Alternator to Battery Charger....

[haywoodphotomaccom]

As suggested by readers of my build post I've copied here too.





The unit is up and running. One or two more leads to be connected for accessory measurments but the alternator is cranking out the amps to the house battery far better than before. This unit charges the starter battery and house battery independently and at a much faster rate.

With my previous setup the alternartor would charge the chassis battery first and quickly fall off leaving little going to the house batteries. The solar typically does a great job charging the house batteries but on cloudy winter days it was barely keeping up with my daily draw. The Gorman trip was a great example of why I wanted this new setup. It was mostly cloudy the two days we were there with very little solar coming in. We went on a couple hour drive around the park but hardly any juice went into the house batteries. A two hour drive now in those same conditions would have fully topped the batteries up.

This last day of watching all the meters (one for almost everything now) I see the house batteries getting far more amps than before. This AM it charged at a steady 50 amps or so on a 30 minute drive. The output to the house battery works in 4 stages similar to the solar for maximum efficiency.

(Disclaimer: I am not an electrical expert of any kind and I am sure there are many other ways to achieve what what we have but this is the one that is really working for what I need. Ramsey would could probably rub two pennies together with a wire in there somewhere and get what we have done for free. Happy to answer any questions if you have any)

[E350]

Haywood, thank you for posting this.

To Haywood and you electrical guys: I am an electrical dummy so please bear with my questions and please feel free to make suggestions beyond the scope of my questions. I am all too familiar with the situation where my question is too narrow and doesn't address more important but unknown to me ssues.

I have been thinking about running everything through the house battery (250 AH UPG UB-8DL AGM a single battery 12v 24.70" x 10.55" x 9.65" 160.94 lbs). I have a specialized type of alternator that generates 110v 5000w which I think I might replace with Haywood's set up if it would provide similar or sufficient power. Am I right that it generates 2520w at 210 Amps at 12v (W = A x V)? My van needs are clearly met with 2520w under the most severe conditions,* so the Sterling Power set up is intriguing.

http://sterling-power-usa.com/12volt-21 ... arger.aspx

And since my van is already set up to use two alternators, I could power the Sterling with a second 12v alternator in the top engine position.

* Yes, I have powered my house with the Auragen during power outages, but it is otherwise overkill for my van needs.

[daveb]

Originally Posted by E350

I have a specialized type of alternator that generates 110v 5000w which I think I might replace with Haywood's set up if it would provide similar or sufficient power.

I'd suggest you call both Mark Grasser of DC power solutions and Adam Nation of Nations Alternator before you jump. Some alternators put out higher voltages that make using Sterling unit useless. I'm fairly sure most of the alternators built by these companies use Denso components but in both cases they use/build/install an upgraded regulator. I could be wrong though and is why it's best to actually talk with them. I know Nations can rig the alternator to control the charge using a remote Balmar regulator but is it really necessary? I'd hate to see you install something that requires you to change the alternator unless that is also in your goal. In my case I went with an XP270 alternator with a modified regulator and it has preformed well. I do like the idea of the Sterling product but it probably wouldn't do much with my alternator setup.


http://www.markgrasser.com/
http://www.nationsstarteralternator.com/
http://www.balmar.net/

[haywoodphotomaccom]

Still watching the numbers on our unit. Love to know what people see actually going to their house batteries. Obviously depends on the battery state at the time but anyone have some data. Be interesting to see what numbers others are getting based on battery condition/state.

[E350]

Daveb and Haywood: I had assumed that the Sterling was some sort of MPPT charger which would convert amps to volts when volts were too low (e.g., engine rpm too low) to charge into the battery and, also, convert unnecessarily high volts to amps when the volts are sufficient to charge the house battery.

But I see no mention of MPPT on the Sterling Power documents.

What is actually going on with the Sterling Power unit and why is it so special?

[daveb]

Originally Posted by haywoodphotomaccom

Still watching the numbers on our unit. Love to know what people see actually going to their house batteries. Obviously depends on the battery state at the time but anyone have some data. Be interesting to see what numbers others are getting based on battery condition/state.

It depends on the batteries state of charge. When my batteries are low I see charge rates in the 20+ amp range which quickly tapers off. I've seen it as low as only a few amps. The voltage is fairly steady during the high amp charge at 14.2-14.5 then drops to about 13.9-14.2 after a full charge.
[edit] I really watched my charge voltages with my Link-10 monitor. When the batteries were low I saw voltages as high as 14.7 and the charging amps @ just over 20. But the batteries were only at 70% DOD. Fully charged the alternator dropped to 13.4 with less than 5A being pushed into the house batteries.
I've also got 270W of solar as well. I haven't seen issues with overcharging as far as I know. I've been using Odyssey AGM's for the starting batteries since 2009 and no issues yet. Before that I was replacing starting batteries every year or so.

As far as the Sterling unit I'm under the impression it is more of a voltage regulator...I did talk with Grasser about it some time back but didn't go into detail about it much as I was discussing alternators. [Edit] Grasser is DC power solutions not DC power products. Although DC power solutions sells upgraded alternators it shouldn't be confused with DC power products known for high output alternators.

[haywoodphotomaccom]

The simple answer I got was basically the controller splits the incoming energy from the Alt into two separate regulated outputs. One is a simple pass through and charges the chassis battery as it normally would. The second output is boosted and optimized to charge the house battery.

On testing I can see the chassis getting 15 amps while the house is getting 50 amps and each at different voltage values. More info coming as I learn more through use....

[daveb]

Haywood I agree with that. Boosting the voltage to 14.8 can provide a quicker charge. It works well with standard alternators that put out lower voltages especially when the typical regulator says "taper off" to a lower voltage when it doesn't need to. I'm taking voltages off my scan gauge and I don't know how accurate that is. Also a long run to the batteries creates a voltage drop and I can see a benefit to anything that bumps up the voltage. I'll actually have to see what the voltage is during a charge at the house battery. Still, I'm not having issues with my setup so no need to change anything on my end. The reason I switched to a higher amp alternator was a load issue caused by my Starcool. The modified regulator was an added benefit. I can see a huge advantage to those with smaller alternators or those people that need a quick charge. Frequenting overcast areas where the solar is useless is a reason to look into something like what Sterling offers as well.

[haywoodphotomaccom]

Screen grab on engine start up:



Screen grab after system goes through diagnostics and is now operating.

[E350]

Haywood: What's "COM" and do they have a system which will charge on the house battery so I can leave my oem vehicle battery/alternator alone?