Can water condense inside an EUC and damage it? (split)

[Funky]

1 hour ago, RagingGrandpa said:

Surface condensation only occurs when an object is cooler than the surrounding air. Not warmer. 

I think it's quite unlikely in an EUC's use case, that the pack is cooler than the dew point. 

Charging it releases heat; discharging it releases heat; and EUC's are stored indoors, so never very cold to begin with. 
 

And if someone would store wheel in garage for 3-6 hours at -10C, -20C temp? And then ride home from garage and bring said wheel indoors?

Also riding at -10C or even -20C temps for (Ride 10 mins, standing 15 mins.) Let's say 30 mins in that cold. And then bringing the wheel indoors +26C temp.

 

I bet the battery is quite cold.

1 hour ago, RagingGrandpa said:

If you don't have condensation forming on the exposed aluminum of your rim and motor, you can be confident it's not happening in the pack. 

And if i do after each ride? What then?

[RagingGrandpa]

1 minute ago, Funky said:

store wheel in garage for 3-6 hours at -10C, -20C temp?
then bring said wheel indoors?

In the winter, the dewpoint of the surface atmosphere is very low. That includes the atmosphere inside your home. If you humidify, it might raise the dew point a little, but still not to summer rainstorm levels. 

Anyway, the cells are inside the restricted atmosphere of the semi-sealed pack. Other things will make condensation much faster than the cells. 
The aluminum wheel rim is exposed to the change in environment immediately: check it yourself, for condensation in that situation. I don't think you'll find droplets in the wintertime, but please convince yourself with this simple check. 
I think it's a rare situation.

(Wipe the rim dry from any wetness you encountered during your ride, then wait a few minutes to check for droplet formation.) 
 

5 minutes ago, Funky said:

And if i <find condensation on my rim>? What then?

It's not good for anything in the EUC, so avoid it by changing your routine. 

The problem is: the air near the EUC is too moist, and the EUC is too cold. 
Likely the answer is as simple as "store it in a room that is less humid." Away from melting slush, wet clothes, cooking activity, etc. 
And the EUC was releasing heat during riding, so get it into the warm dry location right away. Letting it cool off in a cold garage makes the situation worse, if you're going to bring it indoors later. 

[Funky]

29 minutes ago, RagingGrandpa said:

(Wipe the rim dry from any wetness you encountered during your ride, then wait a few minutes to check for droplet formation.) 

Will try it tomorrow.. Doh we got warm winter right now. Lowest it has been -10C.

29 minutes ago, RagingGrandpa said:

The problem is: the air near the EUC is too moist, and the EUC is too cold. 
Likely the answer is as simple as "store it in a room that is less humid." Away from melting slush, wet clothes, cooking activity, etc. 
And the EUC was releasing heat during riding, so get it into the warm dry location right away. Letting it cool off in a cold garage makes the situation worse, if you're going to bring it indoors later. 

Garage storing is when i drive with car to stores, etc.. Euc if left in the cold garage for many hours. (Garage is not at my house.. And without heating.)

Doesn't help that my workplace is also kind of "cold" and all that snow melts on wheel stand, under wheel over 10 hours. At least it isn't too warm (+10-15C) so no condensation.

At home i place my wheel in shower after each ride and leave it there for ~5 hours.  So "dry" place not even close.. Have you been to Zoo reptile house? Very humid and warm. Just perfect place for euc after very could ride.... F.M.L.

 

I could start placing it in my room, on big tray. Tray - so melting snow gets collected..(there still will be water sitting under wheel.) I also have big open top aquarium, so humidity is kind of high all around house.

 

At least if it burns down.. I'll get new room look and new wheel, maybe. (Laughing worried.) 

Edited December 12, 2023 by Funky

[null]

1 hour ago, RagingGrandpa said:

Anyway, the cells are inside the restricted atmosphere of the semi-sealed pack. Other things will make condensation much faster than the cells.

Maybe the air inside the packs isn't humid enough to matter, but south China where these things are produced is pretty humid and of the factories I've seen there weren't air conditionned. I'd worry a bit about condensation on the aluminium walls inside the battery pack, as per graphic. (this when going out in the cold).

As for getting back indoor there can be fairly large temperature delta, I try to make a temporary storage in a corridor, or even put a blanket over the EUC to spread out the temperature contrast.

Edited December 12, 2023 by null

[novazeus]

37 minutes ago, null said:

Maybe the air inside the packs isn't humid enough to matter, but south China where these things are produced is pretty humid and of the factories I've seen there weren't air conditionned. I'd worry a bit about condensation on the aluminium walls inside the battery pack, as per graphic. (this when going out in the cold).

As for getting back indoor there can be fairly large temperature delta, I try to make a temporary storage in a corridor, or even put a blanket over the EUC to spread out the temperature contrast.

i'm storing my v13's outside in these keter boxes made for garbage cans, that work really well, but here in tampa florida, the humidity is practically fog, 24/7. i built houses for a living and i'd tell people, only on the rarest days down here, can u open ur windows, otherwise it's like spraying down ur walls, carpet, furniture, etc etc, with a garden hose. 

so yeah, i'm just in a habit of bagging my v13's every night. pita, but just the bag seems to be enough to slow condensation. i should bag the s22 also because it also sits on a kickstand where condensation could drip and cause problems esp with the motor cables. i should probably open it back up and look at it after my new motor install and get some silicone to seal the cover up better. mine didn't have much white silicone on it, but i think it should. just to prevent moisture from condensation. 

[alcatraz]

Excellent illustration posted by @null

Pack enclosures/heatshrink have cables running out of them. They're hardly sealed like an inner tube.

Even if the moisture isn't in there at the time of manufacture. The cells heating the surrounding air will push some air out of the pack when hot, and later inevitably suck some back in when the pack cools down. Over time the humidity in the pack will equalize with where it's being stored.

That's my theory at least. What do you think?

[Hellkitten]

Anyone ever stuck desiccant bags in or tested them with keeping battery packs dry? 
https://www.mcmaster.com/products/desiccant-packs/

[novazeus]

1 hour ago, Hellkitten said:

Anyone ever stuck desiccant bags in or tested them with keeping battery packs dry? 
https://www.mcmaster.com/products/desiccant-packs/

yeah i did. idk if it helped, but here in florida, it's probably the worse. it's 11:17 pm here now, 57 degrees and 87% humidity. so when the air warms and the metal stays cold, condensation forms. how air "conditioners" work. passing warm moist air over cold radiator coils. the moisture collects, drips into the drip pan and out of the house. but without that, like who wants to run the ac in winter? so all that moisture comes inside and stays there. 

i've had wheels inside here with me and sweat profusely. idk what tesla is doing in these high humidity climates. but yeah, if condensation is bad for wheels, and i know it is, sealed hvac storage rooms would be best. but who is gonna keep their car in their living room. harleys maybe, i've seen that. 

instead of dessicant pouches and big thick lawn bags, i just use big lawn bags, and don't really take care to seal them much, but it's enough to keep them from sweating. florida is a very inhospitable place, always has been. hard on structures, electronics, humans, animals, etc. termites and ants thrive here. 

i used to install these in banks. this is not the normal high security one inch thick safes, but this and dessicant pouches would be the best storage for condensation and fire.

https://www.ebay.com/itm/265725757248

haha, yeah, cash gards, for little remote banks without a vault. but yeah, if u have nice wheels, and a nice house and family, this would be ideal storage. 

https://www.dieboldnixdorf.com/-/media/diebold/files/physical-security/dn_productcard_hardware_tl15cashgardsafe_v01_20161003.pdf

Edited December 13, 2023 by novazeus

[alcatraz]

3 hours ago, novazeus said:

idk what tesla is doing in these high humidity climates

I hear the tesla motor packs are cooled and heated. Would that solve the condensation problem? The outer case is perhaps air tight sealed as well. Maybe there's a dehumidifyer as well.

[novazeus]

the answer to this topic question is absolutely where i live!

i've witnessed it.

it's a big problem, not necessarily for me with my construction/hvac background, but for ur average human in florida, they can't even maintained their homes properly in this climate, much less an electronic timebomb.

idk, maybe i worry too much, but how would u feel, introducing a friend to wheels, and their house burned down. not everybody is aware of the potential fires caused by these large battery packs. i just know if i was explaining to my gfs, safe handling of wheels and their batteries, their eyes would glaze over and they just wouldn't bother. i think they'd love riding, just not maintenance and storage. we're still in our infancy with li-on powered mobility devices. golf carts have been around forever, and even those can blow up occasionally. 

haha, like me telling them to bag their outside stored wheel every night. i sleep way better knowing the wheels are 50 plus yards away from me. 

u know the old phone hack when u dropped it in water, a jar of rice tightly sealed. take a big jar and lots of rice, but i tightly wrapped garbage bag with these dessicant pouches, or a big tub of damp rid, would probably suck any moisture out. might be overkill but i know what condensation will do. 

yeah, just checked on the wheels. no condensation, yet. it's 61f and 91% humidity, so the air isn't warmer than the metal yet. conditions have to be just so. 

Edited December 13, 2023 by novazeus

[novazeus]

5 hours ago, alcatraz said:

I hear the tesla motor packs are cooled and heated. Would that solve the condensation problem? The outer case is perhaps air tight sealed as well. Maybe there's a dehumidifyer as well.

let's hope so. but idk about engineers. i had to lemon law my german built vw toareg a couple years ago after 1200 miles and two years of ownership because it had mold and an inch of water in it. evidently, and i can tell u from 50 years of building in florida, keeping out water is almost impossible. the vw tech blamed me for driving thru water. we drive thru water daily in florida. it's a swamp down here. nobody would live here without hvac and pesticides. 

we just don't have long term info on how theee wheels/batteries in general will hold up. i started in 2017, only 6 years ago. jason started less than ten years ago. and his experience hasn't been pleasant. he did move out west with lower humidity than miami.

[Funky]

21 hours ago, RagingGrandpa said:

 

(Wipe the rim dry from any wetness you encountered during your ride, then wait a few minutes to check for droplet formation.) 
 

There where no "droplets", but to touch it felt wet, (10 minutes later..) when i went over the wiped part with finger. So some moisture where there. (And today temp was only -4C.)

Can't do much. Only option is to stop ridding in winter or continue riding till wheel burns or stops working. Luckily i already have 5k$ ready for my next wheel.. When ever it will be built/manufactured. Also it's 3rd winter going without any problems. Should i start worrying now..? idk..?

 

My daily winter ride is 10-15km/h speeds ~500 meters to train station. (5-10 mins waiting.) Then ~2000 meters till workplace. Idk if battery can get that could, that fast.. Also riding at measly 10-15km/h speeds, is the battery making any heat? As i'm not pulling any performance out of wheel.. Train has heating.. Workplace somewhat warm. And house is very warm. More or less i'm spending 20min max out in the cold while commuting. Walking/Ridding/Waiting in place.

[RagingGrandpa]

The exposed cold aluminum rim is a worst-case; the situation inside the insulating plastic shell will only be better. 
If the rim wasn't making drips, I think it's unlikely for anything inside to be condensing.

Just ride  

(And be attentive to changes in performance: failure to fully recharge is typical first sign of trouble.)

[Funky]

9 minutes ago, RagingGrandpa said:

(And be attentive to changes in performance: failure to fully recharge is typical first sign of trouble.)

Doesn't help much, that i charge my wheel 2 times a month. (Every second week.) Doh i check for 84V every time. And charge fully to 100% and keep charger connected for extra 3 hours after green light appears. 18xl beeps when it's finishes balancing cells.

FYI i don't use any apps while commuting, so can't really check anything. Wheel moves forwards - i'm happy.

Edited December 13, 2023 by Funky

[alcatraz]

10 hours ago, Funky said:

Doesn't help much, that i charge my wheel 2 times a month. (Every second week.) Doh i check for 84V every time. And charge fully to 100% and keep charger connected for extra 3 hours after green light appears. 18xl beeps when it's finishes balancing cells.

FYI i don't use any apps while commuting, so can't really check anything. Wheel moves forwards - i'm happy.

That beep is a fantastic feature. As good as a smart bms IMO. I wish all wheels had it. 

[Hellkitten]

2 minutes ago, alcatraz said:

That beep is a fantastic feature. As good as a smart bms IMO. I wish all wheels had it. 

The Sherman S red light and fan runs constantly until the packs are charged then pulse between green and red with the fan doing the same. When the cells are balanced the light stays solid green and the fan shuts down. 👍 I agree it’s nice to have an indicator to show when things are actually finished. 

[alcatraz]

10 minutes ago, Hellkitten said:

The Sherman S red light and fan runs constantly until the packs are charged then pulse between green and red with the fan doing the same. When the cells are balanced the light stays solid green and the fan shuts down. 👍 I agree it’s nice to have an indicator to show when things are actually finished. 

I had a wheel where the bms simply stopped balancing. Worked fine otherwise.

If you're used to hearing a beep, that would certainly raise a red flag if it stopped. A bms that stops drawing power from the psu being a signal of completed balancing assumes the bms works. Better check the pack end voltage in the app regularly to confirm a full charge.

I've argued that even that trick isn't 100% because the cells could be overcharged to reach that voltage (bad bms). It's another argument for a beep being better as long as that circuit doesn't fail and beep erroneously.

Edited December 14, 2023 by alcatraz

[Seba]

On 12/14/2023 at 4:03 AM, Hellkitten said:

The Sherman S red light and fan runs constantly until the packs are charged then pulse between green and red with the fan doing the same. When the cells are balanced the light stays solid green and the fan shuts down. 👍 I agree it’s nice to have an indicator to show when things are actually finished. 

Actually this behaviour isn't an indication of battery state, but a result of limitations in charger design. There's a comparator circuit that detects if the output current has decreased below certain threshold. This circuit turns off the cooling fan and switches LED from red to green. In some designs, this circuit will also turn off the relay that supplies output voltage, thus physically disconnecting battery from the charger circuit. This relay may however prevent battery from balancing, so in most LiIon chargers it's not used. Normally there's a hysteresis that prevents this circuit to constantly trip on and off, but if there's no hysteresis, this circuit will constantly trip when the output current is near the threshold. When the current will drop further, tripping stops and fan remains off and red LED is on.