Looking into Inverters Options

Hi,

If all you will ever need is 2000 watts the Prowatt PSW is a "no brainer" compared to a similar power rated MSW unit.

BFL13 wrote:

MEXICOWANDERER wrote:
Try this specification on for size...

Using 120 volts as the norm and a starting resting battery voltage of 12.7, how many instant amperes does it take to draw down the battery to 12.00 volts? 11.7 volts? 11.5 volts.

A CCA rating for a battery gives an idea of instant potential but remember, the CCA test rating is for 9.6 volts - far below the voltage minimum needed by an inverter.

Can a single battery power a 2,000 watt inverter? Yes. At it's maximum design output potential? No. For a useful length of time? No. A person may argue "But how about at lower power settings?" My answer to that is "Why was a 2,000 watt inverter chosen in the first place?"

Time for fun:

Same set of batteries, measure the kWh extraction out of batteries powering a MSW inverter which powers a microwave oven. Then substitute a pure sine wave inverter and see how much ENERGY is extracted out of the batteries to heat a liter of water to 60C. This is different than the time element, right? The PSW heats the water faster. But how about the amount of battery energy needed to heat the water? Compare the two. Forget about time. Concentrate solely on how many kWh or fractions thereof was needed to do the job. Inductive motors don't utilize modified sine wave energy the same way as they utilize pure sine wave energy. Same goes for transformers.

I have reported a few times that my MSW 2000w inverter only draws 110a from the battery bank where a PSW would draw 155 amps. It takes a little longer to heat things up, but Peukert gives the advantage to the MSW for AH draw to the MSW at lower amps despite the longer time.

Using the Panasonic Inverter type MW with PSW but setting the MW at lower power might get similar results. Longer heating time but lower amps, and Peukert jumps in to call that fewer AH to get the job done.

Obviously there are limits to all that to be practical.

---- There have been several threads on this topic of 12s vs 6s with high amp draws and how AGMs seem able to do better than wets too. idea is to stay above 11 volts inverter alarm while running the load and how low can the SOC be at the start of the run. To run 100a at 50% SOC you need four 6s or three 12s with wets, and ISTR two AGM 12s.

A MSW Inverter produces a voltage output that is rich in harmonic frequency content.

The abundant frequency components effect power supply performance significantly by increasing core losses in transformers, increasing losses within electrolytic capacitors, changing peak/average charging current values through diodes, etc..., etc...

Any line power connected device that requires input power transformation will be adversely effected by a MSW Inverter to some degree.

I would not just look at Inverter efficiency when deciding, but also quality of service which a PSW Inverter provides since equipment is designed based on a PSW input.

I installed a 600w Prowatt (with relay) and found it to be ideal for our needs. What we do (road days) is put dinner in the crockpot, put that in the sink, and dinner cooks as a drive. Come dinner time, we have a hot meal ready to go.

I have a Samlex SSW-600 and it will not pull 1000w starting loads, it's also noisy. Don't know if I got a bad one if they're all like that. I also have a Xantrex Prowatt 1000w and it is a beast. Also silent.

Hi,

Best bang for the buck is a Prowatt 2000 PSW $355.00. However, it is a throw away if it fails.

My Samlex 2012A (2KW) PSW Inverter/Charger with 4 GC2s, works very well for me.

As far as brands go Samlex works for mee...

Bought a 300 watt pure sine recently and I just ordered a 600 watt with a remote switch from Don Rowe for another project.

Nice units they seem very well made.

MEXICOWANDERER wrote:
Try this specification on for size...

Using 120 volts as the norm and a starting resting battery voltage of 12.7, how many instant amperes does it take to draw down the battery to 12.00 volts? 11.7 volts? 11.5 volts.

A CCA rating for a battery gives an idea of instant potential but remember, the CCA test rating is for 9.6 volts - far below the voltage minimum needed by an inverter.

Can a single battery power a 2,000 watt inverter? Yes. At it's maximum design output potential? No. For a useful length of time? No. A person may argue "But how about at lower power settings?" My answer to that is "Why was a 2,000 watt inverter chosen in the first place?"

Time for fun:

Same set of batteries, measure the kWh extraction out of batteries powering a MSW inverter which powers a microwave oven. Then substitute a pure sine wave inverter and see how much ENERGY is extracted out of the batteries to heat a liter of water to 60C. This is different than the time element, right? The PSW heats the water faster. But how about the amount of battery energy needed to heat the water? Compare the two. Forget about time. Concentrate solely on how many kWh or fractions thereof was needed to do the job. Inductive motors don't utilize modified sine wave energy the same way as they utilize pure sine wave energy. Same goes for transformers.

I have reported a few times that my MSW 2000w inverter only draws 110a from the battery bank where a PSW would draw 155 amps. It takes a little longer to heat things up, but Peukert gives the advantage to the MSW for AH draw to the MSW at lower amps despite the longer time.

Using the Panasonic Inverter type MW with PSW but setting the MW at lower power might get similar results. Longer heating time but lower amps, and Peukert jumps in to call that fewer AH to get the job done.

Obviously there are limits to all that to be practical.

---- There have been several threads on this topic of 12s vs 6s with high amp draws and how AGMs seem able to do better than wets too. idea is to stay above 11 volts inverter alarm while running the load and how low can the SOC be at the start of the run. To run 100a at 50% SOC you need four 6s or three 12s with wets, and ISTR two AGM 12s.

Since this started in the truck camper forum I have a question. Why do you want a 2000 watt inverter? When I was ordering my TC two years ago a couple forum members who were helping me get the options "I needed" kept telling me I needed to get the $2000, 2000 watt Xantrex prosine inverter option installed. Long story short, I didn't get that option but got a smaller/cheaper inverter and I haven't used it yet. Like others have mentioned, you need a pretty large battery bank to utilize that much A/C power. When my wife wants to blow dry her hair or use the toaster, I fire up the Honda generator for a few minutes. Otherwise I use my solar and 2 AGM batteries and all is good.

Samlex.