The Duracell DS10R1i is a very tempting package: A 1,000 watt inverter generator for $200 (non-California model at costco.com until 12/18/11). The major unexpected characteristic might be that it uses a 2-stroke engine, with the associated pros and cons. Some caveats to my test results: (1) The engine uses a 50:1 gas-to-oil ratio but requires 30:1 for the first 50 hours of operation. This additional oil might affect the performance. (2) I tested it at 3,500 feet elevation, which also affects the performance. The temperature was mid-40s, which serves to somewhat counter the higher elevation effects.
I made comparisons to the eu2000i because that's what I have available. There's only one AC outlet, and no DC outlet. There is no "eco" switch to run the generator at a high idle. Parallel operation is not suppported. The generator's specs call for an engine speed range of 3,300 to 4,500 RPM. I observed 3,600 to 4,400 RPM.
Listening test results (no sound meter available):
At idle, the Duracell has two noise components: The underlying steady engine/exhaust noise, and the somewhat intermittent "rink tink" sound that occurs with some 2-cycle engines. The underlying steady sound was about the same loudness as the eu2000i, but higher in pitch which some consider more annoying. The "rink tink" is louder and definitely more annoying. There was considerable visible smoke. With a 500 watt load, neither generator became noticeably louder. The Duracell's "rink tink" occurred less, so it was actually quieter than with no load. With a 1,000 watt load, the Duracell was definitely louder than the Honda, which is to be expected. The "rink tink" and visible smoke were gone. With both generators loaded to their respective rated outputs, their noise levels were about the same, with the Duracell having the higher pitched sound.
I'm going to save the electrical details for the next post. The summary is that I don't think this generator is a very good match for RV use, or as a home backup power source for that matter. It's great when running a steady resistive load, but when the load is a power converter or when the load is changing, the performance is poor. Here are some pictures....
* This post was
edited 12/02/11 11:11am by an administrator/moderator *
2009 Fleetwood Icon 24A
Honda Fit dinghy with US Gear brake system
LinkPro battery monitor - EU2000i generator
Testing with two 500 watt incandescent lamps shows good performance once things are stabilized.
No load: voltage = 121, engine speed = 3,700 RPM
1 lamp: voltage = 119 to 120, watts = 446, amps = 3.7, RPM = 3,640
2 lamps: voltage = 118.5, watts = 961, amps = 8, RPM = 4,400
The generator couldn't handle a 600 watt heater and 500 watt lamp, with voltage = 111, watts = 990, amps = 9, and the generator dropping offline after about 20 seconds. Considering the altitude, this can perhaps be excused.
The waveform looks very good, with no visible difference at any of the power levels.
The very big problem occurs when loads are added or removed. When going from no load to one lamp (0 to 500 watts), or from one lamp to two lamps (500 to 1,000 watts), the engine comes close to stalling for 3 to 5 seconds. During this time the output voltage drops to between 30 and 40, and the engine speed drops to about 1,700 RPM. It would have been nice to be able to compare this with an eu1000i. The really inexcusable voltage drop occurs when dropping a load. When the load goes from 1,000 to 500 watts, the engine immediately overspeeds, followed by an over-compensation that drops the engine speed too low. This results in the output voltage dropping to the 70 to 80 range for a few seconds.
When driving a WFCO converter, a horrible power factor load, the waveform remains pretty good. No worse than the eu2000i, and better than any small AVR generator:
But while the Honda seems to excel with this type of load, the Duracell crumples. The scope picture above was with a 13.2 amp load on the WFCO. The generator would not power it with a 17.6 amp load, and it did not fail cleanly. There was a stable oscillation with the generator's output (and converter output) bouncing between full power and less than half power at about a 5 second interval. The generator never tripped offline in this situation.
Highly magnified, the generator shows an inverter switching frequency of about 25 kHz. The Honda is double that, but 25 kHz is perfectly ok. Many PSW inverters operate at about this frequency.
Bottom line: If you're running lights that don't turn on and off very often, this generator is great for the job. With a typical power converter, the max output will be about 15 amps, as compared to about 40 amps with an eu1000i. I didn't test with a refrigerator or freezer, but based on the other results I wouldn't trust the Duracell to power them. And I wouldn't want any of my electronic equipment enjoying that very nice waveform when all of a sudden the voltage might drop to well below 100 because of a load change. Overall I'm pretty darn disappointed.
* This post was
edited 12/02/11 11:12am by an administrator/moderator *
View edit history
I read somewhere that they are only expected to last for 250 hours of operation.
I wonder what they need to keep going after that if it is true?
What you read was probably referring to the 250 hour EPA test, which certifies that the engine will meet pollution control standards for at least 250 hours of operation. It does not mean the generator only has a 250 hour useful lifespan. As I recall, the Honda is only certified for 250 hours of operation too.
Having said that, I wouldn't want one even if it were certified at 500 hours of operation - especially after reading the original poster's investigation.
The feedback control is too slow. Does it have a stepper motor? When does it react to a load change? Time to redesign the closed loop system. Needs more gain. Maybe you can change the mechanical linkage.
The tag stating "NEUTRAL FLOATING" doesn't sound correct. GROUND most likely is floating.
Salvo writes "The tag stating "NEUTRAL FLOATING" doesn't sound correct. GROUND most likely is floating."
Actually that Neutral floating would be correct.
In this case just like Honda inverter type gens, the neutral connection on the grounded outlet has no connection to the equipment ground. The equipment ground would be tied to the gen frame.
The gen is treated as a two wire power source so the neutral is denoted as "floating".
Now the thing to be concerned about is whether the inverter in the gen would survive having the neutral bonded to the equipment ground? Some inverters can not be neutral/ground bonded and doing so will render it a doorstop.
The reason as to why you would need to have neutral/ground bond?
Simply put, there IS some devices that check to see if it finds neutral/ground bond before it will work. Several examples of this is if your rig has EMS, these often will not connect the RV to the shore power unless it detects the proper power connections. One of course is to see if the shore cord is plugged into an outlet which is wired correctly (neutral/ground bonded).
Another example is nearly every home furnace manufactured with in the last 15 yrs or so has a control board which will lock out the furnace if that neutral/ground bond is not present.
For this and any other gen or inverter power source which does not have neutral/ground bond you would need to make an adapter. This adapter would plug in to that source with floating neutral and wire the outlet of that adapter to bond the neutral/ground. The gen or inverter power source would still be treated as two wire but now the EMS will function.
My real world trial of this generator resulted in return to Costco today. Would not power the WFCO converter in my trailer and the 32" flat screen would not turn on with the gen/ink. My batteries were at 11.2 volts so I'm sure the converter was in the highest charge mode.