48v to 12v Converter/Reducer

[Mooncarter]

IDK. Just seems to me that if you have a reducer independent of everything except for the pack, it has a switch to energize it. Why would you connect it to b- on the controller? Seems as if you are inviting problems that should have nothing to do with charging system.

[Sergio]

Since the OP said he was trying to learn, here is more information.

Club Cars with an OBC use a Coulomb counting charging algorithm.

There should be a single cable (no extra wires) on the pack negative battery post, and that cable must pass through the OBC.

All other wires, charger or accessories connect to the other end of the pack negative cable on Controller B-.

The OBC establishes the baseline for the battery pack during the first few charging cycles (using a different algorithm), and stores that information in volatile memory (the kind that needs power to be preserved).

When you use the cart or any accessory, the current must flow from the battery trough the OBC where it measures that energy.

The OBC then uses that information during the next charging cycle to replenish the energy that was used (plus 10% to compensate for FLA inefficiency).

The process of resetting the OBC, as I mentioned on your other thread, simply involves disconnecting the pack negative cable so the OBC does not have any power to maintain that volatile memory where it keeps the amount of energy stored in the pack.

Once that happens, the OBC no longer knows how much energy is stored in the pack and it starts a new baseline analysis.

If You drain current directly from any batteries in the pack, the OBC will not work correctly.

I personally don't like those reducers without a trigger wire, they are not designed to be switched ON/OFF on the 48v side as it puts a lot of stress on the filter capacitors used.

Get a 48v->12v reducer with a trigger wire, which is a low current 48v wire that connects to the "cold side" or switched side of your key switch.

That way when you turn the key switch OFF, all your 12v accessories go OFF regardless if their individual 12v switches are ON or OFF.

Your existing 12v accessories should be connected to that yellow wire with an inline fuse on your battery #5 positive post.

Our site sponsors sell those converters and as mentioned before fuse boxes if You want to make a neat 12v distribution panel.

http://www.cartsunlimited.net/12v-reducer-.html

[yamahaguy97]

thank you for being more specific about the reason for using b- instead of pack negative sergio. Whether it's a club car or not, I always tell people to get a reducer with a key switch wire. I also have used the type you referenced in your post Also, is the reducer in your picture the one that the input negative also acts as the output negative? in other words is it a dual purpose wire because there is no separate output and input negative wires?

[nnmsgst]

Originally Posted by yamahaguy97

thank you for being more specific about the reason for using b- instead of pack negative sergio. Whether it's a club car or not, I always tell people to get a reducer with a key switch wire. I also have used the type you referenced in your post Also, is the reducer in your picture the one that the input negative also acts as the output negative? in other words is it a dual purpose wire because there is no separate output and input negative wires?

Ok, I just emailed Scotty to order both. What else do I need for the install? I don't understand what the B- means and I'd like to know what the consistent logic is for considering the number of each battery in the bank.

Thanks

[Bobthefish19]

Got a question I'm using a Lester on board charger, can I still have the negative side of the reducer to the negative battery pack or change it to the B- on my alltrax? Thx

[scottyb]

Sergio made an excellent post above about the importance of keeping the on board computer current with ALL of the battery pack use including the DC reducer draw. Hence the connection for all draw to the controller B- which is just the other end main battery - cable - so electrically both ends of this cable are the same point except for the fact the OBC can only monitor and calculate draw from the controller end of the cable and not something connected directly to the battery pack -.

If the charger is upgraded and the OBC is eliminated or bypassed then there is no need to use one end or the other of the main - cable except for one benefit. The benefit being a less corrosive environment at the controller B- than the main - battery post. I hope this helps

[yamahaguy97]

Originally Posted by scottyb

Sergio made an excellent post above about the importance of keeping the on board computer current with ALL of the battery pack use including the DC reducer draw. Hence the connection for all draw to the controller B- which is just the other end main battery - cable - so electrically both ends of this cable are the same point except for the fact the OBC can only monitor and calculate draw from the controller end of the cable and not something connected directly to the battery pack -.

If the charger is upgraded and the OBC is eliminated or bypassed then there is no need to use one end or the other of the main - cable except for one benefit. The benefit being a less corrosive environment at the controller B- than the main - battery post. I hope this helps

Ok so in other words, for the sake of keeping the obc happy, connect your reducers input negative to b- unless the obc is not in the picture anymore

[Bobthefish19]

Thx Scotty

[Mooncarter]

Thanks Scotty. That is what has been confusing me. So the OBC can only read info from the B- end of the same cable.

[nnmsgst]

Originally Posted by Mooncarter

Thanks Scotty. That is what has been confusing me. So the OBC can only read info from the B- end of the same cable.

Allright, now you guys have me totally uneasy. I ordered the reducer and fuse block from Scotty today. Where do I even begin?