Yet another battery question

[fritz_monroe]

I'll be getting a PUP in the next month or so and I've been doing some battery and generator homework.  I want to make sure that I have my information right.

The battery in the PUP typically will be able to last an entire weekend of dry camping as long as I ensure we limit your usage of the lights.  Upon return, the battery can be recharged by using an adpter to take the 30 Amp plug into a standard 110 V recepticle.  This will make use of the inverter to charge the battery, but it will never reach full charge this way.  A much better solution is to use a battery charger.  In getting a battery charger, I should get a smart charger that also has desulfation.

Now generators, if I need to recharge the battery while dry camping, a 1000 watt generator does a fine job.  However this generator is not strong enough to allow use of the airconditioner.  I've seen people mention that they are able to use their AC with their Honda EU2000i generator, but I've also seen others mention that it needs to be at least 3000 watts.  Is there any sort of calculation I can use to see if I would need 2000 watt or 3000 watt for the AC?

This sound about right?

[ffej1010]

Upon return, the battery can be recharged by using an adpter to take the 30 Amp plug into a standard 110 V recepticle.  This will make use of the inverter to charge the battery, but it will never reach full charge this way.

Not all inverters will charge your battery. The one I have in my popup will power all the lights and other 12v appliances, but not charge the battery. So I always make sure I charge the battery before we leave, once we return, and once a month in the winter when not using the trailer.

[wavery]

I'll be getting a PUP in the next month or so and I've been doing some battery and generator homework.  I want to make sure that I have my information right.

The battery in the PUP typically will be able to last an entire weekend of dry camping as long as I ensure we limit your usage of the lights.  Upon return, the battery can be recharged by using an adpter to take the 30 Amp plug into a standard 110 V recepticle.  This will make use of the inverter to charge the battery, but it will never reach full charge this way.  A much better solution is to use a battery charger.  In getting a battery charger, I should get a smart charger that also has desulfation.

Now generators, if I need to recharge the battery while dry camping, a 1000 watt generator does a fine job.  However this generator is not strong enough to allow use of the airconditioner.  I've seen people mention that they are able to use their AC with their Honda EU2000i generator, but I've also seen others mention that it needs to be at least 3000 watts.  Is there any sort of calculation I can use to see if I would need 2000 watt or 3000 watt for the AC?

This sound about right?

There is a calculation. The Honda EU2000I is rated at 2000w or 16.7 amps (MAXIMUM that's important). It's rating for continuous running is 1600w or 13.3 amps.

You need to make sure that your A/C does not draw more than 13.3 amps at full load (preferable a little less).

I have a Carrier MarkV A/C unit. It is rated at 12.9 amps (full load). My Honda generator runs it just fine.

Now, here is where the problem comes in. If you plug your camper's power line into the generator and then plug the A/C into the camper, you have added more load to the generator. This is true even if you have nothing else running. Just the mere fact that the electricity has to run a longer distance, through more wire and several coonections (including your in-house power supply unit), adds resistance which takes more power to overcome.

When I plug my A/C unit into the generator directly, it runs all day and night without a problem. If I run it through my trailers wiring, it will run sometimes but sometimes it will kick the overload circuit on the generator when the A/C cycles.

When the A/C cycles is when the most demand is put on the generator. Cycling means that the compressor inside the A/C unit automatically turns off at times. Then it automatically restarts. When it restarts, it is having to overcome already pressurized gasses and that puts the highest demand on the generator.

I hope this all makes sense to you. I went into some detail because I have heard others say that they have problems running their A/C on a 2000w generator and I suspect that they may be running the A/C through their camper. IMHO that is why you hear this controversy.

The other thing is, most 2000w generators are not as efficient as the Honda EU2000I and will have a continuous run rating somewhat lower (that's one of the reasons for the higher price). The general rule of thumb is 75% of their maximum rating which would put it at about 12.5 amp continuous rating which is lower than the Carrier A/C draw and much lower than the Honda output.

The other plus on the Honda Generator is that it is an "Invertor" generator. I won't go into all the technical stuff but simply put, it means that it will handle a higher "Start-up" load (like when your A/C cycles) than regular generators. That's another plus when running A/C off of it.

Here's a couple of links for fact finding:
http://www.hondapowerequipment.com/gensup.asp
http://www.airv.carrier.com/details/0,2806,CLI1_DIV46_ETI9772,00.html

[fritz_monroe]

As I don't even have my PUP yet, this will help.  I'll take a look at the max current the AC pulls when running.  It makes perfect sense that it would possibly pop the breaker if running thru the trailer.

I appreciate the additional info you supplied.  It's really going to help me out in the future.

Any suggestions on battery chargers?  Are the generic ones worth buying or should I stick to the name brands?

[tlhdoc]

I went into some detail because I have heard others say that they have problems running their A/C on a 2000w generator and I suspect that they may be running the A/C through their camper. IMHO that is why you hear this controversy.

I have a Carrier Air V (I haven't heard of a Mark V model except in hard hat diving equipment) air conditioner.  The amps needed to run the AC unit are less than the normal load the generator will produce.  With the AC unit plugged directly into one of my Honda EU2000i generators it will only run one cycle of cooling.  When the compressor kicks in the second time, the generator over loads and shuts the power off to the outlets.  I had to get a second Honda EU2000i and the kit to connect them in order to run my AC unit.  The EU2000i weighs less than 50 pounds and the Honda EU3000i is around 130 pounds, so it is MUCH easier for me to move 2 of the 2000s.  The cost is about the same.

[wavery]

I have a Carrier Air V (I haven't heard of a Mark V model except in hard hat diving equipment) air conditioner.  The amps needed to run the AC unit are less than the normal load the generator will produce.  With the AC unit plugged directly into one of my Honda EU2000i generators it will only run one cycle of cooling.  When the compressor kicks in the second time, the generator over loads and shuts the power off to the outlets.  I had to get a second Honda EU2000i and the kit to connect them in order to run my AC unit.  The EU2000i weighs less than 50 pounds and the Honda EU3000i is around 130 pounds, so it is MUCH easier for me to move 2 of the 2000s.  The cost is about the same.

HMMMMM!! :confused:

I wonder what the difference is. My brother and I each have the EU2000I and have had the same success with ours (on my A/C unit). In fact, I had the two of them and sold the other one to him because I didn't need it.  I still have the connector kit if anyone wants to buy it .

One thing that we did do (was recommended by a freind) was changed over to Mobile1 synthetic oil. Can't emagine that made much difference.

It could be a difference in the head pressure in the compressor. You might have slightly more freon in yours than I do. Mine seems to cool just fine though. A small amount of freon will make a big difference in head pressure after the A/C has been run for a while. You might time how long your compressor stays off between cycles. It should stay off for at least 5 minutes. If it is cycling to fast, it won't have enough time to bleed off sufficient pressure and that would make it harder to start also.

You're right it is an AirV. I don't know where I got "MarkV" :eyecrazy: . Anyway, the link that I provided shows the AirV.

[tlhdoc]

HMMMMM!! :confused:
 
I wonder what the difference is. My brother and I each have the EU2000I and have had the same success with ours (on my A/C unit). In fact, I had the two of them and sold the other one to him because I didn't need it. I still have the connector kit if anyone wants to buy it .
 
One thing that we did do (was recommended by a freind) was changed over to Mobile1 synthetic oil. Can't emagine that made much difference.
 
It could be a difference in the head pressure in the compressor. You might have slightly more freon in yours than I do. Mine seems to cool just fine though. A small amount of freon will make a big difference in head pressure after the A/C has been run for a while. You might time how long your compressor stays off between cycles. It should stay off for at least 5 minutes. If it is cycling to fast, it won't have enough time to bleed off sufficient pressure and that would make it harder to start also.

I have not tried running the AC on just the "twin", our name for the second generator.  I will try that this summer and see if that makes a difference.  I would love to be able to run it on just one of the generators.  I have a spot to pack one, but taking both of them causes a change in our normal packing routine.  I will also switch to Mobil One oil.  We use it in our vehicles.