Ammo Box Charging Question

[edan]

(moderator – please remove if this does not belong here as I was not sure where to ask this)


Hello,


This is a minor issue but it just got me to thinking and I would be interested in anyone’s opinion on this. Since I have recently moved over to LiPO’s, and having read everything I could find on this, I just wanted to check on my conclusion’s.


As far as charging a LiPO in an ammo box, I found two different opinions concerning having the lid open or closed. One side stated it was best to have the lid open while charging a battery, and the other opinion stated it was best to drill a hole in the lid to pass the wires through, and then close and secure the lid. I decided to ask locally and see how other people charge their batteries and found that quite a few of them charge their LiPO’s and NiMH in an ammo box with a one-half or smaller hole in the lid that is secured shut.


Now, having blown up a few things in my youth, it seems to me that, since a HiMH can blow up with considerable force under certain circumstances, that having the lid secured with a small hole could possibly cause more shrapnel.


Am I incorrect in this assumption?


My understanding is that a Lipo may cause a fire if damaged or a charger malfunction occurs, and that a HiMH can explode if it is deliberately overcharged or a charger malfunction occurs. Please correct me if I am wrong here as I am judging this on what I have read on the internet, not by personal experience.

[EeePee]

Let's say I've had 20 lipos and never cared for them in the least. Which is true. Never been a problem. I charge them in my apartment, on a wooden table, at the highest charge rate I can which can be 5C. Never even gave a poop about them after I drive or after they were charged.

Are you afraid the lipo in your phone is going to blow up? Maybe keep your phone in an ammo box?

[edan]

I am not concerned about charging my batteries.


I do not phrase myself very well sometimes, sorry about the confusion. This was more of a question about what others are doing and if this might be a safety concern. Also, I wanted to check if I understood about this issue since I am fairly new here.


Thank you.

[Natedog]

Edan, all of what you stated can happen and I've seen nimh batteries that were overcharged at the track and they got super hot and vented all over and probably would have caught fire if I hadn't yanked the guy's charger off and tossed the battery on to the concrete floor.

I charge my lipos in a lipo sack sitting on a metal plate or concrete floor when possible. I carry and store them in individual lipo sacks, then in a larger lipo sack, in an ammo box. How much do you value your house, apartment, whatever?

Forgot to say that most cellphones use lithium-ion, we're using lithium polymer which is similar.

[dyecocker]

If you want to charge in the ammo can simply drill several 1/2 inch holes, Probably at least 6 in the sides and have at it. If the lipo does catch fire its needs a vent. If not you just made a nice little bomb. The can will contain the majority of the flames even with the holes, just dont charge next to the curtains

[RadioFlyer]

Edan,

Good on you for taking precautions. However rare LiPo fires are they do occur. Today's batteries are pretty stable but they are not foolproof.

As far as the ammo box is concerned, it probably doesn't matter if it's open or closed since an exploding LiPo doesn't really "explode" in the sense that a grenade explodes. It's mostly intense fire and smoke. I would say it's preferable to have the lid closed as an extra precaution. It is highly improbable that ANY hobby battery could explode with the force required to rupture an ammo box.



Sean

[Boopernator]

I have had no problems safely charging my lipos with the correct charger and power source with lipo safe charge bags. I recently purchased a three pack of ammo cans to store my lipos in. I think I will defiantly convert one into a charging can.

Check this video out. https://youtu.be/8A7An4fXARs

[WHITE-TRASH]

Originally Posted by EeePee

Let's say I've had 20 lipos and never cared for them in the least. Which is true. Never been a problem. I charge them in my apartment, on a wooden table, at the highest charge rate I can which can be 5C. Never even gave a poop about them after I drive or after they were charged.

Are you afraid the lipo in your phone is going to blow up? Maybe keep your phone in an ammo box?

Yup. I treat my lipos like crap. 850 mah 4s charged at 5 amps? Hell yea, I charge everything at 5 amps. I've got some packs that are hard as a rock from being beaten and puffed but they haven't snuck into my house and killed me yet.

[rngrchad]

I've f'ed up a few times and left lipos charged in a hot car. That's the only issue I've ever personally had with safety concerns. They puffed really badly, I let them cool down, discharged them, and haven't had an issue with them to this day. I charge them in plain site when I'll be in the same room as they are. I don't bother with charging them inside anything. However, I store all my LIPOS in an ammo can both in the truck and in the house at around 3.8 volts per cell when I remember. Sometimes I'll leave them fully charged for weeks, and sometimes they will be way under storage charge for weeks. Thing to remember with lipos is if the storage charge drops too much you may run into issues being able to charge them on some chargers(there are ways to spike the voltages to get the charger to recognize them if this happens). Safety wise, I think your smart for taking precautions and asking questions.

I look at it like this; an ammo can is a "fuse" between your batteries and house. Rarely ever are you going to blow a fuse, but god forbid it does happen, it'll keep the fire from taking down your 200,000 mortgage investment.

[GLwagon]

LiPo's have become less volatile over the years, & The old fashioned LiPo sack or otherwise is good to an extent.
The key thing is keeping it off of a flammable surface.
Open STEEL ammo can (not plastic) would be fine if you are in the room.
If one goes be ready to throw the can outside.
Balance EVERY charge, & use the LiPo cut on the ESC or stop before that, & Put the batteries into a "storage" charged state (3.8v per cell)
If a battery is showing distress (puffed) just kill it (salt water bath for a few weeks) & dispose of properly.

[dyecocker]

Thing to remember with lipos is if the storage charge drops too much you may run into issues being able to charge them on some chargers

If you have decent batteries and take care of them this would never be an issue. It takes a very very long time for a lipo to drop enough voltage from storage to under 3 volts.

[YellowYeti]

I am thinking about getting one of these BAT-SAFE » Safe lithium battery handling

[GLwagon]

For the cost of that I can buy 4 Steel amo-cans & separate my packs out into groups to keep them isolated.

As is for the 20+ batteries I have they are in a couple of cans & random LiPo sacks stuck between the stacks, or to hold the smaller loose cells (1s)

Separation & isolation is better than a big fancy box with a hole.

[YellowYeti]

Originally Posted by GLwagon

For the cost of that I can buy 4 Steel amo-cans & separate my packs out into groups to keep them isolated.

As is for the 20+ batteries I have they are in a couple of cans & random LiPo sacks stuck between the stacks, or to hold the smaller loose cells (1s)

Separation & isolation is better than a big fancy box with a hole.

That's fine, just putting it out there as another option, Sorry It might be a good choice for someone that does not have a garage or something with a concrete floor to set ammo cans on, btw the big fancy box with a hole, or holes in this case, also has a filter in the lid to help filter out the toxic fumes that a lipo fire produces, and it is reusable if there was a fire in it.
I watched the videos on it, and I liked what I saw. I did not think the cost was that much (about the price of one Lipo pack, give or take) to help protect not only my health, but house as well. I have never had a fire, and it may be rare, but it is peace of mind as well.

[TheLetterJ]

Why not cut a few pieces of drywall to line the inside of your ammo box if you feel the fire resistance is not sufficient? Drywall is used as a fire barrier in homes, commercial buildings, and even fire "proof" gun safes. Your run of the mill gypsum board has something like a 1/2hr rating per 1/2". I'd trust that over any lipo sack.

[CM9000]

I charge everything at 10amps. the team manager charges his at 20amps. been racing for 5 years and no fires yet. the only way I can get a lipo to catch fire is to take an axe to it. that's bout it. just don't get careless.

[TacoCrawler]

I had a 3s 30C LiPo swell and then burst into a road flare
Simply from charging it at too high of an amp rating.
So be sure your battery can be charged at those higher amp ratings.

Do Not assume that all LiPo's can accept these higher amp charges.

If one purchased an 80c ^ rated LiPo it may accept a higher amp charge.
But if utilizing a 30C LiPo don't expect the same results.

Since I often utilize a 30C LiPo... I only charge it at 2.1 amps.
Over charging (amps) often causes the battery to swell...
And even tho' it might not burst... it could.

There is a significant purchase cost difference between a 30C and 80C LiPo.
Yer average RC crawler hobbyist does not need utilize an 80C LiPo
But it's your money... do with it what you want.

IMO... it's best to charge them outdoors just in case something does go wrong.

If indoors... charge them in a LiPo burn bag or fire resistant container (or both).
Good idea to stow them in those if stored inside your home.

The acrid smoke and fumes are bad if they might burst...
but that's not as bad as burning down your home and possibly others.

Also partially discharge your LiPo battery if it's not going to be used for a period.
The lower voltage means less burst strength, if failure might occur.

If all stowed together... one LiPo bursting can create a chain reaction
and cause the others to ignite as well.

It is a disservice to state that all LiPo batteries can be charged at a single specific amp rating.

Read the LiPo battery's labeling that you've purchased
and charge it according to the mfgr's specification/charge rating.
A LiPo battery should have its charge rate labeled on it.
And it is vital to have an understanding and follow that.

I personally do not own nor use swelled LiPo batteries.
So be prepared for the burst possibility if you do.