(800) 853-2651
SHOP NOW

Bad battery charger?

5

550Doug

Member
Location
Southern Ontario
This spring I've tried to charge up 4 12v batteries but have had no success. Either all 4 are dead (but read 8 to 10 v on a voltmeter) or my battery charger has gone south. It is 25 years old and NOT an automatic unit. How can I tell if the charger is the problem? I do get power out of the leads to the posts.
Thanks
 
Are the 4 batteries wired in parallel and you are trying to charge all four at once or did you try all 4 separately?
 
Check voltage at the battery posts with the charger connected and running.
voltage must be 13.5V or higher to charge a 12V battery. Sounds like your old charger has weak or failed rectifiers, not too hard or expensive to replace. If it has button diodes, many tines the cheap connectors are not connecting with the button terminals. A cleaning and tightning of the contacts will sometimes be all that is needed to repair the charger.
You need an ohmmeter to check the rectifiers for open or shorted condition.
 
Have you checked the individual cells with a hydrometer? With readings of 8-10 you have 1 or two bad cells in those batteries, and you probably won't charge them.
 
its been my experience that batteries as low as 10 have at leastone bad cell and are unchargeable. Most chargeable batteries read in the `11 area. At least thats my experience. Nuff said Henry
 
Hook the battery to a known good battery and read the voltage it should jump up to around 14 volts or so with the charger on.

I have found that older batterise that have been ran down and left setting discharged for a long time may never charge back up. Not sure why but it is mostly what I have seen.
 
HELLO 550 Doug.
To charge the batteries with a 12 volt charger you need to have all the positive posts together and all the nagative posts together. That would parallel them into a single 12V system and a 12 volt battery charger should charge them.
Time to do it will depend on charger rate of charge and batteries condition.
Guido.
 
Shorted diode will smoke the transformer.Crimp connections on clips are often bad.heating at the crimp means voltage drop.Cutting back to clean wire and soldering joints will fix lazy chargers.I like copper clips but most are too cheap to buy and use them.
 
You must log in or register to reply here.

Similar threads

3
Amazing battery
Replies
6
Views
285
BarnyardEngineering
BarnyardEngineering
C
JD 4020 24v Questions
2
Replies
27
Views
1K
cfk
C
J Hamilton
Do I have a defective battery?
Replies
6
Views
314
J Hamilton
J Hamilton
V
4210 starting problem
Replies
1
Views
259
wore out
wore out
B
Farmall 656 Gas no spark, has power to coil
Replies
7
Views
424
wore out
wore out
Tractor Parts Tractor Manuals

We sell tractor parts! We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today.

Copyright © 1997-2024 Yesterday's Tractor Co.

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters
Website Accessibility Policy

Back
Top