200 amp alternator?

[geusterman]

Anybody know of a big alternator us camper guys can use to charge batteries up quicker? Durablasts have a dual amp kit and companies that make big amp alternators but can't find one for our Dodges. George

 

[DBond]

sorry for the hijack but before you go that route have you considered;

a) what is the max charge current that is good for your batteries? I hear this should be less than 20% of the amp-hour capacity of your battery bank, some will say 10% max. I want to go to a 220 amphour setup, so 44A is what I am looking for, and I think the the OEM alternator can do that once the grid heaters are off and starting batteries recharged.

b) The OEM wiring is the biggest issue to charging camper batteries. 14awg has lots of voltage drop, so there isn't enough voltage to "push" the current into the battery. 10awg should be the smallest to get something good flowing, bigger may be needed. it's not just the current rating of the wire that is important, you may need "oversized" wire to get the voltage drop down. 8 awg has 1/4 the resistance, and voltage drop of the OEM 14 awg.

 

[geusterman]

Thanks Dbond. I have isolated the charging system and am using 8awg back for camper battery charging. It is part of my ongoing project to get a way from generators and propane and just do big battery and solar. Our Dodges are not used so much for ambulances and HD work trucks so the market goes to Chev/Dorf's for these big alternators. I want to be able to start the truck as a generator if I need to and charge the camper/RV.

 

[DBond]

I see you are on top of things, Sorry I don't know of any alternators options. The Hemi had a 190A option, don't know if it would fit.

What sort of charge current are you seeing with the 8awg? I have the wire and parts but haven't done the rewire yet.

 

[moparguy]

Some time ago, (years) there was a thread about a big alternator that is common on big trucks, could be found at most any big truck garage. Someone posted the part numbers for the alt. and pulley necessary to run it.



Sorry I can't provide more info, prehaps someone will chime in with a link.



Good luck, RR

 

[moparguy]

Found the old link;



The patriot (05-06-2002, 12:13 PM)

Quote:

Originally posted by K_Arts





I've been looking for a good aftermarket alternator, but can't seem to find one to my liking. I'm very interested in finding a reliable alternator.



Kev







Someone put up a post about a month or two back about refitting a BIG TRUCK alternator to the CTD.

It didnt look like too much of a problem.

I'll see if a search will pull it up.

Eric



Reply to this Message





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The patriot (05-06-2002, 12:15 PM)

http://216. 235. 147. 117/forums/showt... ight=alternator









But the info is to old to access. Lots of good information in those old posts, last I heard Steve was working on a way, but guess it's not gonna happen.

 

[K_Arts]

ha ha ha... just ran by this post. . and whoola Moparguy put up my old post. . whoohoo... I'm famous. LOL j/k



Yeah, I was looking for a bigger alternator to power all of my stereo equipment in my 2000. I found a guy (through a stereo forum) in which makes custom alternators and can gear them in any way you want, as long as you know your pulley size. If your interested, I can throw you his information. Unfortunately, I don't want to publically post it without his permission.



Thanks



Kev

 

[madmax4688]

I am checking with Ohio Generator about a 210 amp one. I will call them back on monday. I used a 210 amp one in my 99 but it is not the same as my 06 so they are probably going to build me one. I am a dealer for them but they are expensive around $600-$700.

 

[Matt400]

I have done 200A alternators on some gas fords from Vital Alternator in Texas.

Service was good and the parts are top notch.

I am sure they could size the pulley to produce the result you want at idle.



Looks like their web site is down at the moment but here is some contact info-

http://www.safetysource.com/adpage.asp?id=2988&uid=04202

 

[K5IP]

I did quite a bit of research into the maximum charge rate that was optimum for my two golf cart (in series) system. My golf cart batteries are rated at 220AH and discussions with designers at Johnson Controls (the battery manufacturers) indicated the maximum (actually optimum) charge rate was 20% of rated AH value, or 44A max. This charge rate was to be established until the battery reached 14. 7 VDC. Then the charge was to be terminated.

Bigger alternators can do a good job of recharging starting batteries quickly (they have very thick plates) but for golf cart, or deep cycle type batteries, which have thinner, but more plates (more AH, but less peak current capacity) charging rates should be limited to the above condition.

I know this defeats the "getting away from generator" idea, but it seems like we are stuck with it.

I designed/built a switching power supply along with an active voltgage limit system for my trailer, but the newer commercial systems (along with a "Wizzard" ) do basically the same thing. I still need a generator to make all this work

Rog

 

[K_Arts]

As you guys probably already know... one thing that you really gotta be careful with is making sure you know at what your charge rate is at any given RPM. For gassers its not such a big deal being that they redline at 6k+. But being that we are redlining at 3k, if the pulley on the alternator isn't measured and swapped with the right size, you'll never reach optimum charging power.

 

[geusterman]

Great discussion. I am jumping over the math for charging amps based on the Dodge Expedition camper which had a larger alternator than stock for his glass mat batteries. The two 6V mentioned above at 44amphours... are controlled by the charger anyway if I am thinking right. Bigger batteries can suck bigger amps I am believing. Correct? George

 

[DBond]

The two 6V mentioned above at 44amphours... are controlled by the charger anyway if I am thinking right. Bigger batteries can suck bigger amps I am believing. Correct? George

If you are just connecting your camper batteries to the alternator, which is typical, there isn't a "charger" inline that will control the charge current. The current will be limited by how much the batteries accept at the particular voltage they are getting from the alternator. This is a somewhat unbalanced system, because the charge current is a function of the voltage, and the voltage is controled by the truck to charge the starting batteries. Starting batteries are usually only slightly discharged, so they charge up fast and the voltage drops to the float level (~13. 8V at 72F) Meanwhile your camper batteries may be 50% discharged. You can't get optimum charge rates for for batteries at different states of charge off a single voltage source.

The 20% guidline is for wet deep cycle. AGM and gel may be lower.

Yes the bigger the battery bank, the more current it will draw off a constant voltage source, but in reality voltage drop in the wires will this increase less then increase in battery size.

 

[betterthanstock]

My understanding is that the ECM controls the alternator field, and the charge is adjusted to protect the alternator, and the batteries. That's why there are battery temperature sensors.

Deep cycle batteries usually require a lower charge voltage than the maintenance-free type, but they need to be equalized at a higher voltage.

Do a search on this. Lots of good reading, such as below:

http://www.rpc.com.au/reindex.html?.../products/batteries/car-deepcycle/carfaq4.htm



It sounds like you need a marine dual winding alternator, with a separate regulator for the camper.

 

[geusterman]

Hmmm... . maybe a bigger project than alternator capacity. I have 8 AWG for the positive running from a selenoid and regulated from key. I would use a heavy pigtail to connect to camper... making sure the wire capacity makes it through to the charger. I may have to have this engineered. I may just keep a Honda 2000 around. Lot easier but it justs limits backcountry time... panning for gold and such. George