Originally posted by SkyWatcher
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Yes, that is generally what I wanted to know if Satyam108 understood since he only posted in and out current measurement which may indicate he's under the impression the charge battery is receiving the same amount of power then the input batteries?
However, until he replies we won't know why he posted just the current measurements and if he understands that current is not a measurement of power.
But you do know that and I generally agree with what you posted but here is how I understand it and measured it.
If battery 1 & 2 are connected in series and are 12 volts each = 24 volts and the current is measured at 1 amp = 24 watts entering the motor and if battery 3 is at 12 volts and the current entering it is measured at 1 amp = 12 watts entering battery 3.
So if we have 24 watts coming out from input batteries and 12 watts going in the charge battery it means half of the input power is being used by the motor and potentially half recovered by the charge battery.
However, the motor has converted part of those 12 watts to mechanical power and at best 80% if it is available at the motor shaft which means we have about 9.6 watts in mechanical power at the motor shaft which we can recover back to electrical if we attach a generator to it and can recover at best 80% if it = 7.7 watts and add it to the charge battery which gives a potential total of 19.7 watts recovered from the 24 watts put into the system.
So things are not looking very good and we also have an other loss factor not yet considered which is Battery charge losses.
Example: if you load test a new fully charged 5 amp hour 12v battery you may get 60 watts hour out of it. However, to charge that battery back you will need to use about 74 watts hour which means a lead acid battery is also about 80% efficient to recover meaning the true potential to the charge battery will be 80% of the 19.7 watts = 15.76 watts of potential recovery of the 24 watts from input batteries giving a score of around 65% energy conversion from the input to the output charge battery.
One may simplify his life and get better results to just use a battery charger to charge the 3rd battery?
So what is it and can you demonstrate it that can make the reality any better then what I've explained and tested?
Regards
Luc
jim
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