โMar-07-2023 06:50 PM
โMar-10-2023 09:04 AM
Grit dog wrote:Nothing you say helps, but you are quite the comedian.
Hope this helps! Cheers!
โMar-10-2023 08:51 AM
โMar-10-2023 08:30 AM
StirCrazy wrote:That would be unusual. Many controllers will take up to 150vdc input. It's the output at 48v that might be a little more difficult to find.
I haven't seen a 30amp mppt that will take a 48v input,
โMar-10-2023 08:20 AM
โMar-10-2023 08:07 AM
โMar-10-2023 07:15 AM
afidel wrote:StirCrazy wrote:afidel wrote:
Personally I'd run the 12V stepdown converter into a 12V battery, either lithium or SLA. That way peak loads for the slide motors and compressor motor get taken up by the 12V battery and the 12V converter can just top that off. I know there are folks that team a couple of 12V stepdowns together to supply the loads, but it has to be much more stressful on the components in them than if there was a decent pool of ampacity there. Since you aren't actually using it for storage capacity a 50Ah 100A LiFePO4 would work great and they're like $160.
The big advantage of 48V is you can use a much cheaper MPPT controller since they're basically priced on output amps and 48V is 4x lower amps for the same watts. Wiring costs are also much lower since you get to drop down to wire gauges which are commonly available instead of double 0 or triple 0 cables.
but thats like I said, keep the battery side all 12 volt and use a MPPT charger (more expensive by the way not cheeper) and stack the panels to 24v. you could probably spend a little more and get one that will handle a 48 volt input, but I don't know if it would be worth it for most people in a rv setting. the one problem you do run into with a all series run is shading.. in a home system where you have solar out in the open it isnt an issue, but for a lot of camping it is. I guess you would have to look at the price increase to a 48v input MPPT VS the upgraded wire size for the 24V setup. wiring is going to be an issue anyway you look at it with the size he wants to run so it will have to be resized.
edit, I did look at my brand and a MPPT charge that wil handle a 48V input is only 160.00 more canadian (one size biger) so it will be tight as to which way is cheeper, but I would go that way myself four 24V panels in a 48V series / parallel set up get the smaller wire size and you get some protection from shading.
What I was saying is that a 30A MPPT can put ~1,500W into a 48V system, to accomplish the same with a 12V battery system requires a 120A MPPT controller which are 3-4x the cost and several times the size and mass.
โMar-10-2023 07:01 AM
pianotuna wrote:
StirCrazy SiO2 make lifepo4 look bad when truly large draws are needed. So why would I get a battery that has essentially a "limiter" (otherwise known as a BMS) on it at 1 C????
โMar-10-2023 06:57 AM
CA Traveler wrote:
StirCrazy Serial panels with bypass diodes which all large panels have is more shade tolerant than parallel panels and this is especially true when there is shade like a A/C involved. It's a factor but not necessarily hugh.
I wanted a more efficient system but adding another panel may be a better price performance option.
For me 1500W solar systems "require" the larger 60/72 cell panels and MPPT. 12V panels for 1500W is certainly possible but last time I looked more panel cost and more panel square footage.
โMar-09-2023 08:19 PM
2oldman wrote:Cptnvideo wrote:I don't know what the OP is trying to do. He's been a bit vague.
I don't see any benefit to adding components (that can possibly fail) to convert back to 12 volts when a 12 volt system is adequate for what the OP is trying to do.
โMar-09-2023 02:08 PM
โMar-09-2023 01:57 PM
โMar-09-2023 01:16 PM
โMar-09-2023 11:37 AM
Cptnvideo wrote:
Old man, I didn't say anyone was incorrect. If you're quoting me, please quote all of the post.
I don't see any benefit to adding components (that can possibly fail) to convert back to 12 volts when a 12 volt system is adequate for what the OP is trying to do.
My 12 volt setup works very well in my 50 amp RV and the OP is buying a 30 amp RV.
โMar-09-2023 09:44 AM
Cptnvideo wrote:I don't know what the OP is trying to do. He's been a bit vague.
I don't see any benefit to adding components (that can possibly fail) to convert back to 12 volts when a 12 volt system is adequate for what the OP is trying to do.
โMar-09-2023 09:20 AM