Nissan Leaf batteries set up.

[Sergio]

There are a few reasons for higher degradation on the 30kWh and it is most related to heat and changes Nissan did.

The option to limit the charge to 80% was removed when the 2014 model year debuted (to game EPA range ratings), so none of the Leafs with 30kWh batteries have that option.

The 30kWh modules are also denser (8 cells per module) vs the 24kWh (4 cells per module) and that increases the heat dissipated within the module given the same operating conditions as a 24kWh module.

If you want to increase the pack life, it is better to charge to 80% and discharge until 0% than to charge to 100% and discharge to 20%.

For a hot environment the best modules were the 24 kWh ones (model years 2015-2016) aka "lizard battery".

[ysrman]

Techdirectclub has a 110.00 power supply he sets up as a charger. it charges at around 15 amps . their cheap bms works well for charging and balancing but not for load control.

[DaveTM]

Originally Posted by ysrman

load control.

?? ?? ??--What is "load Control?"

[ysrman]

i am going to patent that term. I wasnt sure what to call it but its the ability of the bms to shut off the load on the battery when the LV low voltage is triggered. i guess the bms could control a relay or a solenoid that would remove the load from the battery

[n5yzv]

Well, regarding Techdirectclub on ebay, I just ordered their completed battery pack, with 7 batteries (14s), BMS, Charger, in a box, with an Anderson PP ready to go. I started piecing the parts and found it would less expensive to just get it complete. Less hassle too, as I'm a little short on time.

My plan is to pull the existing Trojan's, wire up an Anderson PP. Now, regarding the other "stuff" that is wired up? Well, i'll take them one at a time. It is a used cart, so who knows what was attempted to be wired up. I'm not sure if I want to make a bus bar, or a terminal bar (think "y" adapter). As it sits, to charge I would have to lift the seat, unplug the cart and plug in the charger. Call me lazy. I've considered re-wiring the ClubCar pigtail to allow for charging to keep it cleaner... Thoughts?

I'll post more info as it goes.

[Sergio]

The issue with those cheap BMS that techdirect sells is that they do not use an external current shunt to monitor and limit current in/out and external relay/solenoids to control LV and HV cutoff.

While You can re-wire (as it was done recently by another member) the BMS in order to not run the Motor current through the BMS circuit board by using an external relay to provide the battery protection, you will also lose the SOC calculation since the motor current no longer goes through the BMS where it can measure it.

The BMS can still provide basic cell monitoring by re-routing the motor current.

The other part I did not like is that all of the discharge current goes through the circuit board bolted to the leaf cell terminals, they should have used copper bus-bars given the high discharge currents present in a Golf Cart application.

[ysrman]

Sergio, I think the guy has a good thing started with his ready made pack. I think if we could tell him an easy way to design one for us to use in golf carts he would save a lot of people a lot of time. i dont know how to calculate the current a printed circuit board can handle but maybe a solution is to bolt the bus bars on top of the board and the current would flow mostly through the bars? also if he put an anderson connector for the charge side and 300 amp connector on the draw side maybe having the bns control a giant solenoid? the key switch wire control you suggested works too but is less turn key.

[n5yzv]

I just checked with him. it is a 50A connector. Seems rather small to me.

[n5yzv]

Originally Posted by ysrman

Sergio, I think the guy has a good thing started with his ready made pack. I think if we could tell him an easy way to design one for us to use in golf carts he would save a lot of people a lot of time. i dont know how to calculate the current a printed circuit board can handle but maybe a solution is to bolt the bus bars on top of the board and the current would flow mostly through the bars? also if he put an anderson connector for the charge side and 300 amp connector on the draw side maybe having the bns control a giant solenoid? the key switch wire control you suggested works too but is less turn key.

You know, that's not a bad idea. Use the 50A conn for charging, then wire in a 300A for the motor. Sure, I'll loose some features, but for the most part, it will be very functional.

[Sergio]

Originally Posted by n5yzv

You know, that's not a bad idea. Use the 50A conn for charging, then wire in a 300A for the motor. Sure, I'll loose some features, but for the most part, it will be very functional.

That is the same conclusion we came up in this thread, unfortunately it does make the SOC display function useless.