Solar Panel with Deep Cycle Battery for winter storage

[mgfiest]

I have 1 12 volt deep cycle battery hooked up to a 30watt 15amp solar panel it has a shut off mechanism when it reaches the full charge state. I used this to keep the battery charged when not in use. I check the voltage at least 1 a month and it ranges from 12 - 13 volts, so it appears to be keeping it charged. The winters get very cold in ranges from -10C to -30C maybe at 1 week intervals but it does warm up to break those big freeze. I go and check the voltage on the battery and it still states 12 volts.

The issue is when I go to use it with the load in the spring I get a quick drop in voltage, I can not use the battery to start the fridge which needs at least 10v.

Is there somehting missing in my charging?

[DrewE]

mgfiest wrote:
I have a cheap solar on my vechile battery which stays in and is in working order when spring comes. I have no load on the rv battery and its junkville in the spring. I know the better solar is putting out more voltage and it has its own shutoff installed in it. So I may have to assume that the new rv battery was******to start with... But any who... Theologically I should be able to leave a deep cycle battery on the solar over the winter months?

Theologically? Better ask your pastor or priest or rabbi. :W

An appropriate solar setup should be entirely capable of keeping the battery up over the winter. If it isn't, it seems it's not an appropriate setup for that use.

As I understand things, a good battery generally should survive the winter simply by being charged up fully and then completely disconnected. Self-discharge is quite temperature dependent, and pretty low when the environment is cold. A fully charged battery won't freeze unless you're someplace like Alaska. (Discharged, the electrolyte will freeze at a comparatively warm temperature.) Checking a couple of times and charging a bit if needed wouldn't hurt things.

If there are any small loads on the battery, it of course won't stay charged over the winter.

[mgfiest]

thanks all for the input

[westend]

mgfiest wrote:
I have a cheap solar on my vechile battery which stays in and is in working order when spring comes. I have no load on the rv battery and its junkville in the spring. I know the better solar is putting out more voltage and it has its own shutoff installed in it. So I may have to assume that the new rv battery was******to start with... But any who... Theologically I should be able to leave a deep cycle battery on the solar over the winter months?

Yes, I live in similar climate (MN,US) and my batteries are maintained year round by solar.

I would guess that the small panel doesn't make a lot of power. You really could use 14+ volts in the Winter in Ontario.

I'd suggest to either charge the battery with a 120V battery charger or have it tested at an auto parts store.

Battery University is a good source of battery information.

[mgfiest]

I have a cheap solar on my vechile battery which stays in and is in working order when spring comes. I have no load on the rv battery and its junkville in the spring. I know the better solar is putting out more voltage and it has its own shutoff installed in it. So I may have to assume that the new rv battery was******to start with... But any who... Theologically I should be able to leave a deep cycle battery on the solar over the winter months?

[time2roll]

You need to be close to 15 volts at least once a week.
Do you have a battery cut-off switch?

[pianotuna]

How old is the battery?

What is the voltage coming from the panel (it may not be high enough for winter time charging).

What charge controller do you have?

[Dakota98]

mgfiest wrote:
I check the voltage at least 1 a month and it ranges from 12-13 volts, so it appears to be keeping it charged. I go and check the voltage on the battery and it still states 12 - volts.

Is there somehting missing in my charging?

Yes, & I suspect the battery is shot. Check the water levels, check SG, & attempt charging it with a portable smart charger. Or you can take is somewhere & have it tested.

Take the above advice concerning Solar charging.

[Greydennyhawk]

I have to ask the obvious, why not remove the battery for winter storage?
Also, do you run the gen set once a month, under load for 30-45 min? ( if you have one)
I find that my healthy battery, when re- charged by the generator periodically, stays in good shape all winter!

[Golden_HVAC]

30 watts is barely 2 amps at 15 volts (the charge rate while running from a solar panel).

If your CO meter is still on, that can use 0.8 amps per hour, 24/7. That can use more power than that tiny solar panel is collecting in the short winter months.

I would suggest a pair of 120 watt panels and a 20 amp charge controller.

SunElec.com sells a 140 watt panel for $229. At least one of these will save your battery all winter, if you can keep the snow off of it!

Fred.