Visit our Popular Forums

Gypsymimi · 12-09-2019, 06:42 PM

I have a 22' Airstream Bambi Sport. It has the factory installed 40w solar panel and an AGM battery. It has been sitting in a storage lot for 35 days in the full sun. It has been cloudy here about 7 days. I went and checked it and my battery was discharged with no signs of life on my solar panel display. I was able to charge the battery to 12.8v with an AGM battery charger and get it working again but shouldn't my solar panel keep it charged? I'm confused. There is nothing on in the RV except the carbon monoxide detector. The On/Off switch to the battery is in the On position. Any help would be greatly appreciated.

Thanks!

**wulfraat** · 12-09-2019, 06:49 PM

If the battery switch was “on” then your fridge, stereo and other 12v items were drawing power in stand by mode. Need to keep that switch in the off position when in storage.

40w is marginal to keep the battery charged.

GMFL · 12-09-2019, 06:49 PM

You have 1 AGM battery? And 40 watts of solar?

GMFL · 12-09-2019, 07:00 PM

Here’s the basic math.
Your trailer pulls about 0.5 amp parasitic
That’s 12 amps per day
7 days without much power from your 40 watts of solar due to clouds and winter sun angle.
Could equal approx 70Ah pulled from your (1) 100Ah AGM battery = 70% of battery used = dead battery

**wulfraat** · 12-09-2019, 07:00 PM

If the battery switch was “on” then your fridge, stereo and other 12v items were drawing power in stand by mode. Need to keep that switch in the off position when in storage.

40w is marginal to keep the battery charged.

BayouBiker · 12-09-2019, 07:03 PM

Yeah, something is seriously wrong. /start with the solar charger. What does the display tell you?

Gypsymimi · 12-09-2019, 08:41 PM

Quote:

Originally Posted by GMFL

You have 1 AGM battery? And 40 watts of solar?

Yes, I have one AGM battery and 40 watts of solar

Gypsymimi · 12-09-2019, 08:43 PM

Quote:

Originally Posted by BayouBiker

Yeah, something is seriously wrong. /start with the solar charger. What does the display tell you?

The display was completely blank. It usually tells me that the battery is charging and it has 12.9 volts

Gypsymimi · 12-09-2019, 08:46 PM

Quote:

Originally Posted by wulfraat

If the battery switch was “on” then your fridge, stereo and other 12v items were drawing power in stand by mode. Need to keep that switch in the off position when in storage.

40w is marginal to keep the battery charged.

Will the solar panels still charge the battery if the switch is in the "off" position.

JonDNC · 12-10-2019, 05:32 AM

Quote:

Originally Posted by Gypsymimi

Will the solar panels still charge the battery if the switch is in the "off" position.

It does on my 27 with factory solar. It’s how I store it.

uncle_bob · 12-10-2019, 06:07 AM

Quote:

Originally Posted by Gypsymimi

Will the solar panels still charge the battery if the switch is in the "off" position.

Hi

Yes, that's how it is set up to work.

======

Depending on just what was doing what in the trailer, you could have had quite a bit of current coming off the battery. Unless you have a (aftermarket) shunt based monitor there really isn't any way to be *sure* what is going on.

Bob

AirMiles · 12-10-2019, 07:11 AM

You can determine the amp draw on your Airstream with a Clamp On Digital Amp Meter. This is the one I use: https://www.amazon.com/dp/B01N014USE/ref=emc_b_5_t

I agree you should store your Airstream with the store/use switch in "store" and the solar should charge the battery. If you had it in "use", your amp draw is probably larger than the 40W panel can maintain, so your battery died. A 40W panel would barely be enough maintain the 120W per day of solar my Airstream uses while its stored.

BayouBiker · 12-10-2019, 07:17 AM

Quote:

Originally Posted by Gypsymimi

Will the solar panels still charge the battery if the switch is in the "off" position.

If the Solar system was installed correctly it will, On my trailer they installed the primary lead from the solar controller to the load side of the disconnect solenoid rather than the lead side or the battery hot bus so originally mine did not charge in "off" position. Don't rule anything out till you've tested it.

BayouBiker · 12-10-2019, 07:21 AM

Quote:

Originally Posted by Gypsymimi

The display was completely blank. It usually tells me that the battery is charging and it has 12.9 volts

The solar controller needs some power to run so if the battery is dead and the panels have no sun it will be lack. Otherwise there should be something going on on the controller display. If it is still dark, then it is likely broken unless yours happens to have a power switch (mine does not, its always on).

Gypsymimi · 12-10-2019, 08:20 AM

Quote:

Originally Posted by BayouBiker

If the Solar system was installed correctly it will, On my trailer they installed the primary lead from the solar controller to the load side of the disconnect solenoid rather than the lead side or the battery hot bus so originally mine did not charge in "off" position. Don't rule anything out till you've tested it.

How would I test this? Thanks.

Patti

AirMiles · 12-10-2019, 08:28 AM

Quote:

Originally Posted by Gypsymimi

How would I test this? Thanks.

Patti

You can use the same digital amp meter linked above: https://www.amazon.com/dp/B01N014USE/ref=emc_b_5_t

On a sunny day with the store/use switch in the "store" position, check the voltage across the positive and negative battery post. If the voltage is above 13 volts, your solar is charging your battery. You could also check the amps by clamping the meter around the negative battery cable. If amps read over 0.5, your battery is charging.

Gypsymimi · 12-10-2019, 09:24 AM

Quote:

Originally Posted by AirMiles

You can use the same digital amp meter linked above: https://www.amazon.com/dp/B01N014USE/ref=emc_b_5_t

On a sunny day with the store/use switch in the "store" position, check the voltage across the positive and negative battery post. If the voltage is above 13 volts, your solar is charging your battery. You could also check the amps by clamping the meter around the negative battery cable. If amps read over 0.5, your battery is charging.

Thanks so much!

gator.bigfoot · 12-10-2019, 09:37 AM

Check the input to the solar charger and make sure you are getting voltage there. If not start there. If you are getting voltage then hopefully it's above 15 volts. If not then you have a faulty panel or not enough sunlight. Once you've determined that, measure the output of the solar charger. It should be at the same voltage as the battery. You could disconnect the charger from the battery and see if you're getting a higher voltage. But some chargers recognize that there is no battery and will shut down as a safety precaution.

Thonevan · 12-10-2019, 10:39 AM

I have a 22 Bambi Sport with one 12v AGM Lifeline battery. I have 3 80 watt panels... Mine stays fully charged all year round. I will even run the Fridge on 12 volt, in the summer

JohnTF · 12-10-2019, 11:05 AM

I would avoid having Airstream do anything with solar - too many lack of engineering / design issues .
Even before solar / older Airstreams , they did not care [ would not bother to look into what there systems would do to a battery ] and then the dealers would not bother to take care of what the manufactures , didn't do , to maintain a battery with just a charger ] many yrs. the charger would kill the battery , and besides leaving the battery in the trailer for how many months , yrs. before the sale --- killing batteries .
This is to the point of - never take possession of a new / or used trailer without new batteries / NEW WHEN YOU PICKUP !

Now have a properly ENGINEERED battery , and or solar system installed .
Like most , you do not want to be the engineer - just turn-key & use - that costs money .
Or if you do chose to learn & maintain - you can get many yrs. out of the batteries etc.
My last FLA - Flooded Lead Acid battery bank , ran even my airconditioner and lasted about 13 yrs.