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Gens Ace LiPo Battery Puff

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Gens Ace LiPo Battery Puff

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Old 09-05-2019, 08:41 AM
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Default Gens Ace LiPo Battery Puff

Hey guys,
How much LiPo puff do you live with? What puff (if any) do you consider acceptable and what puff do consider a risk?

Presently, my ST's are carrying 1/8" puff. Batteries in use and displaying puffing are two 2s x 4600 60C LiPo 'Shorty', and one 2s x 4200 60C 'Shorty'. Safety truck is using a 2s x 3500 60C LiPo 'shorty' and it is beginning to display a puff, although right now <~ 1/16". All are hard case, but do not carry ROAR approval stickers.

Batteries are charged at 1C rate and stored in charged status with rotating use every two weeks. Do not keep a record of charge cycles, but all have at or less than ~12 cycles on them. Batteries are not fully discharged during an event. Usually use about 1/3 - 1/2 their capacity for an event.

Curious to hear what you have to say and recommend. Cheers and regards. AC
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Old 09-05-2019, 09:28 AM
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when you say you store them in a charged status, what voltage per cell are you storing them at?

what cutoff are you running these to per cell?

How hot are your batteries coming off at after a run in your vehicles?
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Old 09-05-2019, 09:47 AM
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If the case cracks or bends open a bit itís time for the battery to go, thatís just me.
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Old 09-05-2019, 10:20 AM
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any puff for me is time to trash a lipo. any puff is damage... so no puff is acceptable for my liking.
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Old 09-05-2019, 11:48 AM
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Originally Posted by Cain View Post
when you say you store them in a charged status, what voltage per cell are you storing them at?
Batteries are all stored at full charge, 8.4V. Storage is short term-two weeks at most between uses. Voltage per cell read out is not available on my old MRC Super Brain 989 charger. Gens Ace recommendation for long term, 3 months or longer, is 3.6V-3.9V per cell ,[ 7.2V - 7.8V total pack voltage]. Wondering? Should I discharge them to this lower voltage, even for short term storage?

what cutoff are you running these to per cell?
Discharge cut off on my charger was set to 3.2V. Gens Ace recommends 3.5V cut off. My bad there. Re-set the discharge cycle to 3.5V. So far, though, have not fully dis-charged any of my batteries. Only peak them again for storage following an event.
HW ESC cutoff voltage is set at 3.0V, the minimum recommended by Gens Ace in their instructions. Should I bump this up to option 3.2V or 3.4V? Runtime for my events is split into four sessions totaling 12min total. Battery capacity on re-charge seldom takes more than 1200mAh.


How hot are your batteries coming off at after a run in your vehicles?
Coming off a run event, battery temperature is ambient air temp. This time of year in Houston, ~96 - 98~ deg F with 'feels like' of 106-107. Batteries have never been hot to the touch.
Good questions.
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Old 09-06-2019, 10:50 AM
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the storage with a full charge may be your problem. You should store them at the storage charge rate, which I believe is 3.85V per cell or so. I forget what some places say to store them that long for, but I personally have had lipos stored that way for a couple of months or so and then just cycle them on my charger and they are fine, work great.

I would recommend getting a different charger, one that can show you the voltages per cell. there are some nice cheap options out there. If you need help finding some just let me know.

As for cutoff, in general depending on usage, 3.2V - 3.5V cutoff for lipos Per Cell should be fine. When using my lipos in a vehicle that pulls hard on batteries (4x4 SCT for example) I go with a higher cutoff value like 3.5V per cell, items like 2wd 17.5 spec buggy I do 3.2V per cell. Keep in mind, some ESCs do cutoff voltage stops different than others. Some will let your vehicle still run as the voltage dips briefly before cutoff, however, some as soon as it trips cutoff, it stops. Maclan is like that. this isn't a bad thing necessarily, as it can show you if a lipo is getting weak.

As for battery temp, before charging, I personally make sure the batteries drop down I would say to about 70 - 80 degrees or so. In general if you have multiple packs then you should be fine, as you most likely are not charging them up right after pulling them up but wanted to check.

Ultimately, you leaving them at full charge I beleive is the problem. Promatch batteries for instance I believe in the instructions specifically say to NOT do this.
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Old 09-06-2019, 06:53 PM
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quickest ways to puff a battery:

1) run below 3.2v per cell
2) storing at more than 3.8v per cell
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Old 09-06-2019, 09:06 PM
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Originally Posted by RC*PHREAK View Post
quickest ways to puff a battery:

1) run below 3.2v per cell
2) storing at more than 3.8v per cell
If you were running your batteries every saturday, would you still put them in storage mode?
Or do you think letting them sit for a week at the voltages they finished at on saturdays is fine?
They dont get to 3.8 per cell, but they arent full either.
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Old 09-07-2019, 12:04 AM
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never had a lipo puff and i own so many between quads, electric cars/truck, nitro , even still have some from heli days.

dont over discharge, dont overcharge and always storage charge within a reasonable timeframe.

i've damaged lipos like smashing them up in quads and helis, bent soft packs.. broke hard case, tossed them correctly straight away but i've never ever had one puff on me.
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Old 09-07-2019, 09:13 AM
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Originally Posted by morvlorv View Post
If you were running your batteries every saturday, would you still put them in storage mode?
Or do you think letting them sit for a week at the voltages they finished at on saturdays is fine?
They dont get to 3.8 per cell, but they arent full either.
not ideal, but probably ok. i wouldn't let it go more than a week though. if they're sitting at 3.9-4v per cell for a week, that's probably not going to puff them. longer than a week, you're probably pushing it.
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Old 09-07-2019, 11:36 AM
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I would keep it in storage if its more than 2 days. If you stick the battery on a table, and its wobbles or isn't flat, its bad.
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Old 09-07-2019, 08:07 PM
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honestly the amount of time it takes to just put them to storage charge I would just do it.
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Old 09-07-2019, 08:35 PM
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Reads like I puffed them myself by not storing them at the proper voltage. No excuses. I screwed the pooch there. That won't happen again.

Guys, I really appreciate all your comments and suggestions. And yes, Cain, I will entertain suggestions for a replacement charger.

Cheers and Regards. AC
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