Go Back   Thor Forums > Thor Tech Forums > Modifications and Updates
Click Here to Login
Reply
 
Thread Tools Display Modes
 
Old 03-30-2017, 09:39 PM   #1
Member
 
Brand: Thor Motor Coach
Model: ACE 29.3
State: Florida
Posts: 87
THOR #6007
Can I install an 2000 inverter w/o upgrading my 2 standard batteries?

Buying a 2017 ACE 29.3. Considering having a 2000 watt, pure sine inverter installed. Is it possible the 2, standard batteries which are in he unit will work with the inverter?... we are considering getting a Zamp solar unit to use as part of the system.

A dealer says the standard batteries would be ok...at least in he short/medium term. I see normal size AGM batteries are available but don't know exactly what type I would need and what benefit I might see.

Comments would be appreciated. Thanks.
__________________

__________________
David1912 is offline   Reply With Quote
Old 03-30-2017, 10:06 PM   #2
Senior Member
 
Brand: Still Looking
State: Texas
Posts: 3,867
THOR #2121
I think your dealer is right, but it depends greatly on your expectations.

For starters, just because anyone installs a 2,000-Watt inverter doesn't mean they will use it at that high a capacity, right? You may be going higher-capacity now so you don't have to replace the inverter later.

If for example you mainly use the inverter to power TVs that may not pull that much power, then the batteries will do almost as good as if you install a smaller inverter. Oversizing inverter may mean lower efficiency at very low power rates, but that's not likely a great difference in itself.

Also if you use the 2,000 watts (or less) for a minute or two at a time, two good batteries will be OK -- although not ideal. It's only if you expect to run 1500-watt appliances for many minutes at a time that you will drain batteries too quickly.

Longer term you'd want to look at more battery capacity, but that also depends on your planned use.
__________________

__________________
Chance is offline   Reply With Quote
Old 03-30-2017, 10:44 PM   #3
Senior Member
 
Brand: Thor Motor Coach
Model: Hurricane 31S
State: Texas
Posts: 1,321
THOR #6411
Typical size 24 flooded batteries are rated at 80 AHr so two in parallel would be 160 AHr. For max battery life, batteries should not be discharged any lower than 50% of their capability or in your case 80 AHr. A 2,000 watt MSW inverter needs to draw 170 amps from the batteries to output 2,000 watts (16.7 amps @ 120 volts). So on a good day, you might be able to draw 2,000 watts out of the batteries for 28 minutes. I have two size 24 flooded batteries and a 1,000 watt inverter. Running the frig on propane, watching one TV with DirectV receiver will deplete the battery bank to 50% in about 6 hours.
__________________
Jim & Roy Davis
2016 Hurricane 31S
1961 Rampside in tow
Beau388 is offline   Reply With Quote
Old 03-30-2017, 11:59 PM   #4
Senior Member
 
Brand: Still Looking
State: Texas
Posts: 3,867
THOR #2121
Unfortunately, according to Peukert Law, when these types of batteries are discharge fast, they provide much less energy. As an example, a typical 80 Amp-hour battery is rated at 20-hour rate. That means only 4 Amps X 20 hours.

However, if that same battery is forced to operate at say 80 Amps, it will not be able to run for an hour to make the same 80 Amp-hours. The actual battery capacity at these high-amp rates is much less.

Short of having lithium batteries that handle high currents better, the best approach with lead-based batteries to supply high power is having more battery bank capacity.
__________________
Chance is offline   Reply With Quote
Old 03-31-2017, 12:23 AM   #5
Member
 
Brand: Thor Motor Coach
Model: ACE 29.3
State: Florida
Posts: 87
THOR #6007
Thanks....we would be thinking of getting by from say 7 pm through the next morning.....tv, led lights, possibly small fan, coffee grinder and coffee maker in morning....possibly microwave for 2 minutes....
__________________
David1912 is offline   Reply With Quote
Old 03-31-2017, 12:24 PM   #6
Senior Member
 
Brand: Still Looking
State: Texas
Posts: 3,867
THOR #2121
Quote:
Originally Posted by David1912 View Post
Thanks....we would be thinking of getting by from say 7 pm through the next morning.....tv, led lights, possibly small fan, coffee grinder and coffee maker in morning....possibly microwave for 2 minutes....
I would worry about the coffee maker and microwave the most. That's a lot different than TVs, small fans, or LED lights. I'm not familiar with power requirements of coffeee grinders, although I expect they are not as high or used as long.

Anyway, based on minimal research I've done to engineer the system I want, it appears there is significant variation in how some flooded batteries handle high current requirements. While I hardly take everything I read on internet as gospel, there seems to be general agreement that the Peukert number has a wide range of values for flooded batteries.

In the graph below used as an example (let's assume it's accurate), a 120 Amp-hour battery can be reduced to as low as 20 Amp-hours, and that's at only 50 Amps or so. If taken up to 120 Amps (the equivalent of taking two 80 Amp-hour batteries to at least 80 Amps each to power a 2,000-watt inverter under heavy load), then we may see much less than even 20 Amp-hours; and that's from a battery rated at 120 Amp-hours. It's possible that in some applications the battery bank may only be able to provide 10% or so of rated capacity.

This is why increasing battery capacity can be so important -- not only do we start with more Amp-hours, but the specific discharge rate will be much lower, thereby allowing batteries to deliver a greater percentage of their rated capacity (which is at a very slow 20-hour rate, not extremely fast 4-minute rate).

Chart context is from this site:

BU-503: How to Calculate Battery Runtime – Battery University

By the way, since you mentioned going to AGM batteries, I suspect you already knew most of this. I'm posting in case it helps others who kill their batteries much faster than they expected and can't figure out why.
Attached Thumbnails
Click image for larger version

Name:	IMG_3903.JPG
Views:	133
Size:	39.9 KB
ID:	4363  
__________________
Chance is offline   Reply With Quote
Old 03-31-2017, 12:29 PM   #7
gmc
Senior Member
 
gmc's Avatar
 
Brand: Thor Motor Coach
Model: Hurricane 32A
State: Florida
Posts: 1,661
THOR #2829
Most of that can avoid the inverter...
LED lights should already be 12v... I installed a couple of 12v fans (kitchen and bedroom)... and a 12v TV in bedroom.
If we really need the microwave or DW wants her coffee in the morning - starting the genny for a few minutes is a much cheaper solution.
Can easily make a long weekend on the 2 coach batteries.

I've stayed away from the inverter route (other than a small portable that I haven't used in 3 years...) Adding battery capacity may - and changing battery chemistry will - require a new converter/charger in addition to the batteries. The cost is higher than the benefit in my mind...

Now having a residential fridge changes the equation for benefit - but I haven't gone there yet...
__________________
Greg
Not yet retired...
Florida (Michigan transplant)
2014 Hurricane 32A
2000 Infinity (previous)
gmc is offline   Reply With Quote
Old 03-31-2017, 05:48 PM   #8
Senior Member
 
rickymac's Avatar
 
Brand: Thor Motor Coach
Model: 2014 Windsport 34f
State: Alabama
Posts: 275
THOR #6507
Amps & Batteries

Guys or Gals,

I wish I understood batteries and amps like some of you do. I really appreciate your guidance and comments (Education).

I teach a Sunday School Class every week. When I have a difficult time understanding some part of the Bible, I go to the children's lesson on the same adult lesson that I am teaching and all of the sudden everything becomes clear.

I guess I need to find a cartoon of RV electronics.
__________________
Rick & Jan
with Lilly (Most Active Dog) & Mattie (Laziest Dog in the World)
Wally: 2014 Thor Windsport 34f
Toad: (Wally One) 2014 Fiat 500L Trekking (4 Down)
"Welcome to our front porch"
rickymac is offline   Reply With Quote
Old 03-31-2017, 06:24 PM   #9
gmc
Senior Member
 
gmc's Avatar
 
Brand: Thor Motor Coach
Model: Hurricane 32A
State: Florida
Posts: 1,661
THOR #2829
If you grasp one rule/formula about electricity:
Watts = Volts * Amps
it explains a lot - and why I think there is often surprise about how long (or short) a battery bank will last in an RV between charges...

If you want to power 1000 watt appliance on 110AC it takes just 9.09amps... (adjusting above formula to solve for Amps: Amps = Watts/Volts or 1000/110)
To power the same appliance on 12v takes 83.33 amps... a whopping big difference because of the lower voltage. (1000/12)
(Ignoring the addition of the inverter which would consume some power on its own)

The more amps you try to draw from a battery all at once - the harder it is on the battery - and less life you are likely to get - both on individual charge and overall (this does vary by chemistry with some able to deliver higher amps longer - and others just not capable of going that high...)

This is why electric vehicles run on MUCH higher voltages - the more you can raise the voltage - the lower the amps - and the happier the batteries and the cooler everything stays... Cool electronics are happy electronics.
__________________
Greg
Not yet retired...
Florida (Michigan transplant)
2014 Hurricane 32A
2000 Infinity (previous)
gmc is offline   Reply With Quote
Old 03-31-2017, 08:31 PM   #10
Senior Member
 
Brand: Still Looking
State: Texas
Posts: 3,867
THOR #2121
Quote:
Originally Posted by gmc View Post

....cut....

This is why electric vehicles run on MUCH higher voltages - the more you can raise the voltage - the lower the amps - and the happier the batteries and the cooler everything stays... Cool electronics are happy electronics.
Yeah, that and the fact that they often require more power than 100 RV microwaves.

I'm keeping my fingers crossed for 48 Volts becoming the RV standard. Hope it starts to convert within a few years. The 12-Volt system is obsolete in many ways because it was never meant to power 2,000-Watt inverters, microwaves, residential refrigerators and the like.
__________________
Chance is offline   Reply With Quote
Old 05-23-2017, 07:00 PM   #11
Member
 
w6lmj's Avatar
 
Brand: Thor Motor Coach
Model: 2017 Citation 24SR
State: Florida
Posts: 46
THOR #7515
Interesting discussion. With two wet batteries and a 2,000 watt inverter I suspect I could make a pot of coffee for the thermos and grill a few sandwiches, or possibly fry eggs without starting the generator. With 400 watts of solar on the roof, as long as I did not need the AC, I might mange dry camping with free energy. Or, is 400 watts not enough? And, maybe I would have to swap the wet batteries for lithium. I suspect 100AH lithium would provide 90AH of usable energy and recharge faster that 2 100AH wet batteries, which would only yeild about 80AH of usable energy and be much slower recharging.
__________________
w6lmj is offline   Reply With Quote
Old 11-14-2017, 12:47 PM   #12
Junior Member
 
Brand: Thor Motor Coach
Model: Four Winds 22B
State: Florida
Posts: 10
THOR #9890
I just tested my 2000 watt (not pure sine wave) inverter in my 2018 Thor Four Winds 22B yesterday. Mine has one 12 v battery in the coach. I connected it to the engine battery, plugged the coach main power plug into it, and made a pot of coffee inside with the engine running. NO PROBLEM. I then connected it to the house battery and made a pot of coffee without the engine running. I plugged the pot directly into the inverter. NO PROBLEM. On the power panel it still registered full charge. I keep saying a lot of coffee, but I only made 6 cups at a time because that's what we drink in the morning. I don't know the AH RATING of the battery. It came with the coach which is a week old.
I am having a problem finding a place to mount the inverter. Mine has a off/on switch on the front so it has to be accessible. Suggest you try to find one with a remote.
During hurricane Irma I connected my inverter to my Roadtrek engine battery and started the engine. I was able to run two full size fridges, a freezer, two lights, a fan, and a 65 inch TV for 16 hours straight on about 12 gallons of gas. A lot more current is available at the engine battery.
__________________
Leaves2 is offline   Reply With Quote
Old 11-14-2017, 04:13 PM   #13
Senior Member
 
Brand: Thor Motor Coach
Model: Gemini 24TX (2017)
State: California
Posts: 1,232
THOR #5821
I have an 1800 watt inverter installed in the Gemini, it does fine with the two house batteries, but of course I understand putting an 1800 watt load on it, though it will work, will drain the batteries fairly quickly.
__________________
Laco is offline   Reply With Quote
Old 11-17-2017, 02:29 PM   #14
Senior Member
 
Brand: Thor Motor Coach
Model: 2016 Quantum WS31
State: Washington
Posts: 823
THOR #7205
Quote:
Originally Posted by David1912 View Post
Thanks....we would be thinking of getting by from say 7 pm through the next morning.....tv, led lights, possibly small fan, coffee grinder and coffee maker in morning....possibly microwave for 2 minutes....
We just use our french press with water heated from the stove. We have a coffee maker that brews directly to a thermal carafe. But, we like the coffee from the press better.
__________________
Pat & Becky
Tessa (our Yorkie)was
killed by Pitbull mix 5/11/19
Wenatchee, WA
99dart is offline   Reply With Quote
Old 11-17-2017, 03:13 PM   #15
Senior Member
 
Brand: Thor Motor Coach
Model: Gemini 24TX (2017)
State: California
Posts: 1,232
THOR #5821
I did not have the microwave wired through the inverter, figured as infrequently as we use it when not on shore power, I could just fire up the generator for a few minutes which has worked for us. If you have two batteries, if they are in really good shape, and fully charged, you should be able to get through the night, depends on how much you run your TV.
__________________

__________________
Laco is offline   Reply With Quote
Reply

Tags
batteries, inverter, solar

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


» Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by Thor Industries or any of its affiliates. This is an independent, unofficial site.




All times are GMT. The time now is 03:29 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.6.0 PL2