PDA

View Full Version : Need to upgrade alternator.



Stroble
06-01-2014, 12:20 PM
I added 3 amps to my boat and now I can't listen to music when wakeboarding cause the perfect pass will cut on and off due to low voltage. I was looking to upgrade the stock 70amp alternator with this 160amp alternator i found online. http://www.dbelectrical.com/p-7351-new-marine-160-amp-high-output-alternator-universal-mount.aspx. Will this fit in my boat? I have a 2005 mobuis LS.

David Analog
06-01-2014, 12:56 PM
I added 3 amps to my boat and now I can't listen to music when wakeboarding cause the perfect pass will cut on and off due to low voltage. I was looking to upgrade the stock 70amp alternator with this 160amp alternator i found online. http://www.dbelectrical.com/p-7351-new-marine-160-amp-high-output-alternator-universal-mount.aspx. Will this fit in my boat? I have a 2005 mobuis LS.

Yes, Perfect Pass has always been voltage sensitive.
I always recommend staying with a domestic alternator and getting one that delivers good amperage at lower rpms.
You can run the Perfect Pass on the starting battery along with all boat electronics and then isolate the dedicated stereo bank (including ALL audio components) with a voltage sensing solenoid. This, plus batteries in good condition with sufficient capacity, and a shore charger would negate the need for an upgrade alternator....not that there is anything wrong with upgrading the alternator.

David Analog
06-01-2014, 01:00 PM
Btw, if it is a true 160 amp alternator there will be considerably more drag which means you will need to also upgrade the belts and pulleys. You cannot get more amperage output without more mechanical resistance. It shouldn't be enough to tax the engine but it will be enough to tax the stock drive belt and pulley.

Stroble
06-01-2014, 04:37 PM
I have 2 barriers with a switch, I leave it on all, how would I isolate the starting battery?


Sent from my iPhone using Tapatalk

MLA
06-01-2014, 04:54 PM
The first thing i would want to do its confirm the battery(s) is a full charge to start the day and is in good shape charge holding wise. next would be to make sure the alternator is functioning properly. I failing or failed alternator will not do its job, regardless of what its advertised amperage is. After that, I would be checking voltage at the helm to make sure we dont have a voltage drop. A new 160A amp wont fix that, you would still be back at square 1 with low voltage to the PP.

Turn the switch to "1" or "2" isolates the other from the system.

David Analog
06-01-2014, 04:55 PM
I have 2 barriers with a switch, I leave it on all, how would I isolate the starting battery?


Sent from my iPhone using Tapatalk

With a voltage sensing solenoid (VSS, VCR, ACR). A Blue Sea Add-A-Battery kit will do. It will protect your alternator and preserve the voltage on the starting-bank/boat-systems-side if the scheme is wired correctly. With a big audio system, a large capacity stereo bank, and a smallish alternator, it will tend to increase your dependency on AC shore charging. That's normal.

Stroble
06-01-2014, 07:12 PM
Yeah thanks everyone for all the info, I have the all the amps hooked up to the positive terminal of battery 1 and the negative to all the amps to the negative to the 2nd battery. Would it be best to buy a third battery and a shore charging system?


Sent from my iPhone using Tapatalk

MLA
06-01-2014, 08:12 PM
A 3rd battery and shore charger may be a good investment, but with the given symptom, I dont see either of those a fix, but another battery could very well just pile on to the current low voltage issue.

Go back to the basics and diagnose the low voltage issue at the PP. Once isolated and fixed, not band-aid'd, then I would suggest some rewiring at the switch.