Just switched out our batteries (mismatched group 27's) with a pair of Duracell (Deka) group 31's (matched). I have a Renogy 100 watt solar suitcase. I understand that it won't be enough alone to charge the batteries. I would like to add something else that can be portable to boost the solar charging. I don't want to permanently add anything to the roof right now. We don't do extensive dry camping. We will be going to the outer banks for a week next month and staying at a NP campground. We do have the onboard generator and can run it when we can to charge the batteries if needed and let the suitcase work during the rest of the time. Can I get another solar panel from Renogy (100 watt) and new charge controller (20 or 30amp), disconnect the old charge controller (10amp) on the suitcase and run the suitcase panels (2x50watt) and 100watt panel to the new charge controller and then to the batteries using the alligator clips? Will 200watts be sufficient for the 2 group 31 batteries (105ah each)? I would ask about two different suitcases, but a single 100watt solar panel is half the price of the suitcase and the charge controller would not be enough I would imagine for two 100watt panels. Also another question. I've seen The Wynns use a solar suitcase and they just connected to a more permanent connector underneath their RV, instead of using the alligator clips. Anyone know what and where I can get these?

Search the web for anderson connector. Search parallel vs aeries panel connections and pwm vs mppt controllers. I would search solar panel sizes that will later fit on your roof. Get an idea of what sizes are available then cut out some cardboard and see what will fit on your roof. You want to try and not have the panels shaded by placing them too close to the ac unit etc but at times depending on how you are able to park some shading can occur. Try to work around that. It will save you from gathering a collection of parts if you can later move everything to the roof.

You will want something with less resistance than the alligator clips. If you use a 25' long 12 gauge extension cord, and switch out the ends with some twist lock fittings (so someone does not plug a 120 volt cord into your 12 volt battery system) you will be doing good. Also it will be quick plug and play, not needing to worry about hooking up the clips to the wrong terminals, or open the hood to plug in. Why not permanent install the system to the roof? It will add to the resale value a LOT. I would suggest a larger panel, that is probably less than $2 per rated watt. SunElec.com had a 140 watt panel on sale a few months ago for $229. It has a 12 volt nominal output (actual is about 21 volts open circuit, but will be 14-15 volts while connected to the battery and in full sun). I would recommend a $15 charge controller, PWM and check out this website, search for them, then click on free shipping, and list by price. Get a 20 amp version. Spend the majority of the money on solar panels, not the controller.AliExpress.comSay you have a $500 budget. You could spend 1/2 on a MPPT controller and 1/2 on a single 140 watt panel, or you could buy 2 panels and 1 cheap controller, and get a lot more power from the two panels!I made my own brackets from 2" angle aluminum at Home Depot. 3' long cost about $8 and makes 9 each 4" long brackets. Three holes 3/16" for #10 screws into the roof and 5/16" hole for a 1/4" bolt into the panel frame, and you are ready to bolt the panels to the roof. I mounted my panels so the frame is slightly under the panel.Here are some close ups of my panels mounted to my roof.This is the mount it is held on with three rivets into the frame, and then the bottom half is 6" long aluminum, with nutsert in the upper piece, bolt you can not see from the outside edge pointing inward.I ran #10 gauge UV resistant Romex (grey in color - at Home Depot in 25' long lengths or was it 50' long?) Each run is good for about 15 amps max. I ran it down the back of my refrigerator to the controller, then larger wire to the battery in the next compartment over from the controller.If you want to keep it portable, I would hook up a controller in a storage compartment and then run a short cord - say 3' long to a twist lock connector. Then connect a 25' long cord to the solar panel, with a mating twist lock cord end on it. When you want solar, set it up, and plug it in. Preferable to have a compartment with a factory installed cord cover in the bottom (like the sewer compartment has - I have one on each side of my Bounder near a basement enclosed 120 volt receptacle). I like that my roof mounted solar panels keep my RV battery full, while it is parked out in the parking lot, not near 120 volt power. The Co meter and propane detector together draw 0.8 amps, and can discharge by battery in about 6 days.Good luck!Fred.

A quick search on Amazon.com found these Anderson Connectors.Anderson connectorHere is a picture. We used them 20 years ago for electric forklift battery connectors, they are rated at upwards of 400 amps in our use.You can get them in ratings from 50 to 400+ amps. Good luck,Fred.

I too would get rid of the alligator clips in favor of Anderson Power Pole connectors. You could also use MC4 connectors which are used extensively on large solar panels to connect them together.There's no reason you can't charge your batteries with what you have if it keeps up with your needs. Sizing the solar array is more about how much power you're using than about how large your batteries are.Either way, more solar is generally better than less.You can certainly connect both solar "arrays" to one new charge controller.200 watts will probably only do about 11 or 12 amps unless you get an MPPT controller. You're 10 amp would probably be big enough in all but the most ideal of situations where you had perfect, bright sun on cool panels. Do you know if it will just limit itself to 10 amps or will the extra power burn it up?

Here is an example of a 50 amp. You may find it cheaper elsewhere.

Solar Questions | Good Sam Community

Almot
Explorer III
Jun 04, 2016
You left off the word battery, too.
"I have an additional 100 watt solar panel...300 watts total for 210amps total."

Some people here - I think - have degrees, but probably not too many are psychics :)
wbwood
Explorer
Jun 04, 2016
Almot wrote:
Battery capacity is measured in amp-hours. Not amps.
ok so I left off the word hours...geez

At least my math was correct, professor..
Almot
Explorer III
Jun 04, 2016
Battery capacity is measured in amp-hours. Not amps.
wbwood
Explorer
Jun 04, 2016
grizzzman wrote:
wbwood wrote:
westend wrote:
wbwood wrote:
200 watts will suffice for my two group 31's, correct?
Likely, but nobody really knows what your power usage is.

I have an additional 100 watt solar panel...300 watts total for 210amps total...we are only in the camper in the evening, not during the day....no inverter...all dc usage (fantastic fan, LED lights, maybe an hour or two of 12 volt tv usage, water pump fridge panel, etc)

A typo I assume. (210 amps) A. Its likely you know the answer. I have been doing more then you describe on 200 watts.....so....... :h

105 amps per battery x 2 = 210 amps
grizzzman
Explorer
Jun 04, 2016
wbwood wrote:
westend wrote:
wbwood wrote:
200 watts will suffice for my two group 31's, correct?
Likely, but nobody really knows what your power usage is.

I have an additional 100 watt solar panel...300 watts total for 210amps total...we are only in the camper in the evening, not during the day....no inverter...all dc usage (fantastic fan, LED lights, maybe an hour or two of 12 volt tv usage, water pump fridge panel, etc)

A typo I assume. (210 amps) A. Its likely you know the answer. I have been doing more then you describe on 200 watts.....so....... :h
wbwood
Explorer
Jun 04, 2016
westend wrote:
wbwood wrote:
200 watts will suffice for my two group 31's, correct?
Likely, but nobody really knows what your power usage is.

I have an additional 100 watt solar panel...300 watts total for 210amps total...we are only in the camper in the evening, not during the day....no inverter...all dc usage (fantastic fan, LED lights, maybe an hour or two of 12 volt tv usage, water pump fridge panel, etc)
westend
Explorer
Jun 04, 2016
wbwood wrote:
200 watts will suffice for my two group 31's, correct?
Likely, but nobody really knows what your power usage is.
wbwood
Explorer
Jun 04, 2016
200 watts will suffice for my two group 31's, correct?
wbwood
Explorer
Jun 02, 2016
Went ahead and just ordered a new 200 watt solar kit...
Almot
Explorer III
May 22, 2016
Darryl&Rita wrote:
MC4 connectors are garbage for repetitive connect/disconnect use.

By they way it's made, this is a possibility. Takes an effort to connect-disconnect at times, it feels like the prongs or something else will break any moment. Weather-proof performance is good though.

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