24 volt source to 12 volt battery charger

Dedicated to the memory and knowledge shared by Jim Mettler - All things relating to the flow of electrons in a Pinz.
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captxmas
Posts: 73
Joined: Fri Jun 13, 2008 1:20 am
Location: San Francisco Bay Area

24 volt source to 12 volt battery charger

Post by captxmas »

For those of you have been following my quest to charge a " 12 volt house Battery" from the Pinz 24 volt battery system. I think I found a product that if workable I want to share with the rest of you.

All you Pingauer electrical engineers out there, take a look at this and tell me if it will work. Remember my goal is to provide 12 volt power to accessories, radios, and an invertor while maintaining a charge in the house battery and not draining the 24 volt system while parked/engine off. This product has the ability to wire a switch off the ignition to kill the charging circuit when the ignition is off and chargers at three levels from higher amperage to a conditioning level when no power draw is detected.

If this is a viable product for the application, where would be the best place to tap the 24 volt power in a 710K and where would be the best place to tap the ignition other than under the dash. would a separate shut off switch be better?



[b]DC Source Chargers for charging 12 volt lead acid batteries from a 24 volt (20-30 volt) source


Inexpensive multistage microcontroller based lead acid battery charger voltage charger with 20 VDC to 30 VDC input. Charge 12 volt lead acid batteries. Charge any lead acid battery from a large one, or from a Humvee, truck, fork lift, truck, tractor or back-hoe.
Heavy Duty, Industrial, Marine, and Military versions click here.
For 12V to 12V, 12V to 24V, 24V to 24V chargers click here

.
Model Number PST-BC2412-15
DCDC Charger
Input Voltage Range 24 Volt nominal, range 20 VDC to 30 VDC
Battery Voltage (nominal) 12 Volts
Continuous Charging Current 7.5 Amps
Charge Current Options The peak charge current can be adjusted to 1-7.5[/img][/b][/b][/b]
Charging Algorithm 4 stage, 3 level adaptive microprocessor controlled
State diagram showing the charge algorithm
Battery Size 0.5 AH to 100+ AH
Protections Low input voltage protection
High input voltage protection
Over temperature protection
Output short circuit protection
Battery polarity protection
Dimensions 200 x 164 x 67 mm
7.9 x 6.7 x 2.8 inches
Click Here for a Dimensioned Drawing.
Connection Input: screw terminals
Output: binding posts
Cooling Controlled DC Fan
Operating Temperature 0-55°C
Weight 1.5 kg, 3.3 pounds
Quantity 1-10 11-100 101-500 501+
Prices $154.00 $139.57 $91.85 $74.89
XLR Charger Cable $12.50

The following table describes the display of LED lights at different stages of charging:
Status Completion Red LED 1 Red LED 2 Yellow LED Green LED
Standby LEDs cycle while waiting
Trickle before bulk charge 0-10% The two red LEDs cycle Off Off
Bulk charge 10-90% Off Red 2 and yellow cycle Off
Fill charge (also known as "over charge") 90-99% Yellow and green cycle
Float charge 100% Green flash
Low battery voltage alarm Flash Off Off Off
High battery voltage alarm Off Flash Off Off
Low input voltage alarm Flash Off On Off
High input voltage alarm Off Flash On Off
Over temperature alarm Off Off Flash Off

Q: Can I leave the battery continuously on the charger?
A: Yes, the charger will go into "maintenance mode" and keep the battery topped off.
Q: Can I draw power from the battery when the charger is connected?
A: Probably. . . There is some pulsing going on with the charger which your equipment might not be happy with (it is a pulse-charger, 1 second pulses with 20mS gaps), but if you combine this with the battery the battery will fill in the gaps, so the ripple is no more than it would see in an automotive application.
Q: If I discharge the battery while the charger is attached will the charger maintain a full charge?
A: Yes, When the charger detects that the battery voltage has dropped it knows that the battery needs to be charged and goes into "bulk charge" mode again automatically.
Q: Can the charger be left connected to the battery when the charger is not turned on, or when the input voltage of the charger has been cut off?
A: Yes.
Q: Can the charger be adjusted to lower currents?
A: Yes. There are two trimpots that we can adjust here or click here to view the instructions
Advantages:

Inexpensive DC input charger.

Protects even small 12 volt batteries from gassing or damage.

Charge time is typically 58% charge in 1 hour, 82% in 2 hours, 93% in 3 hours, 98% in 4 hours.

Charge efficiency is 95% for the a SLA, VRLA, or Gel Cell battery and 85% for the charger, making a combined efficiency of 81%. So a 24 volt 100 AH battery would be able to charge a 12 volt 10 AH battery 16 or 18 times before the host battery needed recharge.

Applications:

Auxiliary batteries, hobby batteries, bicycles, and scooters in a car, van or bus.

Microprocessor controlled 4 stage adaptive charging algorithm suitable for Gel, Absorbed Glass Mat, VRLA, or flooded lead acid batteries.

Fully automatic without intervention.

Output short circuit and battery polarity protections. Input low voltage and high voltage connections.

Charging 12 volt sealed lead acid batteries from a vehicle.

Charging 12 volt "jump start" batteries from a 24 volt tow truck or service vehicle.

Charging 12 volt electric bicycle from a 24 volt vehicle.

Four stage charge--constant current, constant voltage, fill, and float. This charges your battery the fastest way possible without damaging the battery. It is suitable for any size 12 volt lead acid battery.


Installation Notes:
A qualified automotive electrical technician should be used to wire the charger into the vehicle.
The BC-2412-15 converts 24 volt power into 12 volt power, so for a 7.5 amp output the input needs over 4 amps. Make sure that the wires connecting the BC-2412-15 are adequate for the current and the length of the run. If the voltage drop in the wires are too much the "Low Battery Voltage" alarm will come on. Wires that are too small may also overheat and melt the insulation, causing a dangerous situation. 12 gauge is usually adequate for runs up to 20 feet of wire (adding together the positive and negative wire lengths).
PowerStream has available the connector that fits into many wheelchair ( we have the 3 pin XLR style in stock ). Consult the manufacturer or a wheel chair technician to obtain the proper cable and plug. (If you know about such things please educate us!)
Try to connect or disconnect the battery when the charger power is "on." It is possible but extremely rare for the charger to go into a temporary fault mode if the battery is connected first, but cycling the power switch will clear this "false fault."
It is OK to leave the unit on the charger when the power to the charger goes on and off.
Mount the BC-2412-15 in an area that will get adequate ventilation and will be free from rain, spray, or excessive dust.

[/b]
Capt Xmas
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audiocontr
United States of America
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Joined: Fri May 01, 2009 1:30 pm
Location: Buffalo NY

Re: 24 volt source to 12 volt battery charger

Post by audiocontr »

Yup, getting close.

Keep in mind that its for LEAD ACID batteries only and 7.5 amps. Its not a lot of amperage. Better than nothing though.
1973 712m
1968 Haflinger
1965 Pathfinder
1978 GMC Palm Beach (Hey, its got 6 wheels!!)
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edzz
United States of America
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Joined: Tue Aug 11, 2009 12:13 am
Location: Coeur d'Alene, ID

Re: 24 volt source to 12 volt battery charger

Post by edzz »

Remember that depending on the way you wire this up you maybe defeating the battery cutoff switch/relay there by putting the alternator at risk.. The Pinz requires some unique considerations.

Also as has been mentioned the implications from their write up this is intended for flooded acid batteries. Gel cells and AGM batteries often have different voltage requirements than flooded batteries.
Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.
PinzHound
Posts: 15
Joined: Sun Sep 05, 2010 10:08 pm
Location: Castro Valley, California

Re: 24 volt source to 12 volt battery charger

Post by PinzHound »

Your plan sounds feasible. I've been looking at the same problem; using the accessories at night and wanting to start the engine in the morning. Procrastinating paid off. While having a rack build by Tim Keller with the SWPA group, he suggested, then mounted the solar panels of H.F.'s 45W solar panel kit @< $150. Big advantage is having both system completely isolated. Folks down there have used them with success. If interested I'll let you now how well it works for me.
captxmas
Posts: 73
Joined: Fri Jun 13, 2008 1:20 am
Location: San Francisco Bay Area

Re: 24 volt source to 12 volt battery charger

Post by captxmas »

Pinz hound.... thanka for the input. We nwed to get together for coffee and see all the latest changes to you rig. When is good? Give me a call inFremont.

Thanks to all others too. I really do want to get the issue settled so I can go out and have fun neyond a few hours.
Capt Xmas
Roverchef
Germany
Posts: 87
Joined: Tue Nov 08, 2011 9:21 pm
Location: Saint Augustine,FL

Re: 24 volt source to 12 volt battery charger

Post by Roverchef »

Don't leave me out...I drink coffee! That's kind of a haul for some coffee thou I would love to see some other Pinzy's. I'm new to CA and my wife says i need to make some friends!
Stekay
United States of America
Posts: 346
Joined: Thu Sep 01, 2011 8:32 pm
Location: Long Island, New York

Re: 24 volt source to 12 volt battery charger

Post by Stekay »

Sounds nice. Grab some Peet's and talk Pinz's with the Troll.
'76 710K
captxmas
Posts: 73
Joined: Fri Jun 13, 2008 1:20 am
Location: San Francisco Bay Area

Re: 24 volt source to 12 volt battery charger

Post by captxmas »

Greeting Roverchef,

You're always welcome for coffee but.......we're about 400 miles apart. ROAD TRIP!
Capt Xmas
Roverchef
Germany
Posts: 87
Joined: Tue Nov 08, 2011 9:21 pm
Location: Saint Augustine,FL

Re: 24 volt source to 12 volt battery charger

Post by Roverchef »

Road trip was my 1st thought! Thanks for the invite Captxmas.
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