Community Forums

**CountryFit** · 02-25-2018, 09:37 AM

i have a magnum 2800w inverter/charger onboard, it works great! but there is one short fall - when i am charging my toad, about 140a draw lasting for 5 hours for a full charge. during the time we can't use induction cooktop or microwave, or the inverter will enter fault.

now i am thinking of installing a simple inverter - just the inverting function, 2000w pure sine wave. let it handle the interior power loads - tv, fridge, kitchen stuff, etc, and leave the 2800w magnum to ev and a/c exclusively (one at a time).

on amazon, there are a lot of those simple units, like aims, simplex, and so on, for $200-400.

does anyone have hands on experience on those to share? appreciated!

MisterT · 02-25-2018, 10:44 AM

this may be an elementary solution, but have you tried using the SHORE button to limit the draw for the vehicle Charging when you want to use one of the other items?

if that is not a working solution, it seems that a secondary Charger would be better suited for the vehicle charging itself, versus using the Inverter/Charger that's already onboard and designed and well suited for the RV. I would think wiring/adding a secondary dedicated charger would be much easier.

**CountryFit** · 02-25-2018, 11:12 AM

Thanks Mr T. The SHORE button is to limit the incoming shore/generator power, but in my case, 1) I am off shore power, and generator is not involved; 2) it inverts to 120v to satisfy the loads. SHORE button may not work well for me.

EV and/or A/C loads are heavy, especially A/C start-up is demanding, 2800w is right on the limit. If I were to get the 2nd inverter for these two, I would need it to be equal or greater than 2800w. That would be a major upgrade, and my space won't fit. An easy 2000w inverter should meet all of my other demands fine (my coach came from factory with a 2000w MSW inverter I later upgraded to Magnum 2800w PSW).

vsheetz · 02-25-2018, 11:23 AM

Why not add a inverter just for charging the EV? Something like a 3000w unit. Would not require any changes to the existing coach setup.

**CountryFit** · 02-25-2018, 11:37 AM

Quote:

Originally Posted by vsheetz

Why not add a inverter just for charging the EV? Something like a 3000w unit. Would not require any changes to the existing coach setup.

Hi Vince,
A couple of points I am thinking -
1) 3000w Magnum would cost $1600 while 2000w easy inverter is merely like $200-400 (but I should have been sober "you get what you pay for"

).
2) Those 2000w PSW inverters are typically small. I can put one in my battery bay easily, along side with the existing inverter.
3) Connections would be very easy - I just need to move "Leg 1" from existing inverter to new inverter; everything else will be as-is. My "Leg 2" is now connected to A/C and the EV charge socket.

But now you open up a good question - maybe I should look at 3000w inverters. Some might be with a small footprint too. Good idea

.

twinboat · 02-25-2018, 11:39 AM

That's 700 AH, how much battery do you have ?
The Xantrex ProWatt 2000 has a low idle draw, <.5 amps, but check the output specs it my be less then 2000 watt output and its not hardwired.

Others that can be hardwired seem to draw more in idle mode.

MisterT · 02-25-2018, 11:44 AM

oh, wow, I didn't read your first post as if you were 'charging' your ev vehicle from your House batteries, while OFF shore or generator power.... that's a lot of draw on an inverter, at least while trying to do anything else... I now see what you mean!

so, your thought is that adding another Inverter to your current House batteries will provide the 'separate' 120v output to the ev vehicle... I think I see better now. You must have a LOT of battery amp hours.

You are not needing another Charger, but an Inverter... makes sense.

**CountryFit** · 02-25-2018, 11:45 AM

Quote:

Originally Posted by twinboat

That's 700 AH, how much battery do you have ?

my batt is li 1200ah.
when both ev charging (or a/c) and induction cooktop are running, it would be 300a draw. a short run for 30 minutes or so concurrently should be fine.

i just looked at my solar charge rate, 108a at this early time

.
(2 controllers, one @72a, another @507w).

Soppy · 02-25-2018, 12:06 PM

I would leave the Magnum inverter the way it is and install a second inverter just for EV charging. There would be less wiring to change and your coach would be able to operate as designed.

vsheetz · 02-25-2018, 12:21 PM

Quote:

Originally Posted by CountryFit

.

But now you open up a good question - maybe I should look at 3000w inverters. Some might be with a small footprint too. Good idea

.

Yes, I would upsize a bit in this category inverter in my experience their ratings are a bit optimistic and you will be pulling hard for extended period of time.

MisterT · 02-25-2018, 12:34 PM

can you 'charge' the ev while towing it?

**CountryFit** · 02-25-2018, 12:48 PM

Quote:

Originally Posted by MisterT

can you 'charge' the ev while towing it?

i could. i had a very topic on it:
http://www.irv2.com/forums/f85/charg...gi-327358.html
have been looking for a low profile charge head but yet found one

**CountryFit** · 02-25-2018, 12:52 PM

Quote:

Originally Posted by Soppy

I would leave the Magnum inverter the way it is and install a second inverter just for EV charging. There would be less wiring to change and your coach would be able to operate as designed.

it'd be easier but there would be a short coming - can't cook while a/c on as both microwave/induction cooktop and a/c are on the same inverter.

BigBillSD · 02-25-2018, 01:02 PM

interesting. Your A/C in on the Inverter? I have seen it done, but it didn't know it was normal.

If you tow that 4 wheels down, the regen could be made to charge it while driving.