Exactly, start by simply disconnecting one wire of the charger from the pack and inserting a standard 60W 120V light bulb (must be an incandescent bulb!) and see if the charger will output its max voltage for long enough to get the pack balanced. Typically a charger has a time cut-off, you may need to switch your charger to an "equalization" type setting to allow it to provide the max charge voltage for long enough while the bulb is limiting the current and the regulators keep everything from reaching max cutoff voltage, so that all low cells get charged with 1/2 Amp and all high cells have the reg bypassing the current until *all* cells start to bypass and that should be the moment that the BMS tells the charger to quit. It may be that you need to reset the charger several times to get it to charge long enough at a low current to get everything balanced again, and it may even be that the charger refuses to deliver max voltage and turns off immediately. In that case, you need to make or borrow a high voltage power supply (does not need to be a charger, just a fixed voltage that is higher than the max pack voltage by several tens, up to 120V. For example if your pack is 120V nominal and you have a power supply that can generate 150V then this works well. If you have no solution then I can help, I have dozens of 48v 1.5A power supplies that look like a large laptop power supply. Put several of them in series to multiply the output voltage and you can build your own power supply for balancing a pack at any voltage. Is your pack 300V then simply use 7 power supplies in series to get 336V from them and wire the bulb in series to send about 1/2 Amp to your pack. Watch the BMS regulate (bypass) the full cells and after a weekend of balancing, your pack should have all the reg lights on that it has balanced it completely.
But start with the simple solution to check if you can use the existing charger and a light bulb. Success! Cor van de Water Chief Scientist Proxim Wireless office +1 408 383 7626 Skype: cor_van_de_water XoIP +31 87 784 1130 private: cvandewater.info http://www.proxim.com This email message (including any attachments) contains confidential and proprietary information of Proxim Wireless Corporation. If you received this message in error, please delete it and notify the sender. Any unauthorized use, disclosure, distribution, or copying of any part of this message is prohibited. -----Original Message----- From: EV [mailto:[email protected]] On Behalf Of Willie2 via EV Sent: Thursday, November 05, 2015 7:01 AM To: Robert Bruninga; Electric Vehicle Discussion List Subject: Re: [EVDL] Suitable Load? On 11/05/2015 07:44 AM, Robert Bruninga via EV wrote: > I think this thread is about individual cell modules, so low voltage. > But I had to remind everyone not to take that above sentence out of > context. Bob I think the thread is about balancing a pack. Though he did not inform us of the number of cells, I would guess 40-45. I suggested that the easiest way to balance is to contrive to charge at a current around the capacity of the miniBMS modules to bypass. Then, charge for long enough, perhaps days, to allow all modules to begin bypassing. _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
