6 volt in series

How should 6 volt batteries be wired in series? When wired in series and place on a charger, should only a 6 volt charger be used? If jumped, should it only be jumped by another 6 volt?

I ask as I have a car with 2, 6 volt batteries in series. It appears that the ground from first battery is grounded normally and the positive terminal from that battery going to the negative of the second battery and the positive of the second battery running on to the normal postive hook up. The previous owner said a charger could not be hooked up, but I suspect that he tried using a regular 12 volt charger with no success.

Thanks for any info and all the info you guys have provided in the past.

JimS

(quoted from post at 00:36:19 01/15/12) How should 6 volt batteries be wired in series? When wired in series and place on a charger, should only a 6 volt charger be used? If jumped, should it only be jumped by another 6 volt?

I ask as I have a car with 2, 6 volt batteries in series. It appears that the ground from first battery is grounded normally and the positive terminal from that battery going to the negative of the second battery and the positive of the second battery running on to the normal postive hook up. The previous owner said a charger could not be hooked up, but I suspect that he tried using a regular 12 volt charger with no success.

Thanks for any info and all the info you guys have provided in the past.

JimS

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wo ways. A 6 volt charger on a single battery at a time (so this takes twice the time, most likely, since you repeat for each of the two batteries). OR, you can connect a 12v charger from the first battery ground to the second battery pos output terminal & charge them in series.
Most likely they are the same size batteries, so this series charging should work just fine and in fact is done from the factory in some vehicles.

I agree with what JMOR said about using a 12 volt charger to charge two 6 volt batteries hooked in series. That's exactly how the alternator charges the batteries in your car.

To jump start your car from another 12 volt battery hook the Pos on the jumper battery to the Pos post on your car that goes to the starter solenoid/relay. Hook the Neg on the jumper battery to the grounded NEG post on the other battery in your car.

ifboth 6v bats arerealitively same ageand same size, 2 6v bats can be cargedin serieswith a 12v charger as jmor said.

Good information from the other replies, but the previous owner sure didn"t know anything about what he was telling you!!!!

What you want to make sure is that they're charged equally. Check the voltage across each battery, and if one is low you'll want to charge it a bit more. You need to compare voltages after both batteries have been off the charger for half an hour. Once that's done, they should be fine hooked in series on the vehicle.

What you don't want to do is to hook a six volt accessory across one battery. That will surely cause the batteries to get out of balance, with one overcharged and one undercharged. Also, only replace the batteries in pairs.

My John Deere D uses this system and has worked fine since 1948. If a battery charge is need I have always used a 12V charger, without any problems. Both batteries need to be as nearly identical as possible to work the best, but I have replaced one at a time without problems.

Elec golf carts have been hooked that way for years. For instance: a 36 volt cart will have 6 of the 6 volt batteries and you use a 36 volt charger. They last several years when properly maintained. Pete

John Deere A uses two 6 volt batteries in series for 12 volts. I could charge either one individually with a 6 volt charger or both connected together with a 12 volt charger. If you suspect a bad battery using the 6 volt chargers you can figure out the one that is the problem. And for extra lights what I had were 6 volt so I just drew off of one with no problems, also the 6 volt windshield wipper off a Plymouth car on the homemade cab. Plowed a lot of acres running that windshield wipper while staying dry in misting rain.

Jim, I will first answer your specific questions:

QUESTION
How should 6 volt batteries be wired in series?

Series wiring is when the + of one battery is tied/connected to the - of the other,,,,,,,theres 12 volts (6 + 6) across the outer (untied) series sum + of one battery - of the other,,,,,,,the 12 volt source and 12 volt load is across the + of one battery thats NOT the tie point above and the - of the other battery thats NOT the middle tie point above i.e. 6 + 6 = 12 volts when wired in series.

QUESTION
When wired in series and place on a charger, should only a 6 volt charger be used?

Its okay to use a 6 volt charger to charge each individual 6 volt battery one at a time AND YOU WANT EACH EQUALLY CHARGED WHEN FINISHED

HOWEVER

You can use a 12 volt battery charger across BOTH series batteries so they get charged at the same time and at the same current

QUESTION
If jumped, should it only be jumped by another 6 volt?

If jumped I would use a 12 volt jump across BOTH series batteries versus a 6 volt jump to only one 6 volt battery. If you only jump one 6 volt battery and the other one is weak the net total supplied current isnt any greater then the weaker battery can supply THATS NOT A GOOD WAY TO JUMP IT Id used a 12 volt jump on the series 12 volt combination

NOTES

In series the voltage is additive (6+6=12) but the available current does not add i.e. if each battery can supply say 500 amps then two identical in series can still only supply 500 amps

When multiple batteries are used, its best if they are identical in size age type and capacity

A 6 volt battery consists of three 2.1 volt cells wired in series while a 12 volt battery has six 2.1 volt cells wired in series

Any more questions?? If I missed anything hopefully the other fine gents can add to this

John T

My D19 AC was that way originally, but I've found I have far fewer battery issues since I went to two 12 volts in parallel.

Reason why is ohms law. On two 6's in series, the internal resistance of both batteries adds arithmetically and when cranking a portion of the available terminal voltage is dropped across this resistance and is not available for the starter.

On parallel 12v batteries, the resistance is halved and the current is halved so you wind up with a 4x gain in loss reduction meaning that you get the performance you mentioned.

I did a 4230 that way and could start it in any kind of weather with no assistance of any kind (heater-ether).

Mark

A battery is like a chain. A chain will only pull as much as it"s weakest link. Batteries in series will only put out as much amps as it"s weakest cell.

Have you ever blown up a battery with your arcing and sparking by the posts? Make the ground connection last away from the battery and unhook that one first.

No, I've never blown up a battery because I've done it for almost 60 years the way you described.