erazz wrote:Can the Accucel charge via the balance plug only?
Redbrickman wrote:Erazz, no worries it is confusing at the moment
I am asking the same question because if you plug in only the balance plug the charger throws an error.
Maybe Gyro has another way to do it, or maybe I am misunderstanding his post.
My aim is to charge the battery without constantly plugging and unplugging the connection to the radio.
Erazz: Yes, but you need to trick the charger, for exactly the reason RBM said. For safety, the charger "actually" only charges while it's own main ("banana plugged") leads are measuring the requested/correct total voltage. This protects you from a lot of of disasterous mis-connections (plugging in a 6S in place of a 2S and exploding, for example?). Now, let's defeat that safety...
In "balance mode" it will use the balance leads (the "balance plug" XST block) to charge between cells until all match, but it still needs to see the total voltage that should be present for the given tap point on the main leads.
As noted elsewhere, in "charge mode", it will (optionally) display all the cell voltages from the balance plug, but it won't charge equally... think of this as a convenience that leads to a lot of confusion. It will show you when it's discharging unequally, but it won't fix it unless told to.
Now, the "trick" part: If you know how the battery is wired internally, you know that the main plug on the battery is electrically the same as the first and last wires on the balance plug. The BP just has incremental wire taps between each cell as well so that the charger can measure/charge those cells independently. So, what you're actually doing when you plug balance and main wires into the charger is cloning the first wire (-) and connecting the main (+) to the appropriate place on the balance plug to match the battery you want to charge. But, you can do that before the battery, too, if you know what you're doing...
I do indeed have some "different ways" of charging my batteries than the standard "1 battery, two plugs" approach. I in fact have a charging "hydra" that could theoretically balance charge 36 batteries at once, including putting matching S totals in series for better balancing (each parallel "line" is treated as a 6S, but can be freely connected as 2+4, 3+3, etc). I won't confuse you THAT far, though.
Where's the trick? The simplest version: Your charger comes with a simple set of alligator clips for charging anything you can stick them to. Get yourself an appropriate XST (balance plug) extension, and strip the first and last wires at unmatching thirds (aka NOT at the same point, to avoid shorting one another). Clip on your clips, and then you only will need to connect the balance plug to your extension, ever again. This will charge one battery from only the balance plug. I can send you a photo of this if you need.
The cleaner OEM version: What I actually use on THESE Tx batteries, being 3S size and having more than one, is the "2x3 = 6" twin adapter that HK sells. It makes the main lead connection for you, as well as mapping cells 4-6 to the second battery... so you can balance charge two 3S batteries and have the charger able to "see" all the cells individually. I also use this adapter for my 450 and prop-plane's 3S batts, since I always balance charge if I can. I have several of these plugged into my 36-battery board, which is how I "parallel balance" 3rows x 2columns x 3S.
The evil parrallel version: If you pick up the 36 battery charging board from HK, it's set up to do 6 batteries of any size simultaneously in parrallel. But you'd still have to connect at least one of the batteries to the board's "main", which it connects back to the charger's main. You can literally short that stupidity by connecting the above "clips on extension" to one of the balance plugs, and then ALL the ports can balance charge without main leads again. In fact, I THINK you can even balance charge bigger batteries than what you've claimed you're doing on the charger, since the charger will balance (for example) the 4th/5th/6th cells BEYOND the 12V tap you claimed for 3S charging -- the tap point is at the right voltage, so the charger is happy.
Another cool side effect of parallel charging this way: if you, like me, come home with a big stack of batteries all discharged to different points depending when you chose to land (or were "unexpectedly thwarted by gravity with an impact modality"), you can plug in your most discharged batteries, and as the voltage reaches the current state of other batteries, simply plug them into the remaining balance ports without restarting the charge cycle. Thus a single charge cycle may start with 1 battery and end up balancing 6 batteries before it finishes. You just don't want to ever connect batteries in parrallel that are NOT close to the same voltage state (this creates an infinite-C charge path between the dis-similarly charged cells).
So, did I confuse you all even worse? Good... my job here is done!
-Gyro
I could fly so much better if a second flight wasn't a requirement....
