Feedback on augmenting current setup please

[MisterMark]

Hello!

Another newbie with solar here. Also a newbie with RV's but I'll save that for another forum.

I have a few questions even though I am fairly certain everything is ok with my plans - I thought I would seek opinions of those in the know because as much as I have researched and learned, I am no expert and simple yet costly mistakes are easily made and best avoided.

Here goes.

There was already a system in place with this RV, a 150 watt panel, a 30 amp PWM charge controller and a 12v garden tractor battery (I think about 20 Ah). This has been sufficient for the few led lights and occasional furnace use (blower motor). Things have changed and I now need an inverter and likely a lot more battery power to bank on as I will be using a computer or laptop with all the accessories that come with it (HD, printer, iPhone charger, iPad charger (monitor if I go with the mac mini). Maximum use looks to be around 175 watts at any time, although it seems likely I will usually be using much less than that for the most part. I plan to limit the usage to around 3 hours a day.

I was told by the original owner if I was to get an inverter to plug it into the last two slots available on the charge controller.

A lot of reading seems to indicate this is the wrong way to go as the inverter should be connected directly to the battery.

I decided upon a 300 watt Go Power pure sine inverter, and am almost ready to pull the trigger on a battery...I've been looking a deep cycle with 105 Amp hours (http://www.canadiantire.ca/en/pdp/mo...-0103199p.html)


I plan to run the inverter directly to the battery (20A fuse in between), and connect everything else to the battery the same way as it currently is (solar panel > charge controller > 20 A fuse > battery)


Am I right to assume the inverter should go direct to battery?
Am I also right to leave the existing wiring for the solar panel and charge controller?
Any major pitfalls with battery choice or anything else here?


I am aware that the sun is getting less and less...so I will likely be investing in a battery charger as well...any suggestions?

Thanks for looking!

[Mike90250]

Inverters should be connected to the battery terminals (with a fuse). What size fuse comes / is recommended for the inverter? A 20A fuse blows at 250 watts !
A 30A fuse and 8 ga wire would be the minimum I would recommend.

Look into a electronic Battery Isolator to allow the vehicle alternator to charge the battery.

[MisterMark]

Great, thanks for the feedback!

I used 20A based upon what I saw in the manual, but admittedly was bit confused as it says (about halfway down the page section 4.3.2 https://gpelectric.com/wp-content/up..._SW150-300.pdf - "

1. Use the included 4 feet (1.22 m) of #10 AWG wire and Anderson Power Pole connectors.
   
   Attach a 40 A or 20 A when using 24 volt version fuse in line with the positive conductor as close to the battery as possible. Extending the included cables may result in excessive voltage drop. Increase overall cable gauge to the next larger standard size for every 3 feet (0.91 m) extended and do not exceed 10 feet (3.05 m) total inverter cable length.
   
   For example: 10 feet (3.05 m) cable = 6 gauge wire "

I'm guessing this means 40A for 12v and 20a for 24v. Of note they have included 10 gauge connectors which I will use and be sure to install a fuse without lengthening the wire.

Battery Isolator is something new for me to learn. I'm guessing I would install this to the engine compartment, however the current system is standalone from the engine entirely so I would need at least ten feet of cable to get to the solar battery in the rear of the unit, and am wondering if this is feasible considering voltage drop/length of cables. Definitely the way to go though if possible, I guess I had initially ruled it out due to my experiences with older vehicles such as this and dead batteries from using too much light!