Basic Nissan Leaf 7 module Lithium setup with Generic Chinese BMS

[reiter284]

I have been reading and reading on doing a battery build for my 2009 RXV. I really like the relay setup outlined in this thread and cutting the power at the accelerator for HV/LV. I was thinking of going with the Chargery BMS 16T because it has current shunt, beeper, balancing, the LED display, etc...

Is there any issues to using Chargery in the same fashion as sergio did with the Chinese BMS?

The two modifications I see are to wire the HV and LV cutoff in series and to switch out to 12V relays instead of 48:

https://www.amazon.com/TE-CONNECTIVI...1260336&sr=8-1

Any other considerations? Anyone recommend a different BMS?

[AussieInSeattle]

Sergio - your PM's are full - can you please PM me or contact me at my handle at gmail.com since I wont be able to respond if its still full. Kind of important.

[Sergio]

reiter284, some folks have used the chargery BMS, you can search the site for those builds.

If You are looking for a better BMS, the Zeva BMS is a good option as well.

You need to keep in mind that any BMS that was designed to control a large contactor typically keeps the contactor ON all the time since it is not a good idea to isolate the pack if the cart is motoring or doing Regen.

I posted some ideas for the Zeva BMS that automatically puts the BMS to sleep when it is not driving or charging.

If You use the Chargery BMS, You can add a 48v relay (the same brand you posted the 12v version) that is powered by the Solenoid big post on the Controller side of the RXV.

Then just run the +12v wire that powers your 12v relays to the 48v relay contacts.

That way when the cart is OFF the 12v relays are also powered OFF.

If the 12v relays are only used to interrupt the pedal signal, You may want to also devise a plan to interrupt the charger in case of an HV condition during charge.

[reiter284]

Originally Posted by Sergio

reiter284, some folks have used the chargery BMS, you can search the site for those builds.

If You are looking for a better BMS, the Zeva BMS is a good option as well.

You need to keep in mind that any BMS that was designed to control a large contactor typically keeps the contactor ON all the time since it is not a good idea to isolate the pack if the cart is motoring or doing Regen.

I posted some ideas for the Zeva BMS that automatically puts the BMS to sleep when it is not driving or charging.

If You use the Chargery BMS, You can add a 48v relay (the same brand you posted the 12v version) that is powered by the Solenoid big post on the Controller side of the RXV.

Then just run the +12v wire that powers your 12v relays to the 48v relay contacts.

That way when the cart is OFF the 12v relays are also powered OFF.

If the 12v relays are only used to interrupt the pedal signal, You may want to also devise a plan to interrupt the charger in case of an HV condition during charge.

Thanks for you input. I definitely want a high and low voltage cutoff. I’ll have to draw out a wiring diagram when I settle on a design.

What about wiring up the chargery with their DCC:

https://www.chargery.com/DCC.ASP

Im thinking wire it up with Anderson connectors for charge and discharge and use the DCC as a two way shutoff. So you have to unplug power and plug it in to charge. But it would be pretty simple. As shown on their common port design.

Any thoughts? Thanks again!

[Sergio]

There are many options, but SSRs get really hot during operation and since bi-directional versions have twice the silicon (MOSFETs back-to-back arrangement) they need large heat-sinks when handling high current.

I would personally use a similar arrangement to the design in this thread, a SPDT 120VAC relay that completes the negative for the LV/HV 12v relays used for motoring and Regen protection when the cart is not plugged to AC power and provides the negative to an 12v HV relay that connects the charger positive output to the pack when the cart is plugged to AC power.

Once you start sketching your plan some of these details will become obvious.

[reiter284]

Originally Posted by Sergio

There are many options, but SSRs get really hot during operation and since bi-directional versions have twice the silicon (MOSFETs back-to-back arrangement) they need large heat-sinks when handling high current.

I would personally use a similar arrangement to the design in this thread, a SPDT 120VAC relay that completes the negative for the LV/HV 12v relays used for motoring and Regen protection when the cart is not plugged to AC power and provides the negative to an 12v HV relay that connects the charger positive output to the pack when the cart is plugged to AC power.

Once you start sketching your plan some of these details will become obvious.

Ok, I think I've got it. Just one last concept I want to make sure I am clear on with this basic design. If you have a low voltage cutoff with the BMS, you cannot charge the pack? You would have to lower the threshold to close the BMS relay to allow it to charge?

[Sergio]

Only if the LV relay is part of the charge circuit.

As I mentioned, only a separate 12v HV relay is used to isolate the charger positive output from the pack.

[reiter284]

Originally Posted by Sergio

Only if the LV relay is part of the charge circuit.

As I mentioned, only a separate 12v HV relay is used to isolate the charger positive output from the pack.

Sorry I should have clarified. When I said the “basic design”, I meant the original design at the beginning of this thread with the simple Chinese BMS, which would be hooked up as common port.

[smbenson]

One quick question. I bought 10 gen 1 battery packs, but got 5 and 5 of the +/- orientation instead of 4 and 6. Is it ok to rotate one of the packs with and put 2 spacers or thicker spacer to get the pack compressed? Also what is the recommended tension on the packs?

Thanks

[Sergio]

I guess you must not have described how you were planning in connecting the modules so they sent modules to be configured as a 10S1P (72v nominal) pack instead of the 5S2P (36v nominal).

Just make sure you add enough spacers between the modules by the sleeves that go through the modules to keep the outside of the modules from pressing against each other.

The through bolts are torqued to 85 in-lb.