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Originally Posted by somfas
(seems 9 leaf modules would be 75.1v and I guess thats not enough?)
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Your 72v lead acid, fully charged would be around 76v. Most people converting to lithium opt for higher V than the lead acid reached at full charge. But since you are already 72V this may not be as important to you. Your controller will work with either 10 or 9 cells. 10 cells give you 83v to 60v and 9 gives you 74.7v down to 54v. 10 cells will give you more available watts so you should be able to get a little better range on 10.
Quote:
Originally Posted by somfas
When I order the batteries, will I need to configure the connections (how they are wired together)? Do they come with any of the bus bars?
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Depends on who you buy from. Some will give you buss bars, some won't and you'll have to make your own.
Quote:
Originally Posted by somfas
I assume when I order the BMS, it will come with instructions. Will it come with the other items I have been reading about like shunts, disconnect, relays, fuses, etc,
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Most likely it will not come with a disconnect, relay or fuse. The shunt is possible depending on which BMS you get and what options, but a shunt isn't a requirement to go lithium, it's an option.
Quote:
Originally Posted by somfas
I will also want a charger with overcharge protection. It seems the controller may somehow help with that, but I want as many failsafe measures in place as possible. Once this is built, I want it to be super safe and super hands off.
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The charger can be set to stop at a certain max V, but it won't know the individual cell voltages. My charger is set to stop charging at 57.6v which would be 4.12vpc if all cells are balanced. The charge termination is also controlled via the BMS. If you set the BMS to stop at 4.15vpc then you'll have two charge stop mechanisms. The controller is not involved in stopping the overcharge.
As for undercharge, that is where you can program the controller as another fail safe. I have mine set to stop when it gets to 45.5v which is 3.25vpc. If you have your BMS also set up to somehow trigger a relay that cuts power to your controller then you can use that as a second method to stop power drain.
Welcome to the lithium addiction!