John deere 3020 charging

[JaredWardall]

I have a 1969 John deere 3020. I went out to try and start it and it just barley turned over. The batteries and pretty much dead. How do I charge them. Do I charge them separately or all at once. Also can I use a charger to jump them to get it running. Give it a boost on cold days?

[bigtiller]

I had a '69 3020 for a dozen years or so but it had only one battery. In cold weather I would sometimes need to put a 60 amp charger on it for about 10 minutes and then flip the charger into the engine starting mode. It worked every time, but what worked even better was a block heater for an hour or two.

Turn the steering wheel while cranking the engine, it will turn over much faster.

[JaredWardall]

Ok thanks. Mine has two of what I believe 6v batteries in series to create a 12v system? Does that sound right?

[Tx Jim]

Jared
According to JDparts.com your '69 3020 should have 6V batteries if it's a diesel. Hook positive battery charger/jumper cable to RH frt(positive) battery post and ground cable to frame(if your tractor is still factory wired).
TY21737 DRY CHARGED BATTERY 2 (SUB FOR AR45450 OR TY6118) (6-VOLT) (850 COLD CRANKING AMPS AT -18ｰ C 0ｰ F) 340 MINUTE RESERVE CAPACITY AT 280 AMPS) (DIESEL) (DO NOT ACTIVATE UNTIL PLACED IN SERVICE)

[rScotty]

I have a 1969 John deere 3020. I went out to try and start it and it just barley turned over. The batteries and pretty much dead. How do I charge them. Do I charge them separately or all at once. Also can I use a charger to jump them to get it running. Give it a boost on cold days?

Charge them with a 12 volt charger just as if they were a single 12 volt battery. You hook the charger to the negative of one battery and to the positive of the other one. You will also see a is a short, heavy connecting wire connecting the two batteries to one another. That is, it connects the + of one to the - of the other.....you don't hook anything there. BUT, the downside of charging it as if it was a single six volt - and in fact the downside of the JD design - is that if one of the batteries is dead and the other good then neither one will charge.

On my JD 530 that had the same system of two six volt batteries and I replaced it with a single car 12 volt. That way works much better unless you are a purist and restorer. And it will work fine on yours too. I'm guessing that back when they made our tractors that six volt batteries were more common than 12v. With all the batteries available these days it really doesn't make any technical sense to use two sixes. Just get any standard 12 volt (most amp*hours) that will easily fit in the battery box.

However, be sure to pay attention to the polarity of the battery connectors. Most all of the older JDs like my 1958 model 530 were reverse polarity. That is, the positive battery terminal is ground, not negative. I don't know if that is true for your 3020 or not.
good luck, rScotty

[JaredWardall]

Ok thanks guys! RScotty, let me make sure I understand you. If I hook up the cables like you said. Pos to the rh side front terminal and neg to the frame it will charge both batteries? And I can do this with a 12 volt charger right?

[rScotty]

Ok thanks guys! RScotty, let me make sure I understand you. If I hook up the cables like you said. Pos to the rh side front terminal and neg to the frame it will charge both batteries? And I can do this with a 12 volt charger right?

Yes, but there are some "ifs" to check first. JD used several different systems back then. That's when many manufacturers were changing from six to twelve volts, from generators to alternators, and away from specialized "floating" dual battery diesel starting systems.

So best to check these things:

1. BTW, I'm assuming that yours is a gas tractor - NOT a diesel - and also that you really do have two six volt batteries like you think. If you do have a diesel, they had an unusual dual battery system and we had better start over.

2. You said that you think it has two six volt batteries hooked in series. That makes sense...it was a common way to make 12 volts at a time when 12 volt batteries were not as common. But I want to double check that we are right. Look at the vent caps on one of your batteries. Six volt batteries have three caps; twelve volt batts have 6 caps per battery. Also, how are the batteries connected together?

3.Check what the frame polarity is on your tractor. If the frame is negative that means that one of your batteries will have it's negative terminal connected directly to the frame. The stock frame connection was an large flat braided cable about an inch wide and a quarter inch thick...and it did not have any insulation on the cable, it was just a big flat bare braided cable. If yours still has that flat braided cable going to the frame...check which battery terminal that cable is connected to.

Take a look and we'll get this system right for you.

If it is gasser.....and those really are six volt batts in series....and the negative terminal of one of the batteries is connected to the frame then connect the 12 volt charger just as you say.
luck, rScotty

[Willl]

Jared, seems to be a little confusion on just what you have as to whether it's a 12V or 6V system.

It is the up most important you find out these answers BEFORE hooking any charging box to it.

Do no harm before good. Or something like that.

[Tx Jim]

Ok thanks guys! RScotty, let me make sure I understand you. If I hook up the cables like you said. Pos to the rh side front terminal and neg to the frame it will charge both batteries? And I can do this with a 12 volt charger right?

Jared
You can hook it up the way I outlined with no problems.

[Tx Jim]

On my JD 530 that had the same system of two six volt batteries and I replaced it with a single car 12 volt.

However, be sure to pay attention to the polarity of the battery connectors. Most all of the older JDs like my 1958 model 530 were reverse polarity. That is, the positive battery terminal is ground, not negative. I don't know if that is true for your 3020 or not.
rScotty

A '69 4020 has a somewhat advanced electrical system over a 530. A '69 4020 has an alternator and is a 12V "negative ground" no matter if it is gasoline or diesel.