Best damn balance charger I ever had

[nativepaul]

Can the terminal voltage be increased as well as lowered? When racing I charge to 4.23v/cell on my current charger and wouldn't want to lose the ability to do so. I had a GT power GT8 which wasn't adjustable and charged to a stated 4.2v/cell but it was inaccurate and that 4.2v was actually 4.185v, when I got a replacement for it I found that there was quite a few extra mAh to be had in the difference between 4.185 and 4.23v/cell, the maximum allowed in the rules I race to.

You mentioned being faster than cellpro 10s chargers, but I thought the cellpro chargers charged the cells individually through the balance leads in the same way, is that not the case? I have 8s packs that I need to charge and was thinking of going with a cellpro 10 so I could charge them quickly whilst other stuff is charging rather than splitting into 4s and taking up both ports of my current charger.

[mistercrash]

The BC168 is adjustable from 1.5V per cell to 4.2V per cell. It won't go over 4.2V. But it does get the cells up to the voltage you set it at.

From what I understand, on most chargers like the Cellpro 10, the balance leads are plugged in just to monitor the cells and to slowly discharge the high ones while the low ones catch up during a sometimes long balance cycle.

I'm thinking that your GT Power GT8 did actually charge your cells to 4.2V but they simply got down to 4.18V quickly after the charge is done. Cells that are a bit tired because of repeated over charge might do that.

[nativepaul]

Originally Posted by mistercrash

I'm thinking that your GT Power GT8 did actually charge your cells to 4.2V but they simply got down to 4.18V quickly after the charge is done. Cells that are a bit tired because of repeated over charge might do that.

No, it's just a cheap Chinese charger with poor quality control, they hadn't calibrated the internal voltmeter before it left the factory and it was reading slightly high. It's just a cheap Chinese charger with poor quality control, they hadn't calibrated the internal voltmeter before it left the factory and it was reading slightly high. Voltages were measured immediately after charging completed so any self discharge was negligible, and that was the only charger I had charged the packs with, so they had been undercharged repeatedly not overcharged ever, it was only when I put a calibrated voltmeter on it and realised it was undercharging that I bought a replacement charger for it with an adjustable terminal charge voltage.

Because of inaccurate chargers like this, and that for every charger that reads high and charges low like mine did, there is probably one that reads low and charges high. LiPos are speced to 4.2v/cell +/-0.05v

4.23v/cell will reduce cycle life over 4.2v, just as 4.2v over 4.1v does, but also gives more mAh and is within LiPos spec and the rules I race to, I wouldn't do it to my sport packs as I want to last forever, but there are better race packs out every year that pretty much force an upgrade at least every other year so race pack cycle life is not so important. I wouldn't mind betting that if everyone registered on here measured their voltages someone would be charging at least 4.23v/cell due to an inaccurate charger with a nominal 4.2v/cell.

[lincpimp]

I have used a hobby king 4s charger like this for years. Basically charges each cell by itself just like this one, however it has no screen or any other bells/whistles. Many of the maxamps packs I reconfigured went on this charger to get them balanced, as using a std charger would take hours. Mine only goes up to 2 amps, but can do multiple packs up to 4s total. And it was 20 bucks. I might have to buy one of these bc168...

[pinkpanda3310]

My first lipo charger was just like that. The brand I had disappeared and it became venom branded. I just don't see them nowa days.

http://www.rcgroups.com/forums/showthread.php?t=1400074

[zeropointbug]

Originally Posted by BrianG

I agree with Arct1k; most balance wires/connectors are good for around 1.5-2A max. The wire size and connector type have relatively high resistance due to their size, so when you start pumping higher currents through them, you get more voltage drop across the wires/connectors. This would cause the charger to think the cells are at a lower voltage than they really are and could overcharge them as a result.

However, this type of charger is a really good idea IMO, but only if the wires where changed to something like 18GA and then a use different higher-current connector.

Brian, unless I'm just tired right now, having the charger recharge the pack through the balance leads would read a HIGHER that actual voltage, then you would have a skewed CV phase than normal, but in the end the voltage of each cell would be spot on the money as current tapers off.

[zeropointbug]

BTW, where did you buy this charger Mister?

[mistercrash]

ebay, many sell them. The prices vary a bit, watch out for the shipping fees, some are just outrageous. Brainanator linked one BC168 at deal extreme for $80 with free shipping, second post up there.

[pinkpanda3310]

Best Damn charger! Thanks master crasher.

I bought this charger only on the strength of this thread. I have used it only once (tonight). I used it to charge a 6s A123 pack that's been sitting on the shelf for months. The cells measured about 3.4v each, it's usually about that point when my current charger slows right up to balance the cells (it takes ages). My packs are made up of reclaimed cells from disfunctional dewalt packs so balancing is essential.

I charged them up at 6A (yes I know what was said earlier). I swear it was only a minute or two before the charger stopped. Highly sceptical, I plugged the battery into my battery checker. One cell read 3.61 and one 3.59 and the rest were smack on 3.60 If it keeps performing without issue then this will be the best damn balance charger I ever had

[A RC Dude]

Originally Posted by Arct1k

Not sure how many amps i'd want to put via the balance wires though... 8amps seems like alot

Exactly what I though. It's an awesome idea, I was wishing chargers did that a two months ago when i bought a new one. I only hope that the balance leads have thick wire for the batteries that can take it

[zeropointbug]

I better get me self one then!

[A RC Dude]

Originally Posted by zeropointbug

Brian, unless I'm just tired right now, having the charger recharge the pack through the balance leads would read a HIGHER that actual voltage, then you would have a skewed CV phase than normal, but in the end the voltage of each cell would be spot on the money as current tapers off.

Actually, wouldn't the fact that the battery has the same wire and connection on both sides of the circuit make the resistance the same in front and behind the charger making the voltage read lower and lower when the internal resistance of the charger goes closer to zero (aka a high rate of charge)? In a since it's making a voltage divider circuit.



In this case the outer 2 resistances are the connectors/wires and the middle is the charger. But in all honesty, I doubt the wires have enough resistance to really matter enough considering that Lipo batteries can actually go slightly over 4.2v per cell. They just cut it at 4.2 for safety and most chargers are programed to read a just slightly higher voltage than actual so in production, the resistor values put in it don't have to be super extreme tolerances to still be safe.

Just my two cents and theory from what little electrical engineering know how I have.

[zeropointbug]

I'm not sure what you are trying to say. But I mentioned this before... say for instance you charge the cells at maximum 8amp, it's charging, it's charging, then nearing 4.2 volts, the charger would 'see' 4.2 volts, but the potential at the cell would be more like say, 4.17 volts, this is because of the losses in the small balance wire. Now, the current begins to fall, and as it's falling, the 'voltage losses' in the length of wire becomes less and less, so for example once it drops to 4 amps, the charger still 'sees' 4.2 volts, but now the cell is sitting at around 4.185 volts. This will continue until it approaches fully charged and the current drops to such a level where the charger voltage and cell voltage are indistinguishable, as the voltage losses are so minute.

[A RC Dude]

Seems correct to me zero, the higher resistance should make the voltage appear higher at higher current.

I now realize my post didn't make much since, sorry.

BTW, yes, I just now saw your post...I loose thread all the time on here for some reason lol

[BP-Revo]

I just replaced my ICE with a Hitec X4-Eighty. It has 4 separate outputs that charge 1-6S and have balance capability. The charger only comes with 1 balance board of each type, so I bought a couple additional ones that match up to the batteries I have.

There's also a temp sensor port for each output (but the sensors must be purchased separately).

The one drawback is that each output only has 80watts of output capability, so if you're charging a 6S pack you're limited to around 3 amps, so it will take a little longer. All of my packs are 2S and 3S (soon to have a few 4S packs) so this was not an issue for me.

http://hitecrcd.com/products/charger...harger/product