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UTV's Off Road ( RZR, YXZ, Mini Buggy, Carts,etc.) => UTV Controls and Electrical => Topic started by: 455bird on November 11, 2009, 05:44:59 PM

Title: alternator
Post by: 455bird on November 11, 2009, 05:44:59 PM
Title: Re: alternator
Post by: fabr on November 11, 2009, 07:12:19 PM
You might want to consider the rpm that shaft runs at. Most alternators don't put out full amps till the rpm reaches somewhere around 5000 alternator rpm or so. Be sure to run the alternator driven with a considerably larger diameter pulley on the shaft to keep alternator rpms up. Most alternators run at 2:1 ratio or more and that is with engine rpms being used ,not a gearing reduced shaft rpm. Just something to think about.
Title: Re: alternator
Post by: 455bird on November 11, 2009, 08:04:06 PM
Title: Re: alternator
Post by: Engineer on November 12, 2009, 09:16:14 AM
The two batteries aren't a bad idea, that way you will never be dead on the dunes cause the lights ran it down, but one or two lights on the busa battery might not hurt if the only way to charge is when your driving.
Title: Re: alternator
Post by: 455bird on November 19, 2009, 03:52:29 PM
Well this is where i'm at and so far and its working
Title: Re: alternator
Post by: 455bird on November 19, 2009, 03:55:24 PM
Next question, can I hook both batteries together? One is on the alternator and one is working off the stator, can I kill the stator?
Title: Re: alternator
Post by: fabr on November 19, 2009, 03:55:45 PM
it's a cool concept. I have considered it before but was always concerned about the output as I have said earlier. Have you measured the amp output at various speeds yet?
Title: Re: alternator
Post by: fabr on November 19, 2009, 03:58:27 PM
Next question, can I hook both batteries together? One is on the alternator and one is working off the stator, can I kill the stator?
Why not run both batteries and both alternators as separate systems? Keep the big unit for the high load lights and fans and the smaller for the engine puter and such? That way you should always be able to start the thing.
Title: Re: alternator
Post by: fabr on November 19, 2009, 04:00:32 PM
Next question, can I hook both batteries together? One is on the alternator and one is working off the stator, can I kill the stator?
To  answer the question though , yes ,you can, just be sure to tap your positive into the new system.
Title: Re: alternator
Post by: fabr on November 19, 2009, 04:01:02 PM
Uh negative also.
Title: Re: alternator
Post by: 455bird on November 19, 2009, 06:27:25 PM
Title: Re: alternator
Post by: Nutz4sand on November 19, 2009, 06:53:30 PM
Other than the obvious spare belt if you have it wired correctly you could run easy if you lost this alternator and run low lights and one fan just to limp/get back to the campsite??

I thought/guessed/assume(d) (yah I know how its spelled!) you only needed this alternator for the BIG lights and perhaps the BOTH fans under hot throttle?

But taking it easy with smaller lights will the motors system run one fan and smaller lights?   
Title: Re: alternator
Post by: fabr on November 19, 2009, 07:12:32 PM
Title: Re: alternator
Post by: 455bird on November 19, 2009, 07:18:50 PM
Title: Re: alternator
Post by: fabr on November 19, 2009, 08:27:56 PM
If you had all the lights and fans running while you were testing it out and getting a 14.6 volt reading you could very well have been reading the battery voltage . An alternator regulator will only supply what it is called upon to provide. Technically  an alternator will provide only the amps needed to keep the battery at full charge.  Now let's assume that you only ran the test for a few minutes you could still get a 14.6 volt reading even if the alternator AND battery were providing that 14.6 volts but not enough amps from the alternator to keep the battery fully charged. A slow run down condition. That's why I keep asking if you have measured the AMP output from the alternator under a full electrical load and compared that to the electrical draw on the system with all lights ,etc. running. If that's the alternator I think it is it's about a 30 amp rated unit?
Title: Re: alternator
Post by: chrishallett83 on November 20, 2009, 06:08:41 PM
What kind of battery are you running? A standard 6 cell lead-acid battery will never put out more than 12 volts.
Title: Re: alternator
Post by: fabr on November 20, 2009, 07:39:05 PM
What kind of battery are you running? A standard 6 cell lead-acid battery will never put out more than 12 volts.
Wrong,14.6 is quite common despite popular belief and the 12V claim. It;s sort of lke 110V can be 105 to 125 or so. These voltages are just nominal numbers.
Title: Re: alternator
Post by: 455bird on November 20, 2009, 09:43:56 PM
I run wheelchair batteries, they hold a charge longer and charge quicker (I think) pulse they are the size of a lawnmower batteries. 
Title: Re: alternator
Post by: chrishallett83 on November 22, 2009, 10:48:18 AM
Wrong,14.6 is quite common despite popular belief and the 12V claim. It;s sort of lke 110V can be 105 to 125 or so. These voltages are just nominal numbers.

I find that hard to believe. I think the 14.6 is alternator output voltage. Yes, the output from a house plug can vary as the generator varies load to keep up with demand, and voltage drop over transmission lines affects your personal supply from the grid.

But I've never seen more than 12 volts out of the terminals of a lead acid battery, even brand new, freshly charged $300 heavy duty truck batteries.
Title: Re: alternator
Post by: fabr on November 22, 2009, 11:14:11 AM
You need to recheck.
Title: Re: alternator
Post by: fabr on November 22, 2009, 11:21:23 AM
Each of us needs to read ALL of this very informative article.Then we can continue the discussion on what a fully charged battery is ans IS NOT.





State of Charge: Here are no-load typical voltages vs state of charge

 

(figured at 10.5 volts = fully discharged, and 77 degrees F). Voltages are for a 12 volt battery system. For 24 volt systems multiply by 2, for 48 volt system, multiply by 4. VPC is the volts per individual cell - if you measure more than a .2 volt difference between each cell, you need to equalize, or your batteries are going bad, or they may be sulfated.

 

These voltages are for batteries that have been at rest for 3 hours or more. Batteries that are being charged will be higher - the voltages while under charge will not tell you anything, you have to let the battery sit for a while. For longest life, batteries should stay in the green zone. Occasional dips into the yellow are not harmful, but continual discharges to those levels will shorten battery life considerably. It is important to realize that voltage measurements are only approximate. The best determination is to measure the specific gravity, but in many batteries this is difficult or impossible. Note the large voltage drop in the last 10%.

 

State of Charge
   

12 Volt battery
   

Volts per Cell

100%
   

12.7
   

2.12

90%
   

12.5
   

2.08

80%
   

12.42
   

2.07

70%
   

12.32
   

2.05

60%
   

12.20
   

2.03

50%
   

12.06
   

2.01

40%
   

11.9
   

1.98

30%
   

11.75
   

1.96

20%
   

11.58
   

1.93

10%
   

11.31
   

1.89

0
   

10.5
   

1.75
 

Battery Charging: Battery Charging takes place in three basic stages: Bulk, Absorption and Float

 

Bulk Charge - The first stage of 3-stage battery charging. Current is sent to batteries at the maximum safe rate they will accept until voltage rises to near (80-90%) full charge level. Voltages at this stage typically range from 10.5 volts to 15 volts. There is no "correct" voltage for bulk charging, but there may be limits on the maximum current that the battery and/or wiring can take.

 

Absorption Charge: The 2nd stage of 3-stage battery charging. Voltage remains constant and current gradually tapers off as internal resistance increases during charging. It is during this stage that the charger puts out maximum voltage. Voltages at this stage are typically around 14.2 to 15.5 volts.

 

Float Charge: The 3rd stage of 3-stage battery charging. After batteries reach full charge, charging voltage is reduced to a lower level (typically 12.8 to 13.2) to reduce gassing and prolong battery life. This is often referred to as a maintenance or trickle charge, since it's main purpose is to keep an already charged battery from discharging. PWM, or "pulse width modulation" accomplishes the same thing. In PWM, the controller or charger senses tiny voltage drops in the battery and sends very short charging cycles (pulses) to the battery. This may occur several hundred times per minute. It is called "pulse width" because the width of the pulses may vary from a few microseconds to several seconds. Note that for long term float service, such as backup power systems that are seldom discharged, the float voltage should be around 13.02 to 13.20 volts.

 

Chargers: Most garage and consumer (automotive) type battery chargers are bulk charge only, and have little (if any) voltage regulation. They are fine for a quick boost to low batteries, but not to leave on for long periods. Among the regulated chargers, there are the voltage regulated ones, such as Iota Engineering and Todd, which keep a constant regulated voltage on the batteries. If these are set to the correct voltages for your batteries, they will keep the batteries charged without damage. These are sometimes called "taper charge" - as if that is a selling point.

 

What taper charge really means is that as the battery gets charged up, the voltage goes up, so the amps out of the charger goes down. They charge OK, but a charger rated at 20 amps may only be supplying 5 amps when the batteries are 80% charged. To get around this, Statpower (and maybe others?) have come out with "smart", or multi-stage chargers. These use a variable voltage to keep the charging amps much more constant for faster charging.

 

Charge controllers

 

A charge controller is a regulator that goes between the solar panels and the batteries. Regulators for solar systems are designed to keep the batteries charged at peak without overcharging. Meters for Amps (from the panels) and battery Volts are optional with most types.

 

Most of the modern controllers have automatic or manual equalization built in, and many have a LOAD output. There is no "best" controller for all applications - some systems may need the bells and whistles of the more expensive controls, others may not.

 

Battery Charging Voltages and Currents:

 

Most flooded batteries should be charged at no more than the "C/8" rate for any sustained period. "C/8" is the battery capacity at the 20-hour rate divided by 8. For a 220 AH battery, this would equal 26 Amps. Gelled cells should be charged at no more than the C/20 rate, or 5% of their amp-hour capacity. The Concorde AGM batteries are a special case - the can be charged at up the the Cx4 rate, or 400% of the capacity for the bulk charge cycle. However, since very few battery cables can take that much current, we don't recommend you try this at home. To avoid cable overheating, you should stick to C/4 or less.

 

Charging at 15.5 volts will give you a 100% charge on Lead-Acid batteries. Once the charging voltage reaches 2.583 volts per cell, charging should stop or be reduced to a trickle charge. Note that flooded batteries MUST bubble (gas) somewhat to insure a full charge, and to mix the electrolyte. Float voltage for Lead-Acid batteries should be about 2.15 to 2.23 volts per cell, or about 12.9-13.4 volts for a 12 volt battery. At higher temperatures (over 85 degrees F) this should be reduced to about 2.10 volts per cell.

 

Never add acid to a battery except to replace spilled liquid. Distilled or deionized water should be used to top off non-sealed batteries. Float and charging voltages for gelled batteries are usually about 2/10th volt less than for flooded to reduce water loss. Note that many shunt-type charge controllers sold for solar systems will NOT give you a full charge - check the specifications first. To get a full charge, you must continue to apply a current after the battery voltage reaches the cutoff point of most of these type of controllers. This is why we recommend the charge controls and battery chargers listed in the sections above. Not all shunt type controllers are 100% on or off, but most are.

 

Flooded battery life can be extended if an equalizing charge is applied every 10 to 40 days. This is a charge that is about 10% higher than normal full charge voltage, and is applied for about 2 to 16 hours. This makes sure that all the cells are equally charged, and the gas bubbles mix the electrolyte. If the liquid in standard wet cells is not mixed, the electrolyte becomes "stratified". You can have very strong solution at the top, and very weak at the bottom of the cell. With stratification, you can test a battery with a hydrometer and get readings that are quite a ways off. If you cannot equalize for some reason, you should let the battery sit for at least 24 hours and then use the hydrometer. AGM and gelled should be equalized 2-4 times a year at most - check the manufacturers recommendations, especially on gelled.

 
Battery Aging

 

As batteries age, their maintenance requirements change. This means longer charging time and/or higher finish rate (higher amperage at the end of the charge). Usually older batteries need to be watered more often. And, their capacity decreases.

 
Mini Factoids

 

Nearly all batteries will not reach full capacity until cycled 10-30 times. A brand new battery will have a capacity of about 5-10% less than the rated capacity.  Batteries should be watered after charging unless the plates are exposed, then add just enough water to cover the plates. After a full charge, the water level should be even in all cells and usually 1/4" to 1/2" below the bottom of the fill well in the cell (depends on battery size and type).

 

In situations where multiple batteries are connected in series, parallel or series/parallel, replacement batteries should be the same size, type and manufacturer (if possible). Age and usage level should be the same as the companion batteries. Do not put a new battery in a pack which is more than 3 months old or has more than 75 cycles. Either replace with all new or use a good used battery. For long life batteries, such as the Surrette and Crown, you can have up to a one year age difference.

 

The vent caps on flooded batteries should remain on the battery while charging. This prevents a lot of the water loss and splashing that may occur when they are bubbling.

When you first buy a new set of flooded (wet) batteries, you should fully charge and equalize them, and then take a hydrometer reading for future reference. Since not all batteries have exactly the same acid strength, this will give you a baseline for future readings.

 

When using a small solar panel to keep a float (maintenance) charge on a battery (without using a charge controller), choose a panel that will give a maximum output of about 1/300th to 1/1000th of the amp-hour capacity. For a pair of golf cart batteries, that would be about a 1 to 5 watt panel - the smaller panel if you get 5 or more hours of sun per day, the larger one for those long cloudy winter days in the Northeast. Lead-Acid batteries do NOT have a memory, and the rumor that they should be fully discharged to avoid this "memory" is totally false and will lead to early battery failure.

 

Inactivity can be extremely harmful to a battery. It is a VERY poor idea to buy new batteries and "save" them for later. Either buy them when you need them, or keep them on a continual trickle charge. The best thing - if you buy them, use them.  Only clean water should be used for cleaning the outside of batteries. Solvents or spray cleaners should not be used.

 
More information - Manufacturers Websites

 

US Battery Manufacturing Company - some good information and data.
Trojan Battery - no real technical info here, but all the specifications.
Exide - not much here but marketing stuff, but you can buy Exide T-shirts.
Surrette - Specs and data on the Surrette deep cycle and marine batteries
Concorde - specs and data on all the Concorde batteries, including Lifeline.
Oerlikan - some really tech info on batteries (Europe).

 
Title: Re: alternator
Post by: Voodoochikin04 on November 22, 2009, 02:20:08 PM
brand new car batteries i have bought range from the 14.6 range to 12.98 but never lower..
Title: Re: alternator
Post by: 455bird on November 22, 2009, 05:41:18 PM
BOY sometimes it blows me away when you can ask a question on hear and it gets this far. Sometimes a yes or no ore even a maybe will work. Boy this went into big time
Title: Re: alternator
Post by: Boostinjdm on November 22, 2009, 06:54:46 PM
High 12's is normal for a new battery.  If you are getting readings higher than that, you need a new meter, or the batt just came off the charger.  Chris is right on the alternator output.  It has to be higher than the batt to provide a charge.  Remember people, voltage is potential energy.
Title: Re: alternator
Post by: fabr on November 22, 2009, 07:19:25 PM
yup


State of Charge @ 100% is 12.7V
   

What most people don't realize tho is that  50% is 12.06V.  12.06 volts is 50% charge and that anytime you discharge a battery below 50% you are severely shortening it's life.
   



   

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