Lipo Charging Fire

Jon - Sorry to read of your incident, lucky you were able to minimise the damage.
The video is scary but enlightening, following other forum discussion l decided to remove the seal
from my ammunition boxes & the video confirms this to be best practice.
However my main concern was containing the fire but the amount of smoke generated was staggering, presume this
smoke contains the horrible black bits coating your sheds contents.My lipos are in the shed stored in an ammo box & others in a firearms safe , so this needs rethinking to avoid the smoke damage.
The only safe option appears to be charging & storage in an outdoor facility.
Colin

JonTappin wrote: Standard balance charge at 1c using a Thunderpower charger, 610C. I didn't specifically check each cell voltage but the charger will not start if the individual cell voltages are too different, I know this as I have had this warning come up on some old packs previously, the charge wouldn't start until I had reduced the imbalance.

Thanks, Jon. I always get the charger started and then check the voltages to make sure they are all similar before I leave it. From your description, it looks like I'll need to make my practice safer so that if it goes up I'll still be OK.

The trouble is, how do you make it safe and reasonably convenient. Charging outside is not feasible in the UK climate. Inside means a shed or a workshop or your house...and it's clear to see that lipo bags, ammo boxes and other containers are not going to prevent significant damage. So how are we all going to make it safe(r)?

Yeah, I've just had to run outside and stop charging as it started raining, by the time I got it all in, the rain stopped, so I got it all set up again and then it started to spit with rain... I love the British summer weather it's so totally predictable.

Chris001 wrote: Yeah, I've just had to run outside and stop charging as it started raining, by the time I got it all in, the rain stopped, so I got it all set up again and then it started to spit with rain... I love the British summer weather it's so totally predictable.

Guys - What I'm considering is to make up long charging & balancing leads so that the charger stays in the shed
with the battery outside. The battery would have waterproof cover over it, large tin etc. & the only item
exposed to the weather are the low voltage cables.
My only concern is voltage loss in the cable - about 4 ft long - anyone know a source for suitable 4 & 5 core cable ( 3S & 4 S ) ?

Thanks
Colin

Hi Colin,

I think I'd be happier with the extension being between the power supply and the charger (assuming they are separate items), not the charger and the batteries... But I can't say why, just a gut feeling.

I've got no shed, so at some point I've got to develop some sort of shelter/strategy for the weather.

Do you think I can use this safety of charging as an excuse to get the Mrs to allow me to dig up the garden and install a bunker?

I wonder if something like this might work.

Ammo boxes with lipos can go in the base. Leads, balance boards, accessories, can go in the drawer. Power supply and chargers in the top. Hook it up to a weather-proof 230V socket on the outside of the house. Closed up, it should protect the contents from the elements - not sure how weather-proof but better than leaving the power supply/charger/lipo completely exposed.

Added advantage is that the whole unit can be rolled/carried in and out of the workshop as well as putting it in the car to transport everything you need - no more getting to Cashmoor to find that you've left a lead or charger at home.

Dave Rogers wrote: Do you think I can use this safety of charging as an excuse to get the Mrs to allow me to dig up the garden and install a bunker?

Think i get it dave - clever idea to contain the initial explosion, force the expansion to fire everything skyward out of harms way.!

[quote="Dante - think you will find most power tool Liion batteries have built in PCB balancer / low voltage cut out. However that technology has historically not delivered the equivalent Power / weight / volume advantages as Lipo. This is changing but at a cost.[/quote]

Can't really agree with you on the circuitry and lower power Kevin. Drills and power tools would need to have all the power available from batteries as they have a harder work ethic and more recharges than our planes demand. The circuits built into power tool batteries are designed specifically for maximum endurance, longevity and power delivery. Furthermore the circuitry is virtually identical to that utilised by our balance boards and have to have greater safety as they are used virtually continuously in industry by laymen on charging regimes that outnumber ours. Perhaps this is why Jeti have gone over to internal balancing on all their batteries utilising simple two wire charging?????

Certainly I have not heard of drill batteries having major problems with charging, safety being of primary importance in industry. I also recall that drill batteries were being stripped out of their casings for model planes etc. during the earlier days of Lipos when they were quite expensive.

You are wrong, Dante. Show me a power tool that completely flattens its battery in 2 or 3 minutes (Impressivo flight) or 8-minutes (Atlas flight with good throttle control) and I might believe that they have a 'harder work ethic'.

Kevin is also correct that most (all?) power tools use LiFe/LiIon technology and not LiPo. These cells can safely be discharged to zero voltage and recharged at high rates, Many use this cell chemistry for transmitter and receiver batteries and here they work very well. We do not use them extensively for powering our motors because they have a higher internal resistance which limits their output power (voltage drops too much as current increases) and they are heavier per mAh compared to LiPo.

My advice for anyone who flies glow/gas only would be to use LiFe or LiIon or NiMH. You can charge these safely in your workshop. But if you fly electric, you will have to use LiPo...and then you'll have to decide how best to charge your batteries safely.

I will change my charging regime, but it's not going to happen immediately...so I won't be charging under a wheelbarrow in the middle of the lawn any time soon!!!