High Output Alternators

[BADS24SSV]

What are you all using? My 100A unit takes too long to re-charge the batteries and isn't enough to keep the charge up while boarding and blasting the stereo. I have the HO 8100 engine.

[Wylietunes]

My 100A unit takes too long to re-charge the batteries

This is due to the fact that alternators make for poor battery chargers. They are not designed or intended to recharge a dead battery. Not saying they wont, given enough time, saying its not what they are intended to.

isn't enough to keep the charge up while boarding and blasting the stereo.

What brings you to this conclusion?

[leetudor]

http://www.wakespeed.com/

[MoneyMike80]

Have you tried running a Capacitor? I had the same issue running 4 amps to the point the boat would shut down. As well I changed to running one yellow top optima(for stereo systems) and one blue top marine optima batterie , changed from 4ga wire to 0ga on my larger amps and every time I pull my boat out I trickle charge both batteries. Make sure everything is grounded to your batteries as well.

[TrueKaotik]

What are you all using? My 100A unit takes too long to re-charge the batteries and isn't enough to keep the charge up while boarding and blasting the stereo. I have the HO 8100 engine.

What stereo equipment are you running and how many batteries are in your battery banks? Are you shore charging at all when done? A alternator amperage upgrade shouldn't be needed for most small to modest systems in these boats.

[BADS24SSV]

This is due to the fact that alternators make for poor battery chargers. They are not designed or intended to recharge a dead battery. Not saying they wont, given enough time, saying its not what they are intended to.

I never run them completely dead. Only to the point of "distortion" due to what I assume is low power then run the boat. But once I get to that point it could take hours to re-charge.

[/QUOTE]What brings you to this conclusion?[/QUOTE]

This is my assumption based on not being able to bring the batteries up to charge while driving and running the stereo. Now I have not actually started with a full charge and run the boat to the point of distortion. But based on math, mine does not seem enough. Assuming 100% efficiency, I need at least 90A (assuming 14.4v) continuous just to run the stereo amps (MHD900/5 and M600/6 and will add another M600/6 and bridge all channels (which will add another 50A) at full RMS power. I know RMS is not actually continuous in the truest definition cause music fluctuates, but this is what I have to go with for my assumptions.

I do shore charge the boat as I have a built in charger. I run 2 AGMs dedicated to the stereo and one for the rest of the boat.

I know you are an audio guy so maybe you have alternate experiences and recommendations?

All: I do shore charge the boat as I have a built in charger. I run 2 AGMs dedicated to the stereo and one for the rest of the boat.

[BADS24SSV]

Have you tried running a Capacitor? I had the same issue running 4 amps to the point the boat would shut down. As well I changed to running one yellow top optima(for stereo systems) and one blue top marine optima batterie , changed from 4ga wire to 0ga on my larger amps and every time I pull my boat out I trickle charge both batteries. Make sure everything is grounded to your batteries as well.

Capacitors are only good for short/high power needs and do not add capacity to the power of the system. Usually for high powered bass when the batteries or alternators are not enough to keep up with bass "hits". they do nothing for charge longevity.

[Wylietunes]

Id steer clear of a CAP, as they are typically only a bandiad to prop up short voltage sags. They will do ZERO to help an actually low supply voltage issue and can actually add to the issue. In boats and other non-daily use vehicles, CAPs can actually be a liability to the batteries.

I never run them completely dead. Only to the point of "distortion" due to what I assume is low power then run the boat. But once I get to that point it could take hours to re-charge.

IF you are hearing a change in the music or experiencing an amp shutting down and it is do to battery voltage, then yes, you have run them dead. Keep in mind that a depleted 12V battery is about 11.6 give or take. Simple 12 volt thinks like lights and blowers will still run, but amps and head units tend to hit their low voltage threshold. For best battery life, its best to not run them below 12V.

So back to my original post. Yes, it will take an alternator a long time to recharge a depleted battery. However, if the stereo exhibits issues once the engine is back running, I suspect a low voltage or battery issue, one in which a higher output alt is not the cure. You may just have a failing alternator, bad battery or bad cabling. Could also be too small of a gauge cabling supplying the system.

Lots to check before I would have the expectation of a high output alt curing your issue. Would hate to see the time and money spent, and the low voltage issue still be there.

I need at least 90A (assuming 14.4v) continuous just to run the stereo amps (MHD900/5 and M600/6

Even with all chnls driving a 2 ohm load, I doubt you are hitting 50A continuous. Add another 10A with a 2nd 600/6. You may see peaks as high as 100A draw, but keep in mind that the system is filtering through the battery(s). The alternator should handle those peaks and valleys.

Have you measured voltage at the alternator output and batteries while the engine is running and the alt is under load of the system?

I run 2 AGMs dedicated to the stereo and one for the rest of the boat.

Is this audio dedicated bank always receiving alternator charge when the engine is running? It should. How is this system configured?

[BADS24SSV]

Id steer clear of a CAP, as they are typically only a bandiad to prop up short voltage sags. They will do ZERO to help an actually low supply voltage issue and can actually add to the issue. In boats and other non-daily use vehicles, CAPs can actually be a liability to the batteries.



IF you are hearing a change in the music or experiencing an amp shutting down and it is do to battery voltage, then yes, you have run them dead. Keep in mind that a depleted 12V battery is about 11.6 give or take. Simple 12 volt thinks like lights and blowers will still run, but amps and head units tend to hit their low voltage threshold. For best battery life, its best to not run them below 12V.

So back to my original post. Yes, it will take an alternator a long time to recharge a depleted battery. However, if the stereo exhibits issues once the engine is back running, I suspect a low voltage or battery issue, one in which a higher output alt is not the cure. You may just have a failing alternator, bad battery or bad cabling. Could also be too small of a gauge cabling supplying the system.

Lots to check before I would have the expectation of a high output alt curing your issue. Would hate to see the time and money spent, and the low voltage issue still be there.



Even with all chnls driving a 2 ohm load, I doubt you are hitting 50A continuous. Add another 10A with a 2nd 600/6. You may see peaks as high as 100A draw, but keep in mind that the system is filtering through the battery(s). The alternator should handle those peaks and valleys.

Have you measured voltage at the alternator output and batteries while the engine is running and the alt is under load of the system?



Is this audio dedicated bank always receiving alternator charge when the engine is running? It should. How is this system configured?

My batteries are connected with the alternator and are all grounded together to the engine. I do not recall the positive cable size, but I believe the main ground cable is a 00ga. I will have to check on the actual voltage coming to the batteries from the alternator. The gauge reads about 13 maybe a little more. But no idea how accurate that is.

Right now the system is configured as follows: Starter/rest of boat battery is connected to batt switch on one setting and the stereo batteries are connected to the other (dual battery switch), but the amps and stereo are connected directly to the batteries. So I can turn the switch off which shouldn't drain the boat battery while just parked and run the stereo. This is how it was configured when I bought it. I am not sure this is the best set-up but at least I know I do not have to worry about draining the starter battery. I need to trace the power to see which switch position is on which battery though as I do like to run power to the boat for charging phones or lighting without draining the starter battery and because the stereo is always on I cannot tell which position is which just from turning it. Correct me if I am wrong, but I believe the switch has to be on all in order for the alternator to charge all the batteries. Meaning if in the off position, none get alternator power?

[Wylietunes]

but the amps and stereo are connected directly to the batteries.

In regards to alternator supply, this configuration leaves you open to isolating the house bank from the alternator, when the engine is running. 2-3 hours of this, before or after anchoring, and your house bank is in a serious hole. Any alternator will struggle to get out off. If you rewire the audio B+ to the common post of the switch, the audio system will always see input from the alternator, regardless of whether the switch is on one or two. If the house bank was run very deep while at anchor, you can leave the switch on one, and isolate the alternator from it. Audio still works as its seeing alternator voltage and you can recharge the house bank back on the trailer. With this config, you can still run the stereo off the large house bank and still isolate the main cranking battery from the stereo. The other benefit, when you turn the switch OFF, all voltage is disconnected from the amp. OFF is off, no parasitic current draws when stored.