DC Generator source

[Rick Hoving]

Thank you for the interest in our DC Generators and please feel free to use this forum with any questions you may have or, don't hesitate to contact us directly for your specific application. We look at each individual installation to recommend the best fit to match voltage, amps required and depth of discharge.

We do not have a single product for every application and our Diesel Battery Chargers have different features than the simple gasoline powered units. There is not any need for a charge controller for any of our units. They simply connect directly to the battery or, bank of batteries with the appropriate sized cable set. The alternators we have directly coupled to our engines (gas, diesel and soon to be released propane) are automotive type that are internally rectified and self regulating. We modify the regulators of our gasoline and propane powered units where we add the two features to control the DC energy of turning the power on/off and making the high/low voltage selection.

We can provide these simple features with a diesel powered Battery Charger, but typically they are provided with an under voltage relay and autostart function where in a 24 volt system where the UV set-point (configurable) is set at <26 volts. We set the runtime for one hour (configurable) where typically this is plenty of time to recharge the batteries to 85-90% of their capacity. The Charger constantly monitors the batteries voltage and if it needs to restart after this hour it will run for up to another hour. When the units are installed and a typical load is introduced, you can idle the diesel engine back to an RPM where to engine is working at its peak performance.

This is a simple procedure and easy to tell where the optimal RPM is by listening to the engine and feeling the vibration produced. It most instances, it is between 1800 and 2200 RPM. The 24 Volt Diesel unit produces 28.8 volts of straight DC energy and as the batteries absorb the power, the amps slowly drops to a trickle as the batteries become charged.

We offer our Duke Diesel Battery Chargers with various features including on-board fuel tanks, cold climate kits, mufflers, full enclosures, cyclone filtration as well as our popular Remote Monitoring System (RMS). The RMS adds the capability to monitor you DC Charger from anywhere you have an Internet connection.

We recommend utilizing our DC Chargers as backup for your primary charging systems whether it is solar, wind, thermal or hydro. Our units do not include "multi stage" charging for finish charging as we find this wastes fuel and takes a long time where the engines run with minimal loads. With the introduction of a backup DC battery charger you can size you primary charging system and battery bank to a more affordable size knowing you will always have a backup in times where the primary system can't keep up and/or, your DC loads are higher.

[Rick Hoving]

Hi Cariboocoot,
Thanks again for including my thread! Our chargers are self regulating - just like your vehicle. Your won't overcharge your batteries, just like your vehicle battery doesn't overcharge if you drive all day and night! We have had great sucess charging all types of batteries including AGMs and recommend deep cycle batteries in general for best performance.
Rick

[Rick Hoving]

Greetings inetdog,
No need for charge controllers with our DC Battery Chargers. The alternators are internally rectified and self regulating just like the ones in your vehicle. As your batteries absorb the charge the amperage drops lower and lower and lower and the batteries only accept what they are capable of.
Rick

[inetdog]

Hi Cariboocoot,
Your won't overcharge your batteries, just like your vehicle battery doesn't overcharge if you drive all day and night! We have had great sucess charging all types of batteries including AGMs and recommend deep cycle batteries in general for best performance.
Rick

Thanks Rick. I notice that in your description you recommend using a timer to limit the amount of time the generator runs. In addition to saving fuel this will also remove the threat of long term overcharge. Common sense (so uncommon these days!)

Zero maintenance batteries for vehicles are built on the premise that a vehicle's charger will not overcharge them and so there will never be a need to add water. In practice that does not work. Some of this can be attributed to faulty voltage regulators, but some of it is just that the set point is actually delivering a constant overcharge which is electrolyzing water. An AGM battery, kept within its voltage limits, will just recombine the hydrogen and oxygen without venting, and a FLA battery bank can have water added as needed.

"In theory there is no difference between theory and practice. In practice, however...."

[Rick Hoving]

Thanks for the link to these DC generators. Although the electrical information seemed a little skimpy on their web site it appears to be a nice unit. Whether they are suitable for deep cycle charging remains to be seen. When time permits contact with the company will be necessary for particuliars. For example the charging specs of 28.8 v for the 24v unit did not say whether the full amperage is maintained at the 28.8 volt level or does it taper once the 28.8v is reached. 160 continous amps at 28.8 volts will have some serious heat removal problems.

I did not understand the 36 volt cut out in the specs.
I can't think of any situation where 36 volts would be reached in a 24v system except when the "magic" smoke is released. If anyone has experience with these units in a deep cycle situation, please chime in with your experience.

Good question Sawmill!
In an extreme case (which we never have seen happen) the internal diodes my fail in the alternator and the voltage elevates to a maximum of 36 volts where the voltage regulator cuts out.
Rick

[vtmaps]

Our chargers are self regulating - just like your vehicle. Your won't overcharge your batteries, just like your vehicle battery doesn't overcharge if you drive all day and night! We have had great sucess charging all types of batteries including AGMs and recommend deep cycle batteries in general for best performance.

What about temperature compensation? In the winter my cold batteries need about 30.5 volts. In the summer, I want my charger to reduce its voltage as the batteries get warm. Actually, I think that is a bit of a safety issue.... thermal runaway can occur in the absence of temperature compensation.

--vtMaps

[Rick Hoving]

What about temperature compensation? In the winter my cold batteries need about 30.5 volts. In the summer, I want my charger to reduce its voltage as the batteries get warm. Actually, I think that is a bit of a safety issue.... thermal runaway can occur in the absence of temperature compensation.

--vtMaps

Our chargers are designed as a backup for your primary charging system and deliver either a single 28.8 volts as with our 24 Volt Diesel powered autostart units or, the selectable 28.8 High setting, 28 volts low setting on the simpler ones. We recommend running the chargers for an hour at a time to restore bulk energy and prevent battery damage from being overly discharged. Nothing can kill your batteries quicker that running them flat. We have systems installed at very remote locations in the Yukon and North Sea as well as the dessert SW at broad range of temperature extremes and never had issues with too low of voltage delivery in the cold or, overheating of batteries in hot climates. Folks that want to start the gas powered chargers and walk away, simply put an hour worth of fuel in the tank and refill it when they are ready to run again. We purposely make them very simple to install and operate with a minimum of items to fuss with. As your batteries absorb the energy and become charged, their ability to accept more energy dwindles to only a few amps and our chargers with their self regulating alternators can't increase the current if they wanted to. The voltage will remain relatively the same through the bulk charging, but the amount of amps delivered are minimal towards the end. Sophisticated multi-stage chargers are available for "finish" charging if you feel it is necessary to bring your batteries up to their last 10% charge, but once a load is applied the batteries will no longer be finished charged. If you want to safely, reliably and quickly replace the DC energy in your batteries, our chargers are for you!

[Cariboocoot]

Hi Cariboocoot,
Thanks again for including my thread! Our chargers are self regulating - just like your vehicle. Your won't overcharge your batteries, just like your vehicle battery doesn't overcharge if you drive all day and night! We have had great sucess charging all types of batteries including AGMs and recommend deep cycle batteries in general for best performance.
Rick

Unfortunately this is not true. Not all batteries take the same charge Voltage, and the settings on your generators are too high for many - especially AGM's.

So basically this is a hopped-up car alternator bolted to an engine. The lack of user adjustable Voltage is a significant shortfall of design. Of course the long wires from the DC gen to the batteries may cause a significant Voltage drop. Although most car alternators in fact temperature compensation it is no place near as accurate as the type used in solar charge controllers. In this instance it would be worse due to the lack of the ability to sense actual battery Voltage.

I can't say I'd recommend this product to anyone, due to the lack of adaptability to individual installations.

[Cariboocoot]

I have removed Mr. Hoving's last sales pitch and am closing this thread. Regrettably he has been less than direct in answering legitimate questions about his product. If anyone has an further inquiries, please send them to him directly.

This thread will be moved to the product review section.