Please recommend higher-amperage alternator for V6 3.0 for better DC charging

[daveemac]

1990 Odyssey, V6 3.0

 

Stock alternator is 70A, which limits my DC charging to roughly 20A from what I've been told.

 

Do you have recommendations for drop-in replacements that will allow me to pull more amperage for house battery charging?

Thanks !

[thewanderlustking]

Do a little research.  This isn't meant to be the rude "ljust google it" response it sounds like lol!  

 

I found one in about 30 seconds.  For instance If you go onto Rock Auto and put your year in (call it a pickup) you get a 100 amp option that comes right up.  Rock Auto is about the quickest most reliable way to look up and cross reference parts.  (Amazon is the worst... at best go there AFTER you have the part number you need).  eBay is really good too and will find you a broader range, but it isn't as accurate as Rock Auto and you should verify with a couple sources or auctions.  

 

Even easier, just call your local parts store, they will most likely also have a higher output option available.  You should probably call them all, see who has the best one, be it price or highest output.  This is also probably smarter way to go as it lets you pull your alternator out to compare and make sure the replacement is going to fit, and quickly exchange it if not.  As a mechanic I can't even tell you how often parts ordered are wrong...  I ALWAYS check every single alternator side by side before installing the new one.  Verify mounting brackets, plugs.  A higher output alternator will frequently be larger, but if the mounting brackets match up, it usually will still fit.  

 

You don't necessarily need to "color outside the lines" and get tricky by asking for a different make/model/year that you found will fit....  That option is frequently available, but takes brand familiarity and knowledge.  For instance on Volkswagens I know I can bolt a 120amp alternator onto a 2.0 4cly that usually comes with a 50-70amp one by ordering a specific 6cyl alternator instead.  This kind of information though requires either some serious digging, asking the right people, etc...  

 

Finally, many towns will have a place that can rebuild alternators to spec and rewrap them for higher output.  This is the kinda place that a good local stereo shop will know about.  These are rarely cheap though.  And there also becomes a point where a really high output alternator starts to sap too much power from the engine under heavy load.  Getting your 70amp alternator rebuilt to pump out really silly numbers is going to take precious power away from the engine.   

 

So be realistic though with your "wants" and do a little math to figure out what you might actually need  A stock alternator will recharge your slightly drained engine battery (from a normal startup) in under 7 minutes. A dead no-start battery will usually be charged up within 14-20 minutes.  The battery isolator in your engine bay adds some minor complexities to this system and they work in different ways.  But in the most basic form, once one battery hits a certain voltage, it switches over to recharge the other one.  If you have a single lsay 100ah sized deep cycle house battery, you once the engine battery is charged, the other one will take 1 hour to charge with a 100 amp alternator.  

 

Google "how long does the alternator take to recharge a house battery?" and you come up with a lot of good information and formulas for figuring it out.  

Edited July 28, 2022 by thewanderlustking

[Maineah]

One issue with the house battery is distance and a #10 wire.

[Ssunrader]

Don’t know if the op ever looked at the responses so far, but I just found that an oem Jaguar XJ6 (93-97) alternator is rated at 120A, and is a bolt on replacement for our feeble 60A alternators. Keep in mind the original ones were specified for a pickup, so engine ecu, headlights, fan, nothing else.

Can be ordered from anywhere rebuilt for about $130.

[Odyssey 4x4]

This is what I found when researching for my build...

 

https://www.lceperformance.com/High-Output-Alternator-130-Amp-3VZ-1988-1992-p/1080012.htm

[Nam]

I ordered one from https://www.excessiveamperage.com/ and so far so good; kind of pricey but it works well so far

[Odyssey 4x4]

8 minutes ago, Nam said:

I ordered one from https://www.excessiveamperage.com/ and so far so good; kind of pricey but it works well so far

 

What did you end up paying / what amperage output? 

[Nam]

3 minutes ago, Odyssey 4x4 said:

 

What did you end up paying / what amperage output? 

I think I paid close to $300. Output varies but the highest I got was about 120A when running AC on the giant inverter (measured with my own amp meter) I also had to replace the belt as it uses smaller pulley to get higher RPM for idle charging current. I also had to replace the stock cable with #2/0 welding cable.

 

It was a lot of work and I don't think I would do it again.

 

The guy from the site was very helpful

[Odyssey 4x4]

16 hours ago, Nam said:

I think I paid close to $300. Output varies but the highest I got was about 120A when running AC on the giant inverter (measured with my own amp meter) I also had to replace the belt as it uses smaller pulley to get higher RPM for idle charging current. I also had to replace the stock cable with #2/0 welding cable.

 

It was a lot of work and I don't think I would do it again.

 

The guy from the site was very helpful

 

When you say it was a lot of work do you mean just installing the new alternator and running higher gauge cables? 

[Ssunrader]

Ok, so I spoke too soon about the “bolt on” part regarding the Jaguar alternator swap. As it turns out, the Jaguar part requires an offset extension to the lower bracket in order to be usable on the 3.0.

 

The stud used to attach the main power cable is also larger, but that is a bit easier to adapt.

 

i will post a picture of the adapter drawing used to attach it to the original slotted bracket when I get it sorted out, in the event that someone else is looking to go with the swap.

[Maineah]

Take the original to a generator shop in many cases they can use a larger field rotor for a amp boost.

[thewanderlustking]

On 10/11/2022 at 9:15 AM, Maineah said:

Take the original to a generator shop in many cases they can use a larger field rotor for a amp boost.

This is your very best bet for upgrading the alternator past the 130amp one LCE has. Again though your local parts store will have some minor upgrades from stock. 
 

Read my earlier response above. And if you still feel you need a bigger charging option, you might be better off putting solar panels on the roof.   Or running an evil generator. 
 

It really depends on why the OP wants to charge the house battery so quickly…