesel.

Batteries aren't an issue when running, of course, or at anchor overnight (because I don't run it once I'm in bed). I can see my battery minder from the v berth, so I can check the state of charge before I fire up the Espar in the morning (also from my v berth). So far, I've always had plenty of juice (with 2 24s).

Mark
Back to top
View user's profile Send private message Send e-mail Visit poster's website AIM Address
DavidM



Joined: 24 Dec 2017
Posts: 153
City/Region: Punta Gorda
State or Province: FL
C-Dory Year: 2006
C-Dory Model: 22 Cruiser
PostPosted: Mon Apr 22, 2019 5:34 pm    Post subject: Reply with quote

thechadmiller wrote:
It's this:
https://www.interstatebatteries.com/products/srm-24

81 amp hours.


Thanks. I have that same battery in my camping trailer. So far it has held up fine for five years.

David
Back to top
View user's profile Send private message Send e-mail
knewlin



Joined: 30 Oct 2006
Posts: 35
City/Region: Smiley Park
State or Province: CA
C-Dory Year: 2000
C-Dory Model: 22 Cruiser
Vessel Name: Secret of Life
Photos: Secret of Life
PostPosted: Tue Apr 23, 2019 11:52 am    Post subject: Solar Reply with quote

We use a Mohoo 100W fold-able panel.
We run a small Engel freezer for cocktail ice and to freeze ice blocks for the Yeti. I wanted a portable panel so we could anchor in the shade and extend out to the sun. So far, so good. The only time we have run the batteries down was during a summer in the SJI with smoke filled skies.

_________________
"The secret of life is enjoying the passage of time..." (James Taylor)
Back to top
View user's profile Send private message Send e-mail
Display posts from previous:   
Post new topic   Reply to topic    The C-Brats Forum Index -> Electrical and Wiring All times are GMT - 6 Hours
Goto page 1, 2  Next
Page 1 of 2

 
     Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum



Page generation time: 0.0714s (PHP: 80% - SQL: 20%) - SQL queries: 32 - GZIP disabled - Debug on