Battery Heaters on their way

[Craig]

For those living in cold climates, see the latest info on heaters

 

[PetePerrim]

Thanks for that but what was the news on the gimbal gasket? I live in New Zealand where its currently 25-30 degrees Celsius so battery heaters are not on my shopping list however the gimbal gasket may be a fix for 'gimbal jerky' (a term I just made up for a jerky gimbal)

 

[Craig]

Hi Peter, that's all the info at this stage

 

[Mazz]

I have been flying in some very cold weather. I received the email too but probably would never use it. Heater just prewarms the batteries to a better operating temperature but even though I fly in -10C weather my batteries are never allowed to get that cold. I keep batteries at temp until I fly (in my car or case) and then I just use the insulation they came with. What I do not like is the insulation and how it sticks on. It is winter here in NY so the insulation is on but what happens when it is hot? I will remove the insulation so they do not over heat but does that mean I need to buy new each time I want to use it? I added some tabs to mine for easy removal but I have already done it a couple of times and they will definitely loose their "stick."

 

[The Editor]

For those living in cold climates, see the latest info on heatersView attachment 332

I do find it strange sometimes in what DJI decide to market before other items!

Whilst battery heaters would be welcome in the winter and in cold environments (we've had them for years in the film industry along with drum heaters and eye-cup warmers to prevent fogging) I would have THOUGHT there is a far far higher demand for multi-port chargers enabling one to charge several packs at once (I would suggest four).
I'm sure the cash registers would Kerching far more for DJI with mult-iport chargers than battery warmers and a darn sight easier to engineer since in reality it would be nothing more than a high current stable switch mode power supply as all the charging and cell balance is done 'in pack'!

Strange.........

 

[huppe]

First I need more batteries.
And a multicharger would be the first thing I want.Realy love this with the Phantom.

 

[Kilrah]

I doubt there will be any multi-charger offered by DJI, as it would still need individual process control (CC/CV) for each battery.
I.e. would be identical to multiple single chargers in one package. So just buy more single chargers and put them in a box.

 

[The Editor]

I doubt there will be any multi-charger offered by DJI, as it would still need individual process control (CC/CV) for each battery.
I.e. would be identical to multiple single chargers in one package. So just buy more single chargers and put them in a box.

No - It wouldn't. It would just need a hefty PSU capable of delivering a stable supply. The DJI 'Charger' is nothing more than a power supply. You just need something that will supply 26.3v at say around 20amps (for a bit of wiggle room/overhead) - You could then charge the TX at the same time as four batteries!


All the clever charging, CC/CV and delta v control and balancing is done INTERNALLY in the battery itself. Yer just need to plug em in

Hell - I could knock one up myself but the problem would be getting those proprietary plugs that go into the battery.

 

[Kilrah]

Nope, the supplied charger is actually a CC/CV supply. The battery's internal electronics handle the balancing and can interrupt the current flow, but can't regulate it.So by plugging one battery to a 20A supply you'd charge your battery at 20A i.e. 4C, and it would either accept it but not like it, or would shut itself down as protection.

So if you wanted to parallel charge you'd have to be very careful all batteries are at the same charge level or insert series diode to prevent batteries discharging into others, and control of what current goes in which battery would be inexistent.

 

[The Editor]

If you say so - How then does the Inspire battery balance the cells either proportionally or digitally if it is unable to control the current down to say circa 1000mA (probably starting at around 3.8v) which it would need to do with a resolution of +/- 1mV in order to balance each cell accurately?

 

[Kilrah]

Very likely after the charge process has ended.
Remember the balancer is connected to the pack 24/7, it doesn't need to be connected externally to do its job.

 

[The Editor]

I REALLY don't like that idea but...... you might be onto something there!

This would mean if anyone just charges, unplugs and flies they are running the risk of using packs with unbalanced cells.
If, as you suggest, the balancing is done off-line and passively then everyone would do their packs a favor by charging, then allowing them to sit there for an hour or so (while they balance). Then fly.

That would be a killer..... a fully charged pack, sitting there on the desk and you have to look at it for an hour before you can use it (if you REALLY wanted to look after you packs that is)

I will have to investigate this further - I shall retire to my man cave while I theorize

 

[Kilrah]

A lipo that is in good condition will need no balancing, or only by a minute amount on a given charge.
The balancer is there mostly as safety (check it's OK), and if needed to correct a tiny offset at a time.

If your pack needs an hour to balance after every cycle it means one or more cells are severely damaged and it's basically already good for the trash.

When we started using LiPos in RC 10 years ago we would use packs for a year without balancing them, unless they were really defective they wouldn't catch fire after 3 cycles.

 

[huppe]

There will be absolutly someone who can make such a charger.I'm sure but not me

 

[The Editor]

Balancing every charge will do no harm whatsoever - only good.
Without balancing you could be more than 0.1v out between cells - maybe ok on a 2 cell pack NOT on a 6 cell pack!

 

[Kilrah]

Balancing every charge will do no harm whatsoever - only good.

Sure, but unless your pack is defective "balancing" will equal doing nothing as cells are already balanced.

Without balancing you could be more than 0.1v out between cells

You could get to more than 0.1V between cells but that would need accumulating small capacity discrepancies over dozens of cycles without any balancing. By balancing on every charge the correction needed to "maintain" balance on each cycle is approximately nothing.

maybe ok on a 2 cell pack NOT on a 6 cell pack!

Makes no difference actually. Both are just as bad.

There will be absolutly someone who can make such a charger.I'm sure but not me

Of course it's possible like everything. Just IMO not worth the trouble to develop something that will have to be quite complicated when you can just get multiple individual chargers. At best someone will take 4 stock chargers, put them in one box and sell the "multiple charger" for the price of 6 stock chargers, lol.

 

[1nspired1]

So let me get this straight, you can't build your own plug as with the Phantom and then hook this battery up to a high quality RC charger and charge as a PB? I was under the impression that the Inspire charger was just a power supply and the battery has all the charger guts / balancer/ and smarts?