Adjusting King Power chargers

OK so the good news is the battery still seems in good shape none of the cells are over charged.

The BMS board now has 6LED's lit up so it looks like you get a LED per cell once charged so just a few more cells until we reach balance. But it is taking a while.

I'll give it a few more hours then give the bike a run and see how she travels.

I'd be keen to manually charge the cells that are low but my only option is to use a LIPO charger that claims it's single cell output is 4.2v. IMHOP this is too high for a LIFEPO4 cell. What do others think?

Also is it best to leave in balance mode on charge or partially use and recharge? So many questions :smile:
 
o00scorpion00o said:
I eventually got the charger and connected it to the battery and it immediately went to green and I heard the relay click.
How do I adjust it without the battery connected? I'd doesn't want to do anything without the battery!
Click to expand...
Did you ever get to the bottom of this ?
I recall hearing about it elsewhere too but can't find the thread now.
I just got one of these 600w units and have the same problem. It's set to 25.1v for bulk charging 6S lipo but upon connecting a reasonably discharged pack the fan ticks for a second and the green led comes straight on with no voltage output. I'm running no BMS and the resting voltage of the pack is 23v so that should but the charger well into the CC zone and free of any early CV shut off limiting.
The 400w unit I ordered at the same time (and have used in the past) doesn't have this problem.
I emailed BMSbattery and their answer was "remove the lid and it'll work" :roll:
 
Hi Hyena,

Nope, my charger went up in smoke! :D

I blew the 63 volt cap, which I didn't bother to replace. I might get around to it some day.

I obviously turned it up too much. Now I know I should have checked the capacitor voltage rating, but I had requested the damn thing to be set for 66.4 volts in the first place. (cap is rated 63 volts )

To be honest, I think I will just keep using my Icharger, at the end of the day I know it will never over charge and the risk of damage of misusing lipo is too great, the stakes are just too high, if one of those cells mis behaves it could be bye bye house, and all for the sake of disconnecting and reconnecting a few wires!

See this thread here http://endless-sphere.com/forums/viewtopic.php?f=14&t=30021

This looks promising indeed and if it works it will change what a lot of people think about LiPo. But for me I would need a 16-18S version.

Anyway, I certainly won't be recommending anyone buy from evassemble, take note Michael!


Mark
 
A bit off subject but... I want to be able to easily vary the voltage of my 600W 10A BMS Battery Charger. I've located the pot that varies the voltage (a Baoter 3296 w 502) which means it's a 5K ohm pot (Correct?). Instead of having to open up the top and hope that I don't drop my tiny screwdriver into the innards, I'd like to replace that pot with one that is more 'finger turnable' and mount it to the top plate. (and also add a volt meter as well) Very similar to what recumbents did here:
http://www.recumbents.com/wisil/e-bent/meanwell/default.htm

My question is: Can any sort of 5k pot work? Is there something else I should be looking for?

Also, what is the best tactic when initially starting the charger back up with the new pot installed? Should one adjust the pot to what would seem 1/2 way? If the new pot allows the voltage to potentially go past the 63V cap limit and it happened to be set there when first started, that would be a bummer.

As you can tell, I have fairly little electronics knowledge.
 
I also would like to know if there is an easy way to mod the charger admin an external potentiometer.
My kp 600w has 250v capacitor and 100v fets, I guess I can mess alot with it.

:)
 
I modded mine by setting the stock pot to low voltage (the lowest I'd ever need = 50V for 12S lipo) and connecting another similar pot in parallel, placing it outside. All works OK and I can set any voltage between 50 and 100V.
 
I turned my 48v-5a ping ( king power ) ? 58.6v to 62v will this adjustment make the amps. a little lower. And can I turn this of to 82v with no ill effect ?
 
The amps ll be same... carefull to not overheat it.
About 82v, I dont know... I might test it on my 48v ping too.
:)
 
I understood, but i was not in the mood to disassemble the charger and check the fets.
Capacitor are easy to spot, and they are 200v on the "300w" kp, but I still need to check the fets.

Btw Im almost sure that the 600w and 900w kp chargers are the same internally. Im yet to receive my lipos from HK, but you can be sure im ll try it at 75v 14a
 
Im a newbie doing this too.. but I think you should look fo voltage rating.
You have to write down the model and look it up on google to see the voltage.
 
the kingpan chargers are built with a special small daughter board in the back end that shuts off the charging altogether when the charger reaches the final voltage. the power led remains lit but the charger will not push current any more during the cycle until it is turned off long enuff for the power led to turn off.
 
you can go analyze that little daughter board to see if you can use the HVC signal from your BMS to the opo isolator on that daughter board. HVC signal is different for different BMSs too. so a ping signalab v1 is different from v2.5 and different from headway or others.
 
maybe someone got a hint for me: i assembled a 12s pack of used 20ah lifepo4 pouch cells, which i charge with the 600w model (from the very first post), 43.6v and 8a. i didn't balance before i did it, and the pack is really out of balance. so during charge cell 2 reached 3.9v and my bestechpower bms cut the charging process and waited until the cell was bleeded to 3.8v and started charge again. of course within 30s the cell was at 3.9v again, because the charger pushed 8a into it.
i tried adjusting cut off amp by turning the 3rd resistor (not the one of voltage, and not the one for amps). but amps still is at 8a until hvc, instead of lowering it so balancing can really happen.
of course i could charge each cell individually through the balance plug but i want to be sure that the charger is adjusted correctly, as i built this for a friend, and want to be sure everything is fine before he receives it.
 
the third pot does not adjust the balancing current. it is there to set the point at which the charger goes into the CV mode by measuring the voltage drop across the shunt resistor so that when the current drops below a certain level, 450mA for the EMC600, then the charger fan is turned off and the TL494 is not commanding the front end to send any more current that it is already making to the back end. that current tapers off as the battery reaches the full voltage and the charger reaches full voltage with the shunt current going through the shunt resistors.
 
dnmun said:
the third pot does not adjust the balancing current. it is there to set the point at which the charger goes into the CV mode by measuring the voltage drop across the shunt resistor so that when the current drops below a certain level, 450mA for the EMC600, then the charger fan is turned off and the TL494 is not commanding the front end to send any more current that it is already making to the back end. that current tapers off as the battery reaches the full voltage and the charger reaches full voltage with the shunt current going through the shunt resistors.
Click to expand...
ok. yes. you described it better then i did. that was i was trying to say. i think ;)
but what causes the current to drop? and what is adjusted: the voltage or the current drop? and how to adjust it? i mean: if you don't know what it's adjusted to at the start - how do you find out what's the correct value?
 
the current drops as the voltage between the output of the diodes and the voltage building up on the battery terminals decreases. it is basically ohms law.

R is constant, I=V/R

you can measure the current at the voltage you wanna charge up to and then adjust the third trimpot so that the current is in the range you want to deliver enuff current that it can meet the balancing current requirement. that is determined by the shunt resistors.
 
Izeman why don't you put a load on the high cell ( light bulb ect.) to help bring it down. The one cell may always charge faster than the rest because of higher I.R. I would balance the pack before using the BMS.
 
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