Using 20s2p setup

[Haste]

Hello,
Going to buy 4 10s 5000mah zippy compacts for 20s2p.

I have a hyperion 1420i for charging, as one 10s20ah pack. How long will this take?

I am going to keep the batteries stored, in a waterproof box OUTSIDE. About 20 feet away from the house. Is this too much security? I have 2 babys so I dont wanna get the harm close.

 

[dnmun]

you can bulk charge the 20S with a lipo BMS to protect it too. then you could wire the battery up permanently and not have to plug and unplug every charge cycle. plus short circuit and over discharge protections as well as balancing like the balancing charger does.

http://www.bestekpower.com/74v20spcmbmspcbforli-ionli-polymerbatterypack/

 

[wesnewell]

Well, that's 740wh, so under 2 hours to charge charged as 10s4p.

Wouldn't store those batteries outside unless you put them in a frig in the shade. Inside a closed box in the sun will kill them quick.
http://www.walmart.com/ip/15162467?wmlspartner=wlpa
Or find a used one for under $50.
Fireplace?
Regular fridge veggie compartment.
Anywhere but what you intend.

 

[Haste]

ah,

my fireplace is a ventless fireplace(natural gas) with a chainmail pull cover. If 4 10s lipos went off, doubt it would vent it from destroying house with black smoke.

So would you run the small fridge? Like at the warmest temp? If closed would it protect the garage if lipos went off?

 

[wesnewell]

Well, I just leave mine on the bike in the garage because I'm too lazy to take the 30 seconds it takes me to remove the pack, but I wouldn't put them in an inclosed box in the sun. I'm not too worried about them catching fire as I ride every day so they don't go unattended for long. If I was going to remove them, a little fridge in the garage set to highest temp would be a perfect place to store them.

 

[dnmun]

do you store your laptop and cell phone in the cooler too? they all have lipo batteries.

 

[wesnewell]

Don't have a cell phone or laptop. With no plans to get either. I've got 4 PC's and voip phone service. My spare lipo batteries are on my wooden desk and I'm not worried one bit about them either. Been there for years and will be there for years more. My BMS (me) watches them. Instructed the wife to bury them with me when I die.

 

[dogman dan]

Small fridge or very well insulated ice chest placed in the shade for summer storage should work. Shouldn't need to run the fridge unless, like me, you live in serious desert. In winter, you will have to charge in place that is relatively warm, if you ride in deep cold. Outside, the box can be a plastic cooler. You can have metal boxes in the cooler if you wish though.

They make bags to charge in, so you could charge in smaller quantities in a bag, inside. Under the stove hood might be the most fire resistant place in the house. Don't nap while charging, so you can heave em out the door if they do start stinking up the house.

Anybody tried putting a thermometer with an alarm on a pack during charging? It's going to get hot before it pops flame right? Set alarm to 120F and you get some warning before they reach 150+.

 

[Haste]

yeah my hyperion has the temperature warning setting also. So LIPO wont do anything unless DISCHARGE/CHARGING?

Anybody always leave them in the lipo bags?

 

[dnmun]

what do you mean by "do anything"? are you asking what causes the lipo to go into thermal runaway?

there is a lot of info that explains why in the literature. if you overcharge the lipo above about 150% or about 5V then it can go into thermal runaway and if you short out the output of the battery then the heat generated by the shorted pack can make the pack go into thermal runaway in some circumstances. maybe we will get another attack on me that brings out more info that is otherwise hidden.

if you bulk charge without a BMS then when one cell in the pack goes to 0V the other cells can be overcharged. if you use a balancing charger and the output of the battery is shorted then the pack can go into thermal runaway.

if you use cellogs then the cellogs will beep but you have to be there to hear the beeps. most of the fires seem to happen when no one is around so the cellogs don't help much except to monitor, not protect.