Battery requirements

[dapope]

Craig, will pm you when I get a shot that's not off my phone.

[Craig]

OK, take a breath! Easy.........

Craig I recently bought a meter that plugs into a power point that you then can plug in the A/C to record various info that would tell you useage in a given period.
From memory it was only $32.90 or so.
http://cgi.ebay.com.au/ws/eBayISAPI.dll ... OC:AU:3160
Is your A/C wired direct or does it plug into a power point?
Surely you could get a rough estimate off the label on it or from the pamphlet that came with it.
Without this meter it would be guessing on cycle length and frequency.
Anyone done these tests?

Thanks Admin,

I didn't ask what my A/C used. Statements have been made here that people run their A/C from their Lithium batteries. I simply asked how many AH's are consumed when running the A/C for the day? I do realise that the load cycle will change depending on various conditions but someone that runs their A/C from their Lithiums should be able to give us a ball park figure. Brian has answered me in another thread and has indicated his set up will use 10amp per hour over what the solar will put in. Those are the type of answers I am asking about. The model of A/C he uses would be my next question.

I saw the bun fight that the Lithium discussion ended up in on the now closed CMCA forum, so let me make it clear that I am not interested in causing that here. I simply wanted to know what the real time experiences have been from those that are using this system. The advantage now compared to the bun fight discussion on the other forum is now there are a number of people using Lithiums.

[TigerMK1]

OK, take a breath! Easy.........

Craig I recently bought a meter that plugs into a power point that you then can plug in the A/C to record various info that would tell you useage in a given period.
From memory it was only $32.90 or so.
http://cgi.ebay.com.au/ws/eBayISAPI.dll ... OC:AU:3160
Is your A/C wired direct or does it plug into a power point?
Surely you could get a rough estimate off the label on it or from the pamphlet that came with it.
Without this meter it would be guessing on cycle length and frequency.
Anyone done these tests?

Thanks Admin,

I didn't ask what my A/C used. Statements have been made here that people run their A/C from their Lithium batteries. I simply asked how many AH's are consumed when running the A/C for the day? I do realise that the load cycle will change depending on various conditions but someone that runs their A/C from their Lithiums should be able to give us a ball park figure. Brian has answered me in another thread and has indicated his set up will use 10amp per hour over what the solar will put in. Those are the type of answers I am asking about. The model of A/C he uses would be my next question.

I saw the bun fight that the Lithium discussion ended up in on the now closed CMCA forum, so let me make it clear that I am not interested in causing that here. I simply wanted to know what the real time experiences have been from those that are using this system. The advantage now compared to the bun fight discussion on the other forum is now there are a number of people using Lithiums.

And very happy with them. still haven't fully exployed the possibilities.

[T1 Terry]

Hi Craig,
To run the air con 24/7 would require not only a large battery bank but a huge solar system as well. Brian's air con is one of those roof top Dometic units.

The split system air con in our bus uses 76 amp @ 13v on full tilt, on a 36 deg day that takes about 25 mins to bring the bedroom temp down to 24 deg C if we put the insulation blankets up on the windows, it runs roughly a 20% duty cycle then to maintain that, haven't tried it over night. Our solar can power it and still have 30 plus amps left over to run all the fridges etc. Can't do any more tests with it because it needs a regas at the moment, I want to swap over to the HC refrigerant so I'll need a fridgie who's up to speed with the new gases to see which one will work best as an R12 replacement. All the reports so far say they are far more efficient with the new gases.

There is a catch 22 using the inverter to power the air con. If the inside temp gets up to 40 deg plus and the inverter cools using the air from inside the bus the inverter can't coool itself sufficiently to power the air con to cool the air so it can cool itself Powering the air con from an inverter only is sort of virgin territory and this was one of the things we hadn't thought about so we need to figure out a solution to this one.
Oone idea I had was mounting pletier effect modules to the heat sink so the mosfet transistored were kept cool enough and the heat sink on the peltier modules could have there own fans. the idea is the 20deg differential across the module would hold the transistor heat sink below 40 degC and the module temp heat sink would be 60 degC, you can cool 60degC with 40 degC air. It's just a theory idea at the moment, haven't had a chance to try the idea out, it wasn't an issue around these parts.

T1 Terry

[Wilbor]

I have an LG split inverter in Wilbor's bedroom, it draws 30amps on 24v through the inverter. I don't run it on the inverter but did test its power usage some time ago for interests sake

Thanks for that ebay link to the power monitor Mr/Mrs/Ms Admin, I just bought one

[John M]

We have an air command Wren Ac which I consider next to useless will cool the bus down and but noisy and power hungry, not practical to use it other than on shore power, it will run off the inverter but draws around 75a @ 12v and more when cycling on, I would estimate its usage at close to 500 AH per day. I have never used the Ac off the inverter other than to see if it works.
I have left the engine driven, ducted system in the bus and find this the best of the lot. It is designed for the bus, with a full payload so does the job easily, we set the bus temp. at 24 deg,while travelling, and the system has no trouble maintaining this and cycling in and out, even in the central west and the top end where the temp outside is around 50 deg. I would like to fit a 240v compressor in series in the system and use that as the alternative, providing I can find a fridgie who understands what I want, I believe the efficiency of the larger unit would more than compensate for the difference in running cost.
I have Just fitted a shade sail to the drivers side of the bus, combined with the passenger side awning, with the windows open, the difference this makes to the inside temperature is quite remarkable.

[Craig]

Thanks for the replies. Maybe by the time I am ready to move on Lithiums they will be even better. Till then it looks like I'll be parking in the shade and running the genny for the A/C

[dapope]

Craig, there should be a way of charging the lithiums and running the gennie at the same time, meaning a smaller generator to do the work. There would be times when the generator is at idle and the air running flat out. anything is possible