A float mode battery charger should charge at 14.7v, right? By glavey (Read 1,214 times)

[glavey]

It's been a little while since I rode my scooter anywhere, so last night I hooked up my trickle/float mode charger up to it and let it charge. Curiosity got to me and I checked what the voltage at the battery was with the charger presumably in the "bulk" charging mode. I was a bit concerned when I saw the voltage go up to and past 16 volts. That can't be what it is supposed charge the battery at... right?

I looked at the user's manual for the charger for technical specs regarding charging voltages, but there aren't any such specs listed.

Ever since I started learning about electronics and cars, I've been taught that 12 volt lead acid batteries charge at 14.5 volts MAX. Has my charger gone kaput?

I have another battery charger, but it isn't a float mode charger, and it charges at up to 10 amps, minimum (compared to the 2 amps limit on the float mode one). I don't think continuously charging a battery is good for it.

For what it's worth, here's the float mode charger I'm using:

[tvnacman]

16vdc seems high, I would connect it to a car battery and see if it stays at 16vdc.

John

[Alleyoop]

Here is a good write up about charging a battery.From what they say it can go up high but it should drop down and not stay at a constant high charge rate.
Alleyoop

www.operatingtech.com/lib/pdf/A%20Guide%20to%20battery%20Charging.pdf

[richardv]

Good link but I have been told that with a small motorcycle battery the charger shouldn't exceed 2.5 amps. Larger will cause damage in a short time. This is for a constant rate charging device. I have never used on of those little multi stage chargers. The one I used had wheels and was for car/truck batteries.

[jct842]

Can't give exact figures but the higher the charge voltage the high the amps of the charge. The biggest reason you do not jump a scooter off a running car engine is since the car charges at very high rates in comparison to a scooter that can and will smoke the regulator on the scooter.

I was talking to a pilot of an experimental aircraft whose battery needed a jump a month ago. He has a rotax aircraft engine. To make this short he jumped off a running car and it cost him $700 and some dollars. Asked him if the car was running and he said yes and "I won't do that again!" He had left a switch on over night to run the battery down.

[tvnacman]

I have had my hands on a few bad batteries some were brand new some old. I checked the voltage while on the 2a charge, I think it was 13.5 to 14.5vdc. When the battery comes off the charger, it has what they call a surface charge. The surface charge gives a high voltage reading like 13+. When you wait a few hours it will drop I like to see 12.6vdc on the low side. If it is 12.4 or 5 and not showing signs of weakness while cranking its fine. If it shows 12vdc or in the 11's its done.

John

[richardv]

Lately I've been seeing little jump-starters that fit in a shirt pocket that are stronger than the one I have that is bigger than a lunch box. I'm wondering if one of those would work in place of the battery on a scooter.

[jct842]

Oct 19, 2015 6:25:52 GMT -6 richardv said:

Lately I've been seeing little jump-starters that fit in a shirt pocket that are stronger than the one I have that is bigger than a lunch box. I'm wondering if one of those would work in place of the battery on a scooter.

you will have to try it and let us know!

[richardv]

I will let you know as soon as I get around to it.