It worked well and the runtime was right around 3h. I used it only until like March for night riding. I charged it always after I used it. Since the day’s have come shorter I charged it again last week and went out for a ride. Problem: The battery died after ~30min. I went home, charged it again but the charger went “green” after ~20min of charging. Clearly it didn’t do much and I did a little test and got ~10min of runtime out of it.
With all the horror stories of unbalanced battery packs I stopped using it (I have the battery pack in the back of my jersey very close to my skin so I don’t feel like having to worry about something exploding on my back). I also haven’t tried to charge it.
Few questions:
- Should I have recharged the battery every few months? (I stored it in my room, summer is humid & hot)
- Could the sweat have gotten inside the battery packet and corroded it?
Any reason I shouldn’t cut open the battery pack and see what’s going on?
I’m in for a new battery pack obviously but I don’t wanna make the same mistakes again ans would also like to get some “quality”. I’ve considered these:
The charger that came with the light charges @1A. Obviously a cheap/crappy charger. Should I get a new one that chargers a little smarter? Will this increase lifetime of my new battery pack?
Thansk for the help guys! And sorry if there is some dumb questions in here (newbie here).
dont generic battery packs exist where you insert your own 18650 cells? maybe you could build your own battery pack with a 4x18650 battery holder (case).
i did that with my electric mosquito swatter. It had a built-in integrated heavy LiPo 4.2V cell in it. It got weaker and weaker.
So i unsoldered the cell, placed a 1x AA battery holder inside, soldered wires to the connection points, and now i am running a 1x14500 cell (3.7V nominal) in it. The swatter has a built in charger (220V plug integrated) .. but the point is, i have now full control over the cell: i can use the built-in charger or take the cell out, test it with my DMM, and charge it with my round-liion cradle chargers, e.g. i4 v2.
Get the Sanyo one, cut it open and solder balancing connector on top of PCB.
Then, charge it in balancing mode using hobby-chrager. That’s what I did, and it lasted me almost 100 cycles this summer (2-3 hours every night, basically). Still measures over 5000mAh.
Also, if you don’t need all the runtime, charge it up to 4.1V/cell (all hobby chargers can do it). This’ll greatly extend it’s cycle life.
Oh, and hobby chargers also can prepare battery packs for long-time storage (3.8V/cell).
I translate “este tema sin fotos no vale nada” means “without photos this does not worth anything”… a typical expression used in spanish forums to ask for pictures….
Servus, Hola & Hi,
I got it. Sorry I’m new here. I didn’t know you guys need a picture first. Here you go:
So now that we have that out of the way let’s get back on topic:
- I don’t really wanna spend money on an expensive charger so the battery lifetime is not that important. If my 1A charger wasn’t the issue (but a bad cell) than I’ll just stick with that charger. But if people tell me that the charger killed the pack I’ll certainly invest in a better one (<$30).
When I buy the Sanyo, why do I have to cut it open and put a PCB in it? Can’t I just use it as is? The whole point is to get a ready to go battery pack is that I’d avoid the soldering stuff.
About getting expensive charger: uh, hobby chargers ain’t that expensive nowadays… Turnigy Accucel-6 is just $23, for example
About soldering stuff: unfortunately that’s required for balancing. Otherwise, pack will “swing out of balance” in a few cycles (usually 20-30), and protection PCB will prevent it from being used further.
Yeah, it could have just swinged out of balance, and now while one cell is undercharged and needs more charging, protection PCB disconnects charger, because other cell already is full.
By the way, getting a hobby charger has some more good advantages - e.g. you can test condition of your cells, measure true capacity, prepare them for long-term storage, etc, and not just in 18650 form factor, but in pretty much every single one - starting with tiny 300mAh 10440’s, up to huge 12000mAh (or even more, if you can tolerate >24 hour charging times) pouch cells.
most likely one or more of the cells in your pack has developed a soft short, so it self-discharges over time and then trips the PCB before the other cells have fully discharged. Happens quite a lot with the cheap Chinese bike lights as the batteries aren’t all that high quality (the complete light is less than what I’d pay for 4 decent cells!).
I’d hit up ActionLED or your local Magicshine reseller and get a new battery - the new ones are supposed to be better and they may also offer higher quality aftermarket batteries for a bit more. It’s the most cost effective way and you’ll hopefully get a decent warranty/ customer service too. You could build your own - I’d personally build a 2S1P pack with the new Panasonic NCR18650B cells and put it on my helmet - but that’ll run to at least $40 with PCB and cable.
Shadowww - well matched decent quality cells shouldn’t go out of balance. The high end packs don’t need balance charging (Lupine, L&M etc), whereas balance charging is a sticking plaster for the cheap packs - it’ll mask the symptoms of soft shorts, but it won’t stop the problem happening. That’s not meant to be a criticism - they’re cheap lights and they’re great for getting people night riding, it’s just economics.
why not try charging the individual cells in the pack? CAREFULLY using needles slide into each side of the cell and fully charge it, do it outdoors in a safe place in case something bad happens (vent with flames)
4 decent cells = $20-$30, I doubt you can get complete light for less than that.
Also, well matched decent quality cells still go out of balance. Most high end packs are laptop battery packs (way higher end than Lupine etc), yet they still have balancers.
Oh, and regarding Magicshine: magicshine battery problem - Google Search
Thanks raccoon & Thanks everybody for the replies! You guys rock.
I just took it apart this morning and snapped some pics:
The little wire which connects the other side of the battery pack with the PCB (?) was loose and not attached. What is it for? Was it even ever attached?
Now to get this thing back to live:
- If I buy the hobby charger should I charge each cell and then solder the loose wire to the port on the PCB?
Or can I just solder it back together and charge it with the crappy charger?
that loose wire is a voltage sense wire and connects to the COM pad at the top of the PCB. I think it’s used to monitor the cell voltage of each parallel bank. No idea if that caused your problem or not, but it’s not going to help being detached!
I’d struggle to get 4 decent protected cells plus a cable plus a holder or something to waterproof the battery for $20. Even $30 would be difficult
I dunno, are those wires in laptop packs balance wires or voltage sense wires? Either way, none of the high end bike light manufacturers balance charge their packs and they don’t have this problem.
Estás juguetón hoy eh??
