lithium battery questions

[Banditz]

Originally Posted by kernal

Brushless motors in EZGO RXV since 2008. Yamaha since 2016.

Thanks! No wonder they are so fast from factory then! I'm new to carts, didn't have a clue they were doing this yet!

[Gregorio]

Originally Posted by Banditz

Great! Thank you!! So this BMS is basically s ESC with another name then, ok good. Then as to the question asked earlier about the max amp draw.... it will be limited by whatever the amp rating of the BMS is. No matter anything else in the circuit. Just like if you max out the motor but still have the stock controller.

The BMS does control charging current to prevent over charging when voltage reaches a certain level. Unless it is a very heavy duty device that can handle the amount of amps going through it like the speed controller does, the only way it can provide discharge protection is to use a huge solenoid/relay that cuts power when voltage drops to a certain level. This would be a very abrupt cut off of power like flipping a switch and would likely happen under load. Imagine how dangerous that could be. A better scenario would be to use the BMS to trigger a very annoying alarm and possibly find an aftermarket speed controller that can cut power at a certain voltage level.

Still does nothing to the total amp draw through the pack. I would assume that as long as the cables and battery interconnection bars are sized accordingly, the batteries themselves would be the limiting factor and would overheat. A temperature probe or two with alarms possibly tied to an aftermarket controller (if capable) could add a margin of safety.

[E-racer]

PingEye3, I like the use of the foam tubing to help seal off the compartment. I mainly use my cart off road and that will help keep the dust out.

[Furyous]

OK, think I have this thing nailed. Need to make a purchase soon so I can get back on the road. I'm thinking this is my best option. More than I wanted to spend, but I figured if I am all in about $1500 I came out ahead. http://evbatterycenter.com/HAC4/inde...eaf&Itemid=605

A couple of questions:

I want to be sure my Alltrax AXE 500 can handle this. In the control panel, it has an overvoltage cutoff setting to 60v, so I assume it is good if I want to charge this to maximum voltage of 58.8v?

I bought this charger as it was a heck of a good deal but it puts out 50.2V. I see on EV Battery Center's website that the chargers are the same brand, adjusted to 58V for certain packs like the one I plan to buy. Does anyone know if these are easy to crack open and adjust the voltage up? With a BMS installed, overvoltage and overcharging should not be an issue, right? http://www.ebay.com/itm/232344777805...%3AMEBIDX%3AIT

[Gregorio]

I just bought that same pack with BMS, brackets and charger from them. Came out to just about $1800 with shipping. I ordered it with double interconnection bars because they were rated lower than the pack itself. I also eliminated the wire with the Anderson connection for the same reason. I will supply my own 2AWG cables and connect directly to the + and - terminals. Should be here in a few days.

I've decided to use this with a XCT400 after talking to them about it. Based on my mountainous location, they were still a little concerned with it and suggested an upgraded HD pack for a lot more money to be safe. However, I'll be monitoring with temperature sensors in various locations to make sure I don't cook anything.

The 500A controller, even though only rated to 500 amps, could pull a few more instant amps than that. The max rating of the pack, is 540 instantaneous. It is the continuous draw that the controller will overcook the pack. If I remember, it is 400A vs only 250A. My controller is only 250

Have no idea how to modify the charger but his price for a 17A model calibrated for this pack was pretty decent. As I understand it, the BMS will only prevent overcharging and overvoltage.

[agpfl]

I have been running this pack http://evbatterycenter.com/HAC4/inde...led&Itemid=680 for 6 months now and am very happy.

The BMS will also balance, protect against high and low temp, as well as other stuff. Look at the the link to his BMS http://evbatterycenter.com/HAC4/inde...ons&Itemid=688.

If you are going to buy the batteries from him, you should also go with his BMS. He will make sure to preconfigure it correctly for the pack you purchase.

[PingEye3]

Fuyrous: I agree with agpfl that the way to go is with the BMS (with WiFi) from Nick at EV Battery Center. I have installed 8 packs from him in the last 2 1/2 years, all with his BMS and charger and absolutely no problems. Since you are getting a pack from Nick, call him and ask him if he can reprogram your charger for you. Ship it to him before he ships the pack to you and you only have the cost of one way shipping and his alterations to the charger. If it is simple to reprogram, he will probably do it for nothing. Tell him, Gary sent you.

[Furyous]

Thanks, Gary!

I ordered the pack and BMS with wifi from him yesterday. I spoke with him briefly but was outside next to traffic and couldn't understand his answer about the charger question. The cool thing is that it is the same brand of charger that he sells so it should be likely to get it reprogrammed.

Here's a thought that crossed my mind yesterday, though- If I keep this charger the way that it is and only charge the pack to 50.2v or so, I would think not only would I be sacrificing speed but run times, right? Just thinking it could be a temporary measure if it cannot be reprogrammed and I have to order a new charger.

SUPER excited about this. I am the President of our local golf cart club and everyone is watching to see how this flies. Several members are due for new batteries relatively soon, and with 70 members they could get a lot of business from us.

[Gregorio]

Originally Posted by PingEye3

Fuyrous: I agree with agpfl that the way to go is with the BMS (with WiFi) from Nick at EV Battery Center. I have installed 8 packs from him in the last 2 1/2 years, all with his BMS and charger and absolutely no problems. Since you are getting a pack from Nick, call him and ask him if he can reprogram your charger for you. Ship it to him before he ships the pack to you and you only have the cost of one way shipping and his alterations to the charger. If it is simple to reprogram, he will probably do it for nothing. Tell him, Gary sent you.

Gary,
Did I see that you are running Alltrax controllers from scottyb? I am going to order today (XCT400 controller, solenoid, fuse, etc.) and was wondering if there is anything special I need from him? Also, do you run a fuse on both + and - terminals? A local guy here insists on both.
Thanks,
Greg

[PingEye3]

Gregorio: I am running a Curtis 1268 400A in my Club Car with lithium. In the three G29's I rebuilt and added lithium, all had XCT 400's from Scotty. In my cart, I have an ANL fuse on my negative cable. But, on all three of the Yami's I installed the fuse on the Pos (+) only in a separate ANL fuse holder. You can see it on the back wall of the battery compartment behind the pack. Coming up soon will be a replacement of my Curtis 400 with an XCT500 Alltrax. Might be scary!!