Sure. Just use these for example: https://hobbyking.com/en_us/xt60-charged-discharged-battery-indicator-caps-5-pairs.html
I’m still searching for a cheaper charger that comes with everything, which is the best one of these (or any others) that could do charge a 4s3p pack in under an hour? http://alienpowersystem.com/product-category/chargers-power-supply/imax-rc/
Why do you want to split the pack? Is it so you can take it on flights? Or simply for the charging?
If you want to take it on an airplane, you need to split your pack in at least 4. Reason is a 12s3p pack of samsung 25r has 324Wh of energy, airlines allow a maximum of 2 batteries between 100wh and 160wh. If you split your pack in 2 you’d have 2 packs of 162wh and you’d be at the mercy of the person behind the counter or tsa agent. If you split it in 3, you have 108wh packs which are still just over the limit. Now the kick is that you can take as many batteries under 100wh as you want, so if you split it in 4, now you have 81Wh packs which are not limited at all.
If you want to simplify charging get a bms and a 42v charger. It really doesn’t get any simpler. Both will run you about $70.
If you want to charge them with an rc charger: You need a power supply and a 12s rc charger. Rc chargers for 12s run above $100, so it is cheaper to get 2 6s chargers a dual 6s charger or make a wire harness to be able to charge them in parallel with one 6s charger.
You cannot have the cells connected in series while charging if they share the same charger as you will blow something up. Trust me, I’ve done that…
I personally went with the BMS as going the rc route only saves a few bucks and over complicates things
I got my bms from batterysupplies and a 42v5A charger from alibaba.
Chargers for 6s are cheaper…
I want to split the packs for airplanes. Even though it is over 99wh, the 3 108wh batteries would be fine as I rarely travel alone, in which case I can leave one behind. I wouldn’t mind doing the 4 batteries though and being able to take it on a plane. Either way though, how would you suggest I charge it? I wouldn’t be happy, but I would be fine with having to separate the batteries for charging. What do you think about having a bms for each pack and charging through there, would that work while connected in series? Also, I could do alibaba for the charger, but I haven’t had a great experience with buying from them as everything takes forever to ship, and I’ve had two things I’ve ordered not arrive. That was completely different stuff though, so if you had a good experience with them, I’ll give it another shot. Thanks, Zach
I would separate the packs for charging. I’m not sure if you can charge them while they’re connected in series but I’m no electrical engineer. I would have a harness made to connect the packs in parallel and charge them that way as it probably is the least expensive.
You could have 4 bms and have 4 loop keys to disconnect the series packs to charge them. That way you could also just remove the loop keys and now you have 4 individual packs without having to open up the board too for traveling.
The way I would do this is
Master loop key on the most positive terminal between battery and load. Loop key between batteries 1 and 2, 2 and 3, and 3 and 4. You can connect them in any order as long as the master is always last to connect and first to disconnect. Disconnected you have 4 packs you can charge individually and are under 100wh and connected you have a single 12s3p pack.
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So I did some reading, and from what I am understanding, it is possible, but not recommended. I would definitely do a harness, but feel like I would mess it up somehow, although I do like the idea of the loop keys but that would get really messy/crowded in my enclosure (if I kept it in the enclosure). If I didn’t have it inside the enclosure, there would be too much on the outside of the enclosure.
Also, do I need a bms/bms’s if I buy a balance charger that will stop charging when full? If the charging port is before the series connector, isn’t it charging separately and not in series?
The loop keys would definitely have to be within an enclosure. It would be a big wire mess otherwise.
You do not need a BMS if you’re using a balanced charger, problem is that there are no 10S chargers on the cheap side. The issue with charging separately while still connected in series is that now you have several grounds at different voltages and if the chargers/power supply are not designed to be protected against this, you will smoke them. I’ve ruined a $400 charger by charging two batteries that shared a ground as two separate packs.
Again, this is all from personal experience and not really technical knowledge as I’m not an electrical engineer.
That’s fine then, I’d be willing to open the enclosure, disconnect, and charge separately. Do you have any dual balancing chargers that could charge a 3S3P battery in 3-45 minutes that you would recommend? This to me looks like the least complicated/easiest airplane possible battery to me. Would you suggest you loop key method over series connectors?
The loop key method allows you to charge without having to open the enclosure, same thing with travel, just take them out and you’re good to go. As long as you have enough space for them…
As far as chargers… I use iChargers almost exclusively but do have friends that have reaktor and b6 chargers from hobbyking.
FYI, you should not charge 25rs in less than an hour. Max charge rate is ~1hour, standard charging is ~2 hours per the spec sheet.
So with that in mind you need a 400W power supply and a a dual 6s charger or 2 dual 3s chargers. Hobbyking also has some chargers that have power supplies included, they usually dont have as high wattage though. I would shop around there if I were you.
Now if you want a really good charger check any of the icharger duos (you need a separate power supply). I charge at a whooping 800W on some of my rc airplanes.
I see what you’re saying with the loop keys, and that is genius. As for chargers, I was looking through hobbyking and found this, https://hobbyking.com/en_us/hobbykingtm-quattro-4x6s-lithium-polymer-multi-charger.html which I think would be good because I don’t need to worry about switching the battery that is charging when one finishes. Would I still need to buy a power source though? It looks like there is one attached.
You definitely need a power supply with that charger. Look at the ones in the AC/DC section for ones that do not need power supplies, they usually only have ine channel.
The power supplies are pretty expensive at hobbyking from what I’m seeing. I would get a 350W or 400W one from progressiveRC. They run about $50-70
And you can either run several small chargers in parallel or the one you posted.
E: heres one from hobbyking to match that charger.
That power source with the charger would be too expensive, I think I’ll just do multiple of these, https://hobbyking.com/en_us/imax-b6-ac-dc-charger-5a-50w-with-us-plug-copy.html or the real ones if the it’s worth the extra money.
That looks good. Just beware of the 50W charging limit. If you buy 4, you are looking at charging roughly in an hour and a half
Sounds good! I’ll order tonight.
Maybe a stupid question, but is it required to use a power supply to run the charger? Why not plug like landline phone power cord to it?
Depending on the charger, you need between 12v-24v dc. If you plug it straight to the wall (110v ac) you will see the magic smoke that makes electric things work leak.
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So basically any box that can downstep 110-120V to the input Voltage of the charger.
that plus convert ac to dc, and have enough wattage for the charger
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Before buying, I stopped and read through this thread quickly, and realized that in thinking of buying four chargers, I forgot my main goal, to make this airplane/travel possible, and searched some more and found this, which I’m pretty sure I will get as it isn’t too big, and is a dual charger. http://m.rcmoment.com/battery-charger-accessories-2128/p-rm2995uk.html?currency=USD&lang=en&aid=rmsmplaus1&gclid=CMDsz4zTndECFUlNfgod62EBuA