Marine batteries for backup power.

[lkruper]

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.

You gave great advice because I did say I wanted to keep my initial cost down and plan for expansion later. One thing I have observed is that there is frequently multiple good responses to the same problem which solve the problem in different ways. All too often some come to this forum and ask for "the way" to solve their problem or create their system. The bottom line is that each individual must acquire all the knowledge from experienced people and use that knowledge in a practical way to fit their own circumstances. That is wisdom, the practical application of knowledge.

I stated a "user requirement" of wanting to keep the cost down and expanding later, which is why I wanted to start with a small 24v system. However I have just realized that I have (in IT lingo) wrongfully merged my user requirement with a "functional specification." My real desire is not to buy something that is no longer useful to me in a few years, or even months. That is wasteful. So my real "user requirement" is not to buy something that becomes a white elephant.

I can think of two ways to do this at present:

1) Buy something that meets my current needs, at least minimally, with a planned obsolescence. A couple batteries that are built to last only a year or two accomplishes this.
2) Buy something that will last longer but still be useful in a different application.

If I purchase a single 12v battery in the Trojan Signature line, either a group 31 or the larger floor washer batteries, a charger and a small 12v inverter, I can later put this small system temporarily in my SUV and have a portable power source. The inverter from that system can also run off the 12v outlet. In the past I had considered wanting this capability.

In the mean time I can test the concept of using this system at my cabin for quiet (non generator) time in emergencies. If there is no real emergency I can still test and exercise my equipment and get experience with flooded batteries.

An advantage to starting with 12v is that I can also get the Optimate 12v battery maintainer on this 12v system and will find other good uses for it going forward which is also a plus.

I do thank everyone for their experience and advice and do appreciate hearing different points of view. All of you have practical experience, something I don't yet have.

[Sunking]

I can think of two ways to do this at present:

1) Buy something that meets my current needs, at least minimally, with a planned obsolescence. A couple batteries that are built to last only a year or two accomplishes this.
2) Buy something that will last longer but still be useful in a different application.

OK here is what you need to know. You want to grow, which is fine if done smartly. You cannot eliminate the fact that some equipment will not be reusable, and some like batteries are expendable and will be replaced every few years.

However there are some basic components and it starts with a wise choice of panels, a specific make and model that makes a good building block that works with your controller. Say 200, 225, or 250 watt panels work good. You want a manufacture you are certain will be around like Kyocera, Sharp, or Panasonic. That way 5 yeears down the road you can still get more panels or warranty claims.

As for a Controller, do not cheap out. Buy a really good MPPT Controller that has a minimum 150 Voc or higher input. Sure a Midnight Solar Classic 150 is over kill right now with up to 5200 watt input and 48 volt battery, it will work just as good at 100 watts on a 12 volt battery for now. Depending on location you can have up to 4 200 watt panels in series. Then it is just a matter of buying panels in groups of 3 or 4 to grow. Planning ahead also will save you bucks down the road by planning panel cable runs and wire size. You will not have to scrap and replace it, just add on. Once you grow into needing a combiner, more than one string of panels, all you have to do is add strings and a Feeder cable.

So starting with a inexpensive battery is fine. Just make damn sure you buy a Temp Correcting Hydrometer and learn how to use it. When battery upgrade of replacement time comes you can then move up in quality.

Another thing is a battery charger. Buy one sold in Wattage, not voltage and amps. Units sold in Wattage are whatever voltage you want.

[lkruper]

OK here is what you need to know. You want to grow, which is fine if done smartly. You cannot eliminate the fact that some equipment will not be reusable, and some like batteries are expendable and will be replaced every few years.

However there are some basic components and it starts with a wise choice of panels, a specific make and model that makes a good building block that works with your controller. Say 200, 225, or 250 watt panels work good. You want a manufacture you are certain will be around like Kyocera, Sharp, or Panasonic. That way 5 yeears down the road you can still get more panels or warranty claims.

As for a Controller, do not cheap out. Buy a really good MPPT Controller that has a minimum 150 Voc or higher input. Sure a Midnight Solar Classic 150 is over kill right now with up to 5200 watt input and 48 volt battery, it will work just as good at 100 watts on a 12 volt battery for now. Depending on location you can have up to 4 200 watt panels in series. Then it is just a matter of buying panels in groups of 3 or 4 to grow. Planning ahead also will save you bucks down the road by planning panel cable runs and wire size. You will not have to scrap and replace it, just add on. Once you grow into needing a combiner, more than one string of panels, all you have to do is add strings and a Feeder cable.

So starting with a inexpensive battery is fine. Just make damn sure you buy a Temp Correcting Hydrometer and learn how to use it. When battery upgrade of replacement time comes you can then move up in quality.

Another thing is a battery charger. Buy one sold in Wattage, not voltage and amps. Units sold in Wattage are whatever voltage you want.

I have thought about this one (http://www.mastechpowersupply.com/pr...uino-nano.html) but more as a hobby. The manufacturer says it actually goes up to 32v and that there is room on the Arduino board to put a temperature sensor. But I can't see buying one of these to dedicate to charging a $100 battery.

[Sunking]

I have thought about this one (http://www.mastechpowersupply.com/pr...uino-nano.html) but more as a hobby. The manufacturer says it actually goes up to 32v and that there is room on the Arduino board to put a temperature sensor. But I can't see buying one of these to dedicate to charging a $100 battery.

Pass on it. What is it you want to accomplish?

[lkruper]

Pass on it. What is it you want to accomplish?

With the embedded programmable microprocessor, the operation of this unit can be automated, and with the addition of a temperature probe, the charging voltage could be adjusted. The Arduino microprocessors are networkable and therefore remotely accessible over the internet. Very desirable for a cabin that is not inhabited all the time.

Do you not like this brand? I know nothing about it.

[Sunking]

Do you not like this brand? I know nothing about it.

Sorry I never touch the stuff before.

[paul65k]

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.

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'm not trying to start a banter or even disagree but a quick question would be if you ABSOLUTELY know for a fact that the batteries specifically designed and sold by Interstate to Costco (Leave WW out for now) are in fact different in the design and manufacture than those sold through Interstate's network of dealers????? These are the only batteries that they produce for others that do actually carry the Interstate Brand (albeit Interstate for Costco).

I ask specifically because while this is a very reasonable assumption (how could they sell them for so much less if not a lower quality product???) I know personally as someone who actually ran a consumer electronics company at one point in my career and sold into Costco as well as the other national retailers and dealers that the margin requirements of Costco were MUCH less (about 25%) of the cost to sell into national retailers. For instance selling to Best Buy and Fry's required 25-30% margin for the retailers to meet their requirements (remember I'm talking Margin and NOT markup here so the differences are even greater) vs Costco who could survive and profit in their model at 6-7% margin.....this of course was a big problem for our "Traditional" channels that were developed and matured during the 70's, 80's, 90's and into the new century while at the same time Costco was redefining the supply chain to the customer and how to deliver a higher quality at a lower cost (read value).

So......with this and again not trying to pick a fight, I would ask if there is anything but the fact that they sell their batteries for less than the traditional channel, when the definitive comment is made that the Interstate batteries sold through Costco are specifically built to a lower standard???? Basic logic and reason without specific experience of the companies business model would lead one to believe this as it would seem to be very logical on the surface.......my real world experience however would lead me to believe that Costco is able to sell batteries at a much lower cost due to their superior volume through significantly fewer outlets with much lower profit margin requirements to meet shareholder expectations.

BTW.....we also created a "Private" label set of part numbers and even designed an alternate set of features and benefits (eventually) not because we needed to deliver products to Costco at a lower cost as we really didn't need to do that with their lower margin requirements but as a measure to protect our other channels that required much higher margins to support their respective business models........Food for thought