Solar / battery / boondocking

[jornvango]

After boondocking for 2.5 weeks, yesterday evening the control panel showed low battery: the water pump barely worked and the fridge lights flickered (eventually I turned off the fridge as it kept making a clicking sound).

These past 2 days, I've been camping in the mountains in Utah: the sun doesn't get up high plus it rises late and sets early.

We have a solar panel on the roof which normally does a good job to keep the batteries charged enough plus I pay attention not to use lights at night and to turn off the water pump when not in use.

I checked the batteries (one month old) and the fluids were pretty low so I added distilled water.

Question: as I usually don't have low battery issues, can this be explained by the low fluid level plus low winter sun that doesn't fully charge the battery? The solar control panel shows between "low" and "good" charging at voltage around 11.

Thanks.

[AirsDream]

Not enough information about your system ... but you're not gonna' get any significant charging if your charging voltage is 11volts. Do you have an ammeter that will give you data about "rate of charge" / "discharge" ? Or something like a Trimetric monitor? Sounds as if you're getting essentially zero charge.

And if your electrolyte levels are low on one month old batteries, that's another sign of some sort of problems; if you have a three stage charge controller, etc. and a properly operating system and are only charging via solar panel(s), you should be able to go months without adding electrolyte.

So you need to get together with someone who knows PV systems and can do some trouble shooting for you. You might want to start by verifying that all your wiring connections are solid, etc. ... 'cause if it worked for 2.5 weeks and then went south, something changed on you.

[jornvango]

Thanks. I have no knowledge about electricity and meters.
The main thing that changed two days ago is that I drove from the desert into the mountains.

The past weeks I've been camping in Death Valley: I thought the dryness might influence lower fluid levels in the batteries.

[Protagonist]

Fun facts to know and tell…

Many solar charging setups have the charge controller powered by the batteries, not by the panel itself. So, if your batteries drop too low, the solar panel worn't charge them anymore once there's not enough juice left in the batteries to run the charge controller.

Can you say, "Catch-22"? I knew that you could.

[jornvango]

Good thinking ...

Is there an easy tool (meter?) that allows me to check the batteries?

Regarding LED replacement bulbs: do they only sell these online? I could only find the fluorescent ones at walmart.

[jornvango]

Also, I've been plugged into shore power since yesterday.

1) Battery indicator on the AS control panel shows full. How trustworthy is this?

2) indicator on the solar panel panel: see picture.
Is this (also) showing me that the battery level is almost full?
The solar panel is hooked up to both batteries (one battery on the positive, the other on the negative)



I feel pretty clueless what to look for when it comes to this ... Any help greatly appreciated!

[Protagonist]

Originally Posted by jornvango

Also, I've been plugged into shore power since yesterday.

1) Battery indicator on the AS control panel shows full. How trustworthy is this?

2) indicator on the solar panel panel: see picture.
Is this (also) showing me that the battery level is almost full?
The solar panel is hooked up to both batteries (one battery on the positive, the other on the negative)

Attachment 199094

I feel pretty clueless what to look for when it comes to this ... Any help greatly appreciated!

Not trustworthy at all while you're hooked up to shore power and your inverter/charger is turned on in either auto/invert or charge modes. The display could be showing the charging voltage rather than the battery voltage. Turn the invertyer/charger completely off and unplug the shore power, then look at the display again.

[Silver Hawk]

You have to wait a couple of hours (not sure of the time), for the voltage to settle down to get a good reading for the battery after charging. Best to get a 'Trimetric monitor' as AirsDream suggested - tell a lot of info you need to evaluate the system - also gives state of charge and volts in and out.

[Jammer]

Originally Posted by jornvango

After boondocking for 2.5 weeks, yesterday evening the control panel showed low battery: the water pump barely worked and the fridge lights flickered (eventually I turned off the fridge as it kept making a clicking sound).

These past 2 days, I've been camping in the mountains in Utah: the sun doesn't get up high plus it rises late and sets early.

We have a solar panel on the roof which normally does a good job to keep the batteries charged enough plus I pay attention not to use lights at night and to turn off the water pump when not in use.

I checked the batteries (one month old) and the fluids were pretty low so I added distilled water.

Question: as I usually don't have low battery issues, can this be explained by the low fluid level plus low winter sun that doesn't fully charge the battery? The solar control panel shows between "low" and "good" charging at voltage around 11.

Thanks.

The electrolyte (fluid) level in the batteries probably has nothing to do with it. Was it below the tops of the plates?

The low winter sun plus the battery draw for the furnace are the two most likely culprits.

[pbearsailor]

At the risk of muddying the waters more here, the OP says he's been boondocking for a couple of weeks, is careful about using power, has a solar panel of unknown size, and doesn't know much about electricity.

I boondock a lot and am doing so now. For me, it all comes down to knowing voltage. I check my digital readout (his digital readout on his solar charge controller is likely fine for this) when I get up, before the solar begins to put out charge. With no load on the batteries, it needs to read between 12.2 and 12.7. If it reads less than 12.2, I know I have used more than 50% of my batteries and I try very hard not to do that if I want my batteries to last. If it reads 11 volts I have probably killed my batteries. For me, if I'm around 12.2 in the morning, I'll either need a good solar day or that generator is going to have to run for an hour or two.

My guess is that the OP slowly got behind on voltage over that two week period and will be lucky if he hasn't at least shortened his battery life.

Keeping a close watch on voltage is simple and it works.

Cheers,
steve

[Wabbiteer]

Took a while but I found that charge controller online & got hints to the age/date of the controller (open the siemens kit and look at photos) .... and it looks like its a couple years newer than your '95 Sovereign. Looking over the little info on the web there is no mention of temperature compensation charging.

So if the Utah mountains in the last week of October is getting into the 20's & 30's overnight the battery chemistry may just be too cold to get even a 25% charge from a days sunshine; compared to the Death Valley daytime highs in the 70's or 80's that kept them charging up to 60 or 80%.

Anyhow - Is the battery compartment on the shady side of the trailer now? That might be a teeny cheat to help them charge, get them warmer. Most 'dumb' chargers want the battery temperature to be between 75 and 80F...

[jornvango]

Thanks. Death Valley got up to the 90s in de daytime! The Utah mountains were in the 30s at night and 50s in the daytime.

I'm still on shore power so, possibly this Sunday when I go back to boondocking, I'll keep my fingers crossed that the batteries provide me with power (I don't have a generator).
Or I can go to Autozone and get a battery checker...

[mandolindave]

#1 I would call boondocking for two and a half weeks a success story.

#2 I don't have solar, so one or two nights with the furnace running depletes my batts

#3 I have a cheap little meter that plugs into a 12 outlet

#4 Off topic Question ( for Protag ? ) Is it dangerous to work on solar wiring without shielding the panel from the sun.

#5 I haven't spent much time in the northeast mountains of Utah How about a few photos? Please

[AirsDream]

If you don't have good portable meters, then do keep an eye on your voltage a couple of hours after "unplugging" from shore power ... and after some minor current draws such as lighting, water heater and fridge circuit boards, etc. That should tell you a lot about the state of your batteries. Your battery voltage should read maybe 12.7 or 12.8 and only SLOWLY drift down while there are small outflows going.

It may just be that you weren't getting enough sun, you single panel is too small to keep up with high current draws such as your furnace fan (probably the biggest single source of battery drain on most Airstreams), etc. That combination could drain your batteries after just a few days, even if the panel were working perfectly. And yes, temperature has a strong influence on battery performance also. But I strongly suspect that the big change was temperature change that led to lots of furnace usage.

In the absence of better metering, keep an eye on your battery bank voltage over the course of some hours to a few days and you'll know a lot more.

[ROBERT CROSS]

Originally Posted by pbearsailor

At the risk of muddying the waters more here, the OP says he's been boondocking for a couple of weeks, is careful about using power, has a solar panel of unknown size, and doesn't know much about electricity.

I boondock a lot and am doing so now. For me, it all comes down to knowing voltage. I check my digital readout (his digital readout on his solar charge controller is likely fine for this) when I get up, before the solar begins to put out charge. With no load on the batteries, it needs to read between 12.2 and 12.7. If it reads less than 12.2, I know I have used more than 50% of my batteries and I try very hard not to do that if I want my batteries to last. If it reads 11 volts I have probably killed my batteries. For me, if I'm around 12.2 in the morning, I'll either need a good solar day or that generator is going to have to run for an hour or two.

My guess is that the OP slowly got behind on voltage over that two week period and will be lucky if he hasn't at least shortened his battery life.

Keeping a close watch on voltage is simple and it works.

Cheers,
steve

^
X2

Fancy is nice but won't take the place of plain maintenance....consistently.

Bob

[AirsDream]

One more thing: if you're not "up to speed" on battery / charging issues, take a few minutes and read this article: The 12volt Side of Life (Part 1) ... the second article that follows this one is also useful background.

It's old but still a good primer. And down just past the middle of the article is a small chart showing state of charge vs. voltage. Print it out and tape it on your fridge. That chart is pretty generic, and all battery manufacturers I've dealt with have their own version of voltage vs. state of charge, but if you don't have anything else to go by, this will tell you a lot. Just remember that to get a reasonably accurate reading on state of charge, you have to be NOT actively charging (no incoming current from shore power or solar panel(s) or generator or tow vehicle charge line), AND you have to have been disconnected from charging for an hour or two with at least some small draw from the batteries as a result of using some power in the trailer.

[lewster]

Definitely not enough information about the OP's system.

• What is the wattage of the solar panel(s)?

• What size wire gauge is used to connect the solar array to the controller and then to the batteries and how long are the wire runs?

• How big is the battery bank and what type of batteries are they?

• Is the solar charge controller PWM or MPPT?

In the absence of any amperage or wattage use information, we use the rule of thumb of 1 watt of solar for each amp/hour of battery bank. This will generally allow for the full re-charge of the batteries each day, assuming that you have a relatively sunny day. Also, battery type plays a big role in how the batteries are recharged and specifically what voltages are needed to fully charge the battery bank each day.

There are many other factors to consider in the design of a viable solar battery charging system, but this would take pages to enumerate.

More information is needed to provide any useful assistance to the OP.

[wbrownrr]

Ditto what pbearsailor said (post #10). That's my standard practice. By the way, about 90% of our time in our AS is boondocking.

[jornvango]

Thanks everyone! I will read and learn.

I unplugged from shore power this morning and ran a few lights for a while. This is what the solar control panel shows:






The sun is up so solar is starting to charge.
How does this look?