Upgrading my camper questions

DanielForrest

New Member
Joined
Jan 21, 2021
Messages
12
Hey guys!

First off, I love you guys. I appreciate all the thoughtfulness and help that you guys give to everyone. Thank you all for your time.

I have a 1990 Terry 30 foot camper. All original electronics. Fuse/distribution box, 120v plugs, 12v lights, shore power extension cord, and there’s a converter that charges the 12v battery when plugged into shore power. It is plugged into its own 120v plug and when it gets power, it runs the 12v system, and charges the battery. (Right?)

When I bought the camper, someone wired in an inverter, direct to the battery and put it inside the trailer. When I got the trailer parked on my property, I added three 100 W 12 V solar panels, and 2x 6 V golf cart batteries and a PWM charger. It’s a Morningstar PS30 older gen, this one: https://cdn.shopify.com/s/files/1/1...15-Straight-Main-Fr_3_grande.jpg?v=1523042233 Works fine.

I recently built a 280ah lifepo4 battery with a daily BMS. Picture attached. And I want to replace my golf cart batteries with it.

Q#1 can I use my existing pwm charge controller or should I get a mppt charge controller for my new lifepo4 battery? My panels are old and I’d like to upgrade soon, so I assume getting a mppt would be a good idea.

Q#2 main question; Can I hook up my inverter to my existing power system such that my existing 120v plugs will work off my inverter? (Instead of just the 2 plugs on the inverter itself)

Q#3 If I CAN hook my inverter to my existing 120v plugs, what do I do so that the plug that my 12v charger/converter is plugged into, doesn’t start up and attempt to charge the 12v batteries that it would be being powered from?

If shore power is plugged in, or my generator is running, the battery would be charging via the 120 to 12v converter. But if shore power/generator is not plugged in, and my 120v plugs would be battery powered through the inverter, what can I do to stop the 120 to 12v converter/charge from attempting to essentially charge the battery from itself?

Is there a work around? Would I need to rewire my distribution box / power system with newer components?

As always, thank you all for any advice or ideas.
 

FilterGuy

What, me worry?
Joined
Nov 26, 2019
Messages
4,710
Location
Los Gatos CA
Q#1 can I use my existing pwm charge controller or should I get a mppt charge controller for my new lifepo4 battery? My panels are old and I’d like to upgrade soon, so I assume getting a mppt would be a good idea.
It depends on the flexibility of the old PWM controller, If you can set the charge voltage to an acceptable level and make sure there is never an equalize cycle, you should be OK..... But getting an MPPT would be a good move.
Q#2 main question; Can I hook up my inverter to my existing power system such that my existing 120v plugs will work off my inverter? (Instead of just the 2 plugs on the inverter itself)
Yes but: If the shore power plug goes to the same 120V, you must add some type of transfer switch between the two. *Never* let the inverter output and the shore power get hooked together.... Well.... you could do it on the 4th of July for a fireworks display! 🙂
Q#3 If I CAN hook my inverter to my existing 120v plugs, what do I do so that the plug that my 12v charger/converter is plugged into, doesn’t start up and attempt to charge the 12v batteries that it would be being powered from?
You need to move the inverter AC input to before the transfer switch on the shore power.

It sounds like you might be planning on upgradding the panels and charge controller. You might want to also consider upgrading the converter to an All-in-one inverter-charger-mppt system. Your shore power, batteries and solar would plug into it and the trailer AC would be powered by it. (And it will charge the batteries when on shore power)
 

chrisski

Solar Boondocker
Joined
Aug 14, 2020
Messages
2,679
Q#2 main question; Can I hook up my inverter to my existing power system such that my existing 120v plugs will work off my inverter? (Instead of just the 2 plugs on the inverter itself)
For my RV, my inverter is plugged into the Shore Power. This will only provide 15 amps of power.

My RV also has an option to hardwire the inverter to the RV, and that would get me 20 amps of power. I did not hardwire it.

I did wire the solar 12 volts from the new battery bank so that it would attach to RV 12 volt power.
Q#3 If I CAN hook my inverter to my existing 120v plugs, what do I do so that the plug that my 12v charger/converter is plugged into, doesn’t start up and attempt to charge the 12v batteries that it would be being powered from?
Yes it does what you said. I trip the converter circuit breaker to shut it off. With no Circuit breaker, I would recommend unplugging the converter. I did forget to trip the circuit breaker once while the inverter was powering the system and I used 700 -1000 watts of power and the 12 votl self resting circuit breakers were going off.

Overall, I think my extension cord from the inverter into the shore power is a temporary solution. I'm getting a higher voltage battery and bigger inverter and plan on hardwiring to something like a transfer switch.
 

DanielForrest

New Member
Joined
Jan 21, 2021
Messages
12
It depends on the flexibility of the old PWM controller, If you can set the charge voltage to an acceptable level and make sure there is never an equalize cycle, you should be OK..... But getting an MPPT would be a good move.

Yes but: If the shore power plug goes to the same 120V, you must add some type of transfer switch between the two. *Never* let the inverter output and the shore power get hooked together.... Well.... you could do it on the 4th of July for a fireworks display! 🙂

You need to move the inverter AC input to before the transfer switch on the shore power.

It sounds like you might be planning on upgradding the panels and charge controller. You might want to also consider upgrading the converter to an All-in-one inverter-charger-mppt system. Your shore power, batteries and solar would plug into it and the trailer AC would be powered by it. (And it will charge the batteries when on shore power)
An all one sounds like a wise idea. Any Recommendations on brand or model? Thank you Filter Guy!
 

DanielForrest

New Member
Joined
Jan 21, 2021
Messages
12
For my RV, my inverter is plugged into the Shore Power. This will only provide 15 amps of power.

My RV also has an option to hardwire the inverter to the RV, and that would get me 20 amps of power. I did not hardwire it.

I did wire the solar 12 volts from the new battery bank so that it would attach to RV 12 volt power.

Yes it does what you said. I trip the converter circuit breaker to shut it off. With no Circuit breaker, I would recommend unplugging the converter. I did forget to trip the circuit breaker once while the inverter was powering the system and I used 700 -1000 watts of power and the 12 votl self resting circuit breakers were going off.

Overall, I think my extension cord from the inverter into the shore power is a temporary solution. I'm getting a higher voltage battery and bigger inverter and plan on hardwiring to something like a transfer switch.
Thank you for the input Chrisski 👍🏼
 

FilterGuy

What, me worry?
Joined
Nov 26, 2019
Messages
4,710
Location
Los Gatos CA
An all one sounds like a wise idea. Any Recommendations on brand or model? Thank you Filter Guy!
Wow..... that all depends on your power needs and your budget.

Will seems to like the MPP line of units and they are reasonably low cost.

If you have money to spare, SolArk has some great units...but they are probably overkill for you (Full 240V Split phase)

Victron has recently released some all-in-ones but I know nothing about them and they will be expensive. (If victron has something that fits your needs, you can be sure it is a good unit... just very expensive)

Growatt seems to be popular, but I have seen enough bad comments on the forum that I would stay away from them.
 

12VoltInstalls

Photon Sorcerer
Joined
Jan 18, 2021
Messages
1,944
Location
Vermont
main question; Can I hook up my inverter to my existing power system such that my existing 120v plugs will work off my inverter? (Instead of just the 2 plugs on the inverter
So if you use the RV 30A cord to plug into the:
1) inverter or
2) the generator or
3) 120V shorepower
then a transfer switch isn’t needed. Power can’t cross… that’s fine imho. I haven’t unplugged from my inverter for three years+.
Is there a work around?
For the converter only I’d be asking if you need it at all. If I’m reading this correctly you want an AIO unit. I’d just unplug the converter but maybe your just replacing the 300W? Or upgrading to 800W or something more?
If you need AC cooling power, I’d consider hardwiring the inverter to the existing breaker box and adding a small breaker panel for the AC unit, using the shorepower cord to feed that only with maybe a 20A duplex outlet from that shorepower panel for whatever down the road.

If this is illogical to you don’t do it, but that would be my approach.
 

Sirtate

New Member
Joined
May 27, 2021
Messages
21
Check out one of these... ($100 on Amazon)
it will automatically switch between the inverter and shore power (or a generator if it's using the camper's shore power cord)
when it is using the inverter, it will cut power to one circuit. (sometimes an A/C unit, or I use it to de-power the 12v converter/Batt Charger)

it isn't instantaneous, so your clocks may not remember the time, but it takes less than a second to switch over.
 
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