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Old 12-12-2013, 05:36 PM   #1 (permalink)
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Join Date: Jun 2013
Location: Germany
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Partygurke - '90 VW Polo 2F

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DIY Alternator (permanent magnetic)


my english still bad, but I try it.

After the battery of my car broke down, i buy a new one.
A LiFePO4 12V/8Ah battery
Safes 13kg! and incrasses the load efficienty from 60% to 90%.

As a result of this, i would reconstruct the alternator.
The old one weighs over 6kg and has an efficienty under 50%
The new one are an modified Brushless Motor with around 900Watts.(about 90% efficenty at generator)

An other coil winding and a "Stern Dreieck Schaltung" i would get a output voltage from 15-55V by an engine speed of 1000-5500U/min

The DIY charge controller should do this:
-controll the chargecurrent about 8Ampere but set the load current on it.
I explain: The controller load the battery with 8A. then i switch the lights on -> they need about 15A. So the controller current raise to 23A. I prevent an overcharge and i get enought Amperes for all consumers.
-overvoltprotection : Output Voltage: 14,5V
-overheatprotection: controller and generator
-undervoltprotection: prevent depth discharge
-autoswitch the "Stern/Dreieck" when the outputvoltage from the generator gains over 55V.
-display load/consumer current/power and batteryvoltage

The generator connect with the cam shaft over a cuppling ( Light and with a 100% efficenty.

I upload pics later

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