1955, is my Battery Charger Jr. overcharging at 6.8V | Ford Thunderbird forum club group 1955-2005 models

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1955, is my Battery Charger Jr. overcharging at 6.8V

  • Thread starter Thread starter photoguy
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photoguy

photoguy

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Thunderbird Year
1955
Evening wonderful people.

I just received my new "Battery Tender Junior", this is a replacement, my other one died from getting wet.

This new one seems to be overcharging? I just read with volt meter, and it's at 6.8V, don't want to ruin my battery, it's less than a year old. The "red" charging light stays on, and keeps charging, hasn't switched to green like it's supposed to do when completed. I know resting voltage should be 6.3-6.4? Should I discharge the battery to maybe 6V and try the tender again? Maybe it needs some sort of reboot?

Thank you!

Screen Shot 2023-06-10 at 6.33.54 PM.png

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How old is the battery? Are there any accessories pulling power? Is it connected correctly? Try disconnecting a battery terminal and try again. With generators charging voltage will be higher than 6v and the regulator will open & close when full charge is restored. I don’t think 6.8 volts will damage your battery. Haven’t measured my generator charging voltage yet but like 12V systems it charge’s around 14.2V. My 6V battery tender does turn green after a short period. Call Deltran. I will go out and measure mine.
 
let it do it's thing. Some of these new chargers have automatic deep cycle charging that almost look like it's overcharging but actually knocking off the sulfites that collect on the plates. Then drop down to the 1 AMP plus or minus to maintain. But keep an eye on it.
 
photoguy said:
Evening wonderful people.

I just received my new "Battery Tender Junior", this is a replacement, my other one died from getting wet.

This new one seems to be overcharging? I just read with volt meter, and it's at 6.8V, don't want to ruin my battery, it's less than a year old. The "red" charging light stays on, and keeps charging, hasn't switched to green like it's supposed to do when completed. I know resting voltage should be 6.3-6.4? Should I discharge the battery to maybe 6V and try the tender again? Maybe it needs some sort of reboot?

Thank you!

View attachment 27831
Click to expand...
Whether it is a Battery charger or the car voltage regulator, the output from them will be higher than the rated voltage of the battery you are charging. Chilton's Auto Repair Manual 1954-1963 page 345, 1955 T-Bird 6 volt battery, the car voltage regulator should put out 7.8 Volts . The 12 volt system charge depends on outside air temperature, 75 °F it would be adjusted to read 14.6-15.4 output voltage to the battery, table 2 page 228 Ford Car Shop Manual 1956 .
 
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