48v 100Ah Evoltion low battery voltage

[WalterM6]

Sounds like a runaway battery. Once the batteries get above a certain level one could start charging more rapidly than the rest. This is likely caused by an out of balance battery. This would push the battery over the BMS HV limit and shut the pack down. Then you would see the discharge down to 12v like you said. In that length of time the voltage settled back to normal and the BMS turned the pack back on. Unfortunately I don't believe Evolution or anybody else has a BT or computer connection where you can read the errors. The only possible solution might be to decrease the charge voltage to about 56v and hope the batteries will come back into balance again. If possible.

[Pat911]

Yes, What Walter said. Cells are not balanced. Too early in the morning where I am. That would explain all symptoms.

BMS detects ONE high cell and shuts off to prevent overcharging that one cell while the other cells are much lower. One minute later the voltage of that one cell drops low enough for the BMS to kick back in and the voltage jumps back up. You will never be able to charge to 100% capacity

During discharge, there is one cell that is much lower than the others and when it reached its shutoff voltage the BMS cuts off. The cell then recovers some voltage and the BMS restores the output. You will never be able to discharge to 0% capacity.

Depending on how far the cells are out of balance, you may only have 10% of usable capacity.

As suggested, You could try lowering the charge voltage and let the BMS balancer work but they are very limited in what they can do, and without access to the cells you'll never know the health of each cell. Only real way to fix this is to gain access to each individual cell and charge them to the same capacity. You could also connect a 16s active balancer for a few days and let it do it's thing. An active balancer can balance with a much higher current, 5A as opposed to the BMS's 0.1A or so.

That's why I like making my own packs. I use a bluetooth enabled BMS that lets me see the state of each individual cell.

Cheers
Pat.

[GCS290]

Thanks guys that is what I was starting to figure out. They have a BT BMS in it but the app isn't working. Trying to get that figured out now.

[WalterM6]

They have a BT BMS in it but the app isn't working

Make sure location is enabled on your cell phone.

[Pat911]

Most Bluetooth capable BMS’s must have a Bluetooth module connected to it as well. Out of the box they are Bluetooth ready, not Bluetooth capable. Do you know if it has been installed?

And you connect straight from the app, don’t go into your phone’s Bluetooth menu to try and make a connection.

[GCS290]

So, the company is of very little help. I sent them all sorts of info running the BT app, while charger, while driving, while resting. They say the battery seems to be fine. Just for the hell of it, and to do my part for the customer, I upgraded all cables, installed HD solenoid, put in stock motor, replaced stock controller, replaced wire harness. The cart acts the same, Re-installed all of the customers parts (except solenoid and original wiring) cart acts the same. Only thing I did not do because I am not charging the customer was remove there lithium pack and install 6-8v lead acid batteries. I am 100% certain it is the battery now. Thanks again for all of your help, now we will see how their warranty process works. I just feel bad for the customer, but I did my part.

[Bama Brad]

Please let us know how Evolution handles this. There are lot of folks that are considering Lithium and Evolution is high on there list of options. If their customer service is lacking, that will make a big difference in our (my) decisions.

[GCS290]

Originally Posted by Bama Brad

Please let us know how Evolution handles this. There are lot of folks that are considering Lithium and Evolution is high on there list of options. If their customer service is lacking, that will make a big difference in our (my) decisions.

So they did alright in the beginning but now that it is on to replacement they want you to go to your local dealer. The dealer closest to use has terrible customer service and they just keep telling this lady all sort of things. (i.e. we have had problems with those, maybe its the wrong charger, even though that is the charger they installed with the battery, etc.) Problem being is there is no replacement battery available, and they have no ship date. The batteries are not code dated either, which I think is odd. I will keep you updated on the end result once the customer gets it figured out. But from what I have seen/dealt with so far I would steer clear. Warranties are great, but only good if you can get it warrantied.

[jonr3]

Any update on this issue?

I contacted Extreme Team as I am looking for a new lithium battery. They said they have identified a software issue on certain batteries and have a new software update…

[GCS290]

Originally Posted by jonr3

Any update on this issue?

I contacted Extreme Team as I am looking for a new lithium battery. They said they have identified a software issue on certain batteries and have a new software update…

So far no update, the local dealer of those batteries told this customer some bs about the charger being wrong. Personally I don't think they could get a replacement anytime soon so they are buying time. Once she gets the cart back from them she is going to call me to go check it out. So we will see, as soon as I find out a solution I will let you all know.