I am looking to build a 6x 18650 battery box to recharge my wifes ipad - any good contenders? I will supply the 18650s
I found this one but I am not sure if its any good or not.
Be careful if she is using an iPad Air or other newer iPad as they are rated for 2.4A and chargers rated for 2.1A can melt under the load.
she has a new ipad mini…. but thats good to know
??? Wtf?
Never heard of that?
All iPad stock chargers except the iPad Air have a 2.1A charger…I don’t think that something will melt, the voltage breaks in and that limits the current anyway…
It is more often a problem that a power bank doesn’t charges with full power due to sensing a “not powerful” source. A solder blob or a ihustler helps often
I’ll just repost this:
I was charging my iPad Air with the Xtar WP2S. I plugged it in at 49% while the WP2s had 2 Sanyo UR18650FM. When the iPad was at 72%, I smelled burning. The charger melted. The cells measure 3.66v each after being removed.
Thanks for reposting, I missed that because I am not subscribed to all the Chargers reviews…
Never had any problems with melting things…
The only problem is that it will not charge with full power on most power banks. The stock charger puts in 1.9A even if the ipad air2 is charged up to 85%, that’s really powerful. My power banks only allow half the current Even if I short the Data Lines or usw ihustler.
If ist empty it May charge faster…
i grabbed that one on ebay… ill see how it does 
ive got 6x samsung 4.3v batteries i plan on using … so if for some reason it over charges by a little bit it wont be a big deal
but i will check the cells after the first charge
You should contact Xtar if you haven’t already and possibly also a consumer safety agency if it’s sold directly in the US market. Even if your device malfunctions or USB cable shorts, it’s up to the product designer to ensure safety either by blowing a fuse or limit the current in some other manner. A design that allows a component to overheat to the point of melting the casing and possibly becoming a fire hazard is not acceptable.
KuoH
That one was reviewed by HKJ.
http://lygte-info.dk/review/Review%20USB%20battery%20box%206x18650%20Qidian%20UK.html
KuoH
http://lygte-info.dk/review/Review%20Charger%20Xtar%20WP2s%20UK.html
didn’t find a problem.
Sounds like you got a defective one that melted.
I’d worry about that a lot. How close was the hot spot to the batteries?
HKJ didn’t do any testing with any iPads - let alone the Air that draws 2.4A.
Understood, but I recall HJK down-rated or gave up on some other battery box that he destroyed by using it with a power-hungry device — I gather it’s a design failure for the box not having a limiter (circuit breaker?) built in that would protect against that happening
(or having one that failed to operate in time).
Either way, curious how far the battery was from the component that overheated enough to melt the plastic cover, if you can tell.
When all else fails, airgap (and nonflammable plastic, which I guess that was) are the fallback protections.
I learned to think about that back in the old days before flameproofing was generally used in home electronics: National Association of State Fire Marshals - Programs