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Charging On The Go...

2590 Views 8 Replies 7 Participants Last post by  ElectriCar
I hate to burn gas, but if I wanted to drive more than 40 miles, would it be acceptable to install a generator to power my Manzanita charger which would charge the batteries as I use them, or should I convert the generators ouput to DC 144V and send it to the pack? Or should I just use the gas burning thing sitting in my driveway?

I notice the voltage reads below 144V as I accelerate, and wonder if that would blow the Manzanita if it were charging while the pack was in use.
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You can bypass the charger with a little electronic genius, assuming you're running a 144V system.

Ever hear of the bad boy charger? I made one but eliminated the transformer. I wanted to charge my pack and since I didn't have the charger yet, you know necessity is the mother of invention so...

Anyway, to use 240V from a generator to it's fullest potential, you would have to connect each of the two hot wires to a bridge rectifier. You have two 120V legs on the 240V connection along with the white neutral wire.

The rectifiers would need to have a heat sink installed, which I did to my 120V charger I dubbed the ******* charger. This will prevent them from overheating. The bridge rectifiers need also to be rated for the voltage and the DC amperage you're using. I used a 50A 600V unit.

You connect the ~ terminals to the AC of the generator. One ~ on each rectifier to the neutral wire on the generator. The other ~ connection on one rectifier will go to one hot leg. Connect the other remaining rectifier ~ leg to the other hot leg from the generator. Then you connect both + terminals to your pack + and obviously the - lead to your pack -.

This is quite crude with no current or voltage regulation and I'd first try it in your shop with the vehicle stopped and pack partially discharged. If you read the DC voltage open circuit it will be a good bit over your 144V pack voltage. However if you connect it before you start the generator, it'll never go higher than the pack voltage. As it charges the pack the voltage will gradually creep up and the current will decrease.

Monitor the AC amperage with an amp meter and start the generator. I've got a 15kw generator capable of putting out 62.5A at 240V. You don't want to overload your generator or the breaker will trip and you want to make sure this will work before you take off on a long trip!

The bad thing about the generator output is during the voltage sag on lead batteries when accelerating or going up hill it would overload the generator and cause the breakers to trip if it sagged long enough. But it should work on level ground at a steady speed as long as you don't create a huge sag somehow. You might end up with $50 in two heat sinks and rectifiers.

NOTE: THIS IS A PROJECT THAT REQUIRES SOME INVESTIGATING BEFORE APPLYING IT ON THE ROAD! It may be that the generator would be overloaded from the start but that would depend on your generator size.
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