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Recommendations for 40ft. Fifth Wheel System

j_a_wolfe

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Looking for recommendations for parts to build and install a solar system for my RV. I'd like enough storage to run the usual suspects when boondocking for at least 2 days without sun. I would like to be able to charge the battery bank from pv source or 125VAC. I would prefer to build the battery bank from cells and add the necessary controls and protections myself. I'm an absolute novice to pv systems but I held a Journeyman's Electrical license. Cost is an issue but not the primary issue. I'm looking for reliability and longevity as well as a little flexibility for upgrades down the road.
Can anyone help a brother out?

Jim
 
Need to know what your power consumption is before this project can start.

You can estimate this by rated power consumption and usage time per day or you can straight up hook up a meter and measure what you use for that two days (or more).

Well an air conditioner be used? TVs? Vent fans? Lighting?
 
The system energy audit and sizing spreadsheet that is in the Resources section of the forum is a great place to start. You need to know how much juice you pull so you know how much battery and PV to put in.

 
Looking for recommendations for parts to build and install a solar system for my RV. I'd like enough storage to run the usual suspects when boondocking for at least 2 days without sun. I would like to be able to charge the battery bank from pv source or 125VAC. I would prefer to build the battery bank from cells and add the necessary controls and protections myself. I'm an absolute novice to pv systems but I held a Journeyman's Electrical license. Cost is an issue but not the primary issue. I'm looking for reliability and longevity as well as a little flexibility for upgrades down the road.
Can anyone help a brother out?

Jim
Mine is a very small 7 x 14 (compared to yours) but my goals were similar - e.g. max Solar + DIY battery.

Suggestions:
1) Start by absolutely maxing out your solar panel situation and this will give you the max incoming power from Solar. I was able to fit 4 x 300w panels.
1628954884571.png

2) DIY Battery - I went with a 14s88p 3000mah 18650 cells managed by Batrium. Its 260ah @ 48v which yields 14.5kwh. **Gives go 2 days (10kwh of consumption) at 69% DOD.
Used water tank heat pads + 1/2" rubber as shock absorber underneath them. <32F they can be heated with about 65w of power.
The 14 packs (of blue cells) you see here on top of cabinets take up 90" long and 15"'ish wide and maybe 5" high. LifePO4 might be a better choice but the will take a bit more room for the same kwh storage as 18650.
The battery is about 120lbs overall.
Batrium (very robust for travel / temps) is the BMS.
1628954995351.png

3) Went with a MPP Solar 3048LV (48v @ 3000w) all-in-one. Once you size your useage - MPP Solar makes a wide variety. For larger power its better if you to 48v battery than 12v or 24v. No problems in 1st 100miles - but someone pointed out that hot-glue could be used to help secure any components inside that might wiggle when trailer bounces... OR look for travel certified equipment as a consideration.
1628955352361.png

4) Wired the 120v + 12v distribution panel so that with a twist of a rotary switch it's powered either by
a) come from the MPP Solar / solar system
OR
b) just skip the MPP Solar and use external 120v. This will let me turn off MPP Solar / batteries for long term non-use.
1628955528765.png

5) Went with Senville Heat-Pump for Heat & Cool,. So much better than traditional RV roof ACs. 100% quiet, soft-start, efficient on power. Don't know your situation - but I've become a fan of heat-pump technology for heat-cool :)
It takes 4-6kwh / 24hrs with 9000BTU heat-pump + 1" insulation to maintain 80F/27C up to 105F/40C and 25F/-4C low in this 98sq ft space.

6) Have an onboard, propane feed generator - tied in with automatic transfer switch on the input side. My estimations are that 2 x 30# propane tanks will give me 'about' 50kwh of power.

Overall - with 1200w of flat panels and summer sun - I'm generating 5-6kwh / day which is enough to run the 9000 BTU heat-pump 24/7 and keep the interior at 80F and 4.5cuft refrigerator cool and lights on etc.

Look forward to hearing about what you decide - please let us know with pics :)
 
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Following, collecting parts and information. I will be installing in a 2015 Redwood 38RL.
Attempting to fit 3KW solar on the ample rooftop.
Have 16S 320ah 3.2v LiFePO4 cells to start
Looks like all Victron for me, everything just seems to play well together and they have some nice all in one options
to tie shore, generator, inverter together.
 
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