BajaNomad

Charge boat batteries off inverter while I'm gone?

Doug/Vamonos - 1-24-2011 at 11:22 AM

Hi. I've been thinking of a convenient and reliable method to charge my boat batteries while I'm away. I just replaced one Optima D-34 blue top for $180 and want it to last. My boat has two of them. I mounted a Guest 2611A 5+5 charger on the boat a couple years ago and use it to charge the batteries when I arrive. But I've been thinking of a way to keep the charger operating while I'm gone. My first thought was just to run it off my inverter and solar system. The input current for the Guest unit is 2.5 amps (110vac). This would require me to keep the inverter turned on the entire time. It would not require a lot of amperage so the fans on the inverter would probably never come on and I wouldn't have to worry about them shorting or the unit overheating. Plus, the batteries would charge the first day and then be on a float the rest of the time. I just don't feel confident about leaving the inverter on over a long period when it is unattended.

My other thought was just to buy a smaller charge controller and connect it to one of my 75 watt panels and let that system be dedicated to the two batteries. Then I just need to brainstorm the wiring to make it simple to connect and disconnect and also redirect the panel to my main array when I'm in town since I need all the panels for my house batteries when I'm there. Any other ideas you are using? Thanks.

bajaguy - 1-24-2011 at 11:40 AM

Harbor Freight

http://www.harborfreight.com/catalogsearch/result?category=&...

or

Northern Tool

http://www.northerntool.com/shop/tools/product_200140124_200...

Bob and Susan - 1-24-2011 at 12:42 PM

those are junk
don't waste your money

be careful...some of the newer "smart chargers" will fry if you use inverted energy to power them

if you really want a charger hooked up us a "dumb charger":O

i suggest just disconnecting the batteries on the boat for safety
use a "perko switch"

if they are down when you return charge or replace them

it's thecost of boating...:(:(

Doug/Vamonos - 1-24-2011 at 01:17 PM

They are wired to a perko and are turned off when I leave. My #2 batt may have died because I rarely use it and probably don't charge it underway as much as I should. I normally use #1. That was my oversight. At a minimum, I will manage them better when underway by selecting a different battery each day.

I'm liking the option of directing one of my panels to a separate charge controller. My house batteries don't need that much amperage when I'm gone.

LancairDriver - 1-24-2011 at 01:32 PM

For years when my boat is stored for the winter I have used a small trickle charger left hooked up for months that shuts off automatically when the batteries are charged. Never had a problem. These are very inexpensive and available at Wal-Mart and probably any auto parts store. No clue how it likes invertor power as I have never tried it.

Hook - 1-24-2011 at 01:34 PM

How long will you be away?

I would think an AGM battery should be able to hold a charge just fine for a few months IF YOU ARE CERTAIN THAT THERE IS NO DRAW.

I would worry more about something going wrong with any charging scheme you might devise since you wont be able to check it regularly. I vote for charging the Optimas and leaving them in as temperature-static a location as possible with NO draw.

Even if they drop below 12.0 or so for a short period, these batteries are supposed to be able to take that.

Bob and Susan - 1-24-2011 at 02:53 PM

with a "perko switch" you should always run it on "ALL" not 1 or 2

Doug/Vamonos - 1-24-2011 at 03:08 PM

Hmmm...there be thieves in our little village. Someone got my two big marine coolers, too.

mtgoat666 - 1-24-2011 at 03:25 PM

Quote:
Originally posted by Doug/Vamonos
Any other ideas you are using? Thanks.


lead acid batteries should be fine for a few months to 9 months storage. disconnect batteries before storing. charge fully before storing. store away from heat, in dry place.

Diver - 1-24-2011 at 05:32 PM

I use a small solar panel and charge controller - works great.

monoloco - 1-24-2011 at 06:45 PM

Optimas are AGM batteries and should only self-discharge at the rate of 5% or less per month. If you want to keep them on a charger, I would recommend the solar panel and a charge controller that you can set the voltage on because AGM batteries charge at a lower voltage than FLA batteries and can be damaged if over charged. Do not have the charge controller set to equalize with AGM's, it will kill them.

Doug/Vamonos - 1-25-2011 at 12:29 PM

Good info. Thanks for all your suggestions.

captkw - 1-25-2011 at 03:21 PM

HOLA, as a marine electrical specialist,thats what we do...I have found those batts are very poor choice in marine app's. most alternator's dont support the correct charging and float voltage,therefore they die rather fast.. but since you have one, a panel and a smart charger with the switch set to agm would do the trick,but trying to find the smart charger down here is gonna take some doing!!what is your motor app.? if you have outboards run a normal cranking batt,if in or a i/o with the right reg it will work but I dont see that till you get to the bigger boats.....batt's are probly the most missunderstud things on boats,not 12 v but 12.9-13.8 and deep cycle....dont get me started!!!!!!

BajaGringo - 1-25-2011 at 06:02 PM

Quote:
Originally posted by soulpatch
Hey Doug,
before somebody stole it last summer I had a very small solar panel hooked up to my 12v stuff through a very small charge controller.....that thing worked b-tchen for years.
I think the total cost was well under $60 because the panel was a 2nd.


I found 2 flexible solar panels to mount on the canvas roof of our center console. They are set up to feed the batteries via a charge controller and it works great....

captkw - 1-25-2011 at 06:09 PM

I like the trojans my self but a west marine cranking batt would fine..what yr and model is it?or better yet whats the total electrical load and if you have a ser#

larryC - 1-26-2011 at 08:42 AM

Quote:
Originally posted by Doug/Vamonos
Hi. I've been thinking of a convenient and reliable method to charge my boat batteries while I'm away. I just replaced one Optima D-34 blue top for $180 and want it to last. My boat has two of them. I mounted a Guest 2611A 5+5 charger on the boat a couple years ago and use it to charge the batteries when I arrive. But I've been thinking of a way to keep the charger operating while I'm gone. My first thought was just to run it off my inverter and solar system. The input current for the Guest unit is 2.5 amps (110vac). This would require me to keep the inverter turned on the entire time. It would not require a lot of amperage so the fans on the inverter would probably never come on and I wouldn't have to worry about them shorting or the unit overheating. Plus, the batteries would charge the first day and then be on a float the rest of the time. I just don't feel confident about leaving the inverter on over a long period when it is unattended.

My other thought was just to buy a smaller charge controller and connect it to one of my 75 watt panels and let that system be dedicated to the two batteries. Then I just need to brainstorm the wiring to make it simple to connect and disconnect and also redirect the panel to my main array when I'm in town since I need all the panels for my house batteries when I'm there. Any other ideas you are using? Thanks.


The 2.5amps that the charger consumes at 110v (sounds high) is aproximately eqivilent ot 25amps out of your house batteries (if your house batteries are12v) to run the inverter and keep the batteries charged. Probably not a good choice. If it was me I would use a seperate panel and a controler and keep them chargd that way. No shortage of sunshine down here.
Larry

[Edited on 1-26-2011 by larryC]

Martyman - 1-27-2011 at 12:41 PM

Quote:
Originally posted by Doug/Vamonos
Hmmm...there be thieves in our little village. Someone got my two big marine coolers, too.

We are missing some boat gas tanks. :?: Maybe we should get a neighborhood watch (with beer) vigilante squad.

Doug/Vamonos - 1-27-2011 at 07:53 PM

Well...I heard Kiki got his walking orders...

I'm toying with a battery for my little 12' gregor and evinrude 9.9 (electric start). It hardly needs anything to crank and I only really need the battery for my little sounder. I was thinking a lawnmower battery or something midsize so it is super light. I pretty much lift my boat up onto the trailer so I don't want an 80lb battery. Probably a larger motorcycle battery would be more than adequate.

LarryC: the 2.5 amp stat was found on the specs of the charger. I'm sure that's at a full output which may only last a couple hours max. Though, I'm certainly no expert. I think the resolution to my problem may be just to manage the batteries better when I'm boating. Like I said, I think I abandoned #2 and didn't use/charge it for long periods.

Doug/Vamonos - 1-28-2011 at 10:51 AM

I was there alone last spring (the only other cracka in camp was Beach Bob) and I woke up at 2am because someone was driving around and inspecting my camp with a spotlight. I looked out the door and it was the delegado cops. To be honest, I didn't like that at all. My bikes and quad were out, my garage was open and they could see my stuff, including generator, outboards, you name it. I'm still spooky enough about mexican cops that I prefer never to see or interact with any of them. Hmmm...I guess I should be careful about saying they saw all my "stuff", seeing how "stuff" recently has taken on a whole new meaning. Bob and Doc said they didn't mind the patrol. But me no likey.

larryC - 1-29-2011 at 08:22 AM

I have a pretty good relationship with the local cops, and I think that they are pretty honest. My garage was broken the summer before last and they came out to investigate and then helped secure it in the hope that nothing else would get taken. When I came down that following Oct. I left the garage door open over night. Well about mid night they came through on one of their patrols and saw the open garage and thought there was a robbery in progress and called in the the rest of the cops from town. By the time I got downstairs to see what was going on they had surronded the place and were searching the surronding bushes for the culprits. It took a while for me to convince them that I had left the garage open on purpose and that nothing was missing. They gave me a lecture about locking up everything at night, and how could I expect them to protect me if I make it easy for the banditos to take my stuff? They had a valid point. Anyway, I don't mind their patrols, and I keep my garage locked up at night. I also don't let Kiki anywhere near my place.
Larry

BajaRat - 1-29-2011 at 09:28 AM

The unique engineering concept of the OPTIMA battery uses long thin layers of lead wound into tight spiral cells. Because they're tightly supported on all sides by high strength cylindrical cell casings, the lead ribbons of the OPTIMA battery aren't required to provide structural strength, so they can be made from high-purity, high-performance lead. This translates into dramatically lower internal resistance and higher output at temperature extremes. OPTIMA batteries can be fully recharged in about an hour, twice as fast as conventional batteries. They also can sit unused four times longer than other batteries, losing less than half a volt in over 6 months of nonuse. Press the easy button, enjoy a cold one and think of another project that might be more fruitful. hope this helps, Lionel

captkw - 1-29-2011 at 09:41 AM

capacitor

Bajajorge - 1-29-2011 at 10:13 AM

I just bought a small solar trickle charge system off the internet for $25, included shipping. Bring your batteries up to full charge before you leave and hook up the solar trickle charger. When you return the batteries will be fine.

woody with a view - 1-29-2011 at 10:15 AM

i use the cheapie from harbor frieght on my tundra. she sits for weeks at a time.

trickle trickle....