LCD Control Panel in Vehicle

Mar 01, 2013

Be careful of those who claim their PWM is like the KZX1250, but with more features!

I’ve gotten a number of customers asking me why there isn’t some kind of remote control panel that can connect to the KZX1250 and install inside their vehicle. Some have pointed me to another PWM maker that claims their PWM is as good as the KZX1250, but with “more features”. To claim it's as good as the KZX1250 is quite a stretch and is being downright disingenuous. Since they didn’t even give it a name and I don't want to point my finger (like they obviously did), we’ll call this PWM, “product X”. Product X may have more features, but make no mistake about it; it lacks important features of the KZX1250 while adding needless features as I will explain.

As with any electronic device, there are useful features and there are useless features. Marketing minds like to add features just to make their product appear to be better because it has more (useless) features. They will convince you to believe you need some feature that will serve no useful purpose just to get you to buy it over one that lacks these useless features. As an example, look at your cell phone. Look at the menus they have; do you use most of these features? I bet you don’t! Most of them are useless but are there for people who have a lot of time on their hands. When they advertise all these features, it looks like it does so much more than the competition that some people just have to buy it.

What product x offers:

An LCD display which indicates the system voltage, duty cycle, the water level, the average current along with SOME features that are fundamental to the KZX1250. Those features would be automatic power on/off and alternator protection by monitoring system voltage and pinching off current. Whether the auto on/off and alternator protection are implemented properly or not remains to be seen (as I have seen other products that had problems with their implementation of the auto on/off), their product still lacks features that distance them from the KZX1250 such as short circuit protection, thermal protection, water resistance and the ability to run cool enough to not need a heat sink; these are vital features that you either understand why you need them or you find out the hard way by experience.

As far as their on/off circuit, they use the controller to sense when to turn the unit on, which means the controller must have power all the time; so when the ignition is off, it will still be drawing some current. When the KZX1250 turns off because the voltage dropped below 13.2V, it completely pinches off current to the whole circuit, including the fan and the controller so there is virtually no current drain (other than some leakage in the micro-amp range). Their version of alternator protection is preset. In other words, it cuts back a certain percentage if the voltage drops below fixed voltage levels. The KZX1250 does this much differently as it takes a snapshot of the voltage it is reading when you set it. This value can be different depending on how long your wires are and where on the chassis you connected ground; so you can’t just say that if it reads say 13.8V, it will cut back 30%; it can vary greatly from vehicle to vehicle and how it is hooked up. When you set the alternator protection on the KZX1250, it takes a data threshold snapshot of what voltage it is reading and it will scale back as much as it needs to maintain the set voltage, even if that means cutting back to 0% duty cycle. This means whatever voltage it’s set to, the system will never fall below it due to the demands of your cell. Knowing what this voltage is isn’t necessary because it will be different on all vehicles and greatly dependent on how far from the battery it is installed. If you use a voltmeter directly on the battery, you will get the true system voltage which is relative to what the unit is actually measuring so for the KZX1250, it won’t matter where you mount it.

After looking at what product X has to offer, I have noticed that they advertise and show off their display as if they believe that is all the customer is interested in. Are you buying a PWM or a display? Nothing wrong with showing off the display, but if the purpose of the device is pulse width modulation; wouldn’t it make sense to advertise the PWM too? The units I have seen do not show pictures of the PWM electronics. You just get to see the outside of the unit. I could be wrong, but these units look awfully familiar to me as the same lame unit that others have been selling in the past. Why not show a close up of the circuit inside like I do with the KZX1250? My guess is there isn’t much to see! After all, if it was such a well-designed PWM, they would be showing off the actual business end of the unit, rather than just the graphical front end. The KZX1250 was designed for reliability and robustness and that is what you are paying for; you can see the quality in the pictures. There are about 100 parts that make up the circuit and that is because it’s designed to last. As far as product x is concerned, the big metal enclosure (which is a heat sink), fewer MOSFET’s and lack of a fan tells me this box gets pretty hot in use. I don’t think I need to tell you what heat does to MOSFET’s here as it is already mentioned elsewhere on the site.

…but the KZX1250 doesn’t have an LCD inside the vehicle that displays voltage, duty cycle, current and water level!

My question to you is why do you need to see these things while driving? I have a GPS in my car and I have a Radar detector. These displays have to be in my car in order for them to be useful, but do the voltage, duty cycle, current and water level monitoring need to be there to benefit from your install? Anyone that’s had one of these for any length of time realizes this is just flash that got them to buy it and serves no useful purpose. So it displays the voltage of your charging system, what good is that? You’ll see the voltage hovering around 14 volts all the time; is this helpful? I don’t think so, do you? The auto makers didn’t think so when they designed their cars; otherwise they would have made it standard equipment. So it shows the duty cycle; while seeing the settling point of the duty cycle is helpful when you are maintaining your cell, it’s kind of silly to watch this every day in your vehicle. It’s like measuring your height or the length of your hair every day to see how much you've grown. Once a week you should be physically checking your system and having the duty cycle displayed inside the vehicle isn’t going to help you if you are under the hood adding water/electrolyte. It shows the average current going to your cells. We all know that once you set the auto current mode, the current is never going to change again. So is it helpful to see a current on the display bouncing around its set point? I don’t think so. Oh, but it also displays the water level. Well if you’re going to rely on a water level sensor to tell you when it’s time to put more water in, you’re going to find yourself in a world of trouble when the sensor fails as they usually do. Do you see a power steering fluid level indicator in your dash? Nope. How about a radiator fluid level indicator? No way. Or what about an oil level or transmission fluid level indicator? Uh-uh….there is just dipsticks that need to be physically checked, periodically. Why is that? It’s because the auto manufacturers want you to physically check these vital systems instead of relying on a visual indicator to tell you when they are low because they know these things are unreliable and depending on them can be catastrophic to the health of your vehicle. They want you to make periodic checks under the hood; which you wouldn’t do if you had all these monitors telling you all is well under the hood. The only fluid level indicators I see in a vehicle is the wiper fluid indicator and the fuel level. The fuel level indicator is necessary for the obvious reasons I'm sure I don't need to explain. The windshield wiper cleaner is not a vital system in your vehicle that could cause damage to the system if it runs out and since the fluid reservoir is buried somewhere in your vehicle, it is not easy to check the level physically and a full tank of windshield washer fluid could last a year or longer, so in that case it makes perfectly good sense to have a warning light in the dash when the wiper fluid is running low. Is the fluid level in your cell a vital system? I think so, don’t you? Anyone who uses a HHO system in their vehicle should be periodically (perhaps weekly) checking under the hood to make sure that not only is the level correct, but that everything is clean and working properly. This is why the KZX1250 was designed without an inside the vehicle display. It’s just a waste of effort that gives you a false sense of security; and it’s only purpose intended by the manufacturer is to lure you to buy it. After using your system for a month or two, you’re going to know how often you need to top it off; you won’t miss the water level indicator, believe me! The display on the KZX1250 was not meant to be a monitor that you constantly watch while driving; it is a tool to help you set up and maintain the system by being right there in front of you where you need it when you are under the hood. Buy product x and you will not have this tool; nor will you have short circuit or thermal protection; those you WILL miss! Unlike LCD displays, the KZX1250 display is a 7 segment LED display that is directly driven by the controller rather than an LCD display that depends on a DC/DC controller to step up voltage to the display and requires a backlight; two things that can fail. The LCD display is just eye candy to get you to buy their product. Probably the most useful feature product x could offer is an indicator telling the user that the fuse needs to be changed; you won’t have to do this on the KZX1250, EVER!

…but the KZX1250 can’t be adjusted from inside the vehicle like product X can!

That’s correct and it’s a good thing for several reasons. For one, why would you endlessly keep changing your settings? Isn’t the concept of using an auto current PWM that you set it and forget it? The definition of insanity is to keep doing the same thing over and over and expect different results. Well, at some point you will know what the right setting is and when you do you will never change it again. I could understand that some people want to change their setting from time to time to see if they get better results using a different setting. This makes sense, but you don’t want to do this too often because it is difficult to track differences. You’re obviously going to check your results weekly or monthly and make small changes then. Before you make the small changes, you want to make sure that you have the same exact water level and the same exact electrolyte concentration that you used the last time, otherwise you’re just not going to get accurate results. This means you are going to have to pop the hood to do these things; so having the ability to change the setting inside is pointless when you’re already going to be under the hood; is it not? You also don’t want to change the setting too often as the controls will wear out and stop working altogether. Having the controls inside will only tempt you to keep adjusting them and perhaps others who see the display are going to play around with them as well.

These remote control displays don’t come without a price. They rely on two RS485 interfaces for communication and a DC/DC converter to power the LCD display and because of that they have extra weak links in them. If one of these weak links fails, you will have an unusable system; is it worth adding these weak links for this silly control panel that isn’t really needed and forego the vital protection that the KZX1250 has to offer? The KZX1250 was designed as a protected one piece design to avoid all those unnecessary weak links, why would you want them?

Where does the PWM box they use get mounted? I don’t see any information as to where to mount their box or that it is water resistant. If this box gets mounted outside the vehicle and doesn’t have the ability to resist moisture like the KZX1250, I don’t see it being a long term solution. If it gets mounted inside the vehicle, I would be very concerned about the safeness of it; especially since there is no short circuit protection and the body of it is a heat sink that gets red hot. Auto manufacturers do not run high current lines through the cab of a vehicle for a good reason; it creates a safety issue that is uninsurable. Putting this unprotected hot box in your vehicle is asking for trouble in my opinion.

Product x also advertises that their PWM has the ability to control a pump to pump more electrolyte into the cells keeping them full and the electrolyte circulated. Let’s see, you’re going to pump an electrolyte such as KOH (which eats metal) through a pump (which usually has metal parts in it) into your cell. Do I need to explain why this isn’t a smart idea? There are pumps that are chemically resistant, but they are quite expensive and because they are made out of a special plastic, they aren’t usually designed to run for long periods of time. The power you use to run them is wasted energy that produces no Hydroxy; therefore, it will take away from your results. This pump is also just another weak link that will eventually fail and if your setup depends on it, will render it useless. Is a pump necessary? I don’t think so.

The LCD display that product x has to offer isn't the first remote LCD control panel on the market. The market has already tested at least one other LCD control panel over a year ago and I don't see much mention of it anymore.

If a lame looking LCD display and controls inside the vehicle are still so important to you after reading this, then I guess you’re going to buy product X instead of the KZX1250. Just remember that I did try to warn you. Trading the reliability of a short circuit and thermally protected PWM for one that gives you a cheesy looking display that shows you unnecessary information isn’t in my opinion a smart thing to do, but hey, what do I know? Maybe I'm missing something. If you think I am, please let me know; I'd love to hear your opinion.

- Regards, FreeMindResearch

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