Something Wonky Going On

[Trebor English]

It sounds like your system is similar to mine, one battery for engine starting and everything else with solar.  If you have a loose battery cable that normally makes contact but is intermittent that could cause the voltage to fluctuate.  Grab the battery cables and try to wiggle where they connect to the battery.  Any looseness could be the cause of the fluctuation.  The battery provides stability for the whole system.  If the battery is bad that could do it too but I would expect that to show up first with failing to start the engine.

 

[Headache]

Well, you are where you are, so let's work with that. I'm not well versed on lithium, but perhaps if the battery is worn out and needs to go, would a small lithium battery with a BMS be a suitable replacement? The BMS would keep the battery from being overcharged- or does it not work that way with her setup?

I'm sorry but I don't know what a BMS is.  My set up is really simple.  Just the charge controller, the panels, the battery, a 12 volt receptacle bank that has 3 receptacles and because I can't get in and out of my van a lot I use that plug in meter to keep an eye on things from inside:

https://www.amazon.com/INNOVA-3721-Battery-Charging-Monitor/dp/B000EVWDU0/

Gotta log!  Library is closing!

 

[Canine]

A BMS is a Battery Management System for lithium batteries. They are like a type of charge controller that comes built in with the batteries. It in part controls the charge to prevent too much charge from coming in. Someone will have to chime in to see if that is a good idea, though.

 

[safarivan]

Just keep an eye/ear on it and if it goes upto 16v or above then unplug the solar panel.

that meter is probably not very precise, very few are these days actually from my experience comparing them side by side.

usually the built in meters on the controllers are though and the fluke brand handhelds are too so anyway, @ 16v that is giving it .5v of slack/buffer.

i think 15.5 is the more accurate number if you are dealing with calibrated and accurate measuring equipment.

does the voltage on the controller display agree with the cig lighter adapter one at any given time?

if you have difficulty remembering numbers there is really only two that are most important. the highest I mentioned, in this case (wet cell) 16.00v and the lowest is roughly, 11.00v in this case.

just try to remember these two parameters 11.00v lowest and 16.00v highest.

anywhere in between should be fine here and if its near the top or bottom either way then as long as its not near there for over five minutes you should be good togo.


these numbers are not one size fits all and there are countless factors involved in every different system and countless opinions about them all too.

this is just my opinion but FWIW if you read what all I went through in the thread I previously mentioned, you can see how/why I learned a whole lot about this stuff in a very time consuming and costly way. and it all began with noticing my fan speeding up. ;-)

I really didnt think much of that either until one time it sounded like it might explode. it was approaching turbo speeds. lol

 

[safarivan]

A BMS is a Battery Management System for lithium batteries. They are like a type of charge controller that comes built in with the batteries. It in part controls the charge to prevent too much charge from coming in. Someone will have to chime in to see if that is a good idea, though.

other than various devices that come with none removable Lithium batts, I havnt used them yet but IIRC since they are such a fire hazard, the L batts have built in charge controllers. is this not correct?

too expensive for me to justify the lithium stuff right now anyway but the less weight for same AmpHours is always appealing.

 

[Canine]

Many but not all lithiums at least have the option of having an installed BMS, but it is spendy. Could easily be a deal breaker for that reason alone.

 

[frater secessus]

What that means is when you buy fantastically cheap stuff, you are going to have problems- that is a verifiable fact. If you want to spend your money trying to fix what probably can't be fixed, that's your choice. If you want to truly fix the fundamental problem, purchase equipment that will work.

All equipment choices are compromises.  If you think $$$ gear doesn't have problems I can correct that with some "verifiable facts", as you say.  This is why gear has warranties, and upgradeable firmware, tech support, and repair departments.

Solar that works ain't cheap. It doesn't have to be exorbitant, but it isn't cheap.

A functioning solar system can be put toghether for very little money IF one understands the technology and the gear available.

It can also be put together for a ton of money if one wants.  Since this is Cheap RV Living I'll say folks here are willing to do extra work to get by on less.

 

[frater secessus]

I noticed about mid-February that occasionally my 12 volt dash fan would pick up speed.  Nothing appeared out of the ordinary on the meter so I chalked it up to my ignorance of charge cycles.  However, over time its occuring more often and today I saw the meter I have plugged into a 12 volt receptacle spike up over 15 a few times.  I remember people talking about 15 being bad so I unplugged my panels and things settled down.

There will be some normal changes in system voltage (and therefore fan speed) at different times.  Changes in electrical loads (draws), changes in charging phase (bulk, absorption, float - as you pointed out), etc.  So it might not mean trouble.

However, over time its occuring more often and today I saw the meter I have plugged into a 12 volt receptacle spike up over 15 a few times.  I remember people talking about 15 being bad so I unplugged my panels and things settled down.

Could be the controller trying to do an equalization and being unable to maintain the voltage;  that would explain the spikes.  It would also be normal.

Digression:  if the walmart battery has removable caps this would be a great time to "water the battery".   Higher voltage tends to accelerate water loss.  Normal stuff, it's why we water batteries.

I noticed that the charge controller stays on all the time.  For some reason I thought when the panels were unplugged it wouldn't be on anymore.

Controllers stay on all the time;  they are powered by the battery bank.  Some go into a sleep mode that takes less power but all do have some amount of "parasitic" draw.  Normal normal.

12.4  this is interesting because the meter plugged into the 12 volt which is wired to the battery shows 12.6.

Which might suggest the meter is reading high and the spikes may not be as high as they appear.

; I was charging my phone but instead of going up it was going DOWN!  Like the juice was being sucked out of it.  The meter showed something weird too but I can't remember what it showed.  As soon as I unplugged the phone everything settled down.  I've charged it several times since without issues.

Sometimes a phone or other device will detect its plugged in and change its behavior:  screen brighter, display stays on longer, CPU running faster.  If (for whatever reason) it's not actually accepting a charge then the phone will appear to be charging but actually draining faster than usual due to the changed behavior.  I don't think it's related to the topic at hand.

I have an LG phone that is bad about that.  Super picky about charging.  There are certain cables, chargers, and phases of the moon it doesn't like.  It's the phone that has my grandfathered verizon 3g account on it so it's a PITA but I humor it.

BTW, give the wiener dogs some scratches from me. 

 

[tripper]

I just bought one of those cheapie $20 newer pwm controllers ( the kind you are seeing now with the 2 usb ports) for a 100 watt panel I installed. It sux. When my rig is plugged into 120v power, the cheapie pwm solar controller won't go into float ever, so it raises the voltage to 14.4 and sits there all day, even tho the battery is fully charged. It does seem to bounce the voltage around some. I just found an MPPT fairly cheap so I ordered it to replace this bad cheap PWM.

The thing with solar controllers is if you go cheap on that component, you will pay in the end for another battery in the not too far future.

 

[Headache]

If you have a loose battery cable that normally makes contact but is intermittent that could cause the voltage to fluctuate.

If the battery is bad that could do it too but I would expect that to show up first with failing to start the engine.

All good there.  I have an appointment with a shop on Tues to look at the front end.  I'll see if they can also check out the battery.   Otherwise it starts good and everything except the weirdness after charging is done seems to function as it should.

 

[Headache]

A BMS is a Battery Management System for lithium batteries. They are like a type of charge controller that comes built in with the batteries. It in part controls the charge to prevent too much charge from coming in.

Oh yeah!  I'm so used to how they operate I forget that's a part of it.   I won't be buying them though.   I call em Barbie Doll batteries.   I'm an AGM gal someday when I can afford them.

 

[Headache]

does the voltage on the controller display agree with the cig lighter adapter one at any given time?

I really didnt think much of that either until one time it sounded like it might explode. it was approaching turbo speeds. lol

I'm not sure.  I've only checked it a few times.   I bought the cig plug meter because I can't get in and out of the van a lot.  It does my knees in. 

The fan hasn't reached turbo speeds yet but it sure seemed like it would that one day.   To be on the safe side I haven't plugged my panels in until I get the battery checked.

 

[Headache]

this is just my opinion but FWIW if you read what all I went through in the thread I previously mentioned, you can see how/why I learned a whole lot about this stuff in a very time consuming and costly way. and it all began with noticing my fan speeding up. ;-)

I did read it, and didn't understand most of it. 

My goal at this time is to be the electronically challenged one that doesn't fry my battery.  It's a personal challenge. 

 / fingers crossed

 

[tx2sturgis]

That controller might be hitting boost or equalization mode, which they will do, depending on the settings.

Also, you should probably check the water level in the battery. 

Can you tell us if the controller manual says anything about 'flooded, sealed, or gel' batteries and if so, is there a way to change the setting?

You might want to try a less aggressive setting. It probably defaults to FLA or flooded, and you can try 'sealed' or AGM setting to reduce the boost voltage a small amount. 

If this cures the issue then we know what is causing it. If not, then something else is going on.

But try it for a few days and let's see what happens.

 

[John61CT]

Yes no charge source should be allowed to automatically equalize or "condition" a valuable bank, including the desulfation pulsing some too-smart garage style chargers do.

If you can't turn that "feature" off, replace the unit.

For those batteries where the manufacturer recommends an equalization routine, do it regularly but manually, following their protocol.

 

[Headache]

That controller might be hitting boost or equalization mode, which they will do, depending on the settings.

Also, you should probably check the water level in the battery. 

Can you tell us if the controller manual says anything about 'flooded, sealed, or gel' batteries and if so, is there a way to change the setting?

Battery gets checked tomorrow.  The controller does have settings but I'm in the midst of doing a storage build in the van and as of today have not located the manual which is a tiny folded piece of paper.  I know I kept it though!  I'll let you know as soon as I find it.

 

[Trebor English]

My controller also came with a tiny folded piece of paper.  It's about an inch and a quarter folded.  One side is Chinese, the other side is an awkward English translation.  I stuck it between the controller and the wall.

 

[Headache]

LOL!! Mine is with a stack of papers in storage...somewhere!

 

[Headache]

Took the van I for a LOF and great news! Battery working just fine. They topped off the water and said it barely needed any.

I'll hook the panels back up tomorrow and see how things go. I'm going to need to run my fans for a couple of days. /fingers crossed