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Safest way to store LIPOs?

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Old 03-13-2011, 10:11 AM
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Wavekatcher
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Default Safest way to store LIPOs?

I have some "firesacks " on order. Should I store the lipos in the firesacks inside steel ammo cans? Making sure to vent the cans? Also where is the safest place in the house? ( I have no garage) Obviously not in my 2 year old son's room. Thanks for any help.....a Lipo noob
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Old 03-13-2011, 02:15 PM
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Default RE: Safest way to store LIPOs?

ORIGINAL: Wavekatcher

I have some ''firesacks '' on order. Should I store the lipos in the firesacks inside steel ammo cans? Making sure to vent the cans? Also where is the safest place in the house? ( I have no garage) Obviously not in my 2 year old son's room. Thanks for any help.....a Lipo noob
Ever consider getting out of California while you still can, and get a home with a basement for storing your LiPos. Realistically, I'd be more concerned about California's fragile economy, water crisis, cost of living and earthquake faults than your LiPos catching fire and further destruction in fire sacks in surplus ammo container. Any way here's the usual common sense advice ... even more relevant with a small child around.

They should be charged and stored in a fire-safe container namely the Lipo sack. They should not be charged near inflammable liquids or solids. If possible a fire extinguisher or at least a bucket of water or sand is mandatory. (NOTE: Some confusion in first sentence. Don't believe the noted author of this safety article meant that "They should be both charged and stored in a fire-safe container ... . Just stored.)

They should never at any [time] be charged inside an automobile even when it is stationary. While storing care should be taken to keep it away from children, after all, children are the most curious lot and would love to go on an inspection rampage. (NOTE: Apparently the author doesn't recommend using those HZ or PKZ 12VDC chargers with cigarette lighter plugs).

They should not be stored in a pocket, bag, or a drawer loosely packed. They may cause short circuit when coming in contact with each other roughly. They should also not be left in direct sunlight or anywhere where the temperature exceeds 140F/60C.

If the above precautions are followed properly, a lipo battery can be stored for about 1 or 2 months without losing much charge. (NOTE: It sounds like the author is saying it's OK to store 1 or 2 months fully charged as he mentions only 'discharge' in the following sentence. Don't believe there is a consensus; common sense seems to be more like no more than 1-2 days fully charged before flying.
But if you are opting to store the battery for a longer period then it is recommended that you discharge[or charge] it to 3.7 or 3.8 volts per cell and store it in a cool place.
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Old 03-17-2011, 11:26 AM
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Default RE: Safest way to store LIPOs?

One of the best tips of Swifts' message is that you should never store batteries at full charge, it was 'hidden' in the last part of his message. I think 50-60% should be fine.
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Old 03-17-2011, 01:24 PM
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Default RE: Safest way to store LIPOs?

ORIGINAL: plane-addict
One of the best tips of Swifts' message ... it was 'hidden' in the last part of his message. I think 50-60% should be fine.
"hidden" ... really? ... Well, come out come out wherever you are and Go Figueroa.

Mucho easier to just measure resting voltage than 50-60% [] capacity
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Old 03-18-2011, 02:36 AM
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Default RE: Safest way to store LIPOs?

It sounds like you are irritated because of my message.... I realize it was short and could have been more clear.

I used hidden in quotes because it got burried away in the last part of your message. You don't have to feel offended.

To make it more clear, I was talking 50-60% capacity, not voltage (of course). If a battery cell has a capacity of 2200mAh at full charge (and close to 4.2 V) then there is no problem at all when it is at 50-60% capacity (which is a 1100mAh or a little more). Voltage will still be at a safe level.
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Old 03-18-2011, 09:55 AM
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Default RE: Safest way to store LIPOs?

ORIGINAL: plane-addict
... it got burried away in the last part of your message ...
Do you think that the last sentence ... "But if you are opting to store the battery for a longer period then it is recommended that you discharge it to 3.7 or 3.8 volts per cell and store it in a cool place" is also "burried?"

ORIGINAL: plane-addict
I was talking 50-60% capacity, not voltage (of course). If a battery cell has a capacity of 2200mAh at full charge (and close to 4.2 V) then there is no problem at all when it is at 50-60% capacity (which is a 1100mAh or a little more).
Yes, agree that an experienced LiPo plane-addict may have a watt meter … or … has a pretty good feel for how much elapsed time it takes with your throttle management method … or … other bench discharge/charge procedure to arrive at 50-60% capacity for how you prepare your LiPo packs for storage. You may know how much mAh capacity to partially putback(recharge) into a discharged LiPo pack to arrive at a 50%-60% mAh capacity before storage. What method would you suggest, if not voltage, that Wavekatcher use for arriving at 50-60% capacity when preparing his LiPo pack(s) for storage.

ORIGINAL: plane-addict
Voltage will still be at a safe level.
So, if it comes down to voltage being at a safe level … why not just tell wavekatcher what you consider to be a safe voltage level for storing his 3S LiPo pack(s)? For example would you consider the voltage range between say … 3.6 volts per cell(10.8v=total for 3S pack) and 3.7 volts per cell(11.1v=total 3S pack voltage) as being acceptably safe for storing Wavekatcher’s LiPo pack(s). Perhaps 3.8 volts per cell(3S=11.4v) is too high or beyond your 50-60% capacity guideline.

Do you know whether the mAh capacity at 3.8v per cell or 11.4v for a 3S LiPo pack is more than 1320mAh(60%)? Can you see that it's easier for Wavekatcher and most by using an acceptable voltage range than capacity range ... unless one is an experienced LiPo plane-addict with a watt meter or programmable LVC or throttle management and stopwatch for so many flight minutes.
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Old 03-20-2011, 10:52 AM
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Default RE: Safest way to store LIPOs?

Do you have any issues? Man... loosen up a little.
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Old 03-20-2011, 11:03 AM
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Default RE: Safest way to store LIPOs?

To topic starter, read this document I have been using as a guideline (Electrify/Hobbico advisory): http://manuals.hobbico.com/gpm/gpmp0...anual-v1_2.pdf

Page 4 (of 4 pages) has a topic about 'Storing and Transportation' for lipo batteries. Your question is answered in the first sentence.

To swift: Do not read that part, it might hurt your ego.
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Old 03-20-2011, 11:16 AM
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Default RE: Safest way to store LIPOs?

Thank you very much. I appreciate the help.
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Old 03-22-2011, 11:24 AM
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Default RE: Safest way to store LIPOs?

• For long term storage it is recommended to charge the cells
fully, then discharge them to 50-60% of their capacity. (Electrifly manual)
The 50-60% mAh can be confusing when preferred measurement uses volts. It reads discharge them to 50-60%. That implies that a 2200mAh pack discharged 60% would take it down to 880mAh having depleted 1320mAh. Others might read that and think 50-60% means 1100-1320mAh when you’ve only discharged or depleted 880mAh or 40%.

It’s much easier to understand and measure 3.7-3.8v per cell. Balance chargers readouts are shown in volts, the E-flite Cell Checker readout is shown volts per cell and total volts as is the CSRC Cell Checker. The CSRC Lipo Fuel Guage indicates cell voltage NOT depleted mAh capacity. The CSRC Low Voltage LiPo Alarm. And the RCU threads when discussing storing of LiPo packs ALL discuss voltage NOT mAh capacity. Or you can use a CSRC multimeter for checking the LiPo pack's total voltage as well as individual cell voltage and a thermometer probe for checking the LiPo temperature after a discharge at or near it's continuous/burst discharge rating.

http://www.rcuniverse.com/forum/m_10...m.htm#10397055
http://www.rcuniverse.com/forum/m_84...tm.htm#8480295
http://www.rcuniverse.com/forum/m_62...tm.htm#6294096
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Old 04-20-2011, 09:05 AM
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Default RE: Safest way to store LIPOs?

Swift427,

You sound like a very angry man?? Whats the deal?? It seems every post I read of yours, you are extremely argumentative. I think you need to lighten up.
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Old 04-20-2011, 09:20 AM
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Default RE: Safest way to store LIPOs?

Wavekatcher,

I see you are in CA. So, You probably don't have issues with freezing temps. Here are a couple ideas that have been kicking around the forums in regards to Lipo storage.

1. If at all possible keep them outside. No matter what container you have them in it will still allow the gas, smoke and fumes to be released into the air if they go bad. Your house will not be the same afterwards.

2. If you have a fireplace (I know your in CA, so not sure you would have one), and it has glass doors, it would be a good spot if you want to keep them inside. If you leave the fireplace damper open the smoke and gases would more than likely go up the chimney, and the fireplace would contain the flames.

2. Some guys are keeping their batts in a barbecue grill outside, as long as freezing temps are not an issue.This seems to me to be the best option.

Anyway good luck.

Tom
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