PRODUCTS

[larglo]

Hi all,

I hope to get a new deep cycle house battery this summer to run my inverter.
I only have one, on board charger at present and am looking at two products that will help me keep the house battery charged and tell me if both batteries are being fully charged
One is a 2 amp, Go Charge Battery Maintainer
Manufacturer: Charging Systems
for about $42.00 and the second is a, Battery Monitor Panel Manufacturer: Sea Dog,, $54.00.

Do any of you have these products or something similar that could advise me if they are worth buying and using?

I know there are much better chargers than this one, but my budget is low, and if these will do the job, so much the better.

Thanks,

Larry

[ready123]

Concern...
Deep cycle and Inverter requires a good charging system or you will just end up killing batteries. That means good quality deep cycle battery, ensuring you stay over 50% discharge... so is battery sized correctly for the daily draw? Good quality Inverter and heavy duty cables to lower losses....

If you are restricted by $$ to buy the quality required to maintain this system, then reconsider why you need an Inverter while away from the dock??
What are you using it for? Could you get the same service via a 12V piece of equipment?

From where I sit I would think you need at least a three stage 20 Amp charger to bring the deep cycle back overnight.
In my opinion reducing the $$ on the charging system to bring a deep cycle back is risking failure of the system

[randyp]

Largo,

I use two Walmart MAXX 29 batteries for house bank and one for engine. The two house batteries are good for 240 amp hours of service. I also have a small 600 watt inverter I use when cruising long term to power my laptop and a fan in the pilot house under the hardtop. This inverter is hooked to the dual bank batteries (wired in parallel). I have a dual bank 20 amp charger that's mounted on the bulkhead behind my port seats in the cabin. Not a beautiful install, but it stays cool and I can easily see if it's charging. I use a single 1-2-all-off battery switch and a Blue Seas ACR to monitor the whole shooting match. I added the ACR a couple of years ago, but you can just use either a single or dual switches. The batteries run about $80 or less each and I have had one set last a good 5 years. Probably would last longer but I switch them out after that just to be on the safe side. The ACR makes life easy since it keeps tabs on both the house bank and the engine battery and does not allow the house bank to drain the engine battery in case I forgot and leave the battery switch on "all" by mistake. I just leave it in on "2" (house bank) and forget about it. I use the set up to stay on battery power for 2-3 days. I also have a small Honday 2000ei generator to power the AC stuff while out on the hook away from the dock. I added this a couple of years ago and also use it for a winter backup in case the ice knock out our power at home.

Depending on how big your power requirments are I think you need at least a 10 amp, dual bank charger. I takes over 12 hours to fully charge my house bank if I've let it drain down for 2-3 days. The single 85 amp alternator doesn't charge it fully unless I'm running at over 1800 rpm for 8 hours.

Hope all that helps.
.

[Paul]

Hi Larry,

If you are going with a single battery, maybe around 120 Ah, you'll still need a charger with at least a 10 amp rating. The 2 amp charger that you're looking at is designed to maintain the battery charge when the battery is not being used for extended periods of time. It's not for bringing it back from a deep discharge.

As far as the 2 bank Sea Dog battery monitor panel is concerned, I've installed one of these in my boat. (picture below) This thing is a piece of crap. By the time a battery bank shows up in the yellow band it's down to 10.7 volts. I would not recommend one of these. Your best bet is an analog gauge with the voltages listed on it or a digital gauge.



Hope this helps.

[larglo]

The only reason for using a house battery/inverter, is to run a 2.5 cu. ft. fridge when we are out on the water for a few hours, perhaps 10 hours at the most.
I don't want to put up with taking and lugging extra coolers, the ice and all that goes with it.
I realize that buying the best is always best, but I have to look at my physical abilities and my wallet.
If anyone has any knowledge of the products I mentioned, it would be most helpful to me.

Thanks

Larry

[randyp]

Larry, I'd recommend the Wal Mart Maxx 29 battery. It's rated at 120-125 amp hours. That should last through a 10 hour run off your inverter to run the fridge. Again, these are around $80 new and last a good time. Suggest you shop around for a 10 amp charger, though. You might get a decent used on here or on Craigslist. As for the battery maintainer, if you just want to know what the voltage of your deep cycle/inverter battery is you can get a decent 12 analog gauge or use a multimeter. Either one should be around $20 if you shop around. So, a total of $100 would get you a good deep cycle battery and gauge. And if you get lucky you could get a 10 amp charger for under $50.

I know the guys on this forum would shoot me, but I used a Sears auto battery charger for years on the sailboat. It was 10 amp and automatic. I still use it at home to keep a charge on the boat batteries when I take them off in the winter. Been using this charger for 30 plus years now, but I did spend some $$ for a deep cycle charger, the one that's currently mounted in boat.

WalMart can fix you up for the deep cycle battery, the gauge or multimeter and the automative charger for under $150 I bet.

[larglo]

Randy and Paul,

Your replies were had not shown up till after I had made a reply. I didn't realize it took that much time and amp's to charge a battery. As I said before, I have one good charger that came with the boat. But I can see that buying a second single battery charger for the house battery may be needed. Buying a single charger verses a double would be less expensive for me. Each battery will have it's own charger.

I guess the monitor panel is off my list and I'll look into the analog gauge for just the house battery. The only time I had trouble with the start battery was when I installed a stereo radio per instructions and the battery went down overnight. But got it corrected.
I'll certainly look into the Walmart MAXX 29 batteries. If Randy can get by 2 to 3 days on 2 of these, I should be able to 10 hours on one.

Thanks very much for all the comments, they have been a great help. Still hope to hear others ideas too.

Larry

[ready123]

What is the Amp rating of that Fridge? You need to take that into consideration in the sizing of your Inverter and battery. Don't forget you have losses when taking 12V to make 120V, you are much better off staying at 12V.
If that is all you want to do what about looking at a 12V fridge to do that?
When I had a smaller boat I used Koolatron which plugged into a cigarette lighter. I brought cold stuff from the house and ran it in the car then connected it to the boats house battery for the weekend. This one is only $120.


http://www.amazon.com/Koolatron-Kargo-K ... B00009PGNR

[Big D]

Larry, just thought I should put out there that what ever your fridge draws, it will spike to at least double that amount on start up. Check the inverter's rating for it's ability to handle this spike, it should be clearly marked. The first inverter I ever bought was for my fridge and it was rated to handle the continuous draw as well as the surge on start up, however, I always had intermitent issues with it not being able to handle the surge. I then added capacitors to help with start up but eventually ended up getting another inverter that was double the rating and it worked fine.

[BobCT]

If you can run the fridge on 12v directly, that's a good option. I have 2 Trojan 6v batteries and have run as long as two days before I was back on shore power.

I have the original Promariner 3 bank charger that came with the boat.

[larglo]

Bid D,

What size inverter did/do you have? Was your fridge a 110 volt? My inverter is a Cobra 1500 watt and if I remember right my small 110 v fridge draws less than 2 amps and not sure what the surge amps are for it.

Depending on more info from you may help me a great deal on how to handle this problem of operating my fridge away from the dock.

Also, Randy, you didn't say if your fridge was 110 volt. My judgement so far is based on your info of lasting 2-3 days on your 2 batteries, but never thought about whether or not your using a 110 fridge.

Addional info would be most helpful, thanks.

Larry

[Big D]

Larry, yes my fridge is 110 volt. The 1500 is plenty. I have a bar size fridge and a 600 watt did the trick though I have a much larger unit now for other reasons. Remember that cheaper units are more inefficient to begin with and that they are typically a modified sine wave which brings down the load's efficiency as well. You need to know that as it will help you size your battery bank. It will drain your battery faster than you thinnk. You should also keep certain things in mind such as fridge out of the sun, minimize as much as practical opening the fridge, keep in coolest part of the boat (not right above the engine), if practical, insulate around it. If it's in a cabinet, add a solar powered fan to exhaust the warm air from the condenser or it will generate enough heat to make it come on more often. Finally, when you're on the hook overnight with an inverter, power management becomes even more important. You may want to consider changing over to an LED anchor light. When your inverter detects 10.5 volts (I think around there) it will sound an alarm and eventually shut down. The sound is most annoying in the middle of the night!!

[Big D]

Larry, I should mention not to skimp on the wiring. It's inefficient and dangerous to use wire that's not sized properly for the current and run (length) of the circuit. The further from the battery bank, the heavier the cable needed. Fuse it properly and use a battery ON-OFF switch (should be in the installation instructions). Most important, if it's not marine rated, you must not mount it in the engine compartment. As such this may drastically increase the distance from the unit to the batteries and the cable size required. Hope all these points help.

[ready123]

You may want to consider changing over to an LED anchor light. When your inverter detects 10.5 volts (I think around there) it will sound an alarm and eventually shut down. The sound is most annoying in the middle of the night!!

WOW..... 10.5V is 0% state of charge for 12V battery and one should try and stay above 50% discharge (12.06V) most of the time.
Poor design of a deep cycle system is the cause of most problems with house battery setups. Cheap Inverters and cabling end up turning much of your battery power into heat not AC voltage.
I am trying to convey that there is more to this setup Larry is looking at than just putting together parts that seem suitable.... certainly not based on what works for someone else's fridge that is not identical in efficiency and layout.

As Larry is concerned about limited $$ he needs to get it right the first time.... important things to consider are Amp-hr draw of cycling fridge, size of cables for distance battery to Inverter, size of inline fuse for power to Inverter from battery, efficiency of the Inverter chosen. Also make sure the cable ends are crimped with heavy duty ring connectors.

[Big D]

Ready, I agree with your comment on the state of charge. I'm, just pointing out that a lot of units will continue to work at low voltages albeit at much lower efficiency, and that one needs to be aware it will take their bank down that low thus affecting battery longevity. In fact, many units won't cut out until there is less than 10 volts input. Best efficiency if I recall is between 12 and 14 volts. A properly sized bank will maintain that range during the draw. I also agree the subject is more complicated and delicate than most people realize. The best one can do is educate one's self and build the best system you can based on what you can afford and your needs, or find an alternative.