Tim Mackey Posted February 25, 2009 Author Share Posted February 25, 2009 OK Terry, let me have a look around and see what I can come up with for you. I take it you are using JST XH type balancer plugs. Quote Link to comment Share on other sites More sharing options...
Terence Lynock Posted February 25, 2009 Share Posted February 25, 2009 Hi Tim, if JST - HX are the little white ones which seam to be on all the batteries I have bought then yes, if I have to make them up I would appreciate a diagram as rampant Lipo cells are not what you would want in your immediate vicinity.... many thanks. Terry Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 25, 2009 Author Share Posted February 25, 2009 Errrmmm most of them are "little white ones" Terry Dont worry- I will make them for you if I have the bits. JSTXH have little tabs at the sides of the top of the plug - like little arrow heads ( I actually slice them off anyway 'cos they are a pain to get out otherwise ) Is this it? Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted March 5, 2009 Author Share Posted March 5, 2009 OK Terry here's your gizmo. Simple and idiot proof as requested, and useable for 2 X 2s or 2 X 3s packs ( not mixed of course ). Ensure the 2 packs you wish to parallel up are at pretty much the same state of charge /discharge as each other before plugging them in to the board. Ignore the wiring colours as different manufacturers use different colours - stupid I know, but another example of how to confuse the beginner... just ignore the colours, and if you have different colours on your packs, again....ignore them - the orientation of the wiring is what matters, and this is set up correctly I assure you. Remember that for charge rates above 1A you must also join the main battery leads with a Y lead. For charge rates below 1A, then just plugging in one battery's main leads to the charger will be fine, as the other battery will be charged effectively via the parallel connections of this balance board. I will pop it in the post tomorrow 1st class. The two packs I used here for the photos were a fair bit out of balance cell wise ( although the pack voltages were similar...within .4V ) Each battery was then plugged in seperately after using the " Timzo " and showed each cell in each pack to be spot on 4.20V. Even woithout actually charging, plugging in two packs to the unit will automatically and quickly equalize the cells in each battery - but of course, if these cells were inbalnced to begin with they will stay that way... but at least matched pack to pack IYSWIM. Quote Link to comment Share on other sites More sharing options...
Stephen Stokes Posted September 28, 2009 Share Posted September 28, 2009 Another question Tim Why don't Li-Po batteries have built in PCB overcahrge/discharge/balance boards built in like the Li-Ion batteries. Is this something to do with the high discharge rating we used? There's so much fuss made, with a built in PCB things would be so much simpler? Cheers Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted September 28, 2009 Author Share Posted September 28, 2009 Some packs do - but I dont like em anyway. The only time I ever had one, it was on a Tx unit, and without warning it suddenly just shuts down as the low voltage threshold is reached! As for balance boards, well these are already built in and wired up too Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted September 28, 2009 Share Posted September 28, 2009 timbo-i wish i lived nxt store to you..............but i couldn't afford the million+ price tag's............ ken anderson..... Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted September 28, 2009 Author Share Posted September 28, 2009 Why Ken...is it because you couldnt lower yourself to slum it with us commoners thenPS off topic a bit ken ? Quote Link to comment Share on other sites More sharing options...
slippyr4 Posted October 18, 2009 Share Posted October 18, 2009 Although the internal impedance of (good quality) lipo packs is low, it's not actually a massive problem connecting different charge level packs in parallel - the math works on the voltage difference between the cells. In crude terms, and an extreme case, two packs with an internal resistance of 25 milliohms each, and say 0.3 V difference between them would result in a 6A current (initially) between cells... that may scare you, but it'll a) tail off very very quickly, and b) it's actually not that big a deal. If using an adaptor such as the one above (which I myself do), probably the current-limiting factor is actually the copper tracks on the circuit board, not the balance taps. The balance wires in practise are usually capable of taking several amps - their resistance probably causes significant voltage drop (but that doesn't really matter, it only reduces the efficiency of the charge), but they don't get hot, so it's all fine. The only appreciable risk of parallel charging is what happens if for whatever accidental reason a pack becomes disconnected? In that instance, the remaining packs will experience a greater than rated charged current. Although that situation is unlikely, I personally like to back off from the maximum current by the charge current of the single largest pack being charged, purely as a safety margin. For example, if I were charging a 2200mAh, 1200mAh and an 1800mAh pack, on paper I could charge (1C) at 5.2 Amps, i'd actually charge at only 3 A, which would result in a safe charge rate if any one pack became disconnected. A separate note: Most of the modern far east mass produced lipo balance chargers use bleed balancers and require the main leads of the pack to be connected when charging. If you're using a parallel adaptor board as above, but your charger needs the main leads connecting too, you can actually connect the leads of just one of the packs - there's no need to connect all of the main leads in parallel (of course provided that you don't overdo the current which will be flowing down the balance leads - this trick is purely to satisify the charger's requirement to have the main leads connected, no more, no less). Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted October 18, 2009 Author Share Posted October 18, 2009 I dont believe I said anything contrary to this anyway. I f yoiu read the whole thread, you will see I suggested that " packs should be roughly equal in charge state", and also mentioned twice, that if charge currents were only around 1A or so, then connecting just the one packs main leads to the charger is sufficient, as the others are then charged ia the balance plugs main "end " terminals. Quote Link to comment Share on other sites More sharing options...
foamidable Posted April 21, 2012 Share Posted April 21, 2012 i bought a imax b6 lipo charger from ebay, or so i thought. later on cruising youtube i came across this video (see link). i contacted the guy immediately and he refunded immediately according to the paypal email i received, but it hasnt shown up at all in paypal account yet. not even appearing as a pending transaction yet, so i'll give them 24 hrs then get on to them i think. you have been warned! Edited By Steve Hargreaves - Moderator on 21/04/2012 21:14:06 Quote Link to comment Share on other sites More sharing options...
Paul McCaughey Posted July 30, 2013 Share Posted July 30, 2013 i know it's an old post but it's relevant to my question. this battery charging stuff has me a bit confused. if i want to charge multiple(3 of them) 2s 300mah lipos i can use a lead like this **LINK** on my charger and just connect one of the batteries up via it's jst power lead to the charger as well? what would my charge current be with setup? i normally go with the lowest setting but i doubt that it is all that quick which is what this is about is it not? thanks in advance! Quote Link to comment Share on other sites More sharing options...
Paul McCaughey Posted August 5, 2013 Share Posted August 5, 2013 any thoughts on the above? need to sort out a charging set up for my brother in law in ireland and only have a week or so to get parts before i head over there. ta Quote Link to comment Share on other sites More sharing options...
Robin Kearney Posted August 5, 2013 Share Posted August 5, 2013 Hi Paul, Yes I use the very same cable to charge the 2s packs from my Blade 130X. I simply plug the single end of that into my balance board, then all the packs into the sockets. And yes, as you say, one of the packs needs to be connected to the main +/- leads from the charger. As for current, simply multiply your desired charge rate by the number of packs. So if you want to 1C charge your 300mah packs and you have three of them, set the charge current to 900mah. I've only ever parallel charged the same brand/spec/size of pack and only if they are similar levels of discharge, which in my case means I flew until the time ran out on the TX and then landed. Quote Link to comment Share on other sites More sharing options...
Paul McCaughey Posted August 5, 2013 Share Posted August 5, 2013 ok thanks. will get that lead ordered up and hope it works. not sure if there was a charger problem last time i was over or if it was the fact i was trying to charge a single almost full pack. if not i have bought a cheap eflite charger that should do the job, (although more slowly). Quote Link to comment Share on other sites More sharing options...
Phil Green Posted October 2, 2016 Share Posted October 2, 2016 Old thread but since its been referenced recently... Balance leads and JST-XH connectors are fragile things and at some stage we must all have had a wire detach from a balance lead. When balance-charging a single pack, the charger will spot this and stop. When parallel charging however, you need to be confident that all the balance connections are intact and secure for each pack, as one good pack will mask any 'missing' balance connections in any or all of the other paralleled packs. This means that whilst you think you're balance charging several packs, unbalanced cells in a pack with a dodgy balance lead or even just having a poor JST-XH connection - could feasibly go over 4.2v, the charger would be unaware. We all know where that ends! I routinely parallel balance charge my bike battery which is two 5S 5000's in series when running, but in parallel when charging, and what I do is to plug in one pack and start the balance charge for a few seconds, long enough for the charger to spot a balance lead problem. Then I unplug that pack and plug in the other one, start the balance charge for a few seconds, again long enough for the charger to spot a balance lead problem, and if all is well plug the first battery back in so they are now paralleled, and start the full balance charge. Its not foolproof - you could even cause the break whilst swapping packs, or you may neglect to insert the balance plug of one pack - but it is just another sanity check and a confidence thing. Simply plugging several packs in and hoping for the best, without checking each pack's balance connections, could possibly be disastrous. Cheers Phil Edited By Phil Green on 02/10/2016 16:28:23 Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted October 2, 2016 Share Posted October 2, 2016 Good idea Phil Quote Link to comment Share on other sites More sharing options...
MattyB Posted October 2, 2016 Share Posted October 2, 2016 I can see the logic, but isn't the problem that it puts twice as many cycles on the balance plug connector, so it's twice as likely to fail on a given charge cycle? Quote Link to comment Share on other sites More sharing options...
KiwiKid Posted October 2, 2016 Share Posted October 2, 2016 I have always put the batteries through a battery checker before charging, mainly to make sure I don't have a bad cell, but I guess that process is also confirming that the balance lead is OK. Quote Link to comment Share on other sites More sharing options...
Phil Green Posted October 6, 2016 Share Posted October 6, 2016 Posted by MattyB on 02/10/2016 19:56:42: I can see the logic, but isn't the problem that it puts twice as many cycles on the balance plug connector, so it's twice as likely to fail on a given charge cycle? I'm just pointing out the possibility of an over-voltage incident Matt, and one mitigation method which I'm content to use. Whether maintenance checks are worth the risk of breaking something is a personal choice. One method which should give complete protection would be to use a separate alarmed balancer on each pack, and to parallel only the main power connectors. Any cell in any of the paralleled packs would then be protected - assuming you're there to hear any alarms Cheers Phil Edited By Phil Green on 06/10/2016 10:38:33 Quote Link to comment Share on other sites More sharing options...
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