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Basic questions on charging via usb port


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Hello, I got my first dna75 device (a sbody macro dna75) one is listed  here

I bought this because of how small it is.  I wanted a small single 18650 and this fits the bill.  However, getting a battery properly seated into this sucker is a major pain in the ass.  Up to this point with my other mods, I've always externally charged, but I'm considering leaving the battery in this device at all times and charging via the usb port only.

I've read dna boards are the safest when it comes to usb charging, not sure if this applies to all dna, or only the dna 200's.

First question, I've read dna75's charge at 1amp, but I also read that only applies to dna75c and some (all?) dna75 devices use the usb port for updates only and not for charging.  I've just got this device and haven't charged yet.

I've always liked the idea of slow charging to extend battery life.  My external charger charges at .5 amp.  If I install the escrib software can you set a limit of .5 amps for charging?  Is there any reason I should strongly consider updating the firmware?   No idea what version of dna firmware this comes with out of the box.

If I charge via a computer port on my home pc, I've read that usb2 ports typically give .5 amps and I believe usb3 gives 1 (maybe 2?) amps.  Is there any concern if I charge this on a usb2 port?  Not sure if it will be fine and slow charge at .5 amps or does the board expect at least 1 amp and charging with anything less could cause issues.

My wall chargers are from phones/tablets and give I believe 2 amps.  I assume these are ok and it will just draw 1 amp.





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The DNA 75 has a built in 1A USB charger. It automatically detects the type of USB power supply it is connected to, so it can be plugged into standard PC USB ports or higher power chargers.

Here is the datasheet for the 75 board....   https://downloads.evolvapor.com/dna75.pdf

Just a personal note-  I've been charging batteries  in the device on all DNA's since 2011.... 

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thx for the quick reply.  To clarify, if I am correct that usb2 supplies .5 amps, is that an issue with this being a 1amp onboard charger?  And if I so desired, could I limit the charging to always be .5amps via escribe?

But I'll read the datasheet and find out more.


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Most electronic devices, not just ecig mods, can and will pull the amperage they are limited to. Let’s say in this case the DNA board is capable of drawing up to 1 amp, if you connect it to a 2.5 amp charger, like a USB iPad charger, the mod will STILL ONLY draw 1 amp. Most phone chargers like iPhones have 1 amp chargers. If you really want to limit the charge to .5 amps, some older laptops with older USB ports, only put out .5 amps.  Now keep in mind for the future, a fair amount of new mods are coming with the ability to charge up to 2 amps, non DNA boards, but the same thing applies, you can’t charge at that higher rate unless the wall USB charger can deliver 2 amps, but it will be happy to pull the 1 amp out of a smaller charger. One exception to the DNA charge limit, was some DNA mods sold by VaporShark, like my VS DNA75  Switchbox, it can charge at 2 amps, because they paid Evolv a few to get customized DNA boards. 

I recommend buying a cheap USB meter, that will tell you voltage, and AMP draw, then you will know for sure what any device and charger is doing. And it will also help you diagnose potential problems. Here is a TIP, that many are not aware of. We get caught up in what the device can pull in amps, and what a charger can deliver in amps, but many forget, or don’t know that CABLES have amp limits too! So you buy a mod that claims it can charge at 2 amps, connect it to a 2.5 amp charger, and it seems to take forever to charge, and you don’t know why. You plug your USB meter inline, and it shows, let’s say 1 amp, or even just .5 amps being delivered. At least know you know the real numbers, but not the solution. Well it’s the CABLE limit!!!

When I bought my first 2 amp charge capable mod, I had to source some better USB DATA cables, so it could deliver the full 2 amps, some cables can even limit the current to .5 amps. CABLES ARE OFTEN OVERLOOKED! That’s what’s great about the very inexpensive USB meters, you can diagnose everything in the chain. There are tons of these on the web, the link below is just for an example:




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