I am just wondering, if I let my Model t sit for 2 weeks my battery goes dead. I usually hook up a solar panel to it and it keeps the battery charged. Could I have a short somewhere draining the battery or could my generator be no good? Thanks for your help, Tony from Staten Island
using a testing light, take the ground cable off the battery, hook one end of the testing light to the cable and using the pointing end, touch the battery, if you have light, there is something draining the battery..
Or just leave one of the cables disconnected for two weeks.
Abattery load tester is always a good investment.
Get cheap one.
Connect it to the battery and see if it reads 7 volts when the engine is running at very fast idle.
After you charge the battery so it reads 6 volts press on the load button and see if the needle on the tester stays at 6 volts for 20 seconds or longer. Or if it dives to 3 or 4 ( with engine stopped).
A good battery will hold enough charge to start a car fora year.
Now that's ironic. I toke my generator to the shop just this morning to have it fixed. FYI. I have had two interstate batteries fail prematurely recently. They are not the quality they once were.
What type of cutout do you have?
If a solar panel will keep it charged then it's a very low/slow leak. Perhaps a bad cell. Be sure the top of the battery is clean and that it's full (add only distilled water). Charge the battery to full capacity then test each cell with a Battery Hydrometer after about an hour.
Each cell of a fully charged battery should have a specific gravity of 1.265 at 80° F. If any cell has a variance of more than .030, the battery has a problem.
To adjust for temperatures above or below 80:
Add .004 for every 10° above 80° F
Subtract .004 for every 10° F below 80° F.
A friend with a late engine and Mitsubishi alternator just had the same problem. The alternator had a plug-in regulator that had shorted.
A shorted cut-out will cause the same problem and symptoms.
Like Aaron says just disconnect the battery and see what happens to it. Another no cost thing to do is make sure everythings off, disconnect the ground cable at the frame and touch the disconnected cable to ground looking carefully for a spark. It'll probably be very slight if it exists at all. It shows a drain on the batt. If the car is wired correctly there's very little to cause a short
Disconnect the batter cable and connect a test light between the disconnected cable terminal and the battery post.
If there is any light at all, something is draining a battery that might other wise be OK.
That is most likely the cut-out with a Model T.
Install a battery shut off switch.
Battery shut off switch....
something else to "go bad".....until it does, while it works it only masks the existing problem.
Something like putting a fresh coat of paint on a badly rusted chassis...may look OK for awhile, but failure (maybe catastrophic) is predictable.
For my basic electrical trouble shooting I first load test the battery. If its good, connect an amp meter between the battery and the cable at he battery. If you see a current drain then start disconnecting leads one at a time until the drain goes away. Then check out that component. Could be anything from a bad horn button, to a shorted wire.
Probably a bad cell. Pretty common. The last two batteries I purchased were from a farm store chain. Both of them went belly up after two years. Same issue: bad cell. Since I don't do much driving over rough surfaces, and the battery is secured well, I just can't understand how a battery can develop a bad cell. But it seems to happen and the only thing I can point to is poor construction. Since these batteries are largely used in older tractors, I am wondering how many people out there in agriculture have experienced the same issues?