Just for clarification purposes so that I understand the benefits of this harness, would this be the harness that I'm looking for if I have two 3S 2200mAh batteries that I would like to charge at the same time using my HKC6 charger? Would I need to charge the two batteries as one 6S battery at 1C/4.4A? Or should I be looking to the series harness for a solution? Thanks.
1st: Yes, you can charge both batteries at the same time with this harness, but you will charge them as 3S battery at 1C/4.4A.
2nd: to charge as a 6S, you mus use a series harness, but you will charge at 1C/2.2A.
PS.: 2 batteries in parallel = same voltage, adds them "mah".... 2 batteries in series = adds them voltage, use the average "mah"
When charging in parallel, you should set your charger to a 1C rate of the lowest capacity cell (or series pack). Also, when charging packs in parallel, you should try to keep them within 0.5V of each other, otherwise you might want to charge up the lowest pack which has the greatest voltage difference till it is near 0.5V of the other packs, then add them in. Otherwise, when parallel charging packs with difference greater than 0.5V which are trying to equalize each other through parallel connection, it can cause a high initial pulse surge of amperage at 2C or above which can be damaging to the cell(s). In other words, if you have a large voltage gap between cells (or packs) in a parallel charge, the lowest one gets hit hard and fast at a high rate. If you're doing this repeatedly, and that same lowest cell is getting a high initial pulse amperage over and over, you could end up damaging that cell.
(sorry if double posted, I posted it before and didn't see it come up)
Ken, when parallel charging same S batteries, 1C is the sum of the capacity of all the packs being charged. For example if you have a 3S 2200mAh and a 3S 1800mAh you can parallel charge them at 4000mAh with no harm since that will be 1C. 0,5V difference between Li-Po is "almost" one fully charged and the other empty and that is not recommended, but 2C initial pulse surge is handled by most brands, since it's for a very short time and that is exactly what happens when you plug the packs together. There's some very good information online about this matter, just google for parallel charging lipos.
Pedro, I understand what the Capacity (C) value is and how it works.
I'm also on those forums you speak of :P I design custom high output headlamps, so while I use many of the same accessories as you folks here on HobbyKing, I haven't used an RC vehicle since my Losi LXT a good 18-ish years ago. (loved that truck!)
What I was saying is that when you hook up many packs in parallel, yes, they all "become/are-seen-as" one "cell", so to speak, and you can accordingly charge then at 1C. The problem is when you have packs of differing voltage levels, and you hook them up and then go to charge them as one large parallel mega-pack.... because of the individuals cells all being hit with the SAME amount of charge, though they can be at *different* levels of charge themselves, and across packs* and the initial amperage surge into the lower cells (or packs) will affect different cells differently, accordingly.
You can actually set this up, by purposely taking cells (or packs) which are over a volt in difference and watch on a DMM what is happening when you hit them with a parallel charge. It's been the topic of quite a bit of discussion on one of the forums I'm on.
I have a feeling it's a bit more of an educational topic in the RC world, and the impact of it differs based on your application. What is happening with your battery cells is much more important when you use them as part of your 'life support equipment' when you're up to and over a thousand feet underground and they are powering your lighting systems. Thankfully we don't have to deal with the Series voltage levels that you folks require, but as our lights become increasingly brighter and helmet systems are being set up with 3 to 8 or more emitters on custom systems drawing up to several amps per emitter, the need for the power to drive those systems is increasingly being found in larger parallel packs, of the older NiMH and all of the newer Lithium variants.
We're also a bit more picky about what's happening to our cells because we often are using them in extremely confined spaces. You think about this all a little differently when your cells are worn at head or hip level, attached to your body. :)
Alberto, you can connect as many same S batteries in parallel as you like.
Voltage will be the same as a single cell and capacity will be the sum of all. To connect 3 cells you can simply use 2 of this product. The thing is 3 cells plus 2 harnesses will probably be more expensive than one bigger cell. Also the wiring might heat under full C.
Ok thanks, I understood, one thing* doesn't matter that I put a 3000ma battery with an other of 5000ma? If the 3000 battery goes empty before the 5000, it will have any damage or something? Because the 3000 one is going to continue discharging until the one of 5000 goes empty?
I use it to charge two batteries in parallel 3S 2650mAh. My charger does not support simultaneous charging. It is necessary to let the two batteries to inner balance and allow both have the same voltage before starting the charging process.