Battery amp limit and regulated mods

[Arvellon]

Hi guys,

I've been using a mech for a while now and I learned a lot about battery safety. But now I'm using a regulated mod again and I have a question.

I know that with a (decent) regulated mod its safe to exceed the battery amp limit but I wonder if it has any other disadvantages than wearing down the batteries lifespan?

So for short: What effects does exceeding the batteries amp limit have when using a regulated mod

Thanks

 

[mimöschen]

If the failsafe features of the board fail, you're toast.
Exceeding the specs of a battery is never 100% save.

 

[bombastinator]

When you do that you activate the boost-buck feature of the chip. This creates a pulsing effect that can negatively affect the vaping experience in various ways
Buck–boost converter - Wikipedia

 

[Arvellon]

I guess I should mention that I'm talking about exceeding it a little bit (max 2 amps)

 

[Rossum]

So for short: What effects does exceeding the batteries amp limit have when using a regulated mod

Much depends on the board in the mod and its software. A regulated mod could (should?) monitor battery "sag" (voltage under load when you're firing it vs. resting voltage) and refuse to allow that value to get out-of-hand. Done properly, that could (should?) keep the mod from over-taxing the batteries.

 

[Rossum]

When you do that you activate the boost-buck feature of the chip. This creates a pulsing effect that can negatively affect the vaping experience in various ways
Buck–boost converter - Wikipedia

A regulated mod is always running boost or buck. That's how it regulates.

 

[mimöschen]

Most dual and/or triple battery mods lack a boost circuit however.

Exceeding the amplimit of a battery always causes some additional voltage sag, so much that the mod might not even supply the desired wattage.

 

[93gc40]

It is never ok to draw more the the amp limit of a battery... so your battery should be rated to max DRAW of mod..... this value may or may not be equal to max output of mod.

You don't want to run 15amp rated battery on a mod drawing 25 amps. Regardless the amps being fed to the atty.

Sent from my SCH-I605 using Tapatalk

 

[bombastinator]

A regulated mod is always running boost or buck. That's how it regulates.

True. But at the limits of the mod the pulses get pretty far apart. Particularly if the battery is getting low

 

[sonicbomb]

Regulated or not exceeding the CDR is not recommended.
Relying on ancillary circuitry in a cheap Chinese mod to provide protection against getting your face burnt is also ill-advised.

 

[untar]

What's wrong with buying the correct batteries for your style of vaping? That is the recommended way to do things if you want to be on the safer side (yes there's no 100% safe, we all know that, this is about relative safety).

Exceeding the CDR, in addition to prematurely aging your batteries, will be a sudden problem if there's a malfunction of your mod (eg autofire) that leads to continuous discharge.

Again, this doesn't mean you'll 100% be reduced to a small crater smelling of bacon (hmmmm, bacon) but you're taking additional risks. Personally I'd say that specific risk is unnecessary and doesn't have any benifits to the vape you get except maybe saving $15. You'll have to buy new batteries soon anyways and they will give you less vaping time if abused, together with the added risk it's hard to argue that it's worth it.

 

[My Batt Hurts]

Apologies for hijacking the thread, but what's the consensus on using a low(er) CDR / higher mAh battery for the extra runtime? If I habitually vape at < 12 watts, is there any harm in using a 10 amp battery on a mod that claims up to 75W?

I prefer 30Qs and VTC6s, but I'm curious all the same.

Thanks.

 

[untar]

If I habitually vape at < 12 watts, is there any harm in using a 10 amp battery on a mod that claims up to 75W?

No, that's fine. You buy batteries tailored to your needs and then have to be aware of the limits you're agreeing with.

(your max power)/(number of batteries * low voltage cutoff)

is the formula used to choose batteries. So if you have a single battery mod and vape at 12W on a mod with 3.2V low cutoff (the voltage your mod regards a battery as "empty")

12W/1*3.2V = 3.75A

In theory you can add 10% efficiency loss on top of that but with your low power that's not necessary, you're nowhere near the limits.
So your 30Q and vtc6 are perfectly fine. I wouldn't go to lower amp batteries than those because their usually high sag can cancel out the added capacity and they won't perform better than the 30Q or vtc6.

The limit of that setup (single 15A battery on 3.2V cutoff mod) would be

15A * 1*3.2V * 0.9 = 43.2W

you have some headroom there (since we're now looking at the limit the 10% efficiency loss is taken into account).

 

[My Batt Hurts]

That's helpful. Especially:

I wouldn't go to lower amp batteries than those because their usually high sag can cancel out the added capacity

Thanks @untar.

 

[sonicbomb]

Apologies for hijacking the thread, but what's the consensus on using a low(er) CDR / higher mAh battery for the extra runtime? If I habitually vape at < 12 watts, is there any harm in using a 10 amp battery on a mod that claims up to 75W?

I prefer 30Qs and VTC6s, but I'm curious all the same.

Thanks.

Mooch answered this specific question in his blog.
You may get an extra 400 mAh or so with a 10 amp cell, but the additional internal resistance that comes along with that configuration negates any gains.
In other words stick with a good 3000 mAh 20 amp cell like the Samsung 30Q.

75 watts on a regulated mod assuming a 95% mod efficiency and a 3.2 volt cutoff is 25 amps at the end of the battery charge cycle. So in your specific example you would need a cell with a higher CDR like the Sony VTC5a if you wanted to run it at 75 watts. A 20 amp CDR cell is good for 60 watts using the same parameters as above.

 

[SnowDog]

I have a similar question. I'm using a Joyetech Evic Primo Mini mod like the one in this link. I assume it's a regulated mod but I don't really know.
Joyetech™ eVic Primo Mini Starter Kit (w/ ProCore Aries) - Vapor Authority

I'm currently using a Samsung 25R 20A 2500mah battery but I'm considering buying a different battery with a higher mah rating and a lower amp rating in hopes that I'll get a little bit longer run time between charges.

The battery that I want to switch to is a LG MJ1 10A 3500mah but I'm not sure if it's safe for my mod and my vaping habits. The photo below is a page from the Joyetech owner's manual for my mod. It says that I should use a battery with a CDR greater than or equal to 25A.

I vape almost exclusively at 14 watts but when I do change my wattage I never go above 18 watts.

Is the LG MJ1 10A 3500mah a safe alternative for my situation?

 

[My Batt Hurts]

Hi @SnowDog - I've read about battery life issues with that mod before. Just in case you're asking for that reason, one user mentioned that reducing the display timeout helped quite a bit (Link to thread).

Have a couple in daily use. My first one did seem to drain the battery quickly - until I reset the screen timeout to a much shorter duration.

Both will easily power a KF2L through a full tank, 1.6 - 1.8 ohms, 8 - 9 watts. Tootler as well

Zero issues with them draining while sitting. (I typically have 10 - 12 mods going at once, different flavors, so any individual one may be a week before needing a fill.) Both from FT, btw.

No issues with the mod (not battery, but not it, either) getting hot. I suspect that either the heat is transferring down from the tank OR the unit is not quite right...

DO check that the 510 pin is clean (power off, battery out, scrub out with an alcohol moistened cotton swab. Leave ample time for it to evaporate out before re-powering.) A poor connection there can mean a lot of heat energy at that point, and an easy transfer of that heat to the rest of the mod.

 

[mimöschen]

If you stay below 60W, go for the Samsung 30Q, LG HG2 or Sony VTC6, whichever you can get cheaper. All of them are 20A 3000mah and perform much better than the MJ1, which lasts longer only at wattages lower than puny 7W.

 

[stols001]

I use Samsungs for my puny wattage needs, and I like them a lot. Less expensive than Sonys and also good runtime.

I will say, a) I bet I COULD go lower on my specs but I am naturally cautious anyway, and I get plenty of headroom (meaning safety) and plenty of run time.

Not stressing my batteries is kind of a personal GOAL of mine. I really wanted to smack the kiddo lately when he insisted that pulsing batteries for short periods was FINE. I also wanted to take back his (protected) mech setup. I did neither, but we argued for a LONG TIME.

I'm just gonna get the twit a 20700 battery as soon as I can, and as soon as I can afford it. God.

It is never "safe" to exceed the battery amp limit. You JUST GOT a regulated mod for SAFETY, right? USE IT SAFELY. period.

Anna

 

[SnowDog]

If you stay below 60W, go for the Samsung 30Q, LG HG2 or Sony VTC6, whichever you can get cheaper. All of them are 20A 3000mah and perform much better than the MJ1, which lasts longer only at wattages lower than puny 7W.

Many thanks! I'll take a look at those.

Can I assume that it's safe to use a battery with a CDR rating lower than the 25A recommended in the owner's manual?