Battery possibly not charging?

Get answers to Bronco-related technical issues.

Battery possibly not charging?

Postby Eck » Sun Jan 12, 2020 11:28 am

So I drove the Bronco yesterday about 75 miles. I took it off the trickle charger with a full charge and when I hooked the charger back up after getting home, the charger was indicating it was below 80%. This morning, the charger light indicates it’s back to fully charged.

Shouldn’t it have been fully charged after starting the day that way yesterday and then driving it? Anything I can do to test it out without pulling the alternator and taking it into a parts store?

I’m running a 3G alternator and a yellow top Optima.


Sent from my iPhone using Tapatalk
69 Wagon, 351W, Explorer EFI & Serpentine, ZF5, 35" tires, 3.5 SL, 2 BL, WARN 8274
User avatar
Eck
Official CCB Member
Official CCB Member
 
Posts: 2460
Joined: Thu Oct 25, 2012 8:33 pm

Re: Battery possibly not charging?

Postby Eck » Sun Jan 12, 2020 12:48 pm

Checked numbers with a voltmeter.

Battery at full charge was right at about 13 and with the truck running, I am at about 13.9. I did not have the stereo turned off and I have a couple of amps installed so maybe this is right?
69 Wagon, 351W, Explorer EFI & Serpentine, ZF5, 35" tires, 3.5 SL, 2 BL, WARN 8274
User avatar
Eck
Official CCB Member
Official CCB Member
 
Posts: 2460
Joined: Thu Oct 25, 2012 8:33 pm

Re: Battery possibly not charging?

Postby horseplay » Sun Jan 12, 2020 2:43 pm

You could try a poor mans load test turn on all the trucks consumers headlights heater and so on. See what voltage you are producing. This wont tell you the condition of the battery but should let you know if the alternator is working.
horseplay
Official CCB Member
Official CCB Member
 
Posts: 408
Joined: Mon Jan 21, 2013 7:24 pm
Location: Grand Junction CO

Re: Battery possibly not charging?

Postby Eck » Sun Jan 12, 2020 2:57 pm

horseplay wrote:You could try a poor mans load test turn on all the trucks consumers headlights heater and so on. See what voltage you are producing. This wont tell you the condition of the battery but should let you know if the alternator is working.


Just tried that and it dropped to about 13.5. Maybe I’m making a to do about nothing? The battery is practically brand new.


Sent from my iPhone using Tapatalk
69 Wagon, 351W, Explorer EFI & Serpentine, ZF5, 35" tires, 3.5 SL, 2 BL, WARN 8274
User avatar
Eck
Official CCB Member
Official CCB Member
 
Posts: 2460
Joined: Thu Oct 25, 2012 8:33 pm

Re: Battery possibly not charging?

Postby horseplay » Sun Jan 12, 2020 4:08 pm

That's not bad at idle. Let it sit for a couple of days the check the battery voltage. A 2-5 amp trickle charge can take up to 72hrs depending on the rate of discharge.
horseplay
Official CCB Member
Official CCB Member
 
Posts: 408
Joined: Mon Jan 21, 2013 7:24 pm
Location: Grand Junction CO

Re: Battery possibly not charging?

Postby Jesus_man » Mon Jan 13, 2020 11:09 am

If it were me, I'd monitor the situation a bit more. You can buy one of those voltage gauges for your cigarette lighter like this:
https://smile.amazon.com/dp/B0773BYS6P/ ... hEbDPN2N82
And just watch it more closely. I'd use actual voltage as opposed to a percentage as well.
Engine off, battery should read above 12v. Engine on, battery should read between 13.5 and 14.5 with a load (headlights, stereo etc.)
1973 Bronco, 351 SEFI, Locked, discs, 35's ZF-5spd and Atlas 4spd. 235:1 Crawl Ratio. It may be ugly, but it's slow.
http://www.ucora.org
User avatar
Jesus_man
Official CCB Member
Official CCB Member
 
Posts: 5987
Joined: Thu Nov 11, 2010 9:36 am
Location: California

Re: Battery possibly not charging?

Postby Eck » Mon Jan 13, 2020 12:24 pm

Jesus_man wrote:If it were me, I'd monitor the situation a bit more. You can buy one of those voltage gauges for your cigarette lighter like this:
https://smile.amazon.com/dp/B0773BYS6P/ ... hEbDPN2N82
And just watch it more closely. I'd use actual voltage as opposed to a percentage as well.
Engine off, battery should read above 12v. Engine on, battery should read between 13.5 and 14.5 with a load (headlights, stereo etc.)


Looks like cheap insurance. I have zero confidence in the original instrument cluster colt meter anyways so at least this will give me a digital readout. Thanks.
69 Wagon, 351W, Explorer EFI & Serpentine, ZF5, 35" tires, 3.5 SL, 2 BL, WARN 8274
User avatar
Eck
Official CCB Member
Official CCB Member
 
Posts: 2460
Joined: Thu Oct 25, 2012 8:33 pm


Return to General 4x4 Technical

Who is online

Users browsing this forum: No registered users and 3 guests

cron