S series controllers and P5 parameter

[Alan Quay]

Hi all,

Has anyone had experience with new (ish) S series controllers from BMS?

I took the bike out for a quick blast today, and it completely cut out on me, after a long, hard climb. The LCD went off, no power, dead.

I got it home, and tried to turn it back on. It came on for about 1/2 sec then went off again.

I checked the battery voltage, 38.8v , re-conected and tried again. Nothing.

Put it on charge, and it all came back too life.

Looks like there is a LVC in the controller that cuts in at about 38.8v

I have now set the mysterious parameter 5 = 0 (was 12) in the hope that was the issue.

Any other ideas?

 

[Deleted member 4366]

38.8v is the cut-off for a 48v battery. I think P5 is more for the battery indicator display, but if yours was set to 48v, the battery indicator would've been showing empty. Which controller do you have? The detection is supposed to be automatic.Perhaps your battery was higher than 42v when you started, which can happen with LiFEPO4s, so it decided that it was a 48v one. What battery are you using?

 

[Alan Quay]

The battery indicator was showing about 50% just before shutdown. I have a brand new 36v 20ah shrink wrap lithium ion from bms....

 

[Alan Quay]

Sorry, forgot too add that controller is an S12P, 36/48v .

 

[Deleted member 4366]

If you read 6.1 of the user guide, it implies that the 48v controller is only compatible with the 48v display, so I'm wondering if you have a 48v controller and 36v display, but I don't see any way of selecting a 48v system. It seems that for the S06, voltage selection is automatic between 24v and 36v. The only sure way of telling is to look for the value of the resistors in the voltage divider. I've never opened one up so I can't say where they are or what they should be. I have a S12S, but I think it's different to a S12P because it's only rated at 23 amps.

It says also that the battery indicator will flash if LVC is reached. Maybe it would be a good idea to do a couple more charges to see if the behaviour repeats.

 

[Alan Quay]

The controller is marked as 36/48v on the sticker. It also has a current marking of (from memory) 22 amps.

I'm hoping that it picked the battery up as 48 volt. Perhaps I switched the bike on while connected to the charger.

For now I have disconnected, recharged and allowed to sit for a while. I will try it again later and see what happens.

Merry Xmas all!

 

[Deleted member 4366]

The S12P is advertised as 30 amps. The photo shows a label with 29 amps written on it.

 

[eHomer]

Sorry to partially hijack your thread Mike, but your theory on minimum battery voltage has given me food for thought with my controller problem.

It's not the same controller as yours, but it does have an associated LCD control panel which enables it to run on 36v or 24v, presumably through the panel's firmware rather than fixed resistors controlling the VLC parameter.

I've been boring everyone on here with my non working Conhismotor 750w controller.

Your mention of the lower voltage limiter made me think it was maybe a possibility on mine too, so I've just tried another experiment.

PO5 on my controller instructions state "P05 Voltage Mode 24 V, 36 V, 48V(24V/36V selectable, 48V)", and when I ordered it from Conhismotor I requested 36v 750w, so I presume it should be the 24/36 volt switchable version, rather than the 48v fixed.

So far I've always tried it with my 36v 10ah Lithium Ion battery packs, which have a fully charged voltage of 41.2v.

So after reading your thoughts in this thread, I tried hooking it up to two 12v sla batteries in series, which gave me 25v.

I then switched the controller to 24v via the P5 setting, and I'm getting a surprising result. The battery is showing as empty, so the controller thinks 25v of battery is not enough juice when it's switched to 24v.

I'm now wondering if the VLC is wrongly wired up in my controller, or if indeed it may be a 48v one instead of a 24/36v ? There is no printed label on it at all, just a roughly penciled notation "36v 750w".

 

[Deleted member 4366]

LVC for a 48v battery is around 38.5v, so a fully charged 36v one like yours works for about 10aH with a KU123 set to 48v. All the same, you've got nothing to lose by putting a 12v battery in series with your 36v one to see what happens.

 

[eHomer]

Second thoughts again.....


Maybe I'm just clutching at straws again.

I just checked the Conhismotor website for my controller/control panel's page and on there they just state it as 36v 750w, no mention of it being switchable 24/36, which their PDF operating manual states.

It's still a bit of a loose end though, what happens when the Panel is switched to 24v ? Is it trying to communicate with the fixed voltage controller, whereas is that just abiding by the fixed resistor method to monitir the VLC instead ?


Merry Christmas every, by the way...

 

[eHomer]

LVC for a 48v battery is around 38.5v, so a fully charged 36v one like yours works for about 10aH with a KU123 set to 48v. All the same, you've got nothing to lose by putting a 12v battery in series with your 36v one to see what happens.

Sorry Dave, my post overlapped your reply.

Sounds like a good idea ! I'll give it a try and report back...

 

[Alan Quay]

The S12P is advertised as 30 amps. The photo shows a label with 29 amps written on it.

Double checked, it has a sticker that says 22A, and 36/48v, S12P.

 

[eHomer]

I just tried it Dave, 36v Lithium in series with a 12 sla, it showed as 54v on the panel, but no joy, not a flicker from the motor.

Sorry to have hijacked your thread Mike, I'll stop confusing it with any more posts about my problem.

 

[103Alex1]

Double checked, it has a sticker that says 22A, and 36/48v, S12P.

Definitely needs unravelling - 22A won't give you that extra push on the really steep slopes at 36V. Did you get any KU123s ? I'd try it with one of them see what you think if you did. They definitely run round 30A.

 

[Alan Quay]

Will stick my watt-o-meter on it and thrash it to to within an inch of its LVC tomorrow.

 

[Deleted member 4366]

Double checked, it has a sticker that says 22A, and 36/48v, S12P.

Very strange!

If you click on the photo in the listing and the zoom in (Ctrl + "+"), you can clearly see Max Current 28 +/- 1A

 

[Alan Quay]

Very strange!

If you click on the photo in the listing and the zoom in (Ctrl + "+"), you can clearly see Max Current 28 +/- 1A

Ok, just checked it with the watt meter: 27.5 amps max, so it looks like the stickers on my controllers are wrong.

Will give it a good run later to see if the LVC problem persists.

 

[Alan Quay]

Ok, managed to get it cut out again, and can now confirm that it's the battery cutting off. Last time it must have recovered by the time I got home and measured it.

I would have been drawing 27.5a for a good 5 mins. After a 5 min break it cam back on I was able to use it on the flat.

Question is, is it faulty, have the wrong BMS in it or am I just asking too much from it?

 

[Deleted member 4366]

Ihave two of those batteries. My neighbour, Saneagle, also had one on his bike. They're all connected to 30 amp controllers. When Saneagle first had his, it cut out at 38.5v because his controller was set to 48v, but we fixed that.

So, you see the wattmeter go off when the power cuts?

 

[Alan Quay]

So, you see the wattmeter go off when the power cuts?

Yes, so I'm pretty sure it the battery cutting out.