17 replies to this topic

[steve whiteside]

Hey everyone,

 

Ive got 400w of solar on the roof which generates about 250w max on a sunny day when the sun is overhead.  Im finding it is not enough and Im constantly sweating the battery levels.  I own a small quiet 1800w generator.  Im thinking of bringing it with me and a few hours a day trying to jam extra juice into my batteries as needed.  I see a Victron 30amp charger that looks just what I want other than it is too small.  

 

https://www.amazon.c...a2-8997e41410bb

 

then I see a larger one but the price jump is too much.  

 

https://www.amazon.c...M1DTDODKXX&th=1

 

Does anyone have charger to mount that is like thee first charger but at 50 amps?  If not I was thinking that conceivably I could buy two of the first chargers and use them in parallel.  

 

Thoughts?

 

steve

[Stan@FourWheel]

Not sure if something like this would work for your needs?  --    https://www.amazon.c...a2-8997e41410bb

NOCO makes charger for a lot less $ as well. Usually $200 - $300 range is very easy to find, depending on what you are looking for.

Edited by Stan@FourWheel, 26 September 2022 - 02:59 PM.

[craig333]

I take it you don't have the IOTA charger in your camper. With 400 watts of solar you should not be having an issue unless you have an unusual load (induction cooktop?). I'd suspect your charge controller or batteries. How many amp hours of battery do you have? What kind of controller? 

[steve whiteside]

I take it you don't have the IOTA charger in your camper. With 400 watts of solar you should not be having an issue unless you have an unusual load (induction cooktop?). I'd suspect your charge controller or batteries. How many amp hours of battery do you have? What kind of controller? 

Not sure exactly what you mean by IOTA charger.  I have the standard charger that was built into my FWC when I bought it new 2 years ago.  If I plug it into shore power it will gradually charge my batteries but not that quick.  Im looking to boost my level of charge within an hour or three, not all day of generator.  WRT my 2020 Grandby.    What I have added is one of these:

 

https://www.amazon.c...e?ie=UTF8&psc=1

 

and one of these:

 

https://www.amazon.c...le?ie=UTF8&th=1

 

also 2 Lion energy ~1.1 KWhr batteries for about 2KWhr capacity.  

 

I actually think my system is working as it should, although I am no expert at these things.  I noticed I generate about 1.5kwhr per day from my 400watts of panels.  

 

My 3 way domestic fridge, set on propane, pulls about 30-35 watts and never shuts off.  Ive got a separate "fridge freeze" that pulls about 40watts 8 hours a day as it cycles on and off.  Ive got a starlink system that pulls about 50watts for 2 hours per day- i keep it mostly off.  Misc charging of computers and USB fans at about 200watts for 2 hours.  I have a coffee maker that pulls 1.3KW for 10 minutes when it is on.  The overhead fantastic fan at about 20watts when used in low.   The math seems to make sense WRT electrical in and out, yes?.  The big pig is the 3 way fridge since it never gets cold enough to shut off and 30w x 24 hours a day is about 800whr which is about 1/2 my total capacity for the day.

 

Stan, thanks for the suggestions above.  I was thinking to hardwire in a charger but maybe that NOCO is a better solution.  I dont need a charger at every season but when it is hot - I need fans + extra 12 v fridge etc...

 

steve

Edited by steve whiteside, 26 September 2022 - 05:59 PM.

[craig333]

I'm not sure what a 3way pulls on propane but its a tiny amount. Either its really on 12v or something is wired wrong.

[PaulT]

If your Iota is the standard 30 Amp with IQ4 for lead acid, it should charge  in bulk phase up to what would be the 80% charge mark for lead acid before dropping to the absorb phase at reduced current.  It would remain there for several hours to finish off the lead acid battery and drop into the float phase.  These are not ideal for LiFePO4 batteries.

 

Instead of adding a NOCO external charger, consider replacing the existing Iota with a IOTA having a LiFePo4  IQ4 smart controller or one of the other RV battery chargers that supports LiFePO4.

 

This is nothing against the NOCO. I have their 16, 7.2, 3.5, and 1.1 chargers for different applications. I like them,  but recommend simplifying your charging system rather than making it more complicated. 

 

With 400 watts of solar, you should have no problem keeping your batteries charged.

 

Paul

[steve whiteside]

I'm not sure what a 3way pulls on propane but its a tiny amount. Either its really on 12v or something is wired wrong.

Well 2 things.  1) the 3 way fridge when running off of propane still has some sort of noise that sounds like a fan running.  This is not the FWC reefer fan that is on top of that if used.  2) I turn everything thing else off in the camper and I get 30w-35w consumed going somewhere  - it seems like to me the domestic 3 way.  Maybe there is some house loads on top of that but all I can figure is most of that 30-35watts is for the dometic.  

 

Has anyone got data on how much a dometic 3 ways consumes of 12v when running on propane?  

 

steve

[ljheptig]

Here is an article you can read on 3-way fridges, I don't think they use 12-volts to cool while on propane

 

What is a Three-Way Fridge? How to Use. - Classic Motorhome Owner

[Vic Harder]

If you want to make sure the fridge is what’s drawing power on propane, why not just pull the fridge fuse?

[steve whiteside]

If you want to make sure the fridge is what’s drawing power on propane, why not just pull the fridge fuse?

Now that is a good idea!  Let me wait till later in the day when things are really cooking and I will turn everything off but the fridge.  Then pull the fuse.  I agree with others and Craig that 30w continuous seems like 3x too much for the fridge on propane.  

 

steve

Edited by steve whiteside, 27 September 2022 - 02:01 PM.