Sorry for all the questions, lots to learn. Any idea how long I can comfortably and safely run a 700 watt inverter and one deep cycle battery from advanced auto, wet cell with 59 amp hour rating if I am running a fan on high at 75-100 watts and a 32 inch tv at 60-70 watts in 85 degree temps outside? Looking to get 6 hours and if this will work, won't bring the Honda 2000 to the tailgate due to wet, risk of theft and for packing space considerations.

Wet cell battery only rated at 59 amp hours? Even a group 23 is mnore than thatThe answer is not long. That battery is likely a MARINE/deep cycle and that means you can only use about 15 amp hours.. Now a 700 watt inverter needs about 3 of those batteries to be happy. At FULL LOAD it will draw 75-90 amps. YOur battery will last about 10 minutes.At light load it might draw as little as 1-5 amps, and your battgery could last 10 hours.. but Trust me you need MORE battery..Minimum would be a pair of GC-2 or one 4D

Probably 2 hrs and you will be at 50% dead.

marcsbigfoot20b27 wrote:Probably 2 hrs and you will be at 50% dead.and you don't want to go any lower than 50 percent because you will start ruining your battery

tealboy wrote:Sorry for all the questions, lots to learn. Any idea how long I can comfortably and safely run a 700 watt inverter and one deep cycle battery from advanced auto, wet cell with 59 amp hour rating if I am running a fan on high at 75-100 watts and a 32 inch tv at 60-70 watts in 85 degree temps outside? Looking to get 6 hours and if this will work, won't bring the Honda 2000 to the tailgate due to wet, risk of theft and for packing space considerations.The DC amps draw is with the divide by 10 rule for the watts, so 170 watts is 17 amps. The thing that will shut down the inverter first is when the voltage it "sees" from the battery gets down to the inverter's low voltage shut off--usually 10.5 volts (but it will sound its alarm before that at 11 volts)That is to protect the battery from getting too low. As soon as the inverter shuts down the amps stop and the voltage goes back up to more like 12.xThe key to keeping the inverter from shutting down is to have a bigger battery and short fat wires from the battery to the inverter.Sorry, I cannot even guess how your set-up would work with that small of a battery. It might hit the inverter's low voltage shut off right away. It won't take very long to shut down if it will run.You can do it, but will need more of a battery. Also, once it does run the battery down, you need a way to recharge the battery, and you won't have the generator to run your charger.

How long will this battery inverter run | Good Sam Community

26 Replies

marcsbigfoot20b
Explorer
Oct 14, 2017
Yeah I saw that one, oddball sized inverter.
pianotuna
Nomad III
Oct 13, 2017
https://www.walmart.com/ip/Tripp-Lite-700-Watt-12V-Power-Inverter/11084218

marcsbigfoot20b27 wrote:
pianotuna wrote:
Hi marcsbigfoot,

I owned a 700 watt motormaster inverter.

I looked up Advance auto to see what they have......didnt see a 700 inverter, but just a power box inverter combo battery inverter jump box, by Canadian tire.
Almot
Explorer III
Oct 13, 2017
tealboy wrote:
I have a small 140/200 peak watt that is capable of running the tv and fan, I tested it and seems to work perfectly fine and based on the above, sounds like going smaller is more efficient?

Possibly, but not important, in your case. The difference in overhead losses of inverter btw 700W and 140W model will be 5-10 Watts at best. This won't change the picture, you still need more batteries.

Inverter 140W continuous and 200W peak? With stated loads anywhere from 135 to 170W?
If loads are 135W - should be alright, inverter will get hot, "should" last for some time.
If loads are 170W, inverter will die "sooner". Peak 200W is meant for short time only, check the manual.
MrWizard
Moderator
Oct 13, 2017
BFL13 wrote:
time2roll wrote:
Guess? 15 amps x 6 hours = 75 amp hours. So you need 150 amp hours minimum. So 3 batteries should be enough. I throw in one more for good measure and unknown conditions.

Or bring the Honda.

Yes, but people seem to be assuming the battery will run down to 50% before the inverter shuts down, when I am wondering if the inverter will shut down right off because the inverter-battery wiring is not good enough. Or it might shut down real soon after it does run for a short time.

I am questioning how people can be assuming that without knowing the actual wiring.

I think we are all stating, what we think is the best case scenario
And that it could be worse

We don't know wire size, we don't know state of charge
We don't know if it's going to alarm in five minutes or 2 hours
We know he can't possibly get six, and most likely will would only get two or three at best
tealboy
Explorer
Oct 13, 2017
As always, lots of great help from many. You were right, the amp hour rating I stated was wrong, it is 79 not 59.

It also sounds like when it comes to inverters, bigger is not necessarily better when the job is small. I have a small 140/200 peak watt that is capable of running the tv and fan, I tested it and seems to work perfectly fine and based on the above, sounds like going smaller is more efficient?

Re the 700 watt, it is owned by a buddy at work. I don't know the brand. The battery is a wet cell from advanced auto.
Almot
Explorer III
Oct 13, 2017
Single 59 AH battery for offgrid camping? Man, where did you even find it that small? :)

Unless you want to run a generator all day long, - get at least a pair of 100AH 12V batteries (or a pair of 225AH 6V batts, same thing). Get a 12V fan like freestanding FanTastic. Get more efficient TV (should be under 40W, these days).
marcsbigfoot20b
Explorer
Oct 13, 2017
pianotuna wrote:
Hi marcsbigfoot,

I owned a 700 watt motormaster inverter.

I looked up Advance auto to see what they have......didnt see a 700 inverter, but just a power box inverter combo battery inverter jump box, by Canadian tire.
time2roll
Nomad
Oct 13, 2017
BFL13 wrote:
time2roll wrote:
Guess? 15 amps x 6 hours = 75 amp hours. So you need 150 amp hours minimum. So 3 batteries should be enough. I throw in one more for good measure and unknown conditions.

Or bring the Honda.

Yes, but people seem to be assuming the battery will run down to 50% before the inverter shuts down, when I am wondering if the inverter will shut down right off because the inverter-battery wiring is not good enough. Or it might shut down real soon after it does run for a short time.

I am questioning how people can be assuming that without knowing the actual wiring.
I try to assume OP can follow the install instructions. Or he can ask.
Part of the reason I throw in one more for unknown conditions.

Also good chance the batteries show up only 85 percent charged.
pianotuna
Nomad III
Oct 13, 2017
Hi marcsbigfoot,

I owned a 700 watt motormaster inverter.
marcsbigfoot20b
Explorer
Oct 13, 2017
Then we have more bad news......its more than likely a modified sine wave inverter which makes it even more inefficient.
The fan motor will start getting hot, hopefully the tv power supply will be ok.

I dont see any 700 watt unit, there is a 750 Schumacher .