Off grid solar generator--wont charge past 11.8V

[Logan005]

Last thing any of us want is a fire, next is to get that battery fully charged and floating. I am no expert, but I know who I think is/are, and I always read their comment's first. Yes yours is a small system, but can still cause a big problem. You and I are both learning and that is a wonderful thing.

[jwpookie47]

I hear ya, don't want to cause a fire. I have researched it and am going to get the fuses today. It took a bit of research to find out what type I needed for my little system. It really is just a small, portable (all hooked onto a dolly) beginner project. And I am very thankful for the advice, esp about the fuse and safety.

[Logan005]

I once had an AGM battery hooked to a light, something fell and pinched the wire together and the wire insulation melted off and turned bright red, ruining the carpet and setting it aflame. I cut the wire from the battery and use a fire extingusher, making an even bigger mess. learn from our mistakes or learn it the hard way. but don't burn the house down.

[Logan005]

the fact that your battery has 35 amp hrs of 12 volts, is why you need some sort of fuse or breaker between it and your load. you can use a simple in line glass or blade fuse or a resettable breaker. preventing arc's and fires.

[jwpookie47]

What in my system would determine what fuse I get? Is it the battery or the charge controller? I have a 12V sealed lead acid 35 AH battery. The charge controller is 10 Amp.

[Mike90250]

Look at the Blue Sea dual terminal fuse block. Bolts right on the battery, has 2 fuses (check what sizes you need) and is tested/approved

https://www.bluesea.com/products/category/0/72//Terminal%20Fuse%20Blocks

DualTerminalMRBfuseBlueSea.jpg

[jwpookie47]

The enclosure has no lid on it-it is just a rolling tool box that I am repurposing. The battery doesn't sit at the very bottom of it, it is lifted about 3 inches so I could build up the bottom to be level. I don't have a fuse. Guess I'll be reading all about fuses tonight. Thanks.

[PNjunction]

With cost in mind, Here are some CC;s I have worked with.

Thing is, even with cost in mind, the controller is the very HEART of your system. Don't cheap out here if you can avoid it. The ones linked are barely beyond toys.

When a toy controller burns up your nice new Optima or Odyssey, there will be tears flowing.

Take a step up in quality and reliability when you want to get a bit serious. We're talking the typical Morningstar, Steca, Xantrex/Schneider, Samlex etc. - even for just the simpler pwm versions. Usually the docs alone make all the difference, nevermind the better product itself.

[PNjunction]

Down side is at 14.4 the controller is set for FLA batteries instead of AGM. They should only be taken to about 14.2V. If your controller has settings for AGM you need to change it. if it doesn't you need to get a different controller.

She's fine as is since most agm's are actually spec'ed for 14.4 to 14.7v absorb in cyclic duty. Some can handle up to 15v even. (temp compensated of course).

14.2v is a poor no-man's land for voltage. Too low for agm, and a tad too high for many gel's.

Ideally, always follow the manufacturer's voltage specs, and make sure that the canned settings in charge controllers actually agree with this!

For example, with Morningstar Sunsaver pwm controllers, there is a jumper for "sealed" and "flooded". Unfortunately, many newcomers see that indeed their agm is "sealed", but when you look at the actual voltages assigned to the silkscreen labeling in the manual, that voltage is too low for agm. " "Sealed", on a Morningstar Sunsaver runs about 14.1 / 14.2v. That is ok for gel, but NOT for agm. In this instance, when running agm, one would choose the "flooded" jumper settings, since that voltage is around 14.6v or so.

[PNjunction]

Ok, here is my charge controller...it didn't say done. But the green light started blinking..which, in the user manual, indicates that the battery is fully charged.

Ok, I've seen those but don't know the actual make or model to guide you further. However, if you are getting up to at least 14.4v that's ok for agm. The previous reference to 14.2v is actually too low. For now you are fine voltage wise. Just keep that thing in the sun well AFTER the led blinks. If blinking means it finally arrived at float, you need at least 8 MORE hours to actually finish the charge. In other words, keep that thing in the sun as long as you can - at least initially during this week.

I don't want to throw too much at you at this point. Just be prepared to replace that battery possibly sooner than later - that is your "learner" battery that we ALL have been through at some point.

SAFETY - you want to get on top of this and develop good habits. Is there a FUSE anywhere in the leads going to the battery terminals? I don't see one from the photo. The idea here is not only to protect any shorted equipment, but to protect the wires! If that 35ah battery sees a short, your wiring will become the fuse instead when it burns. So look into that aspect.

Also, if that enclosure is totally sealed when you put a lid over it, that is a big NO GO. Make sure that enclosure is NOT air-tight. AGM's don't gas under *normal* circumstances like flooded batteries do, but if abused or by accident suffers from a large overcharge (controller failing etc), they DO gas, and you don't want an airtight box to prevent it from escaping.

At this stage, this will get you started and a lot more fun stuff to read about and learn!

[Logan005]

You are getting there. and your interest in learning will get you through this. First get a better CC,and or a separate Low voltage Disconnect (LVD) the one you have will likely damage your battery and any future batteries you may buy. Second: get another 50 watt panel, as your system needs to be over sized to accommodate a worse case scenario. With cost in mind, Here are some CC;s I have worked with.

http://www.ebay.com/itm/301221639758?_trksid=p2057872.m2749.l2649&var=600274352263&ssPageName=STRK%3AMEBIDX%3AIT

http://www.ebay.com/itm/311374534055?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

http://www.ebay.com/itm/151481885806?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

the top link has adjustable (LVD), the bottom two links both have the LVD hard set and way too low, I like the second unit, it has USB and 12volt barrel jacks on the front and an informative display. the bottom link is for projects that require a waterproof CC,

[jwpookie47]

Ok, here is my charge controller...it didn't say done. But the green light started blinking..which, in the user manual, indicates that the battery is fully charged. My battery is a 12 V 35H sealed lead acid battery. I am going to have to take a class in order to understand some of this stuff. By trade, I am a registered nurse..and I'm not considered a dummy, but some I need to learn about the difference between PWM and MPPT CC's. This little unit is hopefully going to be used to power a few things (a light, phone chargers) during power outages.

[Wy_White_Wolf]

Don't run away so fast!

Just because the led indicator says "done", it is NOT done charging! What is really done is the bulk, or possibly the absorb phase. We don't know what controller you are using, but none that I know say done, except for kits - and even they get this wrong in order to please you with a green light.

AGM's need a *minimum* of 8 hours of float to actually finish the charge! You can keep it on after this for maintenance purposes, but that critical 8 hours of float must not be skipped. And ESPECIALLY so with a new battery...

PWM controller so she only has bulk and float. It's as done as the system can get it.

I bought a digital voltmeter that is wired into the system. Today they sun shined all day and the reading got up to 14.4 and the green 'battery fully charged' light was blinking. Success! Thanks for all the advice. I am sure that the battery was damaged from being undercharged for so long.

Down side is at 14.4 the controller is set for FLA batteries instead of AGM. They should only be taken to about 14.2V. If your controller has settings for AGM you need to change it. if it doesn't you need to get a different controller.

WWW

[PNjunction]

Don't run away so fast!

Just because the led indicator says "done", it is NOT done charging! What is really done is the bulk, or possibly the absorb phase. We don't know what controller you are using, but none that I know say done, except for kits - and even they get this wrong in order to please you with a green light.

AGM's need a *minimum* of 8 hours of float to actually finish the charge! You can keep it on after this for maintenance purposes, but that critical 8 hours of float must not be skipped. And ESPECIALLY so with a new battery.

Many wheelchair / mobility chair chargers are also guilty of this leading the owner into a false sense of security until their battery dies prematurely. Even after the charger says "done", it need 8 hours / overnight to actually finish the charge.

So what to do? Put that solar kit you have back out there for at least another day to finish the charge. Under normal circumstances where people are cycling agm's daily, they have to make up for this lack of a finishing charge at some point in the weekly routine - or just buy batteries sooner than later over and over.

If you can't get this thing out into the sun often even when the controller says "done", then do invest in a maintenance charger to actually finish the charge when the sun isn't out.

The other issue is that your "new" battery may actually be toast - highly sulfated batteries are very quick to charge because internally they are very small in capacity relative to what they were new due to an abusive or ignorant environment, such as long retail storage etc.

This is where the Optimate 6 which performs testing and gives you indicators above what most other charger do can really help figure out if your battery is healthy or not.

[jwpookie47]

Update: I bought a digital voltmeter that is wired into the system. Today they sun shined all day and the reading got up to 14.4 and the green 'battery fully charged' light was blinking. Success! Thanks for all the advice. I am sure that the battery was damaged from being undercharged for so long.