toto Posted January 3 Share Posted January 3 I have a reasonable number of various size Lipo batteries that are currently in some state of charge and unlikely to be used any time soon. Mainly some 6s batteries ( from my Beaver which I am awaiting a horizontal stabilisor replacement ) and some 3s batteries. The only batteries that I will be using will be my 4s batteries for my Domino and a Tasman Bush Plane. I have never discharged a battery to a storage level before. Is there anything that I should be aware of in order to get this right. I obviously do hot want to destroy any of my batteries and want them stored safely until needed. Thanks Toto Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted January 3 Share Posted January 3 Just make sure that you choose "storage" and not "discharge" on your charger. 2 Quote Link to comment Share on other sites More sharing options...
MattyB Posted January 3 Share Posted January 3 (edited) Be aware that big packs will take a long time to discharge on most chargers, as they generally only have 20-50W max discharge power. That may not be a problem short term, but it does put more wear and tea on your charger, particularly the fan. For this reason you may want to consider putting together a discharging rig... ...or simply run down those packs to 3.8V/cell in the model with the fuselage model safely secured. Edited January 3 by MattyB Quote Link to comment Share on other sites More sharing options...
Shaun Walsh Posted January 3 Share Posted January 3 https://www.flyingtech.co.uk/accessories/isdt-fd-200-200w-smart-battery-discharger-2-8s-lipo Quote Link to comment Share on other sites More sharing options...
leccyflyer Posted January 3 Share Posted January 3 In the event that I feel it necessary to discharge a pack, it's always seemed to me that the easiest, quickest and safest way to do so is to use the model that it's used in, to run the pack down. It's important to check that the model is well restrained, to monitor the voltage under load and to ensure there is sufficient cooling available and I run the motor at something less than it's full throttle setting, until it's just below 3.6v/cell under load. That bounces back nicely to around 3.85v/cell. 3 Quote Link to comment Share on other sites More sharing options...
toto Posted February 13 Author Share Posted February 13 I updated a battery register that I created some time ago in order to take a view on where I was with regards to any batteries that may require discharging etc. Its not quite as bad as I thought it may be. there is maybe just over a dosen that are sitting there with a charge of about 85% or above. Many others are sitting at a more desirable charge pf between 30 and 45 %. Maybe not the mass exercise that I thought I might have on my hands. Just really the first step to at least being aware of where I am and trying to start coming up with a reasonable regime going forward. toto Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted February 13 Share Posted February 13 toto The important issue is how long the batteries have been sitting above say 50% charge. "Storage" means what it says both for safety (less energy in the battery) and getting the maximum life out of the cells. A charger will/should "balance" discharge so all cells are brought to the same "storage" voltage likely to within 0.01V. It is actually using a LiPo at a high discharge rate that shortens its life the most but dropping the cells to an accurate storage level, particularly if the "no use" period is unknown costs nothing but time but as stated a fully charged big capacity 6s may be best discharged first. . If the battery is at say 40% from use it will not take a charger long to bring all the cells to the storage level. I know if I have worked a battery hard my charger set on "storage" automatically brings the cells up to the storage voltage. 1 Quote Link to comment Share on other sites More sharing options...
toto Posted February 13 Author Share Posted February 13 Hi Simon, Some of these batteries .... particularly some 6s 4800Mah types previously used in my Beaver have been sitting since May2023 and probably have between 65% to 80% charge. I'm hoping the Beaver may be back in use again within the next few weeks. The same batteries are also fine for my Xfly Twin Otter which will also be available in the coming weeks. They MAY be able to be used but not guaranteed. .... what do you recommend in such a situation ? .... leave them as they are ........ bring down the charge " in model " ( tehthered ) with a Watt Meter connected in the circuit to allow the monitoring of displaced energy as it happens ..... or discharge via a charger / discharger ? It's not all. Y batteries that need this attention. My theory is to get any over energised batteries down to a level and then only charge batteries on a needs be basis. I had a bad habit of charging batteries on purchase regardless of the immediate use thinking that if they were significantly charged, then when I need them, they would only need a top up. I have since learned for the better. Toto Quote Link to comment Share on other sites More sharing options...
Simon Chaddock Posted February 14 Share Posted February 14 I would certainly set about reducing the charge to "storage". I fear if the inactive period with a high charge level has caused any reduction in capacity the damage is already done. However if you reduce them to a true storage any damage will stop. When you do want to use them at least all the cells will start from a known level so you will get a good idea from the charger how many mAh has been put it. "Storage" normally represents between 35% to 40% charge so you should see a full charge put in a good 60%. Much less than that and you have to recognise the flight duration could be compromised. In any case after such a long period of non use it would be wise to only gradually extend the flight times monitoring carefully the state of the cells after each flight. I hope this helps.. Quote Link to comment Share on other sites More sharing options...
toto Posted February 14 Author Share Posted February 14 Thank you Simon. I'll set about doing this and that will get my entire battery bank sitting at the same controlled level. It gives me a starting point from which to maintain my batteries to a reasonably safe degree. Cheers Toto Quote Link to comment Share on other sites More sharing options...
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