Why do they specify “10ah” with a charger; doesn’t that parameter relate only to the battery’s capacity?
Probably because that’s what their main costumer uses it for.
I like this port best
1 Like
Ok so the ebay seller has come back on the charger. If we can find 5 buyers it would be $35 dollars each with free DHL shipping to the UK. ($30 is we get to 10 but I don’t think that is likely unless they would ship to 2 different address).
We can ask for all of the cutoffs to be set at 41v or 41.5v - I have just noticed on the listing that it is 2USD more if you want the automatic cut off (something I would need).
Do you think we can get to 5?
EDIT
I have responded and asked for 5+ and 10+ prices with the battery cut off added and set to 41v. I have also asked that if we can get a group together to buy 10+ but with them split over 2 addresses (US/UK) if this would get us the discount.
Norcs
I like that - what would you call it?
XLRs are massive. If you’re going that route might as well get a 4pin XLR
This should work without a BMS. I’m going to use it for my 10s without BMS. There are several people using it without an BMS.
http://www.pedelecforum.de/forum/index.php?attachments/img_0573-jpg.62572/ Shuts right off.
1 Like
I see the link to the diagram. Do you mean the charger we are looking at?
1 Like
Hey, so most BMS start balancing when almost full, no? so if you terminate the charge early you’ll never balance?
I’m running no BMS, and one of those ali bulk chargers, trim pot adjusted a bit lower for cutoff, and on a wall socket timer.
Hm if it’s for your gf, this might be relevant. I’m going to build a charging stand, with the charger, timer and a voltmeter/wattmeter/ah-meter built in. I suppose links would help…
power meter the 20A ones can just go inline. Mine reads 0.2v high around 40v though…
bulk charger 4a I chose XLR, which I like but is a bit bulky. These guys all have a trim pot to adjust cutoff voltage. They may be crap build, haven’t figured out how to differentiate the crap ones from the good. Mine have been through maybe 20 cycles, good so far
I’m using this timer switch, can set to any number of minutes, and it remembers. for the stand I’ll probably go to this one and like a wall switch to cut the power.
Hmm now that my brain’s cooking, does the BMS allow you to set a lower cutoff voltage?
3 Likes
Yep. That’s why I want a pot in it so I can still balance every once in a while. But having my cutoffs between 41V-28V means that my battery should be safe even if slightly out of balance. The BMS still protects the cells when any of them reaches 2.5V and not just the entire thing.
That is pretty cool! I might look into doing something similar at home maybe! Thanks for the awesome idea!
I like the timer switch idea! That’s pretty clever
Does your power meter seem pretty accurate? I have this inline one that I use during charging and bench testing, but I am somewhat disappointed with its precision: Amazon.com
Unfortunately the voltage always reads about 0.2 - 0.4 V high. The faceplate also came attached upside-down… which I only realized after I had soldered on XT-90 connectors. So I had to re-solder everything since it only measures current in one direction
I got a reply back! $30+shipping for the charger. Plastic case and knob to adjust between 36V and 42V.
Anyone else in??? @treenutter @Namasaki, I know you secretly want one too.
And again, this would be for US. If theres enough EU buyers, I can ask for multiple addresses. Or ship from here to you.
1 Like
It really should be in an aluminum case with a fan to keep it cool especially running at 5-10a. My 5a charger that I got from battery supports is in an aluminum case with a fan. I also have a 42v 2a charger that is in a plastic case with no fan and it gets pretty hot while charging. You might want to see if they can quote one with upgraded case and fan.
I have 2 meters, one reads high, and amazon reviews indicate it’s consistently off by the same amount. But it’s still within spec. The other reads low. I tested with a good multimeter so I know how far they’re off. Made a p-touch label with the offset.
I think the offset throws off the watt-hour meter though, which is super useful for getting ballpark state of charge.
I’m pretty sure there are meters that can be calibrated. Maybe if I get bored I’ll try to hunt one down.
1 Like
I’ve been finding it’s a pain to make this adjustment. You have to catch the charger after it switches from CV to CC, but changing the cutoff changes that point. So you have to drain the battery down, repeat, get frustrated and give up. 
I find this is more aggravating with the 4A charger, things change so quickly.
It has a fan, she’s sent me a picture of the inside. Also the 42V 5A charger I got from them before is in the exact same enclosure with fan and remains pretty cool. Upgrading the case to aluminum was $20 more.
I would not change it while charging, I will calibrate it during the first charge cycle and mark the 36V, 41V and 42V point in the pot so that every subsequent charge, we just set it to either storage, full, or balance before we connect the board to the charger.
Hey if you don’t mind, can you please PM the contact info of this mystery power supply supplier?
Or ask her how much a similar 12S version (45 to 50.4V) would cost? thanks!
Will ask. It was an Aliexpress seller. I’ll see if I can find the link, so far we’ve just been communicating through the app messenger
I have had a response from the ebay seller here:
Hello,
Yes, we can adjust the output voltage to 41V and cut off. If you need the automatic shut off function on each charger, the price is 2 usd/pcs more. Yes, we can do the shipping 5 pcs to UK. 5 pcs ship to US. total make 10 pcs. The 5 pcs chargers shipping to US, do you need the input 110-220V, or also input 220V like in UK ? If need 5 pcs input 110-220V , the price for this is 2 usd/pcs more.
So total :
5 pcs 36v 4.5a LIthium battery charger with automatic shut off , Free DHL shipping to UK. 32 usd /pcs. 5 pcs 36v 4.5a LIthium battery charger with automatic shut off , Free DHL shipping to US. 32 usd /pcs.
If 5 pcs 110-220V 36v 4.5a LIthium battery charger with automatic shut off , Free DHL shipping to US. 34 usd /pcs.
Best Regards Stephy
Does anyone have thoughts on this one?