ok im going through the thread http://forum.freeflysystems.com/index.php?threads/one-battery-or-two.214/ And i my self am debating on moving to a 2 battery set up. im assuming i just can't charge to batteries plug em in parallel and start flying. What are the particulars to dual battery charging and flying. Trying not to have a mid air explosion.
I bought a EC5 'Y' connector (parallel!) and I think that's all you need. But I haven't used it yet. Haven't really seen the need. But realistically it gives you redundancy for the batteries, I believe. But AFAIK, battery failure isn't the #1 cause of crashes. And all I have are the big 8000mA batteries, and it seems like two of those is going to make my CS8 too top heavy, or too heavy, period. EDIT: that's way too many 'but's in one sentence. Sheesh...
yeah those are the same batteries i have. Im still feeling around for flight times on the CS8 with 5dmk2. since its really my main cam that i use for all my work im just trying to prevent loosing my main tool of work.
I think if you wanted to fly dual batteries you'd be better off with 5000 or 6000mA batteries. Dual 8000s is awfully heavy for a 4S system. But I'll let others weigh in. <- bad English pun
Actually Jei and Steve, you're both on the right track. All is does take is a suitable Y-cable to allow you to put two batteries on the battery plate -- plus the necessary Velcro to hold them there securely. The harder part is to charge them up in parallel. That's where you need a battery charger that can charge two LiPo's of the same capacity/charge history and balance them so that they're at the same voltage. I've used QC 6200's and a Superduo charger and it does extend the flight time. I don't have precise data to hand but it's not a factor of two, of course, because you have the additional weight of the battery, but going from memory it's something like a 1.5 x factor. You do have the added security that if one LiPo decides to be an ex-Lipo in flight, then the other LiPo will get you home -- if and only if the ex-LiPo doesn't drag the remaining LiPo's voltage down to nothing. Based on what I've seen on this forum and experienced myself, moving away from Deans connectors to EC5s is a Smart Thing to do. The Deans are just not rated for the kinds of currents that a heavily loaded CS8 will pull from a LiPo. Andy.
Andy, I bought a couple of 4S Zippy 8000 bats on the recommendation of Kraus. They came with a different connector, which I (very carefully) removed and replaced with an EC5. I liberally applied solder to the inside "bowl" of the connectors, applied heat shrink to close the small gap, and they feel very secure. But I wonder...is there a special kind of solder I should use for the LiPos? I've been making connectors for my batteries for a while, but they've been the smaller bats that I use for my gimbal and my ground station. But like you said, there's a lot of current flowing through these things... Thanks! Steve
Hmm now this is a funny thing now. cause my CS8 came with deans and i changed the lipos to deans from the EC5. and now your saying that i should have changed the connection to the board not the lipos. Just trying to get straight information on a standards and best practices had been frustrating not to mention expensive.
That happened to me, too. The power distro board leads were Deans, and when I got my batteries I noticed that they all had EC5s. Quadrocopter apologized for that and confirmed that they recommend EC5 for the battery connections. So I replaced the PDB's connector and it's all good now.
Steve if you can bet a solder that is silver based it is considered to be better. Of course the price is higher.
Hi Steve: Geoff Scholl did a great video on EC5 soldering. As far as I'm aware he was using (as do I) just a 60/40 resin cored solder. I happen to prefer lead-free, but there's nothing special about it beyond that. Andy.
Hmm. I've not heard of anyone using silver solder for battery connections. I thought that required brazing. See http://en.wikipedia.org/wiki/Solder Andy.
Sorry didn't mean pure silver like a jeweler. I am using Qualitek Lead Free with a Tin/Silver/Copper mix of 95.5/4/.5 percent. Someplace I saw an article that this was a better product for electrical connections. What I found from a technical view: Sn-Ag-Cu (Tin-Silver-Copper) solders are used by two thirds of Japanese manufacturers for reflow and wave soldering, and by about 75% of companies for hand soldering. The widespread use of this popular lead-free solder alloy family is based on the reduced melting point of the Sn-Ag-Cu ternary eutectic behavior (217 ˚C), which is below the Sn-3.5Ag (wt.%) eutectic of 221 °C and the Sn-0.7Cu eutectic of 227 °C (recently revised by P. Snugovsky to Sn-0.9Cu). The ternary eutectic behavior of Sn-Ag-Cu and its application for electronics assembly was discovered (and patented) by a team of researchers from Ames Laboratory, Iowa State University, and from Sandia National Laboratories-Albuquerque. Sn95.5Ag4Cu0.5 217[45] – yes Lead Free, Cadmium Free formulation designed specifically to replace Lead solders in Copper and Stainless Steel plumbing, and in electrical and electronic applications.[17]
Dammit...I was wondering what that little hole was for, and why the solder is leaking out. LOL. Thanks!
Gary, do you have a source for this online in the USA? I found a number of places that sold various formulations, but none that matched this exactly. Thanks!
Steve do a search on Qualitek 50-21750. There is probably an electronics wholesaler/distributor in the bay area that has this. http://www.altex.com/Qualitek-Electronic-Lead-Free-Solder-12-LB-Spool-50-21750-P145690.aspx http://www.amazon.com/Qualitek-Electronic-Lead-Free-Solder-Spool/dp/B004GIDV44
In addition to Andy's reply, I would 1st DISCHARGED the lipos until they both have equal voltage levels. Connect them in parallel only after they are equally discharged, then charge them together as one. I see some major safety issues in linking two fully charged lipos.
On the Hyperion Super Duo, given you have two batteries of the same type/vendor/capacity, you can use the SYNC charge setting EDIT: regardless of the discharge state provided that the two batteries are at more or less the same charge state (see Steve's correction below and my observation that a difference of 0.1 volt doesn't seem to upset the charger). The charger then brings them up to the same voltage and balances the cells in each of the individual batteries. Andy.
Andy, this does not apply to parallel charging multiple batteries, right? I'm very careful to check each pair of batteries when they come off the copter, and I keep them together. As long as their voltage level is within 1-2%, I go ahead and hook 'em up in parallel. That way I can charge 4 batteries at once.
Andy, my understanding of the SYNC setting was for batteries over 7S where you can connect 1 lipo to the two ports of the charger in series to obtain the higher voltage? From my reading of the manual the SYNC setting only mentions using batteries in series and nothing regarding parallel connections.
Thanks for making me re-read the alleged "manual" for the Hyperion! I was wrong but not in the way that your question suggests, Sam. (And it's a valid question, I hasten to add -- let me first correct what I said. See page 3, paragraph 6 of the "manual": NOTE!! SYNC MODE Charging (selected in similar way to SYNC BALANCING above) is intended to be used only with two packs of the same brand, capacity, type, and lifecycle history! For example, two packs of CX5000 4S lithium polymer purchased at the same time and used together as a 8S flight pack in series when flying a particular model. At the start of SYNC MODE charging, both packs should be at roughly the same discharge state. Otherwise, you should SOLO MODE charge each pack separately, and when both are done use SYNC MODE balancing before connecting in series for flight.See http://media.hyperion.hk/dn/eos/EOS-NET&DUO42-MAN-EN46.pdf (emphasis added) Note that it describes charging two 4S packs. Sure, you can combine in series after charging to make an 8S pack, but the charger sees them as two 4S packs. Where I was wrong is that the two batteries should be at more or less the same discharge level (not at different charge levels as I had said above). In practice, I've found that they can be about 0.1 volt different and doesn't seem to matter. So, to your point. No, you can charge any pair of batteries as long as they're the same vendor, capacity and close to the same charge capacity. As you can see from the quotation from the manual, what you do with them after charging can be to create 8S batteries - but you can also use a splitter cable and connect up two 4S in parallel. Hope that helps. I'll correct my original posting. Andy.