Battery bank upgrade.

[Blue~Go]

That's not the exact same solar controller I had in my rig, but it's very similar. Mine had just a red and a green light, as I remember (or maybe it was yellow and green?), and one of them would always be lit up during daylight (indicating things were happening). Geez, I'll have to go back and look at photos of it. At any rate, I should think that one of your lights should be lit during sunlight. The yellow most likely, or maybe just the green if the batteries are full (I'd think that would light up even if the batteries are full?).

Have you ever the rig out in the sun and not plugged in, so you can see what the solar is doing on its own? How about putting a voltmeter across your battery terminals when the sun is out and you are not plugged in, then covering up the panel (or I guess maybe removing that little fuse from the front of the controller would be easier) and seeing what happens. What if you use some juice so your battery needs charging.

One thing to know is that you won't ever "take in" any power from a solar panel if you don't need it. For example, on back to back days where I am in the same place, same sun, same everything - if my batteries are close to fully charged, I might only take in 14 amp hours (say) from the solar panels through the controller. OTOH, today I took in 56 amp hours (because my batteries were down and could use it). It's like if your batteries are one of those automatic dog water bowls, when the dish is full, no water will come down into it.

If it comes down to it, I can look up the manual for my controller (which I don't have installed any more but saved the manual).

[kyidletime]

Thanks Blue. Now that you mentioned it I do believe that some of the led lights were working on the controller when I didn't have the rig plugged in. I'm going to do as you suggested and unplug from shore power and draw the battery down a bit and see what the controller does. I'll let you know. I do believe that I;m going to install some kind of battery monitor though. Although not as expensive one as I'm sure that you have. Any suggestions anyone?

[A Rooney]

Pd,sells chargers,so translate accordingly.....long post on this at the yahoo group,I have the same charger and essentially it's one size fits all (except for the override "wizard")and yes it will not harm your batteries,and yes it will charge your batteries.Will it top off and maintain your batteries to their fullest potential of amps/cycles is a different question.According to lifeline in reference to their batteries(and probably applicable to all Agm)if your batteries are not fully charged,they will eventually walk down to the level they are accustomed to being charged.I use the philosophy/strategy expounded by Ralph at bogart engineering,If you have use a programmable,temp compensated at the battery, Solar Charger in conjunction with your Vanilla (pd4655)charger,together they complement to create a complete system.Essentially the pd does the bulk of the charging when necessary,and the solar charger programmed to the absorption voltage specific to your battery brand,charges that top 10% or so that can be a challenge to one size fits all,non temp compensated at the battery chargers like the the pd4655.Of course 3 group 31's represent a lot of amps and would probably satisfy all your needs even if maintained to 90% however you pay a lot for Agm batteries,why not get their full potential/life cycles ?? Rooney

[caconcourse]

I do believe that I;m going to install some kind of battery monitor though. Although not as expensive one as I'm sure that you have. Any suggestions anyone?

I replaced my solar controller with this Coleman 3-stage controller ($74), which has a voltage and amp display, so it serves as a battery monitor, as well as showing the solar charge current and providing a much improved charging algorithm. I picked it because it was the exact same size as the stock SCI controller (MK/15) on our 2001 Concourse. I think your controller has a slightly smaller footprint.

http://www.amazon.com/Sunforce-68032-Co ... B004RCX91E

I added a second 50W panel behind the original (purchased from another owner) and added a third thin 50W panel bolted to the air conditioner cover, for a total of 150W. This configuration has kept the batteries topped off in our driveway for over a year (except when travelling of course) with no loss of fluid. As Dale pointed out, the solar controller will turn off the solar input current to the battery when the batteries are fully charged, so you will probably not see any solar charging going on while you are plugged into shore power.

Clay

[kyidletime]

Thank you for all of the great information and suggestions. I haven't been able to check out the solar controller today, there no sun.
Alan

[Blue~Go]

There are a few ways that I can think of to go with battery monitoring. One inexpensive and accurate way exists IF you can easily check your batteries after they have been in the resting state for some hours (say at least four and ten might be better). Resting means no charging or use. For some people, that just doesn't exist, but for you it might. No charging is more important than no use if the use is very minimal, I think. But true resting state is best. So, when the battery is in the true resting state, you just measure the voltage either with a voltmeter across the terminals, or with a cheap hard-wired volt meter ($10). Then you find the chart for your batteries that equates resting voltage with state of charge (SOC). I say "find the chart," because, for example, my Lifeline batteries use different voltages for different SOC than a very common chart I see floating around the internet.

Why don't more people use this method? Well, if you are "living aboard" it can be hard to get to a true resting state. Or maybe you don't like looking at 5 a.m. (before the sun comes up if you have solar charging). Maybe you always have loads drawing. Etc. But if you can work this out, it's certainly cheap and easy. As pointed out, some solar charge controllers have built in volt meters - the same caveats would apply for finding SOC.

The next category is shunt based monitors also known as coulomb counters. How these work is that you put the house battery negative wire straight to a shunt, then everything else is on the other side. In other words, the shunt intercepts EVERYTHING and nothing goes straight to the battery negative post. If you have a negative bus, then the shunt goes between the battery negative post and the negative bus. Then the meter basically just counts amps in and amps out. There are settings that you make for size of battery bank and other charging factors that you get from the battery mfgr. when you first set it up. Then you can read out various voltages and the all-important SOC. These also give a reading showing what different things are drawing, what's going in, etc. They aren't perfect because they don't automatically adjust for your batteries deteriorating - you have to guess at that and do it yourself periodically. What I mean is, say you start out with two house batteries and the total amp hour capacity is 200, so you program that into the monitor. Two years later your batteries are not brand new and so their capacity is lower. Without a 20 hour load test, you kind of have to guess. I take about 20% off each year. Figuring 7-8 years is a good long life, but I'd rather be conservative (SOC then would read lower than actual vs. higher). There are a few other factors that can make them less than perfect, but on the other hand they are very useful. I have one. Some solar controllers come with "smart" displays that incorporate this type of shunt based meter (e.g. Blue Sky IPN remote).

The last category (that I know of anyway) is an algorithm/voltage-sampling type of meter that basically just shows SOC (although it does show voltage as well - it doesn't show anything about amp hours in or out). They almost sound like voodoo magic, but... they work. The one I know of (Smart Gauge) was invented by a British guy who lived on a narrow boat and was an electrical guru. I don't even fully understand it, but basically it samples your battery voltage nine jillion times per hour (or something) and then uses that plus algorithm(s?) to give you the SOC. They are very accurate when discharging and reasonably accurate when charging (when charging it uses what it last knew plus some guesswork to give you SOC; when discharging it gives you that PLUS the tons of voltage sampling for more accuracy). I have one of these and its really impressive. The other plus is that it's a five minute (meaning one hour, but you knew that ) installation. No shunt, no working with the large cables. You just run a 14 gauge wire to the battery terminals (yes, to the actual terminals! not the bus bar) and away you go.

As mentioned I have both a shunt based monitor and the Smart Gauge. What would I choose if I could only have one? Hmm, that's a tough one! I'm not sure. I guess partly it depends on what type of person one is. If you just want to know the SOC, want an easy install, and don't want to worry about estimating battery deterioration or etc..... I'd go Smart Gauge. I guess maybe that's what I'd choose if I could only have one. If you have a large (read: expensive) battery bank, then it's not that hard (for me at least) to justify both. Plus, the way it worked out for me was that I already had a shunt based monitor and I really wanted to check out the Smart Gauge to see what it was like so now I have both.

On the other hand, if I was not motivated to spend a bunch, and if I had a good way to have resting state fairly often - I'd wire in a $10 volt meter and press the button!

[A Rooney]

My post of the morning was via my phone so I didn't catch I was responding to the end of a first page post ,but it was Germaine so I left it.The shunt battery monitor I use also by bogart engineering,(it's own electrical guru Ralph)is designed to work with their solar charger,tho either can function solo,they really function on another level when connected in tandem.Strictly speaking the trimetric monitor software,determines Soc,firstly after you enter the absorption rate voltage specific to your battery,it charges your battery at that rate (temp compensated at battery) till the current your battery accepts at that voltage drops below a certain level,at which time it considers your battery full and it drops to a float voltage.Second,if you prefer it will also count the current out from your battery since last full,and replace it not just those amps,but a small percentage of amps over,again as recommended by the manufacturer of the battery.Another battery monitor I am aware of then those mentioned is by Zamp solar,it is a shunt I believe that connects directly to the battery negative and communicates by Bluetooth and app to your smartphone and can I believel be set to send you alerts should your Soc fall below a certain level of your determining. Rooney

[Manitou]

I do believe that I;m going to install some kind of battery monitor though. Although not as expensive one as I'm sure that you have. Any suggestions anyone?

I replaced my solar controller with this Coleman 3-stage controller ($74), which has a voltage and amp display, so it serves as a battery monitor, as well as showing the solar charge current and providing a much improved charging algorithm. I picked it because it was the exact same size as the stock SCI controller (MK/15) on our 2001 Concourse. I think your controller has a slightly smaller footprint.

IMAG0810.jpg

http://www.amazon.com/Sunforce-68032-Co ... B004RCX91E

I added a second 50W panel behind the original (purchased from another owner) and added a third thin 50W panel bolted to the air conditioner cover, for a total of 150W. This configuration has kept the batteries topped off in our driveway for over a year (except when travelling of course) with no loss of fluid. As Dale pointed out, the solar controller will turn off the solar input current to the battery when the batteries are fully charged, so you will probably not see any solar charging going on while you are plugged into shore power.

Clay

2 extra panels with no increase in cable to the battery size? What about that inline fuse at the battery? (I'm not picking a fight, I really want to know what I can do as a little budget based bump in solar safely)

[Blue~Go]

Not that you don't have to keep safety/over-current protection/wire size etc. in mind, but the primary issue with having a lot of solar power and thin wires is that you will just never see a lot of your power. In other words, you are "giving power away." Since solar panels really make precious little, I hate to give any away!

It's not too hard to figure out what the optimum wire size will be (or, conversely, how much you are losing with a smaller wire size). What you need to know are three things:

1) Panel(s) amperage and voltage (and are they wired in series or in parallel if you have more than one).

2) Length of wire(s) run from solar panel(s) to solar controller.

3) Length of wire run from solar controller to battery (or positive bus).

From these numbers you can calculate either how much you are losing with an existing wire size; or how much you could "not lose" with a larger wire size. Having a long run from the panels to the controller, and then from the controller to the batteries is tough. You can work with it, but not with small wires. The reason Chinook was able to use such small wire is that the panel is very small and really only meant to maintain the battery in storage, and, well..... that was then and it's not the best setup. Controllers and solar planning has come miles. I guess you could compare it to what would your cell phone look like if you were using one from 1998 or even 2003...?

One issue with the original Siemens panel (at least the one on my rig) is that it is very low voltage compared to modern panels. That makes it hard to pair effectively with any newer panel (you can pair it with a newer one, but they will both be dragged down to the lower voltage).

None of this is to say the original panel is bad (Siemens made good panels), but just that it was designed for maintenance charging in a "bygone era" in terms of solar tech.

I have to run now, but later I could post a couple of scenarios, if one added say, a 100 watt Renogy panel to the Siemens. (I think a much better idea is to just forget the Siemens panel if you are going to get "serious" about solar.) Alternatively, Clay's way of getting a matching panel is next best for a smallish system on the cheap (nothing wrong with that).

[caconcourse]

2 extra panels with no increase in cable to the battery size? What about that inline fuse at the battery? (I'm not picking a fight, I really want to know what I can do as a little budget based bump in solar safely)

When it comes to solar, your "actual mileage may vary" from specs, and the amps in real life seem more like half of the rated specs. The original wiring is rated for at least 7.5A, which is the value of the in-line fuse, so I feel safe expanding to that capacity without worrying about upgrading the wires. The 50 watt panels were rated at about 3.5A, but I never saw that even with the original panel, 1.5 was more typical, 2.5 was the highest I observed. So the three panels theoretically could exceed 7.5, but I've never seen them come close to 7.5 even. This is probably due to geometry and inefficiency, with shading effects, etc. My Chinook is in the open driveway facing north, so it does get the full noon sun, but gets more in the morning and less in the afternoon. The controller also throttles the output to the batteries according to need, so even at noon, if the batteries are full, there is low current. In the summer, I left the fantastic fan on via thermostat control, and the solar covered that easily while keeping the batteries up.

As Dale pointed out, I was looking for a significant improvement for a small investment. When the Chinook was new, the 50W solar panel was a pretty nice feature, so I think of my upgrade as three times better than original, rather than an optimal performance solution, and it was inexpensive, with practically no impact on usable roof space. (I had seen a factory unit that had two panels instead of one, which is where I got the idea of getting a second Siemens panel.) As long as there is "enough" power for our needs, I don't mind giving some away to inefficiency. One panel was marginal, two was sufficient, and three is reliable, at this point, but our need is modest.

Here's a picture. Also shows my homemade Fantastic fan shroud from the back.

Clay