RX200

[jay_fj]

Hi guys, I just got an rx200, brand new batteries, but unfortunately no charger, and it'll be a while ( around 2 weeks ) before i could get the charger.

now my batteries are rated 3.75,3.69 and 3.77v, My question is will the Rx balance the difference with the 3rd battery? to make them all almost equal, and is it safe to vape on this voltage difference.

also if the Rx won't balance it, my main question, I can i take out the other 2 batteries and only keep one battery? would it charge like that or would that be dangerous

 

[fq06]

I have heard that it balance charges but it seems people are assuming that based on the ability to see individual cells voltage but that doesn't assure that it will actually balance charge.


It is always best to charge outside of the mod but I have plugged in at work before but that's really just to give it 0.1 to 0.2 volts and since I always charge outside the mod I know my batteries are at least close.
If all you do is charge in the mod and you have 1 or 2 weak cells, the weak cell(s) will drift further and further away from balanced each charge/discharge cycle if the mod doesn't balance charge.

With good cells that are close to each other in capacity and discharge capability you should get away with a handful of cycles before they drift too far for the mod to fire (they say more than a few tenths of a volt different and mod protects).
The danger of it is if one or two cells drift too far and you get 4.3v in 1 cell and 4.1 in the other two and then after the day they are down to 3.5v in 1 and 3.3v in the others... you will shorten the life of the cells. Especially the one that's over charging because if not a balance charge it will just look for a total of 12.6v at full charge and not care how the batteries total up to that ending voltage and if two are lower that one will end up with more than 4.2v and the others will have less.

I don't think it will charge 1 cell but shouldn't hurt to try.

 

[BillW50]

The RX doesn't read the battery voltages very accurately. And those readings you have given could all be sitting at the same voltage. While some have charged them by USB and haven't had a problem. Some have bricked theirs by charging by USB too. As all those would do is to give the check battery error. Even with fresh new batteries. If it were me and if I didn't have a choice except to use the USB for charging, I would only charge them up to say 75% or so and not charge them any further.

 

[fq06]

Yeah, true it does not read very accurately. I checked mine after a day of vaping and the cells read quite a drift but all checked out on the charger to the tenth of a volt.
So I guess even if it did balance charge it can't do a very good job of it.

 

[Neunerball]

Yeah, true it does not read very accurately. I checked mine after a day of vaping and the cells read quite a drift but all checked out on the charger to the tenth of a volt.
So I guess even if it did balance charge it can't do a very good job of it.

Due to that lack of proper balance charge, I'd rotate the batteries within the mod, before using the USB for charging.

 

[pescadore]

If you have a 1 amp USB cell phone charger, I would use that vs the laptop or desktop. I don't think the RX has a balanced charger like the DNA200 so I would also probably rotate the batteries within the mod to maintain equal charging as much as possible.

 

[MarkS]

My first thought is on wondering why the third cell is so different. I have only seen 0.01-0.02 V difference, but that was measured by a multi-meter. From what I have heard from others is that charging cells in the RX200 is not recommended. I use to do that in a pinch and didn't experience any problems... until my Mod died (not from being able to charge, other failure).

 

[Moueix]

Those ratings are "nominal" which by definition means theoretical. It is the "balance" between the 4.2v starting value, and the value they deem as being the point of being recharged. The on-board hardware and firmware should take all 3 batteries to 4.2v, so you're fine.

HOWEVER, it is a good idea to use married batteries, that all have the same amount of number of cycles through them. Ideally, start with 3 identical new batteries. Since this isn't a parallel device, nothing is going to go boom on you, but it's good practice to keep your batteries as "even" as possible, even in a serial device.

 

[fq06]

The on-board hardware and firmware should take all 3 batteries to 4.2v, so you're fine.

So you're saying it will balance charge?

 

[BillW50]

Due to that lack of proper balance charge, I'd rotate the batteries within the mod, before using the USB for charging.

Want to explain why rotating your batteries to an electronic engineer is supposed to do? I know Mooch would like to know too.

 

[fq06]

I've heard people say that one of the 3 bays will discharge it's cell more than the others but I haven't seen it in mine. I usually pull and charge around 3.5v at the end of the day and they always read to the same tenth.

 

[Cloudy Peak Vapes]

Want to explain why rotating your batteries to an electronic engineer is supposed to do? I know Mooch would like to know too.

My understanding is just that it's another easy to do, safety precaution. I use a multimeter, so I know my batteries are all draining evenly, but I still tend to swap sides just in case one sled drains slightly faster. That's why I read to do it, and I used to be OCD about it. Nowadays, I tend to swap if I check voltage and still have plenty left. My HexOhm for instance, I tend to pull and meter after a few hours, or when I get home, since there's no voltage readout. If I'm putting them back in, I'll swap sides. My batteries all drain evenly, but why not do it if you think on it.

And I will shamefully admit that I rarely charge my Reaulaux batteries on my charger. I trust evolves board, and have my settings on that mod display individual cell voltage on the charging screen. Hasn't let me down yet, though it's something I've always preached against doing. It just takes a long time.

I do know that the RX200 has the Joyetech board, so I'd probably charge externally. At least until it's confirmed that they balance charge properly. A multimeter is always handy for that, and inexpensive.

I'm no electrical engineer, I just know I read many times to not just pair batteries, but switch sleds. Again, my meter suggests it's unnecessary, but I do it if I think to.

 

[fq06]

One way to confirm is to put 2 cells in at around 3.7v and 1 at 4v and see what the end voltage is for each cell after the charge is complete but I don't care enough to be bothered and won't sacrifice good cells for the test if it doesn't balance charge and ends up over charging my batteries.

 

[BillW50]

@TBCAmor: Charging the Reuleaux DNA200 through the USB port is fine. Although at some point that USB jack is probably going to get loose and may not work anymore. The RX200 is different though. It too has taps off of each battery, but as far as anybody knows, it it only used to measure the battery voltages and not for balance charging.

When you discharge and charge batteries always in series, even married batteries voltages will start drifting apart. Charging them in an external charger resets them all back to the same voltage again. Or a functioning balance charging will too. But rotating which bay each battery sits in won't help this problem at all.

Now the RX200 most likely draws some current off of each cell individually to read the battery's voltage. Now if it draws more current than another, or reads one cell longer than the others... now battery rotation makes perfect sense. But even still, it is very iffy if you can even keep the batteries at the same voltage for very long. I have two Reuleaux DNA200 and two RX200 myself. So far I haven't caught the RX200 doing something I didn't like yet, but others have reported they have.

 

[Cloudy Peak Vapes]

@TBCAmor: Charging the Reuleaux DNA200 through the USB port is fine. Although at some point that USB jack is probably going to get loose and may not work anymore. The RX200 is different though. It too has taps off of each battery, but as far as anybody knows, it it only used to measure the battery voltages and not for balance charging.

When you discharge and charge batteries always in series, even married batteries voltages will start drifting apart. Charging them in an external charger resets them all back to the same voltage again. Or a functioning balance charging will too. But rotating which bay each battery sits in won't help this problem at all.

Now the RX200 most likely draws some current off of each cell individually to read the battery's voltage. Now if it draws more current than another, or reads one cell longer than the others... now battery rotation makes perfect sense. But even still, it is very iffy if you can even keep the batteries at the same voltage for very long. I have two Reuleaux DNA200 and two RX200 myself. So far I haven't caught the RX200 doing something I didn't like yet, but others have reported they have.

For sure. I just never once have charged a non built in battery with a mod. I have 10 charger bays ready, so no need. I think having to charge my LiPo DNA 200 via USB gave me the trust in evolvs chip. But yes, that port can break or malfunction, so I'm probably wiser to charge externally. Especially since I'm not exactly short on chargers lol.

And I know it's a different mod altogether. Like I said, rotation is probably not needed, especially if you monitor your batteries. I just do it when I think to. And I would be hesitant to charge in the RX as a permanent solution. I don't have any Joyetech chipped devices, so that's based on no personal experience. Paying attention to your batteries on a new mod is probably most important of all. With three cells in series, I'd definitely meter them. I payed attention to both devices to make sure they were balancing for about a week. Maybe unnecessary, but gives peace of mind knowing that the 12.6 volts I'm putting in front of my face are at least charged evenly.

I'm probably gonna pick up a Joyetech device, Wismec 100 looks nice, the centurion is sexy, but not worth the price. Everyone seems to love em.

To the OP, if you have to use the device to charge for a couple of weeks, you're probably ok. I'd just keep an eye on it and never leave it charging unattended.

 

[TechnoGeek]

I've heard people say that one of the 3 bays will discharge it's cell more than the others but I haven't seen it in mine. I usually pull and charge around 3.5v at the end of the day and they always read to the same tenth.

No balance charging. The batteries are in series, the mod pulls power in series, this discharging them in series, it charges the same way. So, the first battery in the series gets drawn from the most, while the last battery is passing current through the next two batteries up in the series, thus giving the least current draw. So, IF you use the on board charger, (which you shouldn't) you want to negate this as much as possible, rotating batteries accomplishes this. Great example, the RX200 can't even monitor the current voltage well, turn it off then 10 clicks to see what it thinks the batteries voltages are...take note of these...NOW remove batteries and check with a volt meter... USUALLY one is pretty close, one is off a bit, and the third is WAY off....think series, and further away, further off....

 

[fq06]

Yeah, I looked at the individual voltage level once and it is useless. Nowhere close to accurate.

A long day at work I might plug it in for 30 min just to make sure but that probably puts in 0.1v at best... probably not even that.

 

[BillW50]

@TechnoGeek: That isn't how series batteries operate. If perfectly matched, they all drain the same and charge the same. The problem with series batteries is no battery is perfectly alike another one. Even right off of the manufacturing line. One is going to have just a tad more capacity than another one. Now charging and discharging in series will make the difference greater and greater with every cycle. When you charge individually or with balance charging, it resets the difference back to zero. If you don't believe me, just ask Mooch.

Now some RX200 seems to be doing something unique. As one battery will drop in voltage far more than the other two batteries (one has confirmed it is cell #3). For some reason, the battery taps we think is just for reading the individual battery voltages, is drainning cell #3 more. My gut feeling is that the RX200 has the hardware for balance charging, but Wismec couldn't get the firmware to operate it correctly. So they would have disabled balance charging. In either case, there is a hardware and/or firmware problem going on here.

Oh and to read the individual voltages from the RX200 (mine hasn't been off more than 0.11v from a multimeter). You turn it off and hold the down and fire button for 5 seconds. 10 fire presses from off displays the board temperature in Celsius.