Author Topic: 78 550K overcharging?  (Read 638 times)

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Offline 90blacknight

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78 550K overcharging?
« on: February 25, 2020, 07:51:43 AM »
Hello all,

I started the bike (78 CB550K) for the first time after the mild rebuild and I'm seeing 14.95 volts at around 4500 RPM. I installed a new regulator/rectifier combo unit. The battery is good. When I fully charge the battery I'm getting 12.9 Volts. Is 14.95 volts too high? I can try putting the old OEM rectifier and regulator back on and measure the results.

Thanks!

Offline bryanj

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Re: 78 550K overcharging?
« Reply #1 on: February 25, 2020, 09:25:14 AM »
A lead acid battery will handle that but check fluid level regularly.
Only reason for overcharging is when black wire at reg shows less than battery voltage due to bad connectors
Semi Geriatric ex-Honda mechanic and MOT tester (UK version of annual inspection). Garage full of "projects" mostly 500/4 from pre 73 (no road tax in UK).

Remember "Its always in the last place you look" COURSE IT IS YOU STOP LOOKIN THEN!

Offline 90blacknight

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Re: 78 550K overcharging?
« Reply #2 on: March 08, 2020, 11:38:02 AM »
A lead acid battery will handle that but check fluid level regularly.
Only reason for overcharging is when black wire at reg shows less than battery voltage due to bad connectors

You were absolutely right! Cleaned up the connectors and voila! 13.4v at 5000 rpm. Thanks!