What kind of alternator do i need for my system

This article will help you make the right choices when shopping for a high-capacity alternator, such as one of the models from Balmar—boating's premier manufacturer of marine alternators and charging system upgrades. Before you invest in a high-output charging system, save yourself a lot of trouble and dollars by ensuring that you buy the correct system for your application.

Charging systems vary by type of boat, as well as a collection of other variables including engine type, engine room space, belt type and size, battery bank size and battery chemistry.

Selection criteria you should consider include the following. The Acceptance Rate of the battery—what percentage of its total amp hour capacity it can accept—is different for some battery chemistries. High output alternators like this extra Large Frame Balmar Series Alternator delivers current similar to some gensets, with up to 5kW of output. A standard flooded battery, of either the starting or deep cycle type, can accept charging current equal to 25 percent of its available capacity. Gel batteries can accept 30 percent, AGM batteries can accept 40 to 50 percent, and newer technologies like lithium ion or TPPL thin plate pure lead, such as Optima can accept even more.

They need to be charged by a large case or extra large case alternator to produce enough charging current, due to their nearly unlimited appetite for amps. Your alternator should be capable of delivering rated output equal to the maximum acceptance rate of your house battery bank. For flooded batteries, size your alternator toward the bottom of this range.

As we add electrical and electronic appliances to our boats, our battery banks become incapable of handling the loads created by these new stereo subwoofers, floodlights, satellite TV systems, refrigerators and other thirsty power consumers.

We start shopping for bigger battery banks or consider adding a battery which requires us to take a look at our charging system. In other words, if your house battery bank is made up of flooded batteries with an amp-hour capacity rating of Ah, the maximum acceptance rate of those batteries would be 25 percent, or amps, the ideal alternator would also be rated at amps.

If your house bank consists of Ah capacity AGM batteries, the maximum available capacity would be 45 percent of , or roughly Ah. To maximize charging efficiency, a amp rated alternator would be required. Unfortunately, mounting a large-case alternator is not feasible in many vessels. In comparison, typical headlights are also about a 10A draw, a defroster can pull up to 15A, and air conditioning typically draws more than 20A.

In a lot of cases, you can upgrade to an aftermarket radio without worrying too much about installing a high output alternator. However, there are cases where you'll clearly end up piling on more than the factory alternator can handle. When you start installing a bunch of aftermarket audio equipment, especially powerful amps, things can quickly get out of hand.

For instance, installing a power amp that draws 70 or more amps in a car that shipped from the factory with a basic stereo, could cause huge problems if the alternator is only capable of putting out 60A to begin with. Factory electrical systems have differing tolerances, but if you're planning on upping the requirements by more than 10 or 15 percent, then a high output alternator may be a good idea.

If you just need a little extra juice, a car audio capacitor may be a better choice. Since a high amp alternator will be putting out a lot more juice than the factory unit, and your power and ground cables were chosen with the OEM unit in mind, these cables might not be big enough.

When you install a high amp alternator, or when you have someone else install it, you should consider replacing both the ground straps and the power cable that runs from the alternator to the battery with heavier gauge cables.

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Select personalised ads. I am considering changing to an alternator. Smallest alternator I can find, to physically fit is a 65 amp alternator that produces 65 amp at idle, and 90 amp on the highway. All electrical components are original, with no additional instruments. By reading your article, more amps available are better that not enough to supply the system.

If I do this, am I safe? Cheers, Rob. Your email address will not be published. Your Website. Save my name, email, and website in this browser for the next time I comment.

This site uses Akismet to reduce spam. Learn how your comment data is processed. Summit Racing Equipment. During his year career in the auto industry, he has covered a variety of races, shows, and industry events and has authored articles for multiple magazines. He has also partnered with mainstream and trade publications on a wide range of editorial projects. In , he helped establish OnAllCylinders, where he enjoys covering all facets of hot rodding and racing.

OnAllCylinders says: April 7, at pm. We have made the edit. Thanks for bringing it to our attention—and for reading! Mike King says: August 20, at am. Steve Lapp says: October 4, at am.

Ronald A. Gooden says: July 6, at pm. Aaron Geister says: July 27, at pm. Chris Park says: August 16, at pm. Yes; agree it will reduce horsepower available: as much as 1. Negligable, imho. Pat says: August 8, at am. Cheers Pat. Afton Jackson says: May 24, at pm. AnalogDan Wilson says: May 25, at pm. Ismael says: September 9, at pm. OnAllCylinders says: February 13, at pm.

Jordan says: January 25, at am. Joe says: March 9, at pm. Karmyn says: October 9, at am. Christopher F says: October 19, at pm. Kevin Z. I have 3 amps in my 98 silverado, watts, what size alt. Annette says: January 10, at pm. What alternator voltage do I need for a c1 62 vette I am installing electrical steering. I notice on the bottom of the victron BMS there are some input sources which come from victron lithium batteries, are these a requirement?

Any thoughts would be very helpful. It works by controlling on the negative side of the circuit, and if you get into the small details it requires you to isolate the grounds of everything else on the boat. The bigger the boat the harder that is to achieve and I have come to the conclusion that it isn't a very good option for anything except boats with outboards.

To answer to comment above: Victron Batteries with their external BMS give you much more options to build a fully integrated system. When you try to replicate this using other batteries that have an internal BMS it is much harder to achieve. I spend a lot of time trying to help people out with this and some of the Victron components are very useful but they still don't give the same level of control as when they have access to the BMS.

Below are a few ways you can use Victron products with Non-Victron batteries: The Victron BMV energy monitors can be programmed with alarms and an external relay circuit to either operate on voltage alone or on state of charge. You can use their output to control loads and charge sources. You would require some external relays in addition. Because they are just looking at the voltage of the bank as a whole and not at an individual cell level it doesn't give quite the same level of control as you get with an external BMS.

That would require you to set the parameters to give you more cushion. The effect of that is you have to shut off the charge a bit before the battery is full and shut off the load a bit before it it empty, giving a bit less capacity than the rated while still protecting the battery.

The Victron Battery Protects can be programmed to be relays controlled by a signal from the BMV Energy Monitor, so they can be the relays described above to shut off the load or the charge. They can also be programmed to act on their own and shut off when the voltage drops below a preset level. Regarding the second diagram, and Ryans question.

I need it as a current limiter to solve altenator heating problem when charging LiFePo4. Thanks in advance. Thank you so much for this post! Now, if I connect my I would be really happy if you enlighten me in this question, cannot wrap my head around it Yes, when you connect a Lithium Battery to your alternator the charge voltage will drop to just above the battery voltage and will only rise slowly until the battery is nearly full.

The battery in this case is such a big load that it determines the outcome. You can liken the effect to connecting strings of lights to a portable generator. The more lights you add the dimmer they get. Eventually if you add too many it will give up! I want to use a buck boost dcdc On a Ram Promaster and it has a amp alternator in it.

Would I need to upgrade the alternator to a amp? Its unrealisting to expect a nominal Amp alternator to actually put that much out on a continuous basis. Alternators are rated under the most favorable circumstances when they are cold but once they get hot the performance drops off considerably. I want to monitor the status of two banks. Thank you Peter for this excellent post. In a system using the Buck Boost controller Sprinter van , would you also need an automatic charge relay such as the Blue Sea systems ACR or does the Buck Boost controller manage that function?

Thank you. You can program how it behaves, for instance you can use its built-in vibration sensor so it only turns on when it senses that the engine is running. This feature was added so you could install it with a minimum of interference to the vehicles wiring and thus avoid any warranty issues.

To; Mr Peter Kennedy Thank you so much for all the precious informations. I am building a camper van now. When Lithium battery gets full, does the built-in BMS will shut off further charging from alternator? They said using the above Sterling charger, it would be fine, but I want to be sure. When you said " Or the van start battery will be just getting charged after Lithium battery is full?

I plan to set up solar panel W; but am curious if I can just start alternator alone first, and later adding solar? Or just using alternator alone is bad idea?

Thanks you. Tere is lots of info but my application is simple - to install lithium into a coach being converted to a motorhome. It is a 24V system and very hight alternator capacity and I'm looking to install about Ah of capacity. Which o fate above do you suggest. Lots of options but O'm not sure which to choose. Ta Andy. My system incorporated starting batteries as buffers for alternators in the event the bank was isolated form an LVC or HVC event.

ONe issue I hadn't realized until doing some testing was that when I isolated the bank and the alternators kept boosting voltage as the regulator could not sense any battery voltage so kept increasing voltage trying to charge the batteries blindly. The carefully dedicated voltage sense wires of equal length were run directly to the LFP04 bank with twin Victron multiplus 's and once bank was isolated could not provide charging effect feedback information.

I am not an electrician but was told that accurate voltage sense is critical to accurate charging as just and few tenths voltage sense differential has a huge impact. What would you recommend as a work around to have best most accurate. I no longer have that boat. I shied away from my first choice of lithiums because of lack of knowledge with how to control the alternator issues with the Etec Outboards. Thanks in advance for your wisdom and advice. That is an interesting comment. Where to connect the voltage sensor of the regulator requires some thought.

In the top drawing it would go on the start battery because that is the primary battery that is being charged. If the only battery being charged is the Lithium battery then the BMS should turn off the regulator when it is full so there is nothing to sense as it is turned off. If you had some other arrangement you might want to put the voltage sense of the regulator on the load side of the battery system so that the battery protect would shut it off in the event of low battery. I believe the regulator can consume power through that voltage sense connection and you dont want that to bypass the control mechanisms.

My understanding was if the voltage sense of the MC was off or disconnected it wouldnt work at all. I dont have a test bench here with an actual alternator so I could use a bit of feedback from others who have tried this. I have a sprinter rv van and will be updating to lithium I already updated solar using most of the Victron parts and accessories from PKYs last fall.

I may go up to amp lithium but am concerned that the possible high current draw my fry the amp Sprinter alternator. I am considering instead of the Victron Cryrix-li-ct to use a 50amp dc to dc battery charger to limit the draw to keep the alternator from being overtaxed.