can't charge battery with home made hydro power

i built a hydro powered generator and although it will run a string of  LEDs but will not charge a batery .i read 6 volts on my multimeter and am using a 6 volt 3400 mah batery 

http://www.youtube.com/watch?v=1miqdV7ERZs

sort by: active | newest | oldest
6V won' charge a 6V battery for a start. Whatr kind of battery is it ?
feedbuck (author)  steveastrouk5 years ago
the battery is a lead acid battery from an old camcorder
There are three 2v cells in a lead acid battery.three rule of thumb is to allow 2.2v pet cell to charge them. So you need to supply 6.6v at the terminals to charge it.

How OLD is the battery. I doing remember when u last sea a lead acid battery in n a Camcorder
feedbuck (author)  steveastrouk4 years ago
It's old , i never throw anything away could be from the late 80's early 90's .It still showed 1.94 volts when i hooked up the multi-meter so i figured that it would work
i am rethinking the battery and am thinking of buying some rechargeable D cells. ( i hate to though because so far i have spent nothing). this is my first foray into electronics as such , i am a video artist , so i am feeling my way through this
.thank you for your advice , i will keep you posted
feedbuck
Its deader than a very dead thing. Give it up ;-)
jbaker225 years ago
You are trickle charging the battery. You read the current produced in series with the load. That will help you determine how long it will take to charge it with this. http://www.csgnetwork.com/batterychgcalc.html
How much current is the generator producing?

Do you have a protection diode in between the battery and the generator so the battery is draining through the generator?

Its typical to need about 5% more voltage then the battery output to ensure your charging the battery. With the protection diode in place you also have to consider the forward voltage of that diode. If the diodes forward voltage is 1V then you only have 5V reaching the battery. You either need to get more out of the generator or move to a smaller battery.