Married Batteries... Why ?

[ShaneW]

Thanks for that link @GerharddP, very interesting.

http://batteryuniversity.com/learn/article/bu_803a_cell_mismatch_balancing

extract from that page:
Let’s look at what happens to a weak cell that is strung together with stronger cells in a pack. The weak cell holds less capacity and is discharged more quickly than their strong brothers. Going empty first causes their strong brothers to overrun their feeble sibling to the point where a high load can push the weak cell into reverse polarity. Nickel-cadmium can tolerate a reverse voltage of minus 0.2V at a few milliamps, but exceeding this will cause a permanent electrical short. On charge, the weak cell reaches full charge first, and then goes into heat-generating overcharge, while the strong brothers still accept charge and stay cool. The weak cell experiences a disadvantage on both charge and discharge; it continues to weaken until giving up the struggle.

This is exactly what I was looking for and although they are referring to battery packs its very interesting and reasonably relevant to a series mod configuration. Scary thought that the weaker cell could potentially go into reverse polarity the question is would someone realise that this is happening before it ever gets to that point? In a 2 battery configuration I would think they would definitely notice this as the series voltage is going to be horrible and indicate flat battery (regulated mod)

 

[Silver]

My question is would the electronics on the mods be intelligent enough to know when things are potentially going pear shaped and tell you to replace batteries or just stop working as a safety measure?

 

[GerharddP]

Thanks for that link @GerharddP, very interesting.

http://batteryuniversity.com/learn/article/bu_803a_cell_mismatch_balancing

extract from that page:
Let’s look at what happens to a weak cell that is strung together with stronger cells in a pack. The weak cell holds less capacity and is discharged more quickly than their strong brothers. Going empty first causes their strong brothers to overrun their feeble sibling to the point where a high load can push the weak cell into reverse polarity. Nickel-cadmium can tolerate a reverse voltage of minus 0.2V at a few milliamps, but exceeding this will cause a permanent electrical short. On charge, the weak cell reaches full charge first, and then goes into heat-generating overcharge, while the strong brothers still accept charge and stay cool. The weak cell experiences a disadvantage on both charge and discharge; it continues to weaken until giving up the struggle.

This is exactly what I was looking for and although they are referring to battery packs its very interesting and reasonably relevant to a series mod configuration. Scary thought that the weaker cell could potentially go into reverse polarity the question is would someone realise that this is happening before it ever gets to that point? In a 2 battery configuration I would think they would definitely notice this as the series voltage is going to be horrible and indicate flat battery (regulated mod)

Question is why risk all that? Just marry batteries, a lot let fuss. Some guys go and say "well i cant afford 2 new bats as well". I understand this as my budget is tight these days as well but can you afford an eye/corrective surgery if something goes wrong?

Glad I could help, this site has taught me so much. Problem is guys go to the site, look at it and go BBBOOORRRIIINNNGGG and just leave. I will extend my knowledge to all that ask so if you dont understand a certain topic etc ask and i will assist as far as I can.

 

[GerharddP]

My question is would the electronics on the mods be intelligent enough to know when things are potentially going pear shaped and tell you to replace batteries or just stop working as a safety measure?

That is exactly what I'm saying. Unless you have a very well designed balance board (that will bump up the price of the mod a lot) the mod might not react in time if at all. Remember its a very dog eat dog market and unfortunately the east competes with price and not with quality.

 

[ShaneW]

Question is why risk all that? Just marry batteries, a lot let fuss. Some guys go and say "well i cant afford 2 new bats as well". I understand this as my budget is tight these days as well but can you afford an eye/corrective surgery if something goes wrong?

Glad I could help, this site has taught me so much. Problem is guys go to the site, look at it and go BBBOOORRRIIINNNGGG and just leave. I will extend my knowledge to all that ask so if you dont understand a certain topic etc ask and i will assist as far as I can.

Look I personally am still not going to bother about marrying my batteries but that is only because I am very much aware of their state, I have a pool of batteries that are all the same age and are in reasonably equal rotation. I will never mix 2 types of batteries or a battery that I know is old with one that is new... the description scenario above is quite an extreme example of what could happen if you make a mistake

Having said that ... I am not advising that anyone follow the way I choose to do things, rather play it safe

 

[GerharddP]

Look I personally am still not going to bother about marrying my batteries but that is only because I am very much aware of their state, I have a pool of batteries that are all the same age and are in reasonably equal rotation. I will never mix 2 types of batteries or a battery that I know is old with one that is new... the description scenario above is quite an extreme example of what could happen if you make a mistake

Having said that ... I am not advising that anyone follow the way I choose to do things, rather play it safe

I understand that it is extreme but there is sufficient evidence that these things do happen and I for one do not want to worry about if I will be next. Thats all I'm saying. The reason I get excited about discussions like these are not because of experienced guys like us but rather the "noob" that says screw this marriage business (insert joke here) and does get hurt. The world is so unforgiving that it will be headline stories about how crazy we as vapers are and that just boils my blood. It seems that the IQ or research capabilities of the average reporter these days are comparable to your garden variety snail.

PS. Not all reporters were harmed in the typing of that comment but if the shoe fits........

 

[ShaneW]

I understand that it is extreme but there is sufficient evidence that these things do happen and I for one do not want to worry about if I will be next. Thats all I'm saying. The reason I get excited about discussions like these are not because of experienced guys like us but rather the "noob" that says screw this marriage business (insert joke here) and does get hurt. The world is so unforgiving that it will be headline stories about how crazy we as vapers are and that just boils my blood. It seems that the IQ or research capabilities of the average reporter these days are comparable to your garden variety snail.

PS. Not all reporters were harmed in the typing of that comment but if the shoe fits........

hahahaha... point taken and I agree fully. Am going to edit my OP in the hope that someone might not misinterpret my comments and hopefully reads this thread to completion.

 

[GerharddP]

hahahaha... point taken and I agree fully. Am going to edit my OP in the hope that someone might not misinterpret my comments and hopefully reads this thread to completion.

Didnt want to sound like I'm hounding you bud. I have great respect for you guys. When it comes to my family and friends with vaping

 

[Khan83]

My question is would the electronics on the mods be intelligent enough to know when things are potentially going pear shaped and tell you to replace batteries or just stop working as a safety measure?

Hey @Silver . I don't know jack about batteries or the internals of a mod but one thing I learnt recently is not to rely solely on built in safety measures if there are separate dedicated devices for it.

The onboard charging on the RX200 was supposedly slated as being good enough to evenly charge all 3 batteries . I did it this way for two months mostly because I was a bit too cheap to invest in a dedicated charger.

After checking the voltage on the mod I found that all 3 batteries varied drastically in their readings(erratic depending on the charge but if I recall correctly , always over 0.24 volt difference between them) . After getting a 4 bay charger they've all seem to come within close rage of one another now , never exceeding 0.04 volts.

Don't know if the initial difference was enough to cause issues but considering the power hungry coils we use nowadays I don't feel comfortable relying on just the onboard electronics.

 

[GerharddP]

Hey @Silver . I don't know jack about batteries or the internals of a mod but one thing I learnt recently is not to rely solely on built in safety measures if there are separate dedicated devices for it.

The onboard charging on the RX200 was supposedly slated as being good enough to evenly charge all 3 batteries . I did it this way for two months mostly because I was a bit too cheap to invest in a dedicated charger.

After checking the voltage on the mod I found that all 3 batteries varied drastically in their readings(erratic depending on the charge but if I recall correctly , always over 0.24 volt difference between them) . After getting a 4 bay charger they've all seem to come within close rage of one another now , never exceeding 0.04 volts.

Don't know if the initial difference was enough to cause issues but considering the power hungry coils we use nowadays I don't feel comfortable relying on just the onboard electronics.

Cheap balance board. Like I said the world doesnt care..... 0fks given guaranteed. Thats why a DNA200 is +-3k and a "affordable" knockoff chip is 1/3 the price.

 

[Khan83]

Cheap balance board. Like I said the world doesnt care..... 0fks given guaranteed. Thats why a DNA200 is +-3k and a "affordable" knockoff chip is 1/3 the price.

Exactly . Safety doesn't come cheap but as you mentioned , much cheaper than surgery .

Read somewhere that Wisemec may consider disabling onboard charging on the next software update but it was most probably on Reddit so I'm taking it with a pinch of salt

 

[GerharddP]

Exactly . Safety doesn't come cheap but as you mentioned , much cheaper than surgery .

Read somewhere that Wisemec may consider disabling onboard charging on the next software update but it was most probably on Reddit so I'm taking it with a pinch of salt

I would also think they should as it gives them indemnity. I am not saying all batts die explosively but as a side note I have had one almost brand new tisiyi vent while on charge in the charger. Never went below 3.6 V.

 

[Khan83]

I would also think they should as it gives them indemnity. I am not saying all batts die explosively but as a side note I have had one almost brand new tisiyi vent while on charge in the charger. Never went below 3.6 V.

Hence one of the reasons I NOW rather err on the side of caution . Technology may have come a long way in terms of "fail-safes" but it never hurts to take precaution

 

[Kuhlkatz]

Remember that married batteries do not apply just to Regulated Mods only.
You need to have some balance in multi-battery serial or parallel mechs as well, as these are likely pushed harder than regulated mods. These units do NOT automagically switch off if one of the cells drop below a specific threshold faster than it's counterparts.

Unfortunately a mech mod is only as intelligent as the current person vaping on it...

 

[johan]

Hahahaha apologies, perhaps Meneer is a more appealing term... I only use as a sign of respect.

Why would you say it's a safety concern, what do you think could happen?

Thanks for Video and he only affirms what I am trying to get at (1hr33m)... Married batteries is not the bee all and end all and unless the 2 batteries are vastly different or you running them down to discharge hell, I really don't see the issue.

What we do have to remember though is that these batteries are being used by people that don't fully understand what they are doing with the electrical circuits they are creating, and perhaps don't know the state of a battery or its charge level. For this reason I agree that's it's safer to tell them to marry the batteries.

"Why would you say it's a safety concern, what do you think could happen?" A battery discharged well below 2.5V with a husband/wife on the other side pulling serious current, will heat up and might start venting, ... and I fully agree with your last paragraph, if you don't know basic physics, use "married" batteries, irrespective whether its coupled in parallel or series.

Note: to whoever read this: Batteries are supplied without brains, so please use your own!

 

[Quakes]

Hi All


Sorry for bringing this thread back from the dead, but something I was wondering.

I got 2 Married batteries that was running in Parallel in a regulated mod. Will I be able to use them in a series mech mod?

 

[johan]

Hi All


Sorry for bringing this thread back from the dead, but something I was wondering.

I got 2 Married batteries that was running in Parallel in a regulated mod. Will I be able to use them in a series mech mod?

Yes, proviso you don't exceed the batteries maximum current specification. Please note; in series connection the current available will be half what is was in parallel connection. (i.e: each individual battery maximum current specification = 10A, and fully charged voltage = 4.2V. Parallel connected: maximum current = 20A and maximum voltage = 4.2V. Series connected: maximum current = 10A and maximum voltage = 8.4V).

 

[Quakes]

Yes, proviso you don't exceed the batteries maximum current specification. Please note; in series connection the current available will be half what is was in parallel connection. (i.e: each individual battery maximum current specification = 10A, and fully charged voltage = 4.2V. Parallel connected: maximum current = 20A and maximum voltage = 4.2V. Series connected: maximum current = 10A and maximum voltage = 8.4V).

Great, Thanks for the reply