Marine batteries for backup power.

[PNjunction]

I am not planning on powering my two refrigerators (95w 3.2 cu ft, 700w Energy efficient) with batteries but will power them doing the day while running on generator.

You may also want to look into a smaller ac/dc fridge/freezer like an A.R.B. and see if the efficiency is worth using these smaller units as compared to your original plan. At least in the case of critical items like prescription meds and other things that really need tending to. It isn't large, but perhaps worth a look. ARB's are pretty bulletproof, although it is more of a camping-style setup.

[lkruper]

You should consider the golf cart batteries at Costco instead of the marine ones. They are around the same price but will last longer. The biggest issue would be that they are 6v, so you would need 4 to get a 24v system.

I did not notice this right away, but the link Sunking gave with cycle curves does show the difference between the two Signature lines, one with Marine (24, 28, 31) and other Signature including T105. (http://www.trojanbattery.com/markets...ble-energy-re/)

Looks like Trojan T105 have double the cycles as their Marine.

But, the caveat here is that we don't really know about Costco's golf cart batteries. They are Interstate and I did not find any cycle data on Interstate.

[lkruper]

Tip: If you didn't actually measure the wattage of the TV, just know that the sticker is a worst-case scenario of full backlighting. If you are just going by the sticker, that's great for your calculations since it is unlikely you are using 100% full backlighting in the first place leading to a larger power hedge. I'm talking the typical lcd tv.

In normal use, you can save a LOT of power by running a lower backlight. Do NOT confuse this with "brightness". In my case, I reduced the power draw to HALF of the sticker rating by reducing the backlight (again, NOT brightness) to a very low level.

You may want to experiment and see just what your level of tolerable backlight reduction is. How low can you go before it becomes unusable? Saving up to 25% or more of the sticker value should be very easy. You may not want to use a low level backlight all the time under normal grid-power, but when the juice goes out and the batteries kick in, just remember to reduce the backlight as much as comfortable. When testing, give yourself some time to get adjusted to it before making a decision as the abrupt change can sway your decision too soon. When you see the power savings, that might be the arbiter instead!

A kill-a-watt ac meter or clamp-on dc ammeter at the battery terminals will reflect just how fast that power requirement goes down with even moderate reductions in backlighting.



The Stanley may actually do a better job if it offers a standard 13.6v float. The NOCO doesn't really do an active float, but "float monitoring", designed for guarding against parasitic loads and long-term self discharge. Even though it has a "trickle" stage, (version 1's, version 2 have a different optimization technique) there is not much trickling at all taking place. Thus, your batteries are just going to self-discharge until they reach a trigger point or a high parasitic load occurs. This may not be desirable if you desire true active float instead.

I have the TV on power save, but have not played with the backlighting yet. I will do that. Can you recommend an inexpensive active float charger that would maximize the life of batteries in float/backup most of the time?

[lkruper]

You may also want to look into a smaller ac/dc fridge/freezer like an A.R.B. and see if the efficiency is worth using these smaller units as compared to your original plan. At least in the case of critical items like prescription meds and other things that really need tending to. It isn't large, but perhaps worth a look. ARB's are pretty bulletproof, although it is more of a camping-style setup.

I spent a long time comparing Engel, ARB, and others like them. Bottom line was I could not justify spending that kind of money and ended up buying a traditional Energy Saver 14.5 Frigidaire for the cabin basement for 1/3 to 1/2 the cost of the good AC/DC brands with much more storage space and even an icemaker.

The small Supentown 3.2 in the kitchen is 95w and 1.3 amps and about 5 years old. If that one dies, I will consider an AC/DC model in its place. Fact is, I am not off-grid and don't really think I will have extended outages. However I am planning for El Nino just in case. If the outage happens in the wintertime, my basement acts like a root cellar and outside would be a freezer.

I also have a good stock of Mountain House, just in case.

[lkruper]

My comments are general and broad. Just remember battery manufactures are not created equal. In general terms a Deep Cycle will last about twice as long as Hybrid. But you cannot compare say a Wally World Golf Cart battery with Trojan RE as you are now comparing a 1-2 year battery to a 5 to 7 year battery. The take away is if you compare Acme Battery Company Hybrid and Deep Cycle battery line, the Deep Cycle is going to last roughly twice as long, bu thas some current limitations.

As to daily cycle vs Emergency or infrequent cycle you are now working on Calendar Life. Batteries have both Cycle and Calendar life, which ever comes first. Cycle every day, and much shorter than Calander life. With Emergency Stand-By use, you can use a smaller battery and discharge to 50 to 80% DOD. But there is a catch with the smaller battery. You are much more likely to exceed the maximum Discharge Rate on a smaller battery. In which case you are now looking for Hybrid or AGM. Like I have always said Hybrids have a place, but a niche place.

You are on the right path, keep it up. Its YOUR MONEY. Spend it wisely. Don't be like the 95% of those who come here after the fact wondering what went wrong.

Thanks. One of the reasons I wanted flooded batteries is to get some real experience with measuring SG and adding water, etc. I really don't care if they don't last that long, and to be honest, when I get tired of them I will likely re-purpose them to be used as backup for something at home and get something else to learn from.

[PNjunction]

I have the TV on power save, but have not played with the backlighting yet. I will do that. Can you recommend an inexpensive active float charger that would maximize the life of batteries in float/backup most of the time?

Hands down, the smartest of the bunch for floating for those batteries would have to be the Tecmate-Optimate 6. 240ah is the end of it's spec for maintaining. A 50% duty cycle in float (30mins on, 30 mins test, repeat - at 13.6v). This will take place AFTER it finishes the 12-hour long-term test. Some users forget this. Floodies won't overflow, and agm's that have dried out from prior abuse or age are given time to cool in between. Real-world smarts, not just hype.

Still, for BIG batteries, use a proper amperage charger for bulk at least. ALL low-amperage chargers are not ideal for bulk charging big batteries. In your instance, for just maintaining a large one, the Optimate 6 is my recommendation for an inexpensive yet truly smart charge.

At last count I've tested / own about 25 or so chargers. Many are GOOD, but the Optimate is the wisest of the bunch.

[lkruper]

Hands down, the smartest of the bunch for floating for those batteries would have to be the Tecmate-Optimate 6. 240ah is the end of it's spec for maintaining. A 50% duty cycle in float (30mins on, 30 mins test, repeat - at 13.6v). This will take place AFTER it finishes the 12-hour long-term test. Some users forget this. Floodies won't overflow, and agm's that have dried out from prior abuse or age are given time to cool in between. Real-world smarts, not just hype.

Still, for BIG batteries, use a proper amperage charger for bulk at least. ALL low-amperage chargers are not ideal for bulk charging big batteries. In your instance, for just maintaining a large one, the Optimate 6 is my recommendation for an inexpensive yet truly smart charge.

At last count I've tested / own about 25 or so chargers. Many are GOOD, but the Optimate is the wisest of the bunch.

I have been meaning to ask you about the Optimate 6 for 24v banks. I presume it won't work because it is for 12v batteries, correct? However since I am so inexperienced with batteries, I would feel much better checking out my new batteries right away.
And if it can be used for an active float, that means it does double duty.

If there is no way to use the Optimate for 24v, this charger might sway me towards my first batteries being two golf cart batteries instead of Marine.

[Sunking]

But, the caveat here is that we don't really know about Costco's golf cart batteries. They are Interstate and I did not find any cycle data on Interstate.

You are correct most house brand batteries are made by Interstate like all Wally Worlds, NAPA, and just about all off brand names.

Interstate makes a fair battery with their Name on it. What they make for Wally World and Costco are lower in quality and you wil not find much in the way of specs or performance. As they say, you get what you pay for.

Also as you noticed, Trojan makes several lines of batteries from consumer grade to Industrial grade. Trojans top of line is Industrial followed by Premium, Signature, Marine, and Automotive. Although the Industrial Line is initially expensive, they are the best value. You they cost 2 to 3 times more than the lower lines, but they last 4 to 5 times longer making their long term cost less expensive. You can pay now or later? Now is always the least expensive.

[lkruper]

You are correct most house brand batteries are made by Interstate like all Wally Worlds, NAPA, and just about all off brand names.

Interstate makes a fair battery with their Name on it. What they make for Wally World and Costco are lower in quality and you wil not find much in the way of specs or performance. As they say, you get what you pay for.

Also as you noticed, Trojan makes several lines of batteries from consumer grade to Industrial grade. Trojans top of line is Industrial followed by Premium, Signature, Marine, and Automotive. Although the Industrial Line is initially expensive, they are the best value. You they cost 2 to 3 times more than the lower lines, but they last 4 to 5 times longer making their long term cost less expensive. You can pay now or later? Now is always the least expensive.

I just had a thought. Why would Interstate give such a good deal to Costco that it would undercut their own brand name sales? Come to think of it, I don't really consider shopping at Costco such a good deal for many things, even though I have a membership.

So, I can give Costco $170 for two golf cart batteries or spend a little bit more ($260) on the Trojan J185H-AC 12V Deep Cycle Battery and get a real battery.

[Sunking]

I just had a thought. Why would Interstate give such a good deal to Costco that it would undercut their own brand name sales?

Does not work that way. Interstate wins either way. Their profit margins are higher than their own label, and no risk. Think about it. Say Wally World orders 10,000 batteries. Interstate makes them, puts them on a truck going directly to a Wally World, and gets a check.

Interstate labeled batteries on the other hand get made sit in the warehouse (which cost money) waiting for a buyer tying up cash in inventory, and them ship them out in a lot of different trucks to multiple locations. Just a lot more overhead expenses and smaller volumes.

[inetdog]

Does not work that way. Interstate wins either way. Their profit margins are higher than their own label, and no risk. Think about it. Say Wally World orders 10,000 batteries. Interstate makes them, puts them on a truck going directly to a Wally World, and gets a check.

Interstate labeled batteries on the other hand get made sit in the warehouse (which cost money) waiting for a buyer tying up cash in inventory, and them ship them out in a lot of different trucks to multiple locations. Just a lot more overhead expenses and smaller volumes.

I did not think of the whose warehouse difference with carrying costs. Thanks for the description.

[PNjunction]

If there is no way to use the Optimate for 24v, this charger might sway me towards my first batteries being two golf cart batteries instead of Marine.

There is a 24v Optimate - the Optimate Pro-2 or Pro-S, but only supports up to 100ah or 40ah, each 12v battery connected individually, etc. VERY interesting to me, but perhaps a bit too tricky and maybe not enough current. The battery geek in me will have to check it out further before I could recommend it for your 24v situation.

At this stage, I think the highest quality biggest bang for the buck would be a Samlex SEC2415ul 15a charger. For more cash, and a quicker charge, perhaps the 2425 25a model. No tricks, just quality 2 or 3 stage charging, standard full time float. Good build, good docs, and configurable for single or multiple banks if you ever decide to go multiple bank. You can see it and the docs and full specs here:

http://www.samlexamerica.com/products/ProductsList.aspx?cid=S15

I'd have no problem putting these on high quality batteries. My 12v version works great. Specs were tight and no surprises when I put the 87V Fluke on the battery terminals and watched it to see if it earned it's keep. It did.

You supply the cabling. Surprisingly, they supply crimp/solder pins which were of high-quality and not pot-metal. Small details like that, when they could have gotten away with cheaping out is refreshing in these days. It is almost as if they actually care about their product!

[lkruper]

Does not work that way. Interstate wins either way. Their profit margins are higher than their own label, and no risk. Think about it. Say Wally World orders 10,000 batteries. Interstate makes them, puts them on a truck going directly to a Wally World, and gets a check.

Interstate labeled batteries on the other hand get made sit in the warehouse (which cost money) waiting for a buyer tying up cash in inventory, and them ship them out in a lot of different trucks to multiple locations. Just a lot more overhead expenses and smaller volumes.

Thanks for sharing those details. Perhaps my comment was over-nuanced. I was thinking that if it were known that the highest caliber Interstate batteries could be purchased at Costco for 1/2 the price, nobody would buy the real thing. So ergo, the Costco batteries are not the same.

[NorthRick]

You are correct most house brand batteries are made by Interstate like all Wally Worlds, NAPA, and just about all off brand names.

Interstate makes a fair battery with their Name on it. What they make for Wally World and Costco are lower in quality and you wil not find much in the way of specs or performance. As they say, you get what you pay for.

Also as you noticed, Trojan makes several lines of batteries from consumer grade to Industrial grade. Trojans top of line is Industrial followed by Premium, Signature, Marine, and Automotive. Although the Industrial Line is initially expensive, they are the best value. You they cost 2 to 3 times more than the lower lines, but they last 4 to 5 times longer making their long term cost less expensive. You can pay now or later? Now is always the least expensive.

Here's why I went with Costco batteries even though they are not "best value" as Sunking put it - things change. One of the downsides of a FLA battery bank is you can't add more batteries to it down the road without problems. Going into setting up a system you determine your usage, loads, and all that other good stuff, and set up a system that meets those requirements. But, in my case, the future use/requirements were likely going to change some years down the road, or maybe not. I just didn't know at the time. So, I went with the least expensive reasonable battery bank knowing it wouldn't last as long, BUT, expecting that my needs would be different at the end of their life. It isn't best value to spend the money on batteries that last 10yrs when in 5, I will need/want a different configuration.

The reason I suggest the Costco batteries to OP is that he said he would probably be changing things later down the road.

[PNjunction]

BUT, expecting that my needs would be different at the end of their life. It isn't best value to spend the money on batteries that last 10yrs when in 5, I will need/want a different configuration.

I am SO glad you said that! That logic rarely gets mentioned.

It would be a total shame that due to our/ new-op's best efforts to calculate their daily needs, to actually be in error, or encounter an unseen future load, and be stuck with GREAT batteries that are now not applicable for the job, and the budget to replace them with the proper capacity is out of the question.

That's why I recommend a "learner bank" of at least medium quality. Then unforeseen errors or future loads won't be such a financial disaster when a higher-capacity / higher quality battery are needed.