Overclocker
10 kW
$20 at banggood
OEM seems to be Minghe BST900
anyone tried this? it seems like you could simply punch in your volts and amps and you're off bulk charging your high voltage pack from a 24v power supply
Like a BMS (should)?redilast said:Maybe there is some kind of cheap circuit board that can cut the current off that you can combine it with?
amberwolf said:Like a BMS (should)?redilast said:Maybe there is some kind of cheap circuit board that can cut the current off that you can combine it with?
Alan B said:Plating is caused by voltage exceeding the proper termination voltage. As long as the voltage it correct (for the temperature) and re it doesn't hurt to let it sit for a short time as the current decays toward zero.
You can always make a current sensitive dropout relay if you want, but I have done manual charge termination for years without problems. Just don't leave it for days, as the termination voltage causes slow degradation of the electrolyte. It is best to delay, charge just in time and then immediately discharge, leaving the pack at 50-60% most of the time.
Depends on the BMS. If the BMS is designed to cut off charge input once cells have all reached their "full" level (and perhaps some in balancing mode), then the BMS itself can provide this function.Overclocker said:this cutoff function is provided by the charger, not the BMS
Then perhaps that ought to change.Alan B said:BMS Cutoff voltages are generally outside of the range you want to work with, they are a "safety net" rather than an optimum value. For example they may not cut off till over 4.3 and under 3.0,
amberwolf said:Like a BMS (should)?redilast said:Maybe there is some kind of cheap circuit board that can cut the current off that you can combine it with?
bobc said:I'm using one of those & it works very well. However I have a lot of old SLAs which are solar charged, so am effectively charging the bike from lead acid batteries not direct from the solar array (the solar array just tops up the SLAs).
What I've learned about controlling such a boost converter:
1) RH button switches output on, LH button switches it off
2) when 'on' RH button toggles between Volts and Amps display
3) up/down buttons alter setpoint for volts or amps (whichever is being displayed)
4) "save" an altered setpoint by a long press on LH button - display should flash once
With large boost ratios (e.g. I'm charging a 60V battery from a 12V supply) the output current available reduces below the setting - I seem to get just 2A charging current.
And yes I keep an eye on things when it's charging. When the arduino based charger controller is finished (soon I hope) this will terminate the charge by opening a series relay when any cell voltage gets up to 3.5V.
whereswally606 said:Use one too, put bobc on to them, we both charge lifepo4 from them
I have tried with 12v battery as source
3x 12v server supplies in series = 36v
and a 54v esp120 server supply
great to have as they can charge any voltage higher than the input. Cheap mans satiator.