Jump to content

 

Welcome to TheMalibuCrew!

As a guest, you are welcome to poke around and view the majority of the content that we have to offer, but in order to post, search, contact members, and get full use out of the website you will need to Register for an Account. It's free and it's easy, so don't hesitate to join the TheMalibuCrew Family today!

miked272

Alternator upgrade for 1500w amplifier in 1988 Malibu skier

Recommended Posts

miked272

Hi All where would I look to find a higher output alternator for my 1988 Malibu skier? It has the 350 Mercruiser with 260 HP. I'm installing new stereo components and want to make sure the electrical system can keep up with the increased load. Can I just find any Chevy alternator to bolt on, or are there specific alternators for marine applications like this? I believe I will need at least a 120A alternator to handle the load. I don't plan I blasting the music often, but I don't want to end up draining the battery during day outings where we do crank it up>

Any suggestions are appreciated.

Share this post


Link to post
Share on other sites
JasonK

Put in a second battery too! I rebuilt my alt. long ago and did find at least 1 replacement with higher output, but I don't think it was as high as 120A. Good luck

Share this post


Link to post
Share on other sites
REW

First YES you need a marine specific alternator. The automotive ones are not sealed and will make sparks that can/will ignite fumes in an enclosed engine compartment. There are a couple of marine supply houses that will have the larger output alternators however they get real pricey.

Good luck, let us know what you find.

google is you friend

http://www.boundlessoutfitters.com/Alternators-s/9.htm?gclid=CjwKEAjw-ZqrBRDt_KjhjcbzhhISJAAlRGvlZnHGVfSllxWkG5Kl8hS1cn4yCk12OgZlMVNuKSiyORoCPmjw_wcB

Edited by REW

Share this post


Link to post
Share on other sites
jk13

Mechman has marine offerings now. But pricey.

Most newer boats run a larger stock alternator than yours. Call Bakes or Skidim and see if there is a bolt on solution that they know of.

Share this post


Link to post
Share on other sites
mikeo

Before you go too far down the road of a new alternator, make sure you really need it... While the casual glance math might lead you to believe that you need an upgraded alternator, chances are you don't. The 1500W is power delivered to the speakers at peak output for a specific load (2, 4, or 8 Ohm typically); You can't just take 1500W/12V=125A and immediately think you need to upgrade your alternator. Take a look at the fuses on your amplifier, I'm betting they're 2x 30A or 2x40A and use that to calculate how much power you need. If your amp has 2x 40A fuses and you're running it at 99.9% of capacity then you _might_ be using close to 80A @ 12V = 960W of power drawn from the system. If you're concerned about "brownouts" (power drops) then you could put in a large capacitor (1-3 farad) in line with the power lead to the amplifier to smooth out the power delivery.

I've never needed more than one battery in a boat, and was disappointed when Malibu "forced" me to get a second battery in my '15 (but I understand their logic with the new dash system). I typically run 3-5 amplifiers for 8-12 speaker systems and the only time I've had a dead battery was when my GPS tracker didn't shut off during the off season.

Unless you're sitting around in a cove listening to music with the engine shut off all day you shouldn't need to upgrade the battery or alternator.

For reference: on my '93 Eschelon I ran 10 speakers with 3 amps from one battery and the stock alternator; 4x tower (400W), 4x cabin (400W), and 2x (250W) sub, total 1050W @ RMS amp power.

Edited by mikeo

Share this post


Link to post
Share on other sites
gorilla

I've got a Mechman 240amp on my boat. Works great, but my stock 95amp one would supply enough juice to keep the batteries topped off, but wouldn't charge of I ran the batteries down while anchored. I always have my battery charger hooked up when the boat is out of the water. I'm pushing 4700 watts, have 4 Kinetik batteries and the 240amp will now charge if I need it to. I ran my stereo for almost 6 hrs Saturday and batteries were reading @ 12.1v when I left the cove. Voltage gauge read 13.8 on the 25 minute ride back to the launch ramp. Checked the batteries at home and read 12.5 with my multimeter. So, recharged to about 90% in that short ride.

Moral of the story, an extra battery and stock alternator is plenty good if you launch at 100% charge.

Share this post


Link to post
Share on other sites
electricjohn

I've got a Mechman 240amp on my boat.

It takes 5 of your HP just to turn that thing. Sounds like it should be water cooled. Edited by electricjohn

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...