My latest EV project


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Davo99
Guru

Joined: 03/06/2019
Location: Australia
Posts: 1585
Posted: 02:52am 20 Sep 2021      

  galderdi said   Am I missing something though 48v at 600ah is 24kwh. That would be massive and $1200 is very cheap.


I wasn't thinking of your requirements so much for your Vehicle as Godoh's for his Home.  You certainly wouldn't want to be carting round  1100Kg of batteries in a sports car! I presumed you would understandably need something more light weight and power dense like a Lipo derivative.  LA is still a very viable Tech for many things, I don't think mobile application's is one of them however!  :0)

Yes, it is cheap for the reserve you get and makes the Commercial lithium battery derivatives look like a joke IHMO.  There seems to be a LOT of deliberate Misinformation about Traction Batteries parroted by the lipo obsessed, which I believe is the apt term for the way many go on.

We have discussed the Fork batteries here for home use  and the reality is they are VERY cost effective with few drawbacks for STATIONARY/ off grid application.
When one considers a power wall is  12Kwh useable and costs $15K and a $1200 (plus ancillaries) 24Kwh pack gives 19Kwh useable, it puts things into perspective.
Double your spend on another Forklift pack and you have 38Kwh  Reserve and you would rarely have to dip below 50% DOD if that ( They are rated to 80% DOD which is often maligned) and they are going to have a Very long life and give a lot of reserve.

If one threw a generous size solar array at the things which would also be cheap as chips now, I'd say people in the typical weather conditions of Oz, (Barring maybe tassie or mountain areas) would rarely have to rely on a generator.

To this end, I'm currently playing with an idea  for running inverters mainly off solar.  It's hard ( and expensive) to find controllers that will supply the kind of amps an inverter will pull.  My idea is to have a Smallish/ low cost Controller and by pass it with heavy loads.

I bought some Battery charger boards off Fleabay. They simply switch on and off at a set voltage parameter. Using a large array and small batteries with a decent  Inverter, The voltage monitor bypasses the controller when the voltage drops, say when the inverter is running.  When the batt voltage comes up after being fed whatever amps the panels can produce ( possibly hundreds) the voltage monitor drops the 500A relay and the charging is all handled at a much lower rate but the controller.

I don't see a need to run through a controller when there is big amps being pulled that can come straight from the panels. There are panels that are suitable for both 24 and 48V setups so it's relatively straight forward. The Chyneese Hybrid Inverter/ Chargers I have been looking at will charge at a rate less than they will supply so create a negative drain on the batteries even if there is sufficient solar input available to power the load. This way would by pass that road block and keep the batteries seeing as little discharge as possible.


Would be interested to hear what sort of batteries you are intending to use and the reasons behind them.  Seem to be different ones coming out much more regularly these days.