LIPO batteries. How long can they be left at full charge?

[Freelander]

Ok.

We have a very strict regimen.

Go run.

Storage charge battery.

Plan to run.

Balance charge.

Run.

Storage charge immediately after.

Repeat.

Recently our charger is over charging(?) On storage mode. It keeps charging and will not stop. It charges at 1 amp. Stopped it now twice at ~3.9 all cells.

Now we just watch and pull the plug (figuratively) at 3.8

It used to stop and beep at ~3.822

Is my charger fiddlesticked?

There are no setting options for target voltage on storage mode in the interface.

No deal breaker. Just have to watch and stop the charger now.

Is it bad to leave a Lipo at full charge for up to a week? Obviously leaving a Lipo in a discharged state for a week is bad.

Do we need to be so anal about always leaving our batteries at 3.8v?

I mean. It's working really well for us.

Should I get the charger looked at? It's under warranty.
It's a pain in the ass to have to watch it. It was much nicer when it just stopped and beeped at us.

 

[Rcproponent]

Is that a venom charger by chance??

mine has done this since the day I bought it which is why I don’t use it anymore lol.

fully charged for prolonged time lessens the life of the bat and also is when the battery is at its most “dangerous” it’s just best not to do it. ??‍ I never leave mine charged for more than a few hours to a day at the absolute longest

 

[3d-rc.myshopify.com]

thats a bomb waiting to happen.

 

[arrmadillo]

Definitely get the charger warrantied. Leaving lipos fully charged for a week is not good, just looking to wreck your lipos. Can you do it, yes, will they still work, yes, but why. There's a reason to put your lipos at storage charge, it's good for them. It's all about the chemical makeup of lipos, they don't like over discharged, nor like fully charged for prolonged periods, unless you like a short shelf life or buying new lipos. I don't even leave my lipos fully charged for 24 hours.

 

[parcou]

All replied here are good....if this was happening to me I and pulling the plug at 3.80 I would be concerned about the balance charge part of it... What I mean as I watch my charger storage/charge 3S Lipo, not all cells get to 3.80 or 4.20 at the same time...so in storing or charging I would want it to balance the cells that need a bit more time to get to the right number at the same time not overcharge the other cells. If I pull the plug in my case...some cells could go over before the other cells reached the right point.

You might not have this issue if you can hit it for "al"l cells but I have seen some drag on some batteries I charge for the 8 lipos have for my RCs. I have seen the charger storage charge for more than 10+ mins waiting on one of the cells to get to 3.80 before it beeped for all "done"

 

[Freelander]

I see what you are saying. You're absolutely right: I can't get the cells perfectly balanced at 3.8 by simply interrupting the charging.

I'll have to take it in.

It's actually a store brand charger so I don't have to mail it or anything. It'll take a few days minimum because of infection mitigation protocols at the store but it'll be way quicker than any other brand's charger.

I guess we'll have some fun running this weekend then I will drop it off on Monday.

Thanks for edjumacation, guys.

 

[KevinC]

I stopped using the storage charge function on my charger some time ago due to the fact that it took forever, sometimes a few hours to charge at 1 amp.
Heres what I do now......I take my depleted lipos (3.6V/cell) and put them on a balance charge, bring them to about 3.85V /cell then stop the charge. I check the voltages after the battery sits for a few minutes and the voltage sags back down to 3.8. Yes you have to keep an eye on your cells while doing this but I can get my batteries stored in about 13 minutes as opposed to 2 hours.

cheers,
kev

 

[olds97_lss]

Yep, I'd get a new charger. Isn't worth the cost of many lipo's or damaging them and having it overcharge them on you accidentally. Something is clearly wrong with it. The last thing you would want is to have it overcharge your packs beyond 4.2V.

I have a hitec D7 and it wasn't overcharging for me, but it was taking hours to balance for storage. $250 charger. It's now in the closet and has been replaced.

 

[LibertyMKiii]

Since we are actively discussing LiPo care. I was under the impression that a very high rate of discharge could be bad for a battery. Is that not true?

I was trying to read up on how this would effect the cells and other than heat concerns of the cells I cannot find anything that says this will damage the chemistry within the cells.

 

[jkflow]

Some Lipo basics, sometimes we (including myself) are a little to anal about this stuff. Always good to stick to the routine but helpful to know some limits.

Lipo storage is 3.7-3.9V and good for month at end without damage. The 'ideal' is around 3.8V, for HV it's ~ 3.85V.
Been there, done that many times for years on multiple lipos. I don't charge up or down when within those limits.

Leaving fully charged (above ~4V), yes damage will occur i.e. typically some puffing. I wouldn't do it for more than 2 days on purpose. Been there done that as well, minimal issues. Had 2 Lipos left charged by accident for 2 weeks, light puffing and still in use today but these are degraded for sure.

For letting Lipo's sit (i.e. yank the cord and it's not balanced) the Lipo does not have to be balanced, it can care less.
It does care if you apply a load i.e. do not use it in this condition, balance charge prior. Uneven cells discharge unevenly and you can have one at critical damage level while the other is still at 'ok' level.

Chargers:
All chargers (BOLD STATEMENT! , prove me wrong ) you can set the current for storage charging just like for normal charging.
BUT: If your Lipo is above storage level it will take a long time to bring it down! That is discharging. The 1A is believable (from above) if that is the case.

Finally:
OP question on bad charger. Same thing just happened to me on an older charger, power cycled and was fine after the fact. Definitely a warning sign, if it's permanent I'd throw it away at the next opportunity you get for a solid replacement. Something is seriously wrong, keep an eye on it.
If that is the balance circuit I wouldn't charge with it at all.

 

[KevinC]

Chargers:
All chargers (BOLD STATEMENT! , prove me wrong ) you can set the current for storage charging just like for normal charging.
BUT: If your Lipo is above storage level it will take a long time to bring it down! That is discharging. The 1A is believable (from above) if that is the case.

@jkflow
The venom quad pro will NOT allow you to increase storage charge rate above 1A......if you know a way to change it please let me know. If you don’t believe me I will post video.

cheers,
kev

 

[jkflow]

Ok, I just pulled out my old charger. That one is indeed limited to 2A in storage mode. Forgot about that little detail. 1A is a little odd though.


Challenge accepted! By all means this is all in good spirit.
Your manual states that you can select the current just like in normal charge modes. The way I read it, the battery must be connected to set those values. A little odd but try it.
Technology is the same on this charger as one of my older ones i.e. I can set mine all day long.

 

[KevinC]

Trust me bro I’ve been over that page 100 times. When I saw that 2A charge I thought mmmmm I can change it.......not a chance.
I even contacted venom about how they advertise this, yet in reality....it ain’t happening. They got back to me and said the same thing I’m telling you.

I plan on running tomorrow if weather is decent. After I get back I will post a storage charge attempt at trying to increase past 1A.....standby.

cheers,
kev

 

[Be Ready]

I’ve been on the Anti- Venom band wagon for awhile now. I can’t discharge on anything but 1a ... Takes forever the Venom Duo is just a junkie charger all around.

 

[KevinC]

I’ve been on the Anti- Venom band wagon for awhile now. I can’t discharge on anything but 1a ... Takes forever the Venom Duo is just a junkie charger all around.

Your avatar says it all.....?

 

[jkflow]

Trust me bro I’ve been over that page 100 times. When I saw that 2A charge I thought mmmmm I can change it.......not a chance.
I even contacted venom about how they advertise this, yet in reality....it ain’t happening. They got back to me and said the same thing I’m telling you.

I plan on running tomorrow if weather is decent. After I get back I will post a storage charge attempt at trying to increase past 1A.....standby.

cheers,
kev

I concede! Something that hasn't been heard for a while but I digress ?
Agreed, you can't change it. That is about the oldest charger technology still on the market today. I think I bought that charger ~10 years ago.
Sad that it's still around nowadays just in a different case/name. I still use it as an emergency backup.

 

[Freelander]

Anyways the store has my charger now. It's only 3 ½ months old. They have shitloads of stock but won't just do an exchange. They want to bench test it. Hopefully it will replicate the fault. Otherwise there's a 30 dollar shop fee.

 

[Flaremaster]

Is that a venom charger by chance??

mine has done this since the day I bought it which is why I don’t use it anymore lol.

fully charged for prolonged time lessens the life of the bat and also is when the battery is at its most “dangerous” it’s just best not to do it. ??‍ I never leave mine charged for more than a few hours to a day at the absolute longest

Is there any way to get it back to its old length. I accidentally did this as I had no way to discharge it, with my only car being under maintinence, and not knowing how to discharge it any other way

 

[Flaremaster]

Is that a venom charger by chance??

mine has done this since the day I bought it which is why I don’t use it anymore lol.

fully charged for prolonged time lessens the life of the bat and also is when the battery is at its most “dangerous” it’s just best not to do it. ??‍ I never leave mine charged for more than a few hours to a day at the absolute longest

Is there any way to lengthen the life again? I accidentally left ot for a week as my only car was not usable and I had no other way to discharge it

 

[jkflow]

One week doesn't do much. No, you can't put life back into a Lipo.
Wouldn't worry about that too much. Any swelling that you might have experienced will most likely disappear.
You might have taken out 0.1% of the life, not worth mentioning.