Lipo storage, slight swell

[Tony Kenny]

HI Guys,

After reading a note in RCME this month this reminded me that my larger 4S lipos have got a slight bulge and I've been fully charging all my batteries after each use. Often then not using them for many weeks. I hear this is bad.

I'm planning on investing in a charger that has a 'storage charge' facility and a discharge facility. I'll also go for a dual-charger so if I can go flying last-minute, I have a cat-in-hells chance of having time to charge them. DC capabilities will also be useful for charging at the field from the car or a leisure battery. (Don't worry, my car has a 7kW LiPo itself and the engine is more 'generator' than engine so I don't expect a flat). Should I look for anything else?

My favourite at the minute is this: **LINK**

For these slightly bulging batteries, would I be OK just discharging them to a storage level and letting time tell if the bulge gets worse? The alternative is to shell out another £120 on replacing them!

[Former Member]

[This posting has been removed]

[Tony Kenny]

Looks good, but it's only a single charger so I can only charge one battery at a time, unless I buy 2.

[Martin Harris - Moderator]

From observation at my club, there seem to have been several "makes" of LiPo that have exhibited a tendency to swell in the last year or two. A pair of Dynamic 3S 2200s that I bought for my Me163 ballooned noticeably after just a couple of months but they continue to perform OK nearly 2 years later.

[Tony Kenny]

I think the Overlander RC-D100 looks potentially a good one.

[McG 6969]

Hi Tony,

You could have a look at the iSDT range of chargers. Available at Banggood or HK.

I have the smaller iSDT Q6 200W from Banggood and it's a great piece of kit.

Storage charge, discharge, IR and the power input is a XT60 so you can use a larger 4S or 6S for charging at the field. If charging multiple Lipos there is an optional 'splitter' plate that makes it possible.

Worth to have a look, I think.

Cheers

Chris

[onetenor]

Talking of batteries

https://deals.survivalfrog.com/easy-power-rechargeable-batteries-v-of.php?pid=3&product=easy-power-rechargeable-batteries

[Steve Colman]

I bought an Ultrapower UP240AC Duo charger from Banggood about 6 months ago and it's been absolutely fantastic!

AC/DC, Internal power supplies, High power output, all the features anyone could want apart from IR monitoring. It was almost 100.00 Euros (about 80.00 quid) but well worth it.

Steve.

[Tony Kenny]

Posted by Steve Colman on 27/12/2017 17:45:57:

I bought an Ultrapower UP240AC Duo charger from Banggood about 6 months ago and it's been absolutely fantastic!

AC/DC, Internal power supplies, High power output, all the features anyone could want apart from IR monitoring. It was almost 100.00 Euros (about 80.00 quid) but well worth it.

Steve.

Does it have storage charge mode? I found it on banggood, but it doesn't list that as a feature.

[Caveman]

Hi Tony, I've got this charger, which is mentioned above:

**LINK**

You can read the manual here:

**LINK**scharger-power-supply.html

It will do all the functions you need.

As far as I'm concerned it's a cracking bit of kit!

Cheers GDB

[Steve Colman]

Posted by Tony Kenny on 27/12/2017 18:22:57:

Posted by Steve Colman on 27/12/2017 17:45:57:

I bought an Ultrapower UP240AC Duo charger from Banggood about 6 months ago and it's been absolutely fantastic!

AC/DC, Internal power supplies, High power output, all the features anyone could want apart from IR monitoring. It was almost 100.00 Euros (about 80.00 quid) but well worth it.

Steve.

Does it have storage charge mode? I found it on banggood, but it doesn't list that as a feature.

Hi Tony, Yes it has storage charging mode.

[Former Member]

[This posting has been removed]

[Martin Harris - Moderator]

Posted by onetenor on 27/12/2017 17:59:28:

Talking of batteries

https://deals.survivalfrog.com/easy-power-rechargeable-batteries-v-of.php?pid=3&product=easy-power-rechargeable-batteries

Handy if you're in the 'States but I suspect that postage and import duties might be a bit of a double whammy.

BTW OT, if your connection is a bit slow, hitting the "Add Posting" button while it's waiting results in multiple postings - which seems to be happening to you a lot lately.

Also, web links are better posted by highlighting some text and then clicking on the fourth button from last on the panel above the text box - which opens a dialogue with a box marked URL - just paste your link (include the http~). Doing this creates a clickable hyperlink.

[Tony Kenny]

Posted by Percy Verance on 27/12/2017 19:04:31:

Tony

If you feel you'd probably need to charge pairs of packs regularly, you'll need plenty of ooomph. I'm no expert, but I think somewhere in the order of 2 x 100watt outputs? You'll also need a big leisure battery to complement it for on field charging. My HiTec X2 has twin 400watt outputs, which seem to handle any capacity of pack I connect to them. Not the cheapest around though at £200+

If you need to charge lots of packs with a reasonably quick turn round, you'll struggle to do it on too tight a budget.

Edited By Percy Verance on 27/12/2017 19:08:36

Thank you, good advice, I will replace the connectors, I also prefer not to have to tighten screws before every single flight, even then, there's nothing to say they won't work loose in flight.

[Steve Hargreaves - Moderator]

Posted by Martin Harris on 27/12/2017 19:28:57:

Posted by onetenor on 27/12/2017 17:59:28:

Talking of batteries

https://deals.survivalfrog.com/easy-power-rechargeable-batt

BTW OT, if your connection is a bit slow, hitting the "Add Posting" button while it's waiting results in multiple postings - which seems to be happening to you a lot lately.

Good point well made Martin.....

Extra posts deleted....

[MattyB]

Without knowing more about the cell counts, capacities and number of packs you intend to charge it is very difficult to recommend a charger an power supply setup. Do you intend to parallel charge? What C rating do you wish to charge at? All important things we need to know.

Even so, nowadays I always recommend a setup that can handle at least 6S and provide a minimum of 300W, and ideally 500W - that give you the absolute to grow into larger models as and when you want to without further investment. A charger to do this can be sourced relatively affordable (look up the Turnigy Reaktors), though don’t get too hung up on having dual outputs as the need for those can be removed if you charge in parallel using a high power setup. Converted server PSUs can provide bulletproof high current delivery for ~£40 and an evening’s soldering work.

[Brian Cooper]

I hate to be the purveyor of gloom and doom but from observations done over a few years by myself and others at various different clubs, it seems that the quickest way to kill a Lipo battery is to put it into storage.

Many folk have discovered (to their cost) that after putting their Lipos into "hibernation" for a while, the things don't fully wake up again -- and it makes no difference how much you paid for the battery when new.

If you want to keep them alive, charge them up 100% and keep them charged.

B.C.

[Brian Spearing]

Thank you, good advice, I will replace the connectors, I also prefer not to have to tighten screws before every single flight, even then, there's nothing to say they won't work loose in flight.

I’m probably missing something here, but what are the screws?

[Tony Kenny]

Posted by Brian Spearing on 28/12/2017 08:01:21:

Thank you, good advice, I will replace the connectors, I also prefer not to have to tighten screws before every single flight, even then, there's nothing to say they won't work loose in flight.

I’m probably missing something here, but what are the screws?

aha! That's me being a prize numtpy and replying on the wrong thread!

[Tony Kenny]

Posted by Brian Cooper on 28/12/2017 07:44:19:

I hate to be the purveyor of gloom and doom but from observations done over a few years by myself and others at various different clubs, it seems that the quickest way to kill a Lipo battery is to put it into storage.

Many folk have discovered (to their cost) that after putting their Lipos into "hibernation" for a while, the things don't fully wake up again -- and it makes no difference how much you paid for the battery when new.

If you want to keep them alive, charge them up 100% and keep them charged.

B.C.

Hi Brian, Thank you for the input. I might get a charger that logs data to the PC, label them all and keep half at storage and half at full charge and see how they perform. Not sure how much flying I'll get this year as I'm starting a master's degree in addition to running a business, so might have plenty of opportunity for long gaps between usage.

[MattyB]

Posted by Brian Cooper on 28/12/2017 07:44:19:

I hate to be the purveyor of gloom and doom but from observations done over a few years by myself and others at various different clubs, it seems that the quickest way to kill a Lipo battery is to put it into storage.

Many folk have discovered (to their cost) that after putting their Lipos into "hibernation" for a while, the things don't fully wake up again -- and it makes no difference how much you paid for the battery when new.

If you want to keep them alive, charge them up 100% and keep them charged.

This is completely contrary to the research done by the battery manufacturers who are spending billions at present improving the power packs for electric cars and home storage solutions. I assume you ran a fully controlled test where all other variables (charge and discharge rates, storage temperatures and voltages, number of cycles etc) were kept the same so that only the storage regimens were different? If not your observations are meaningless, sorry.

For example Dendrite growth reduces capacity and current delivery, has been well researched and is known to occur at an increased rate when cells are held at elevated SOC (state of charge). Nissan know this to their cost, so I am not sure why you believe storage at elevated SOC is not damaging to lithium cells.

[Gordon Tarling]

There's a very good reason that the battery manufacturers send their goods out in a reduced charge state. I don't think any battery manufacturer has ever sent batteries out with a full charge. Storing batteries in a cool place at the correct storage voltage is the best way to ensure a long life.

[Brian Cooper]

Matty, 

My observations are not meaningless. No, they are not controlled tests in laboratory conditions but REAL observations collected over a number of years in REAL, everyday conditions. In other words, in the REAL world.  It seems that once a Lipo has been charged to 100% from new, they don't like going back to storage mode afterwards.

The results may well be different to what the battery manufacturers are recommending but I can only go on personal experience.

But hey, it's a free country and people are at liberty to keep their Lipos however they choose.

Happy New Year.

B.C. 

Edited By Brian Cooper on 28/12/2017 12:43:38

[Chris Channon]

100% agree Brian, storage after a bit of use seems to decrease battery capacity.
Regards Chris C

[MattyB]

Posted by Brian Cooper on 28/12/2017 12:33:42:

Matty,

My observations are not meaningless. No, they are not controlled tests in laboratory conditions but REAL observations collected over a number of years in REAL, everyday conditions. In other words, in the REAL world. It seems that once a Lipo has been charged to 100% from new, they don't like going back to storage mode afterwards.

The results may well be different to what the battery manufacturers are recommending but I can only go on personal experience.

But hey, it's a free country and people are at liberty to keep their Lipos however they choose.

I eagerly await your citation of sources that back up these views...

My observations over ~10 years of Lipo use are exactly opposite to yours. All of my powertrains are low stress (I normally tune them to a max discharge rate of 20C and don’t have any EDFs; the only exception is my EFXtra which pulls about 27C at full throttle from memory), and all my packs are stored at 3.8-3.9V/cell. All charging is at a max of 2C (normally in parallel), all charge/discharge cycles are logged and I also check internal resistance periodically. Beyond the normal (very slow) degradation of capacity associated with lipos going through hundreds of cycles I have seen zero packs that have exhibited the characteristics you state. Many of my packs have done 500 cycles plus, with a couple approaching 800.

The only exceptions were a couple of HK lipos that arrived DOA, and the very first 3 3S 2200s I ever had which (you guessed it) were charged to full after every use before I knew better. The result? One just about made it to 100 cycles, the others died after 60-70. Luckily a fairly cheap lesson in battery care, and one that has saved me huge amounts given I’ve since moved up to large 6S packs.

Edited By MattyB on 28/12/2017 15:01:45