Battery Maintenance/Storage

[backcountry birds]

My trailer has two Interstate GC2-ECL-UCL batteries wired in parallel.

I store it away from an electrical source and sometimes there is a couple months between use. Should I pull the batteries everytime and plug them in at home to a trickle charger?

Is their a solar trickle charger that would work or would that be worse since it may overcharge?
Should I just not worry about it as long as there isn't a parasitic draw? Or maybe disconnect the batteries from each other?

Thanks for any suggestions.

 

[67cj5]

My trailer has two Interstate GC2-ECL-UCL batteries wired in parallel.

I store it away from an electrical source and sometimes there is a couple months between use. Should I pull the batteries everytime and plug them in at home to a trickle charger?

Is their a solar trickle charger that would work or would that be worse since it may overcharge?
Should I just not worry about it as long as there isn't a parasitic draw? Or maybe disconnect the batteries from each other?

Thanks for any suggestions.

Just charge them connected, connect the NEG from the Charger to the Neg of one Battery and Connect the positive from the Charger to the positive of the other Battery,

You could put a 100/150w Solar panel on the Trailer and get a good quality MPPT Charge controller and it will maintain the batteries and it will do it all it's self, once fitted you can set and forget, It will not over charge the Batteries once set up right.

Hope that helps.

 

[Buddha.]

If you used a multi stage solar controller I don’t think you’d cook the batteries.
Or you could do a master disconnect for when the trailer isn’t in use.

 

[DiploStrat]

Lead acid batteries want to be kept fully charged. A properly designed and executed, repeat, PROPERLY designed, shore or solar charger will keep them happy and not overcharge them. Lacking that, fully charge and then physically disconnect from all loads.

 

[backcountry birds]

Thank you all! This is extremely helpful. I really like the idea of using solar.

Any recommendations on a solid controller and solar panel combo. I would rather not break the bank, but don't want junk either.

I already have a large solar panel for when I'm camping. So just looking for a small one I can use in storage.

 

[DiploStrat]

Here you open a range of possibilities.

Do you want a maintenance (trickle) charge system, or one that can carry your loads when living/camping in the tailer?

I would vote for designing a proper solar charging system designed to support camping. Any system of that type will easily handle maintenance charging while in storage.

There are lots of good chargers on the market. I am using Victron, but Blue Sky works as well.

With lead acid batteries the critical point is that the charger have the ability to be set for a L O N G absorb stage. (Many Go Power! controllers lack this ability - don't ask how I learned this! )

 

[john61ct]

Victron SmartSolar

as above extending Absorb / CV hold time, but that's only while daily cycling

in storage just keeping topped up, keep on lower Float voltage only, in fact low end of the range on your GCs' datasheet.

Could disconnect for 3-4 weeks then hook up for a few days at a time, assuming isolated from all vampire loads

but likely keeping hooked up all the time is fine.

 

[broncobowsher]

If maintenance is all you want, it only takes a tiny solar panel to keep things happy. But upsizing the solar to help cope with actually using the batteries is generally what people will reccomend. Start by taking a power audit of what you use and how you want things charged. Do you run lights at night? Do you have a fridge that runs at night? Are you planning on adding these kinds of things? How long do you use the trailer when you do use it? A little 30W panel might be enough. Or a 100W might not keep up with future plans. But you have to know how much solar you are going to run before you pick a charge controller.

Two of my go to charge controllers are;
Basic: Sunkeeper SK6 (or SK12 depending on needs)
Fancy bluetooth phone interface super programable, can do other battery chemistry later if you choose for lighter, more powerful batteries stuff: Victron (and various sizes and interfaces)

 

[DiploStrat]

...

as above extending Absorb / CV hold time, but that's only while daily cycling

in storage just keeping topped up, keep on lower Float voltage only, in fact low end of the range on your GCs' datasheet.

...

Agreed. The long absorb stage is only critical to achieving a "full" charge and reducing the chances of sulfating. The conventional wisdom with lead acid is that they should be fully charged before storage. Once in storage, you need only a float or maintenance charge.

As you have not described your trailer and its actual use, it is a bit hard to be more specific.

N.B. If you go with Victron, spring for the bluetooth enabled Smart Solar as opposed to the less expensive Blue Solar. Again, don't ask how I learned this!

 

[67cj5]

Thank you all! This is extremely helpful. I really like the idea of using solar.

Any recommendations on a solid controller and solar panel combo. I would rather not break the bank, but don't want junk either.

I already have a large solar panel for when I'm camping. So just looking for a small one I can use in storage.

You might be better off buying the Victron Smart Solar 100/20 MPPT Controllor because if you want to add more/extra panels the 100/20 will future proof your setup for a long while,

Get a 100w/150w Panel from Amazon like EcoWorthy etc or any of the other brands out there, Just Make sure you buy A "Monocrystaline" Panel, and that should keep your batteries topped off as well as give you enough power to stay off grid for ever if you are just running a Fridge and lights and charging gizmo's etc,

A 150w panel can produce more than enough power for most Camping needs unless you are taking all your high wattage kitchen gadgets from home etc.

Hope that helps.

 

[backcountry birds]

Thank you. It's a fairly new teardrop build, but I bought it used so didn't discuss the setup with the vendor so am trying to learn what I need to know. It doesn't have an alternator. Had two 6V deep cycle batteries wired in parallel.

I'll have to read more about how to do a proper audit. I'm heading out to where it is stored today so I'll try to get the specific on the fridge which is the biggest draw by far.

Other than that I use a few lights at night just when cooking or working and occasionally the fan.

My typical trips is 3 days to a week. However, I used it for 3 weeks straight this past winter only charging it off my trucks alternator when driving and the solar panel it came with. It worked great and I never ran out of power, but it also was cool outside so not 100° days or anything.

The trailer has a built in voltage meter in the back galley that I checked to try to get an idea of how charged the batteries were, but was a bit of an inexact science.

The solar panel it came with is pretty large probably 100w, I'll check today. The solar panel has a box on the back that may be a built in controller I suppose, where you select battery type, read voltage, etc. I have to manually connect the solar panel to the batteries using pigtails and felt the setup was a bit large to leave out full time. It's a portable unit with a bag, not permanently attached to the trailer.

My thought was find a small solar trickle panel charger just for maintaining the battery that I could set on top.

I'm not against buying a good controller, but my batteries are stored in the front in a lock box so not sure exactly where I would mount it that would be accessible.... assuming it's not removeable.

Here is a photo of my batteries and how they are hooked up.

 

[67cj5]

Thank you. It's a fairly new teardrop build, but I bought it used so didn't discuss the setup with the vendor so am trying to learn what I need to know. It doesn't have an alternator. Had two 6V deep cycle batteries wired in parallel.

I'll have to read more about how to do a proper audit. I'm heading out to where it is stored today so I'll try to get the specific on the fridge which is the biggest draw by far.

Other than that I use a few lights at night just when cooking or working and occasionally the fan.

My typical trips is 3 days to a week. However, I used it for 3 weeks straight this past winter only charging it off my trucks alternator when driving and the solar panel it came with. It worked great and I never ran out of power, but it also was cool outside so not 100° days or anything.

The trailer has a built in voltage meter in the back galley that I checked to try to get an idea of how charged the batteries were, but was a bit of an inexact science.

The solar panel it came with is pretty large probably 100w, I'll check today. The solar panel has a box on the back that may be a built in controller I suppose, where you select battery type, read voltage, etc. I have to manually connect the solar panel to the batteries using pigtails and felt the setup was a bit large to leave out full time. It's a portable unit with a bag, not permanently attached to the trailer.

My thought was find a small solar trickle panel charger just for maintaining the battery that I could set on top.

I'm not against buying a good controller, but my batteries are stored in the front in a lock box so not sure exactly where I would mount it that would be accessible.... assuming it's not removeable.

Here is a photo of my batteries and how they are hooked up.

View attachment 659478

I can't make out whether they are hooked up to produce 12v @75Ah or 6v @150Ah ??,

If you have a 100watt Panel that will work finea and it can produce around 5.56Ah per hour so to start off with it will do fine,

The little box on the back of the panel is normally just a junction box and if it is Don't mess with it, Ok.

Do you have a picture of the little box on the back of the panel ??

 

[backcountry birds]

I can't make out whether they are hooked up to produce 12v @75Ah or 6v @150Ah ??,

If you have a 100watt Panel that will work finea and it can produce around 5.56Ah per hour so to start off with it will do fine,

The little box on the back of the panel is normally just a junction box and if it is Don't mess with it, Ok.

Do you have a picture of the little box on the back of the panel ??

I'll take a picture today and get the exact model. My understanding is it's a 12V system as they are wired in parallel. That's certainly what my meter in the back says!

 

[67cj5]

I'll take a picture today and get the exact model. My understanding is it's a 12V system as they are wired in parallel. That's certainly what my meter in the back says!

Cool,

Well I would disconnect the Vehicle charging and get a Victron Smart Solar 100/20 MPPT charge controller and hook the panel and the batteries to it, Then it will be putting in power from sun up to sundown,

With the Victron Smart Solar 100/20 MPPT charge controller you can set up what you want it to do from your Smart Phone as well as see the condition of the battery charging as well as how much power the panel has put out as well as Ah and Volts and a whole heap of other stuff so they are really worth buying and you can set them up to suit any type of Battery Tech.

 

[Joe917]

2X6volt batteries in series are 12 volt .