Enginer Dc-Dc converter current inc?

I had a lot of support from Enginer (Jack) especially since I was one of the first to install in the 2010 prius. Jack was generous with me as I was passing back data for the 2010. I find that the Enginer kit is well worth the price if you have a installer close by and you do quite a bit of driving in town. Else you need to be very good with HV stuff. I don't want to divulge the exact amount I spent but I can say it is much less than the $7k that was mention. I wish there was more info on doing a CalCars type of PHEV for the Gen3 prius. I would not hesitate if there was a company as supportive as Enginer behind the product.

On the subject of the dual converters, all I can say is the heat is not very easy to deal with. I also upgraded to 4 gauge cables in my battery pack to handle the extra amps.

 

As a Hymotion owner, who also considered the other alternatives, I think mrbigh is not giving the Enginer kit the credit it is due. In the OP's example, even at $7k it isn't nearly the price of the Hymotion kit (add another 50%), AND, there is 8kw of batteries, as opposed to Hymotion's 5kw (about 60% more total capacity depending on allowed DOD). The ONLY reason I bought the Hymotion kit was because of the Florida rebate which brought the price back to about $5K. And for the price I paid, I'm very happy, and I can tell that it is a very high quality product, although there are a few quirks, such as the behavior at 34 mph. (Also, for those in California, I don't think Hymotion is CARB legal, but I think the Enginer kit is) Given enough driving distance, both kits will deplete their batteries and go a distance on electric, with the $/kwh of the Enginer kit far ahead. I don't have that kind of distance to go, only around 10 or 15 miles, so the Hymotion is better in my situation, using more electricity per mile than the Enginer kit is capable of. I also corresponded with Jack, and he was very friendly and helpful, even offering to work with me when the Enginer kit was just starting so I could install two inverters.

But too, I greatly respect and believe in the kit that mrbigh has done, and it is great that it works out for him and others who have written about it. The BMS+ method though does not have installers in various locations, that I know of, so it requires somebody with a good deal of mechanical aptitude.

There are also a few other even more obscure methods, of which I tried to investigate the ManzanitaMicro method but didn't get anywhere. The charger also functioned as the inverter, so it seemed worthwhile.

 

The 5KW inverter has a 16 amp fuse on the output side. This is a good indication that it is not meant to run in excess of 16 amps. However the voltage can be adjusted for Hybrid battery packs of 400 volts DC non-prius Hybrids. It is only when you have a higher voltage Hybrid battery pack that you can get something closer to the rated 5kw.

 

You can treat the "5000W" converter the same way as a car amplifier's power rating. Back in the days, I remember seeing car amps that claim 1000 watts but came with 60 amp fuse. That's only 720-864 watts give or take. This is not even considering that class AB amps are only 50-60% efficient. The idea of 5000 watts is peak output, not continuous that everyone expects.
True that the fuse is 16 amps, but it's a slow fuse. It can easily handle higher amperage for short period of time without blowing. I don't see anywhere on the converter that states 5000 watts continuous. Also increasing the voltage output might also decrease amperage output putting the converter back down to the same output as the Prius.

 

I think Jack would do everybody a favour if he put a rating plate on the converter. Instead we are fishing around for information (sometimes misinformation).

 

I think that is justifiable comparison with the power amplifier. According to the excel spreadheet on the SD card the maximum current I occasionally get is 18.3 Amps at around 242 Volts. Those are peak values. So that is just over 4.4 kW maximum on the output side. Keeping into account that inevitably a converter will have loss due to heat we can calculate that the converter has an efficiency rating of 88%. Which is pretty good actually considering a lot of heat is being disipated by the heatsinks in the converter.

Personally I think it is fair to say it is a 5000W converter but we have to keep in mind that there will always be some loss and that it is just the maximum power it can provide.

 

I think it is just that we are dealing with a Chinese company, and they are notorious for exaggeration. For example, Chinese made motor-controllers for electric cars will advertise 600 amps when in reality they only deliver 300. And I mean 300 peak, with typical output around 250-275. Cheap chinese cameras often claim 10 megapixels when in reality they are more like 3 megapixels with software interpolation to increase the size of the image, etc.. I think anytime they believe they can advertise a number that the average person won't easily be able to verify, they will exaggerate.

 

True, most of them like to exagurate. But in this case Enginer even provides the tools (display and SD card) to verify it. The 5000W is the maximum (peak) power consumption of the converter.

If you buy a regular cheap 100W lightbulb, it will provide about 15 Watts of light and the remaining 85 Watts is pure loss in the form of heat disipation. Lightbulbs just have a very low efficiency rating.
Should we demand the lightbulb manufactors put 15W on their 100W bulbs? We could, but they would still consume 100W each hour. And they should be able to handle that 100W.

 

Related to topic, has anyone done an end-to-end efficiency study of the Enginer kit? This would involve integrating the power delivered over time (current * voltage) by the converter and comparing to recharge energy received from the grid with a Kill-A-Watt or other meter. I'd do it but I'm waiting on the mail to get my BMS16C swapped out.

IMO, converter efficiency in the steady state is far more important than peak output. The converter heats up quickly when pushing close to 3.4 kW e.g. 14A at 240V.

 

How reliable is the converter? Mine fried after just 240 miles of driving.

 

Mine failed after ~ 30 miles. I contacted Jack, paid to have it shipped back to Jack and he sent me another one. About a week later, I was up and running. If he could get these things made in Taiwan instead of the mainland, he could really be on to something.

 

Are these converters out of the latest kits that failed? My first, built in 3/2010 (a very early 5 kWh converter), lasted until 8/2010, when I blew a relay in really hot weather. I have not had a problem with the replacement.

 

I'm not and expert on these DC - DC converters but it appears heat is the enemy. Air is horribly inefficient way to remove the heat, unless your a magnesium block VW, this is why we have two cooling systems in the prius. How about water cooling? Sounds crazy but I put these systems in pc's all the time.

I'm sure this statement is going to bring out the nay sayers, I do believe we have the technology.... Lets be part of the solution not the problem.:mod:

 

Water cooling is a good idea. It's something i'll be investigating...

 

How about extra heat sinks and fans? Treat it like a large CPU. I do realize that it takes energy to run fans, but that could come from a small battery pack that gets charged with a wall wart off the same A/C circuit as the main charger whenever plugged in, rather than from the car's 12V system. I think getting cabin air to flow freely into the spare tire well would also help.

 

Yes. Mine was one of the new 5KW converters.....and it was not a heat displacement issue, it was a quality issue with manufacture of the unit. I suspect trained monkeys had something to do with it judging from the missing screws and poor soldering work. But to be fair, it could have just as easily been orangutans and the replacement did look much better.

 

thats the case with a lot of cheap china stuff soldering is always bad.

i dont want to ride in a car wiht thats kind of soldering in a 240 volts 15 amps system
good that the replacement is better. pfffff

 

Good idea. I'm also waiting for a new BMS16D versions 3.1. The old one (a v. 3.0) only updated every 40 seconds instead of 10 seconds, the signal accros the USB cable was too weak. But it is a good idea, trying to find out what the 'average' efficiency of the entire system is. You would have to record a few charging cycles.

I did notice that the average current on all previous trips was around 8 to 8.5 Amps. But when the voltage reaches 245V or higher (that was the limit under load on my kit) there will be no current output, should you take these 0 Amp period into account as well?

Personally I expect the kit to be quite efficient when you simply look at what goes in and what comes out. Probably something like 80% or maybe even higher.

 

China is certainly capable of producing high-quality electronics. For example, most of the Apple computer, ipods, iphones, etc.. are produced there and Apple has very strict quality control requirements.

The problem is often that the companies who want to get things manufactured in China do so with the intent of making it as cheaply as possible.

Personally, I would be happy to pay an additional $500 to $1,000 for an enginer system if I knew that it was built to a higher standard and would not fail for several years.

 

Energy = sum(i * V) * deltaT, assuming that the time interval for each measurement, deltaT, is constant. This result is in Joules, which you then convert to whatever power/energy units that your Kill-A-Watt-type wall meter uses. My guess is that the efficiency is lower, 65-70%, when including the charger efficiency, cooling fan, and Peukert's law for the battery string. Periods of zero current are a zero in the summation. But, as you know, the system is in standby in such a state and is drawing power from the battery string, so one particular class of inefficiency that you can also measure is the energy delivered by the battery string when the inverter current is zero.