How do I know how full my batteries are?

[SternWake]

Looks like you'll be tight at the limits of a 30 amp controller.

I've not researched all the current controller offerings.

I have a BlueSky SB2512i and the IPN pro remote battery monitor which allows user adjustable voltage setpoints, but it is only good to 25 amps. You can run more than one Blue sky controller in parallel, the 2512 models are pretty small.

Look into Rogue and Morningstar too. Sorry I don't have much knowledge on the latest and greatest, but adjustable float and Absorption voltages are the Key to getting good battery life living on Solar while van dwelling.

It also allows you to take on other brand batteries when the first set have lost too much capacity to meet your needs.

The Bs 2512i controller has a default Absv set at 14.2v. If I were not able to raise this to 14.9v Via the IPN pro remote, I'd be going through batteries every few months.

I regularly change the setpoints when i cycle my AGM instead, and that wants 14.7v.

When i am not cycling daily, I lower absv to 14.1 for 30 minutes and float at 13.1v, and disconnect the AGM entirely from everything.

When not cycling daily, a controller does not need to hold higher voltages all day long compared to when it is cycled. You can see where one size fits all, is not recommended, in more than one way.

 

[anm]

I've seen a charge controller available on eBay by a company listed as EPSolar. A 20 amp version with remote temp sensor is available there for $72 with free shipping (from China of course). It appears that this same controller is marketed as the ViewStar, and possibly also the Renogy LCD. Looking in the manual for the EPSolar VS2024BN, it appears that 'all' of the charging parameters are user adjustable, including voltage levels 9-17 volts, and duration up to 3 hours (float of course just runs forever after). Equalization can be set to 0 giving no Equalization phase. You can access the EPSolar VS2024BN manual here, it will download the PDF onto your computer.

I think some agency in China comes up with a design and then makes it available to Chinese manufacturers for production and marketing...

 

[riffraff]

Well cloudy skies today messing up my experiment, although it's supposed to get sunny around noon. Had to run the fan-tactic fan for a bit tho.. 80 feels hot at the moment.

 

[ccbreder]

At last a way to determine SOC on sealed batteries.
go here; http://www.pbase.com/mainecruising/smart_gauge

 

[riffraff]

Btw the controller I have is here:
http://www.blueskyenergyinc.com/products/details/solar_boost_2000e

It's now reading 14.04 and I'm running my fan-tastic fan at the same time.

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Also the light is blinking which, according to the manual, indicates a greater than 90% capacity

 

[SternWake]

It appears that the Sb2000-e does have selectable voltage points.

If the Absorption light is blinking at 14.14 volts, then I'd go in and move up the absorption set point to 14.4.

It also has the option for a battery temp sensor. If you have employed the use of this and it is really hot out, then the 14.14 makes sense. If you have not employed it then do some adjustment and get that battery upto 14.4 daily. 14.14 is too low and you will drastically shorten battery life through chronic undercharging.

http://www.blueskyenergyinc.com/uploads/pdf/Manual_BSE_SB2000.pdf

 

[riffraff]

At last a way to determine SOC on sealed batteries.
go here; http://www.pbase.com/mainecruising/smart_gauge

$320 eh? The reviewer/blogger seemed very impressed with it. Looks nice. Maybe something I'll invest in once I get working again.

 

[SternWake]

That Maine Cruising Chap posts the best information available with regards to battery charging that I have found anywhere. If he is impressed with a product, I'd certainly consider it. He even bashes my IPN pro remote battery monitor, and I can't argue with him there. its claims to accuracy are just not supportable.

He has lots of U tube videos as well that are very pertinent to this electrical forum:

 

[riffraff]

Sounds like a trustworthy source! Ok my kindle is at 8% juice.. need to do it. I cranked up the knob to 14.5, pictures to come.

 

[riffraff]

Okay here are some pictures I took of the controller while the battery box was open:



and after I turned the knob a bit:



I'll try to not run the fan or charge anything tonight.

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A couple other pics inside the box:

 

[riffraff]

Another thing I am curious about. With the alternator hooked up, when does it charge the house battery? Any time I drive or does it have to be fairly low on power?

Can anyone eyeball the wire going into the controller to see if it's of proper thickness?

 

[riffraff]

A clamp on AC/DC Ammeter might be a good investment for you.
Clamp it over any one wire in a circuit, and it will tell you how much current is flowing through it.

http://www.amazon.com/gp/product/B0...d_t=201&pf_rd_p=1535523722&pf_rd_i=B001VGND88

Went ahead and ordered this. Similar product at Lowe's was twice the cost. Will try on Tuesday. In the meantime, batteries have got to 14.54 without a load today using the new controller settings.

 

[SternWake]

The DC clamp on meter will tell you how many amps are making it into the house battery from the alternator. There are so many different ways to allow the house battery to see alternator amps, there is no one answer to your question without significantly more details and test results. Aquisition of that meter is a great first step. you can always bump up the wire size, or run a properly fused additional wire in parallel from alternator(+) to isolator, and from isolator/relay/solenoid to house battery. Ground paths should be just as thick too.

 

[riffraff]

What about the pictures of the controller hookups I posted? Is it possible to tell from those if the wires are too thin?

 

[SternWake]

The pics of your solar controller appear to be 12awg but might be 14 awg. Wikipedia will have conductor diameters listed if you care to measure. the wire might have the gauge printed on it as well.

Do note SAE wire is thinner than AWG in terms of the numbers before the gauge.

The wire also looks to have that plastic covering over the regular insulation. The wires from controller to the fuse/circuit breaker to the batteries should be as fat as you can stuff into the terminals, and be a short run to the batteries too. If these wires are very stiff, make sure to add some stress relief so road/engine vibrations do not weaken the wire receptacle on the circuit board.

The quality of the crimping has a huge effect on resistance and durability. While i do not like the insert stranded wire, crush under screw connections so common on these types of devices, they will have less resistance than the crimps in your picture. Also those insulated terminals are usually LOW quality, using steel or aluminum instead of tinned copper.

Another Mainsail link showing the proper and best ways to do things:
http://www.pbase.com/mainecruising/wire_termination&page=1

I thought we were speaking of the alternator feed to the isolation solenoid/ACR to the house battery, and these should in general be no thinner than 6 awg wire to take advantage of the biggest charging source in most every vehicle, which is the alternator.
The alternator can, if properly wired, quickly get a depleted battery to ~80% state of charge. After this point thicker wiring is not really effective as the battery cannot accept high amps, and this is when having solar can really get the batteries very close to the elusive 100% SOC

 

[riffraff]

I got the multimeter. Have to admit it's a little intimidating not knowing much about how it works, reading the directions and safety precautions. I suspect i'll begin by testing the wires going to the controller (at the controller) with one of the panels covered with a blanket, then the other to see if both are working correctly. I suppose if they are, but I'm still only getting 6 amps or whatever from them when both are exposed to Sun midday then I'll blame thin wiring for the lack of correct power.

 

[SternWake]

Can you get on the roof and clamp the meter over a single wire of a single panel?

Set to Amps DC, put it next to the wire, press the zero button, wait for it to read zero, then clamp it over a single wire. it will read - or positive, you can flip it over, and the other wire usually reads a little bit different.

Knowing how to properly use a multimeter is not especially difficult, try to find some u tube videos on the matter. Even if they are not clamp on meters, lots of the other capabilities are the same. Just with these, you do not need to open up the circuit and install the meter inline to read current, and can read current upto 400 amps, where as the inline digital multi meters are limited to 10 amps, for the most part.

View it as a toy to experiment with, and you will learn how to use it quickly. The only issue is getting just one wire to clamp the meter over. Clamping over two wires on the same circuit, it will read zero.

 

[riffraff]

As soon as the clouds clear (1pm according to weather.com) I'll give this a shot and get to the bottom of this!

Charged my mifi overnight, woke up to an inverter telling me the batteries were at 12.3v. Ouch!

 

[ccbreder]

The one thing to note on a multimeter is to not use the ohm part on a live circuit.

 

[riffraff]

Checked just now after an hour sitting down at breakfast and they're reading 13.7v. What the.. guess the readings are highly inaccurate as Stern pointed out during and the time after a load is on them. Makes it kind of difficult for me to know what 50% is and when to stop using them. I've been not running the fan at all at night for now and rarely charging my electronics (thanks taco bell, Starbucks and the library for helping me the there). Kind of defeats the purpose for me getting the house batteries tho if I don't use them.