8 volt system charging

[fortyfords]

I have a 50 Ford with an 8 volt system, is there a way to put a charger on that will charge the battery; like a 12 volt charger with a voltage dropping resistor or maybe a 9 volt zenor diode? Any help would be appreciated. Thanks

[jerry shook]

I have two cars with 8-volt. it will charge with a 6 volt enough to crank then the car will finish charging when running. The 8-volt works great never had a problem after years of use.

[JSeery]

I really don't know anything about 8v batteries, but believe they are used in golf carts among other things. There should be chargers available.

[rotorwrench]

Golf cars have multiple batteries in series so the chargers are made for the end result (32-volts or more). I have a 24-volt charger that was made by one of the oldest surviving manufacturers of these products and they make them in several voltage ratings. Some of the old commercial battery chargers had an 8-volt setting but I haven't seen one in years.

I would question whether the system was 8-volt or a modified 6-volt system with the charging rate adjusted up. I have yet to find a car that was manufactured with an actual 8-volt system and I've checked a lot of manufacturer's information so far.

[lotsagas4u]

You can get a 8 volt battery minder, you have to order it direct from them though.

[blucar]

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The 8 volt systems use to be very common in the larger cars/trucks/tractors. A good battery charger will have 6/8/12 charging systems, the voltage required is changed by flipping a switch.
In an automotive application, the regulator (6v) has to be adjusted up to put out 8v.
I ran an 8v battery in my '36 Ford for years when I lived in Eastern Idaho, really improved the starting at 20+ below zero. When I replaced the 21 stud engine with a well built 59AB I continued to use an 8v to compensate for the higher compression.
The two volt difference between 6/8 has no effect on the lights, radio/heater. My '36 has the original 6v Philco 9 tube radio. Other than a couple of tube replacements the radio is original. The same is true of the '39 Ford hot water heater, the electric motor therein has never been touched. Can't remember the last time I had to replace a light bulb in the '36.
Electric golf carts do use 8v battery's, they are huge, a total of six batteries = 48 v.
Golf cart batteries are not suitable for automotive use. They are deep cycle, not starting batteries.. Starting batteries are made to give a big jolt to crank an engine. Deep cycle are made to slowly provide power over a long duty cycle to run electric motors.

[koates]

Another option is try your local electronics supply stores for a WORKSHOP BENCH VARIABLE DC POWER SUPPLY UNIT. These can supply a variable DC voltage output of between 1 volt to 30 volts or so. They can be used to charge batteries of various voltages and be adjusted to suit your needs for an 8 volt battery. A six volt charger may also be able to charge an 8 volt battery at a low rate of around 1 or 2 amps depending on the charger especially if it has a high/low setting switch. Regards, Kevin.

[tubman]

Most chargers put out more "open circuit voltage" (no load) than they are rated at. The load draws the voltage of the charger down to it's rated level. The solar charger I have on the 12 volt battery on my boat lift has an OCV of around 20 and it works just fine. If you put a multi-meter accross the leads of the charger (with no load) and read more than 8 volts, you are probably good to go. It may take a long time to reach full charge though.

[Jack E/NJ]

>>>12 volt charger with a voltage dropping resistor >>>

Yes. If amp ratings are similar, a 12v charger & 12v bulb in series (a variable dropping resistor) can be used to charge just about any battery up to 12v. The bulb would be bright for a dead battery, gradually dimming to a steady glow as the battery reaches full charge. Jack E/NJ

[old Tom]

from the tractor forum:
Battery tender offers a 8V charger. I use to use them but changed all my equipment to 12V. As far as adding a drop resistor that shouldn't be difficult on a trickle charger. You need to drop 1/3 of the supply voltage. Just insert a inline resistor to drop to 8V based on max working current of the trickle charger. Be sure to use a cement style resistor with proper wattage with heat sink to dissipate the heat efficiently. Tie a 9.2 V 5 amp zener to load side of the drop resistor to ground_neg side of trickle output. That will set output/battery side to a constant 9.2v when battery fully charged to alleviate over charging....

[Mike in AZ]

have seen the 8V batteries at Tractor Supply....maybe they have a charger, too....Mike

[old Tom]

use an 8 volt battery on the Delco Light plant that I recently restored. It is a 32 volt system, so two 12 volt and one 8 volt batteries make 32 volts.
I use the following resistor in line with a 12 volt charger- Uxcell Green Aluminum Chassis Mounted Wirewound Resistors 10W 10 Ohm 5%

It does get hot after several hours of charging.



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jeffcat
12-27-2016 16:42:31




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Re: 8V charging in reply to henryv11, 12-27-2016 05:46:45
You can also put an automotive light bulb in line. You will find different bulbs alow a different current flow. Will be brighter or dimmer. With the charger on 12 volt hooked up after you have just finished running you vehicle. "Fully charged battery. " You want to measure around 9 volts or a tad less with your digital meter. The in line bulb will most likely just be glowing. The filament in the bulb acts as a current limiter. This is VERY VERY old school, but it works! Now remember you do not want to leave this hooked up too long. Check it a couple of times and see how the voltages read. Back in the Very old days the local hardware store would have a shelf full of batteries they would keep charged for your home battery powered radio. You bring your battery in and swap for another. They had a silicone rectifier at the end of the line and you would have 19 or 20 6volt batterys in series. Just plug them into the wall socket. You bough I think it was an 80 or 90 volt battery for the plate voltage. The 6 volt was for the elements and used far more power. Some of the radio guys will add more to this.

[40 Deluxe]

You will never get an 8 V. battery fully charged if you try to charge it with only 8 volts. A fully charged lead/acid cell will read 2.1 volts, so times 4 equals 8.4 volts for a full charge. This means a charging voltage of about 9.3 is needed. To keep a 6 volt battery fully charged, 7.2 volts is needed. Modern 12 V. systems run around 13.8-14.2 and some as high as 15. Sealed Maintenance Free batteries need the higher voltage. When Joe Cheapskate replaces that battery with a cheap discount store battery, he will soon have acid grunge all the battery top from overcharging.

[fortyfords]

I can't thank everyone enough for all the replies, you have been a great help. Thanks, I'll pick a path.

[blucar]

I know it takes some of the fun and satisfaction of allowing contributors to the forum to impress us with their knowledge, however, clicking on Amazon.com will turn up several examples of 8v battery chargers/tenders..

[rotorwrench]

Deltran Tenders, like the ones on Amazon, are not the best type in the world. I've had a 12-volt one that lasted less than a year before it crapped out. The charge amperage was too low while it did work.

We all seek and impart knowledge or we would not be here.

[FlatheadTed]

I have charged one with a 12 volt .Ted