new controller and reduced range

Hi all, I recently replaced my controller and have had some range issues since. Its rated as a 48V 1500w controller but since I started using it i only get about half the range I used to and power keeps cutting out with lots of juice left in the pack (cant get it much below 51V) I suspect they gave me a mislabeled 60V controller and it's cutting out as a low voltage protection but would like a 2nd/3rd opinion on this.

Eyford01 said:

Hi all, I recently replaced my controller and have had some range issues since. Its rated as a 48V 1500w controller but since I started using it i only get about half the range I used to and power keeps cutting out with lots of juice left in the pack (cant get it much below 51V) I suspect they gave me a mislabeled 60V controller and it's cutting out as a low voltage protection but would like a 2nd/3rd opinion on this.

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Sounds like a good theory to me. Are there any options you could set on it?

Nothing on the outside, sticker on it states 48V with under voltage protection at 42 buuut same batteries/ motor/ everything else and it's my only working controller at the moment which is why I'm hesitant to open it up and start mucking around. I've seen some controllers on ebay listed as 48/60v. Does anyone have any experience with these? Are they intelligent enough to detect voltage in or could there be a switch inside the case?

I'm betting some cells in your battery don't like 1500w.

If you have a display or lights on the bike that are powered by the battery, and those remain on when the controller cuts out, then it's probably the controller LVC.

Some controllers have jumpers on the board inside to set it's LVC. Others are programmable, if you have the right software (from the manufacturer) and cable. Others are automatic, and set their LVC when the battery is connected, so if the battery is at a voltage near the "border" between two set points, the controller might set itself to the wrong LVC. No way to know what those set points are, however, without experimentation, on any specific controller.


If they turn off when the controller cuts out, it's probably the battery shutting down due to cells dropping below LVC under the load (especially if this controller pulls more current than teh old one). Leaving the battery on the charger for days (or weeks) anytime it is not in use may correct this, at least temporarily.

Thank you all for the replies. The controller I have on there now is a 1500 my last one was a 1000 ( I thought I'd mentioned that in the first post but I guess I forgot). Still running on the 1000w back wheel motor I have a new 1500w front motor not installed on a rim yet. I was mid upgrade when my old controller failed and winter hit and I packed it all away. Batteries are 2 x 48v 10ah packs both packs behave the same way, on the old controller they'd shut down at 42v now they both quit at 51-52. I have a 20ah pack as well that someone gave me that the BMS is cooked on, I charged the cells individually and each test well and new BMS is on the way. What would the dangers be in short term testing on an unprotected battery? It would tell me for sure if it's the controller and all I'd need to do is run it down to half capacity and see if it shuts off, if it still quits around 50v it's the controller if it keeps going it's the 10ah packs. There are no lights/display hooked up to the controller. I opened the ends but cant see any switches or connectors. I can't slide the whole board out because I stripped the screws holding the case to the heat sink, pretty sure they used a thread sealer on them. I ordered a new controller from eBay for $55 shipped from the US to Canada, if nothing else it'll be good to have a back up on hand and I've got a couple extra motors kicking around anyways.

Edit: also the batteries are almost always on the chargers at the moment unless they're in use and I've been getting a decent amount of use out of them lately

thank you all for your input but it's a problem I don't need to worry about anymore due to theft, luckily I had taken my battery with me and they were nice enough to leave my lock behind.......