Questions about battery bank and generator charging.

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akrvbob said:
Bindi, at the top of the page is a series of menu buttons. If you go to any other page on the site there is a series of buttons underneath it. One of them is "Electrical" and one of them is "Solar." Hold he mouse over them and the pages on those topics will drop down. The Crimp and Strip pages are there. I never did get to a page on wire gauges. Just haven't had time. One of these days!

The forum looks like those pages but it uses different software. Eventually I will get those buttons on the forum too.
bob

Thanks Bob. I couldn't remember how I found them....don't always remember everything I read either. You've done some very helpful articles, so I try to point people that way..."try" being the keyword.
 
Yes, I am on a limited income and also did not want to waste money just buying "something". Like you, I read about facing south, however, I also believe they were talking about permanently mounted panels. My little panel in the picture was facing directly at the sun at 10:00 a.m. and was putting out 3.88 amps (rated optimal output 3.98) so I like the fact that I can aim it and adjust during the day. And I will double that when I get the other panel.

From what I have read here and other places, fuses are to protect the wire, so you will need to know what size wire you will be using before you can decide on the fuses.

Measuring the watts you will use daily is the first step to deciding how many panels you need. But regardless of whether you put the panels on the roof or make portable ones, I would buy wire and charge controller based on the maximum # solar watts you think you will ever have. You will save money in the long run.

My little set-up: 70 watt panel, 30 amp charge controller, 30'-10 gauge solar cable, 10 gauge wire for controller to battery, 10 gauge ring terminals, butt connectors, 30 amp in-line fuses- $200.00. One more Renogy panel-$110.00. (free shipping)

This site on wire gauge might help:http://www.freesunpower.com/wire_calc.php


Sorry, I didn't see your question about the weight. The panel weighs 16 lbs.
My Sprinter is a 2003. It pulls up hills great...just tap the shifter down to the needed gear. I love it but it is very difficult finding competent Sprinter mechanics. I have learned more a lot on another forum that deals with Sprinters.

Enjoy researching solar and looking for your van! I looked a long time for my van. Now I'm just waiting until I can go camping fulltime!
 
Bela said:
Yes, I am on a limited income and also did not want to waste money just buying "something". Like you, I read about facing south, however, I also believe they were talking about permanently mounted panels. My little panel in the picture was facing directly at the sun at 10:00 a.m. and was putting out 3.88 amps (rated optimal output 3.98) so I like the fact that I can aim it and adjust during the day. And I will double that when I get the other panel.

From what I have read here and other places, fuses are to protect the wire, so you will need to know what size wire you will be using before you can decide on the fuses.

Measuring the watts you will use daily is the first step to deciding how many panels you need. But regardless of whether you put the panels on the roof or make portable ones, I would buy wire and charge controller based on the maximum # solar watts you think you will ever have. You will save money in the long run.

My little set-up: 70 watt panel, 30 amp charge controller, 30'-10 gauge solar cable, 10 gauge wire for controller to battery, 10 gauge ring terminals, butt connectors, 30 amp in-line fuses- $200.00. One more Renogy panel-$110.00. (free shipping)

This site on wire gauge might help:http://www.freesunpower.com/wire_calc.php

That is a very affordable system, I have seen panels with the same ratings selling for quadruple the price. That wire gauge link was very helpful, there is a lot less loss than I originally thought.
 
Quality copper cabling/ wiring is expensive, it also gets heavy so at some point, overkill is just wasting money for very little additional gain.

Yes, most internet sources will say to take power for the isolating device from the starter battery. This is usually easiest. It is not best. A direct alternator feed right from alternator (+) to the Isolator to the house battery is usually a much shorter circuit path, and it bypasses the undersized OEM alternator ciurcuit. It is a parallel circuit, a percentage of current will still flow through the OEM circuit. The parallel circuit will make the voltage regulator "See" the depleted house batteries better, compared to taking power from the starting battery.

This parallel Alternator charging circuit Should be fused on both ends. I have A 140 amp circuit breaker on mine. When I disconnect the circuit with depleted house battery and all current is forced to flow through the OEM alternator circuit, and current drops by 40% and when the OEM circuit heats up( because it is too thin and too long) the amps drop even more. Bridging the contacts again bringing in the parallel circuit again changes the engine tone as the alternator goes from making roughly 20 amps back up to 50 or 60. It takes about one engine HP for the alternator to produce 25 amps.

One can also put the parallel circuit directly from alternator (+) to engine battery (+), again fused at both ends. This makes more sense when the auxiliary battery can be mounted right next to the engine battery.

If the Isolator device is mounted right to the firewall near the starter battery, the parallel circuit can go from Alternator(+) to the Starter battery side of the isolator device.

Anyone seeking to increase alternator amps when the batteries are depleted can add this parallel circuit from alternator (+) to Engine battery side of isolating device. This will also help the engine battery recharge faster if it too is depleted. no Original wiring needs to be touched for this upgrade.

This parallel circuit will make little difference when battery state of charge is above 80%.

2 six volts batteries wired in series make one big 12 colt battery. Charge it as one big 12V battery.

Batteries wired in series will not have batteries feeding other batteries as will unmatched parallel batteries will.

Equalization cycles on batteries is a controlled overcharge in an attempt to get all the individual cells up to their maximum specific gravity. After many charge and discharge cycles the individual cells will all be unequal and an Equalization cycle should be performed. A Hydrometer is NEEDED to do this properly. Some batteries need a lot longer at a lot higher voltage than others to get the SG up as high as it will go, so the automatic EQ feature on some smart chargers, might or more likely will not do this. but the fact that such a charger can do EQ voltages in the 15's is a big bonus in and of itself.

Do note that EQ voltages can damage some electronics like fridge circuit boards, so delicates should be disconnected from the battery during an EQ charge where the voltages will be 15.2 +.



Some chargers a have an equalization feature, and it might or might not be effective. Without taking specific gravity readings, you will never know. Hydrometers are cheap. Get the turkey baster type with the glass float. Make sure to rinse it off after use. Make sure no bubbles are sticking to the float during a reading. Use eye protection, and clothes you do not care about, or wool. New batteries should be fully charged and a baseline specific gravity reading taken, noting the temperature.

I am using my Hydrometer regularly on my Newish flooded battery. The manufacturer(USBattery) recommends higher than normal voltages with a 14.4 acceptance absorption charge, then a 15.3v finishing charge, and I am adjusting my solar setpoints to see how what is needed to get SG to go as high as it can go. Generally i am finding I need my Schumacher to max out the SG and that the days are not long enough for my solar to get the SG up above 1.275 in all cells even when i set a 15.3v "finishing charge" as my Float voltage.

I am not happy with this USbattery so far, but it is meeting my needs.

---

The only time a DC to DC laptop "car adapter" will charge slower than the provided AC to DC power brick is if the car adapter is not rated at the same wattage as the provided power brick. I've had issues with the ciggy plug portion of the 'car adapter' and my laptop will say to hook up a 90 watt power adapter. when this warning would come up, if I were to push in the plug a bit deeper then this warning goes away and the laptop charges normally.

Avoid the universal type of 'car adapter' these are generally rated for only 60 watts and are meant only to charge the laptop with the laptop off. Look on your power brick, multiply the output volts times amps and that is the maximum wattage your laptop will ever ask for and which the power brick is able to pass. Make sure the 'car adapter' is of the same wattage or higher.

Ciggy plugs receptacles feeding these car adapters need to be quality and wired with fatter wire. Most stock vehicular Ciggy receptacle wiring cannot handle 7 amps for 3 hours without overheating

My newer 400 watt PSW inverter uses a minimum of 0.7 amps MORE, At All Times to power a 120ac power brick than my DC to DC car adapter. I am using the PWR+ brand purchased from Amazon. I no longer use the Ciggy plug, but use an Anderson powerpole connector for a much better connection with much less voltage drop.


You can buy LED bulbs which install inside incandescent fixtures. They have gotten a lot better recently. My conversion Van came with a bunch of t10 base bulbs with either 194 or 168 or 014 incandescent bulbs in them. I have installed LEDs in all of these. I have tried many different types. the ones with CREE LEDs, even a single one is the way to go. the conrcob style replacement bulbs do not really use the reflector correctly in my Van.

Do not rule out conversion vans just because of the existing Incandescent lighting. Here is a 194 incandescent bulb next to some corncob style LED bulbs with the T 10 base.
LEDcomparison_zpsf198269a.jpg
Even the dimmest is brighter than the incandescent and draws 1/4 to 1/10 the amperage of the incandescent.

I would not let the fiberglass scare you off to much, in terms of mounting things to it If you were going to do nuts and bolts to a sheet metal roof, you can do the same with fiberglass.


You do not need to go to the lengths I did on mine, but I have significant glassing and carpentry skills. This pic is from '07 before I was done painting.
KYC130Mount_zpsf3539236.jpg

I now have a 68 watt unisolar panel on the other side for 198 watts total. Wish I had about 250, and I live in Sunny Southern California. If I were in Northern Climes I'd want 300+.
 
SternWake said:
Do not rule out conversion vans just because of the existing Incandescent lighting. Here is a 194 incandescent bulb next to some corncob style LED bulbs with the T 10 base.
LEDcomparison_zpsf198269a.jpg
Even the dimmest is brighter than the incandescent and draws 1/4 to 1/10 the amperage of the incandescent.

I would not let the fiberglass scare you off to much, in terms of mounting things to it If you were going to do nuts and bolts to a sheet metal roof, you can do the same with fiberglass.


You do not need to go to the lengths I did on mine, but I have significant glassing and carpentry skills. This pic is from '07 before I was done painting.
KYC130Mount_zpsf3539236.jpg

I now have a 68 watt unisolar panel on the other side for 198 watts total. Wish I had about 250, and I live in Sunny Southern California. If I were in Northern Climes I'd want 300+.
The reasons I plan to get a cargo van instead of a conversion van is because the cargo vans come extended, and the conversion vans do not. I can pretty much add what I need, without all the extra electronics already incorporated into the conversion van. Plus I hear that people buy conversion vans, only to find out later they leak. There are quite a bit of conversion vans for sale around here, but a lot more chevy cargo vans.

I need to figure out a way to house the house batteries, some form of a vented box. The 8d size box is large enough to fit 2 trojan t105s, but its over $100 for a sealed/vented battery box. Im wondering if it would be more cost effective to go with an agm set up, so I can just strap the battery to something. I would be nervous building my own battery box, in the event that the batteries might leak. I plan to store them inside the van, after all. I read that the agms do not leak, even when they are broken.
I read the agms require a lower voltage to charge, except for Concorde. Since most of the less expensive charge controllers are not adjustable for the high voltage of trojans, I might not even go with them.

Is a battery monitor really necessary? I have heard recommendations for the trimetric 2025, but this requires a lot of additional wiring. I have seen some people use a cig adapter monitor, like http://www.amazon.com/INNOVA-3721-B..._sim_hi_1?ie=UTF8&refRID=1HWG2PNNH5WE0JFW2DXA.
Or will a charge controller be enough?

Your van looks great, that roof job looks so clean and professional. Makes me want to learn how to work with the stuff. I love the way you did those locks too, I hadnt even considered panel security, lol.

Im hoping 200w of panels will be enough, but after playing with the solar calculators I have a good idea of how much energy is used. Its amazing the difference an hour or two makes on these scales.

Is there any benefit to having 2 batteries in parallel? Say 2 12v 90 ah opposed to 1 12v 175 ah?
 
I've never had a battery monitor. All I have is a Dometic fridge with the low voltage cutoff set to "high" so I keep an eye out for the red light and if it comes on I run my generator or unplug my laptop. I figure it's close enough that I'm not damaging my batteries too horribly.

I also don't have a vented box for my batteries. I've heard some people say they're sensitive to the fumes but I've never had a problem. I do have a permanent air vent in the floor so that might be keeping things relatively under control. I have my batteries in those plastic boxes they sell at Walmart, so if they do leak some sort of liquid it should get contained.

The number of batteries does not make a difference, all that matters is the total ah assuming they are both 12v.
 
Four 225 amp 6 volt batteries are easier to move. One large 12 volt battery is very heavy. Two smaller ones are easier to move. It is only the weight advantage. There are disadvantages to parallel batteries.
 
No, a battery monitor is not necessary.

But Voltage is only accurate as to battery state of charge on a rested battery, one which has not seen any charging or discharging for several hours.

Surface charge always tricks people into thinking their batteries are more charged than they are, especially if they take a voltage reading right after shutting off the engine, even an hour later readings will be skewed. Also turning off all loads when the battery reaches 12.2 is premature, because battery voltage will rebound for a long while after the loads are removed.

The voltmeter is a great tool, but one must understand they are not accurate indicators as to state of charge. watching one often one can notice the trends and tendencies of voltage during charge and discharge cycles and can better make estimations as to battery state of charge. I like having an amp hour counter/battery montor. I see my voltage then guess the amp hours from full, press a button and see how close my guess was.

Also the voltmeters which plug into the ciggy plugs are notoriously inaccurate, especially if something else is drawing juice from the same circuit as the ciggy receptacle is on.

Ideally one wants to take a voltage reading right from the battery terminals
http://www.amazon.com/SMAKN-3-5-30-...924&sr=1-1-catcorr&keywords=voltmeter+4+digit

Batteries in parallel should be the same size age make model and condition. BIg batteries are hard to move. If one cell in the big battery dies, off to the store. If a cell fails in a dual battery bank, one can unhook the bad battery. Usually the bad cell will go unnoticed and the bad battery drags down the good battery though. Anybody noticing that their paralleled battery bank just seemed to be lower than expected voltage should unhook the batteries and see if one of them drops to ~10.5 volts, indicating a failed cell.

I also had one battery which failed, but only under load. It would read 12.8 with no loads, but a small 3 amp load would drop voltage to 10.5. remove the load and back to 12.8 in a minute or two.

A digital Multimeter should be considered a necessary tool to carry.

Proper venting of flooded batteries is always a conundrum. I kept some flooded batteries inside for years but I'd often smell them charging. Things in their proximity corroded. One spilled and ate through the paint on the floor. Later I made a battery box to put them below the floor behind the driver's seat, with an access hatch from above. this was great from an interior storage aspect. Right now I have a single AGM in this compartment, and my flooded battery is in my engine compartment so I can easily check specific gravity. But my system is wired so either battery can be used for either duty at the flip of a switch.

AGM are significantly more expensive. The AGM's vary fairly widely in recommended charging currents from brand to brand too. Some of them like Odyssey want huge charging currents when the battery is cycled deeply, and do not make for good solar recharged batteries. But Odyssey are excellent batteries, when recharged with high currents. Low and slow on an odyssey will not yield their maximum lifespan or potential.

Other advantages of AGM are low self discharge and that they can accept higher charging rates. I have a Northstar AGM and it is an impressive battery. At 90 A/h, it holds higher voltages than my 130 a/h flooded battery for the same amount of A/h removed from it. It also has 930 CCA compared to the flooded battery's 630.

But the NS battery has a resting fully charged voltage of 13.07, the Flooded battery is 12.8. If I were to leave them in parallel the flooded battery would always be drawing from the AGM.

One can go all battery nerd and do everything possible to treat them as best as possible for maximum life span, or one can realize they are just batteries, and temporary beasts. use them until they no longer have enough capacity to meet one's needs then replace them.

Most people fall somewhere between these 2 extremes. Proper knowledge of how to best treat batteries is wise, but the effort required to do so is not always worth it.

Even the best batteries, treated well, are going to fail at some point.
 
SternWake said:
Even the best batteries, treated well, are going to fail at some point.
I need need to find a good balance of price and performance, as well as longevity. Looking at the prices of these batteries, I can see why people try to cheap out this step. Since this will be my primary power supply, I need to make sure it is adequate.
Does anyone have experience with the brand Universal Battery? I understand they are made in china, but it is the only AGM with comparable amp hours for a reasonable price. For example the Universal UB4D is 200 ah, and about 330 dollars. This is pretty close to the budget of the flooded bank I was considering, with slightly less amp hours. A brand name AGM such as the Concorde PVX-2120L has 212 aH at 12v, but it is close to $600.
If I go with the t105s, It will be anywhere from 250-300 dollars for the 2, and I will get 225 ah.
I have read of people who vandwell having flooded batteries without a vented box inside the van, but as I plan to have an LP system with a heater and stove this is probably a bad idea.
I have a digital multimeter, and I enjoy playing with it to see the current and rates of things around the house.
Another question- Do all charge controllers make noise? I was watching a video of someones solar install on an RV, and he had a morningstar controller wired inside one of the "basement" bays. When he put the camera close to it, it seemed to make a buzzing noise. I am not sure if it was another component of his RV though.
 
I am glad you brought up universal battery, I hope people with these chime in, I am leaning toward a UB because of price and I think a 200ah or a little less would be ideal for my 200 watt renogy kit, I have lung difficulties and do not want a wet cell battery, plus I just aint smart enough or sometimes able to do maintenance on another item, trying to keep it simple, and like sternwake said, they will all eventually fail, especially with me being electrically dumb,lol  
 

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