Best and most affordable charger for lithium leaf 14s pack
 

Ok guys so the hunting buggy is almost finished. Im at the battery part now. I have 14s leaf pack. I also ordered the Zeva bms16 with the monitor and temp sensors. Whats the best bang for my buck on a charger thats a smart charger. By that i mean hooks through the zeva to turn off at 57v . also where is the best place to get copper bus bars? I still havent done that part yet.

Re: Best and most affordable charger for lithium leaf 14s pack
 

The only charger that I know of that communicates through CANbus with the zeva is the Elcon charger.

Re: Best and most affordable charger for lithium leaf 14s pack
 

Do you know which one by chance and a good place to purchase it?

Re: Best and most affordable charger for lithium leaf 14s pack
 

For my charger I use a 10 amp power supply I bought for under $100 from Jameco electric. It is supposed to be a 57.6v power supply but it has a potentiometer to allow you to adjust the V it turns off at. I currently have it set to 57.0v cutoff.

Since you don't have to worry about memory or boiling the electrolyte then you really don't need anything fancy. Just something that'll shut off when you want it to as a backup. The BMS should stop the charge where you want it, the charger cutoff is a backup.

Re: Best and most affordable charger for lithium leaf 14s pack
 

I found a fixed 58.8v charger in the USA and have seen many guys use a 58.4v and im not really sure if the .4 over ia going to be to much. Every other 58.4v i can find is in china amd will take a month to get here.

Re: Best and most affordable charger for lithium leaf 14s pack
 

I don't know that BMS, but I know the AIMs converter/charger rated at 36/48v I use with my inexpensive Xiaongiang (sp?) BMS (overkill solar) works well. I monitored it the very first time and a suspect cell with higher IR spiked up and the BMS shut the charger off until it could get it balanced and then re-started the charger. I use this for both my 36v and 48v carts that I've built Li-Ion batteries for. $230.00 and can easily be mounted for on-board charging.

https://theinverterstore.com/product...8aAiHCEALw_wcB

Re: Best and most affordable charger for lithium leaf 14s pack
 

Bronsonj, you have it the wrong way around. The BMS should be the final, fail safe protection, not the first. The charger should cut off when required, with the BMS only intervening if the charger fails to shut off correctly.

True, you don’t need anything fancy, but you do need more than a constant voltage power supply. You need a constant current (CC) and a constant voltage (CV) power supply.

You set the charge current, say 10A and the maximum voltage, say 57v as in you case, then the charger will start charging in CC mode at 10A until the voltage approaches 57v. Once the current requirements drop below 10A, the charger switches to CV mode and holds the voltage at 57v until the current drops to about 10% or 20% of the CC value, or 1 to 2 amps. The charger should then switch off.

Only if a single cell goes above the preset voltage or if the pack voltage goes above the preset voltage should the BMS intervene and cut charging.

Cheers
Pat.

Re: Best and most affordable charger for lithium leaf 14s pack
 

So is a fixed 58.8v charger to much for a 14s leaf pack?

Re: Best and most affordable charger for lithium leaf 14s pack
 

No, 58.8v is the correct voltage to charge the batteries to 100% (14 x 4.2v). You will get a longer battery life by only charging to 4.1v per cell (57.4v) or 4.15v per cell (58.1v), but 58.8v is ok.

Cheers
Pat.

Re: Best and most affordable charger for lithium leaf 14s pack
 

Sorry Pat, you're right. I did get that backwards. Power supply cutoff and BMS as backup.

I did check and my power supply does CC until the V gets up to the predetermined mark then it holds there until it shuts off. My power supply does 10.6 amps until it gets to the voltage threshold then does CV.

My power supply is model EVS57-10R6 by a company called TDK-Lambda. I picked mine up for just under a hundo from the online auction site. I checked the retail outlets and they are over $300 now! I did a search for my model number on the auction site and found nothing... :thumbdown: But I purchased that back in 2019 after my purpose built lithium charger died, so I'm thinking it's just been replaced by newer models.

But back to the original question, you need to figure out how high you want to charge your cells. 4.10vpc? 4.13vpc? 4.15vpc? Assuming 4.13 that'd be a 57.8v power supply, although most power supplies offer a potentiometer to adjust the final voltage.

If you do the power supply then I'd recommend something that automatically disconnects it from the battery pack when done. I used this 120v AC relay:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

It's coil is activated when I plug the cart in, it gets 120v AC. Then it has several other connections so one of those is used to connect the charger to the pack. This way it automatically connects when the cart plugs in and automatically disconnects when the cart is unplugged. I also wired in the 12v charger for the 12v power through the same relay, so both chargers are completely disconnected from their respective batteries when the cart unplugs. That plus it's only one extension cord required to be used to charge both packs. :thumbup: