I'm usually quite militant about charging and discharging my LiPos whereby I will fully charge them just before a flying session and then put them back to storage charge almost as soon as I return home. This means that my LiPos generally never remain at a fully charged or discharged state for more than a couple of hours max. I do this more for longevity reasons than for safety.

To try and increase the amount of flying practice time I can get in, I had a brainwave that I could maybe drag my backpack of FPV gear into work some days and then back again afterwards which would mean I could stop off at the park on my way home when it's usually empty (~8:30pm) and when there is less chance of any drone rage so I can fly 3 or 4 packs. Because I get home from work quite late, if I was to go home first, charge up some packs and then head back out, it will be too late / too dark, so that's not really an option.

The only drawback with doing this is that I would have to charge the packs in the morning before I leave for work and they would remain in my backpack fully charged for around 12-13 hours before they got used which is a bit out of my comfort zone. I also travel on public transport and the London underground so I'm not sure whether or not carrying around fully charged 4S LiPos in an enclosed environment is a particularly sensible idea from a safety point of view.

Does anyone on here keep their LiPos fully charged for these sort of extended time periods and if so, have you experienced any detrimental effects by doing so?

My both 5300mah (car) 850mah (micro) 2s are more than a year old. Both of them went through 100+ cycles. And they still works the same way as they were new.
I believe it is because, i never left them fully charged more than 2 or 3 hours. Also i always storage charge them right after using. And i Never discharge them below 3.6v.

You can never be too conservative with all things lipo.  With that said I try to keep my charge time below 24 hours. That tends to be recommendations by manufacturers and others.  Also I storage charge when done with them, and deep storage charge if storing longer than a couple weeks.  I've always had long life with my lipos and never a safety incident, knock on wood, in 12 twelve years.

Typically I charge, fly, and drop them to storage within about 6 hours total, but I've just started doing pretty much what you're proposing now the days are longer in the UK. A couple of times I've charged them at night to fly the following evening (I don't have time in the morning to charge or fly, usually), so they sit full for about 24 hours. Although I don't take them with me on the commute, so I can leave them at home in a safe place.

But yeah, the idea of a bag of lipos letting go on the Tube is pretty scary. And some of the old, busy lines like Central do get stupidly hot in the summer

I am not as discipline as you guys. I have left lipo fully charged for at least a week. I didn't see the immediate damage but some of my old packs aren't as good as the new ones. Maybe I don't get as many cycles compared to being more diligence, but the convenience is worth it to me. It allows me to fly without rush and charging my packs the last minute. My time to fly is very limited, so I rather sent that extra hour flying instead of charging. Speaking of charging, I have also charged the packs over 1C when I am in a rush.

The guys I fly with like to get out early on Saturday morning, so I usually charge the night before which means the packs sit for 8-10 hours before use. I don't really worry about this in terms of longevity, what I don't like is the fact that a fully charged packs individual cell voltage will drift UP over that period. I'm not sure how much over 4.2 volts a cell can go before it becomes a problem. You could charge to a lower voltage, say 4.1/4.15V per cell, then top them off in the field on your car battery or fly them that way. I've heard of guys doing that anyway to get maximum number of cycles out of their packs.

(22-May-2019, 04:27 PM)voodoo614 Wrote: I am not as discipline as you guys. I have left lipo fully charged for at least a week. I didn't see the immediate damage but some of my old packs aren't as good as the new ones. Maybe I don't get as many cycles compared to being more diligence, but the convenience is worth it to me. It allows me to fly without rush and charging my packs the last minute. My time to fly is very limited, so I rather sent that extra hour flying instead of charging. Speaking of charging, I have also charged the packs over 1C when I am in a rush.

You maniac!

Charge right before using in my case, so one hour most. Never discharge past the 3.8v so, charge, fly, store. Charging mostly below 1C also. Too much care with my gear I know

OK, based on what you guys have said I think I'm probably going to do it. Maybe I'll do a test run one day next week to see if the hassle is worth it. Get up at 6am, stick 4 packs on charge, leave the house at 7:30am. Drag my backpack of gear weighing almost 10kg 100 miles in and out of London, then stop off at my local park at 8:30pm on my way back. The things we're prepared to do just to try and get 30 mins of flying time in  

(22-May-2019, 04:25 PM)Banelle Wrote: But yeah, the idea of a bag of lipos letting go on the Tube is pretty scary. And some of the old, busy lines like Central do get stupidly hot in the summer

Yep...that's the line I use...right across the middle of London I figure there are way more Lithium batteries already on the tube in commuters electronic devices that would make a few 4S LiPos in my backpack insignificant by comparison. I might skip doing it during the height of summer though. The 35+ decree Celcius heat in a sardine-tin like environment with no aircon isn't pleasant at the best of times, let alone with a humongous backpack to try and squeeze in with as well 

I normally charge my lipos the night before going to use them. But sometimes (I think that less than 5...) I couldn't go out flying the next day and I have to wait to the next Saturday for using them. In this cases I left them fully charged around 5 days that is a thing I don't like to much, but the discharging rate of my chargers its to low to use them to discharge the lipos to storage...

Now I've bought a discharger that uses 3 light bulbs and (I think the brand it's aokoda) so If I can't fly, I storage the lipos with it (it's much quicker than using my imax or my isdt chargers...)

Usually I try to be nice to my packs and charge them maximum a few hours before flying and then storage charge right when I get home from flying. Sometimes this doesn't work out though, so now and then it happens that I charge a few packs, but then it turns out I can't go flying right away but perhaps next day, so I just keep them charged.
What worries me more is that it happened for a few times now that I came home from flying with some packs discharged to as low as 3.5v per cell, but I wasn't able to put them back in storage right away, had to wait till the next day. I think that might possess higher damage to the pack than keeping them fully charged for a few hours/days - please correct me if I'm wrong.

Snow: I'm sure you have though about that, but how about charging the packs at work? Of course I understand that not all workplaces would allow to do such thing, but since you're working as a software engineer, my experience is that software dev companies are usually quite relaxed about such things (well smaller ones at least).

(23-May-2019, 05:41 AM)izzy26 Wrote: Snow: I'm sure you have though about that, but how about charging the packs at work? Of course I understand that not all workplaces would allow to do such thing, but since you're working as a software engineer, my experience is that software dev companies are usually quite relaxed about such things (well smaller ones at least).

Sadly, not a chance. It is unfortunately not one of those small software houses with a relaxed laid back type of atmosphere. I work for a corporate company in the financial district in a large open plan office which contains rows of adjoined desks and consists of 300+ workers across various departments. I think I might get a few strange looks (and questions) if I had my desk all laid out with a charger and a load of LiPos  

If I do try this thing on the way back from work and someone spots me, then a guy flying a quad dressed in office attire is probably going to look rather odd / amusing

I was working from home today but did a dry run this evening by visiting the aforementioned park for a flying session at 8:30pm. There were just a few teenagers in the skateboard park and another group sitting in the field but in a place where they wouldn't be endangered by my flying. Youngsters don't tend give a monkeys anyway so you know you're likely never going to get any grief from them, unlike the grumpy older generation who always seem to have a chip on their shoulder

I had the whole place to myself for the duration of 4 packs with no real interruptions other then 3 dog walkers, but they appeared and then left again pretty quickly so I just stayed airborne with a bit of care while they were present in the field. Being in the cool evening air and flying during dusk also felt quite therapeutic, and the RunCam Eagle Pro 2 performed flawlessly in the low light conditions. With the goggles on you wouldn't even know it was starting to get dark. I just needed to increase the brightness by a notch on my FatSharks and it was a good 'un

I came away feeling completely relaxed and de-stressed, unlike the fruitless and frustrating session in the morning at the same spot because of too many dog walkers.

So next week I'll try out my plan of dragging all my stuff into work and back, then stopping off there for a flying session on the way home

Nice, the reason we all fly.

Did another test run this morning at the same park at the crack of dawn to see what is was like really early in the morning. Got up at 4:30am, Charged 6 LiPos (I really need to start parallel charging so I can do more than 4 LiPos at the same time), then got to the park just after 6am. The place was deserted. I managed to fly all 6 packs in an hour with no interruptions. So early mornings and late evenings seem to be the times to use this park.

Then I stopped off at the kiddies playground on the way home which was also empty and had a bit of fun with my 1S UK65 Whoop. I was back home by 8am

Now I've just got to try and stay awake for the rest of the day