Want to add 200W Solar Panel to Factory Solar Package?

[acoleman43]

WJC That's awesome! Keep us posted. In my opinion it seems 200W panels is the way to go (unless you can afford and have room for 300W panels). They tend to produce more watts per sq/ft than 100W. But they have to fit on the roof. Also, If you're planning on keeping your inverter, make sure your charger (probably a converter/charger combo that is your AC/DC panel) is compatible with lithium batteries. If not, add another item to your list. If you end up with a multiplus, that would be your charger/inverter and you would disconnect/bypass your current charger....to the tune of about $1200.

TucsonJim you say you use about 130-140 amps on a normal day. That's not bad at all. What do you do to minimize load?

[TucsonJim]

WJC That's awesome! Keep us posted. In my opinion it seems 200W panels is the way to go (unless you can afford and have room for 300W panels). They tend to produce more watts per sq/ft than 100W. But they have to fit on the roof. Also, If you're planning on keeping your inverter, make sure your charger (probably a converter/charger combo that is your AC/DC panel) is compatible with lithium batteries. If not, add another item to your list. If you end up with a multiplus, that would be your charger/inverter and you would disconnect/bypass your current charger....to the tune of about $1200.

TucsonJim you say you use about 130-140 amps on a normal day. That's not bad at all. What do you do to minimize load?

My normal day is 10 minutes of drip coffee brewing, 5 minutes of microwave, and running the furnace a couple of times in the Arizona winter. The biggest load is running the 12V compressor refrigerator which draws about 65 amps a day. Most of the time, we're outside, so there's not much other useage other than a light from time to time.

BTW, I went with 100 watt panels because I could piece them into nooks and crannies on the roof.

Jim

[WJC]

Design is under control I think, the setup would look like this:


I did a quick spreadsheet to calculate adherence to limits:



The four panels that I calculated (in 2 panel series in a parallel array) were within limits for the wire and controller. I definitely have options for panel selection.

I also added a third panel in series and limits were ok except I would need a controller with a higher power limit

Will

[KSC_Travels]

I have 2 x100Ah LiFePO4 on order to replace a pair of flooded batteries. I have upgraded the charger to support LiFePO4.

Plan is to expand the battery bank beyond 200Ah going forward probably after the solar upgrade.

Nice!

Keep an eye on your cable/fuse/busbar ratings to/from new batteries and other components. Most 100Ah LiFePO4 batteries are capable of discharging all of their 100 Amps at once (x2 = 200 Amps in your case). So along with the other stuff you are planning I would suggest you also make sure you wire/fuse appropriately with the new batteries. A 200A short circuit is a significant amount of current with serious "smoke" (and safety) potential. I think most folks I have seen on here have gone with 00 to 0000 gauge cables for their setups.

Note: I haven't done any of this (yet)! Just passing along some of my own planning considerations and learnings from reading here (and elsewhere)... and helping you spend money

You can see some examples of Jim's cable sizing and protection in Post #13.

Cheers!

[WJC]

Thanks for the heads up on wiring. Batteries are currently connected with AWG 4 gauge wire to the inverter and shunt/buss bars. This should be OK for now (less than 3 m length) but will need to revisit if current draw starts to approach 100A.