JUST 10 HOURS ON THE HOOK

larglo · Post by **larglo** » Sun Feb 20, 2011 6:02 pm

Hi all,

In my quest to get 10 hours of running my fridge on the hook, I took the first steps today. Went to Wally World and as luck would have it, only had 1 Maxx 29 battery in stock, so bought it. Today I installed it along with the inverter in the area below the seat of the dinette.
Last year I had installed a 110 outside outlet next to the shore power hook-in (for this purpose) and using an adapter I made, from the shore power hookup to the 110 outside plug, hooked it to it. So, from the inverter to the shore power, it gave me 110 throughout the boat.

After turning on the inverter, I flipped the breaker on the panel. The clock on the microwave came on, and then I turned the temp control of the fridge and it came on. The inverter gauge read 13.6, and after the fridge came on it went to 13.0 and stayed there. The fridge was not on at all, so didn't leave it on for long.

As soon as I can, I'm going to test it by getting the fridge at operating temp, cut the shore power and see how well it does just on the inverter. I got to get a DC analog volt gage and get it hooked up though, so I can keep an eye on the voltage drop, before I try this.

If I can get 10 hrs, I'll be happy.

Larry

Big D · Post by **Big D** » Sun Feb 20, 2011 6:17 pm

Larry, don't know that I understand exactly what you've done with the shore power/inverter hook up. Just make sure you can not run shore power to the inverter (even by mistake) or you will blow the inverter. The more expensive ones with automatic switching require shore power to the inverter but I suspect this is not the type you have.

larglo · Post by **larglo** » Sun Feb 20, 2011 7:09 pm

I can't hookup the inverter power unless I unhook the shore power, that's the beauty of it.

I took an old shore power cable and modified it to use with this setup. I'll now buy a factory adapter cable, as soon as I get the money, there about $60.00 now that I know it works.

I'll try and get pic's and post as soon as I can.

Larry

Big D · Post by **Big D** » Sun Feb 20, 2011 7:17 pm

Gotcha. When hooking up to the entire ship's system with an inverter, you need to be aware that anything normally plugged in should be unplugged or circuit shut off as many electrical devices draw current even when powered down such as wall transfomers, TVs, stereos etc. If your inverter is turned on for the fridge, all such devices will draw power as well.

farfrompuken · Post by **farfrompuken** » Sun Feb 20, 2011 7:18 pm

How big of a fridge are you trying to run? and what size inverter are you using? could be you're tripping the safety on the inverter because the fridge draws to much.the inverter will still run,just not put the voltage out you need.

larglo · Post by **larglo** » Mon Feb 21, 2011 12:36 am

The only thing that will run off the inverter is the fridge. All lights except one are 12v. The one 110 v light was added by the previous owner. The microwave and A/C unit will be used only off shore power. All I need is to run the fridge for perhaps, up to 10 hours when we go for a spin on the lake and do some fishing.

I may expand the inverter power later to run the microwave, but only the fridge for the time being.

farfrompuken,

there was no problem, I was just trying my newly installed battery, inverter and hooking it to the main power system on the boat through the shore power plug-in. I turned off the main breaker switch before turning on the inverter for safety reasons.

Larry

Allen Sr · Post by **Allen Sr** » Mon Feb 21, 2011 5:11 am

How many watts is the inverter? May not be large enough to kick the compressor on is what I'm getting at. When I had my road trucks I used a 1500 watt min. cause of fridges. usually if they aren't large enough they will blow a small breaker internally on the inverter. Just trying to help. Waiting to see how you make out.

prowlersfish · Post by **prowlersfish** » Mon Feb 21, 2011 6:33 am

I have a full size refrige and a genset . But I still use a cooler and ice to keep drinks in when I go out .

ICE and a cooler simple ,cheap and easy

keep a ice pack in you refrige too and you will be fine

larglo · Post by **larglo** » Mon Feb 21, 2011 9:02 am

Well, I'll try this again, I have discussed my thoughts about putting together a battery/inverter system that will allow me to operate my 110 volt mini fridge for a period of about 10 hours while on the hook, (for what ever reason) After much discussion, and receiving great suggestions, ideas,,,,pro & con, I decided to go ahead with my plan.
I was hoping to buy 2 Maxx 29 batteries, but only one was on the shelf, so got it.

Last year I bought a 1500 watt, inverter with 3000 watt surge ability, but had not had the opportunity to use it, till now.

I installed the battery, inverter in the area under the set in my F25. I wanted to test it the other day, and in doing so, I turned the main breaker OFF at the panel. I did this before I turned on the inverter. All 110 power was off, in the boat. After I turned the inverter on, waited a short time and then turned the breaker switch in the panel back on.

I again waited a few seconds and turned the temp dial on the fridge, till I heard it come on.

The fridge had not been pre cooled, so turned the inverter off after several minutes, and re hooked the shore power back up.

I'll leave the fridge on now and let it cool, so I can later unhook the shore power, turn the inverter back on, and let it run the fridge as long as I can during the day, checking how long it will run. In the mean time, I will buy a DC analog volt meter, so I can watch the battery closely, of it's power drain.

If my day long test goes well, I'll consider my setup a success in getting my 10 hours on the hook.

This was only a test, and I consider, all went well, and there were no problems.

Larry

wowzer52 · Post by **wowzer52** » Mon Feb 21, 2011 11:19 am

Larry, Don't forget, running your battery down more than 50% to 60% will shorten the life of your battery. I have destroyed many batteries by running them down too far too many times and they only lasted one season. That gets expensive.

larglo · Post by **larglo** » Mon Feb 21, 2011 11:25 am

wowzer52

Yes, it would be, and something I couldn't afford.
What is the recommended voltage,,,not to go below? I thought I read somewhere it was 10.6 volts. Is that correct, what is it, if not?

Larry

wowzer52 · Post by **wowzer52** » Mon Feb 21, 2011 11:57 am

My two group 27 house batteries run 13.8v to 14.2v at full charge and when they get just below 12v I recharge. I have my Garmin GPS set to show battery voltage so it's easy to keep track. I don't know how accurate this is but when I know what is normal for my system at full charge and/or running voltage I then do not let my voltage fall more than two volts at any one time while at anchor. If my voltage gets too low the inverter will shut down and I know I have gone too far. I have only had this happen once when I only had one house battery and I wasn't paying attention and I believe it was approx 10.5v like you said. I would check the spec sheet for your inverter to make sure you know at what voltage it shuts down. I have used several different inverters and they all seem to shut down at different voltage.

g36 · Post by **g36** » Mon Feb 21, 2011 12:06 pm

volts charge

12.6+ 100%
12.5 90%
12.42 80%
12.32 70%
12.20 60%
12.06 50%
11.9 40%
11.75 30%
11.58 20%
11.31 10%
10.5 0%

this is measured voltage while under load

Avoid discharging the battery below the 40% level whenever possible.

Big D · Post by **Big D** » Mon Feb 21, 2011 12:13 pm

You'll be fine Larry. As long as you wired it according to recommendations and used good quality material, you'll be OK. Power consumption calculations are only a benchmark for designing a system. The real test on how many hours you get out of it is by being on the hook under your regular conditions. That's when you're likely to have several other things running off your bank at the same time as the fridge.

A dead battery voltage is higher than you think. The difference between a fully charged battery and a dead one is less than 1 volt, where 100% charge is 12.75 volts and 0% charge is 11.65 volts. To maximize battery life and get the 800 to 1500 charge cycles of life you're paying for, don't exceed a 50% discharge which will be 12.25 volts. Go below that and you will reduce the available charge cycles left in your battery's life. You'll need an accurate meter since you're monitoring only a .5 volt difference.

Probably a little more complicated than you wanted but stick to the above numbers and you'll be OK. If you go below 11.65 volts, you need to increase the bank's capacity accordingly unless you want to replace batteries every year.

I've been using my inverter for years and I'm a happy camper uh boater. I also have a genny but couldn't justify turning it on to warm up a baby bottle in the microwave for 15 seconds. It's a good upgrade.

kallen · Post by **kallen** » Mon Feb 21, 2011 12:17 pm

Remember that what you take out takes longer to put back in