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Please can I get some advice on LiPo batteries. I intend to buy a 3300-5000mAh battery to run an offshore power boat model. I will be taking the battery with me to Hungary to use on my local river which I have found is ok as hand luggage properly protected from short circuit. My problem is that at present, I only go there three time a year so the battery would remain unused for 4 months at a time. If I leave the battery with a safety charge, will it last for four months unused or will it fall below the critical voltage. If it is felt that it will not hold the charge, I will have to carry it with me forward and back. Thanks.😊
I use lipo batteries in my transmitter and last year I had to take time away from the hobby because of my health.
When I checked my transmitter the battery was still showing 10v on a 11.1v lipo this is a full year after last charge so you should be fine for 4 months as long as it's charged before it's left in storage.
Former tug nut now switched to sail because of health
I have found a similar situation with li po batteries. After standing for some time when I have connected them to the charger there are not as depleted as I thought.
I had an interesting find last year when I was in a second hand shop in North Wales. There was a large metal ammunition box that appeared to be of WW2" vintage and they only wanted a tenner so I bought it.
I keep my li po's in it with the higher capacity ones also in the box but in the fire resistant bag. The box of course has a lid that securely closes with two catches.
Not sure it's a good idea to leave your lipos for that length of time with a full charge, I personally, put my lipo batteries into "storage" mode otherwise you may find they expand if left fully charged for long periods. I may stand corrected. X mod rifle range warden, I to use old .762 ammo boxes to store my lipos👍
There is no dark side of the moon really Matter of fact......it's all dark.
Hi all, Lithium-Ion and Li-Po batteries do not take kindly to being stored long term fully charged. When they are new they will do it but after 2 to 3 years of intermittant use, can start to swell a bit and that is where the dangers start. When you give these cells the final run of the season and they show a charge in the the 3.3 to 3.5 (or so) volts per cell then they can be stored relatively safely. (This is called a holding or factory charge) Re start them with a balanced charge before you next use them. Do not constantly fast charge them as thi could induce swelling of the pack earlier.
The old Ammo box is a good idea, any strong metal box will do but store them where it does not get very hot or very cold and ideally not in the house.
Lipo cells are accepted as hand luggage by most airlines and a holding charge is recommended when flying, so remember to take a small 12v DC balance charger or 'Intelligent' charger with you to other countries, you will always be sure of a power supply, like a car battery even where the mains voltage is different.
Small black plug-in cell monitors are readily available from places like Component shop and are a good guide to cell condition. One is these is quite essential as we use these cells more and more.
Good morning all, Many thanks Ron for your information. Can I ask:- say you only using your batteries every four weeks or so, should we leave them with full charge or should we reduce voltage to holding charge for that four weeks?. I understand this could be a "how long is a piece of string" question. Norman.
There is no dark side of the moon really Matter of fact......it's all dark.
My charger has a storage setting which i always use after a sail as insisted by our local battery supplier guru. No problems at all with durability, full charging or high amp useage. Wrap 2 elastic bands around your stored lipos so you immediately know its status. The first elastic band is put on to a used battery immediately upon removal from model. Works for me now i am nearing 70 and my brain function 'aint what it used to be'
I have now left the batteries at a storage charge of 3.85 volts per cell. I will let you know where they stand when I return in August. The ammo boxes are a great idea. I bought two from ebay at £12 each. They are of super quality. I have transported one with the boat to my boating river in Hungary. The other is here. Thank for all the advice. It made things a lot easier than they could have been during my first uses of LiPo batteries. They are much easier to use now that I have some experience.😊
Thanks Doug. I checked the percentage fill when I received them. They were 31% at 3.67 volts per cell. I am now at home so I cannot check them again until August.😱
Evenin' Peter, hope you noted the % capacity before you left, be good to compare with the value in August. One more tip; store batteries cool. It slows down the internal chemistry which reduces the capacity. See attached tips from the fly-boys😉 Oh! And welcome home, cheers Doug 😎
Attached Files - Click To View Large
Young at heart - slightly older in other places 😉 Cheers Doug
Hello all. I have now returned to Hungary after 4 months. I left the batteries at a storage charge of 3.85v per cell. The reading now on both batteries is 3.85v on 3 cells and 3.86v on one. Strangely both batteries are exactly the same. Conclusion is that relatively new batteries hold their charge very well even if not used for months. I will keep checking them every visit. Unfortunately these batteries might not be used for a couple of years as I found that 2 4s 4500mAH units (using only one at a time with the other supplying balance in the water) were a bit too heavy for the boat and made it low in the water at the stern. I have replaced them with much smaller and lighter 1800mAH LiPo`s. We will see how long they last under load.🤓😉
Hi Pete, Do you have a Battery Capacity Checker? Like in the pics? Open circuit voltage is NOT a reliable indication of the battery's charge state😲 As you can see in the pics my two bats, 1 LiPo one NiMh, both show voltages above the nominal value. But the capacity / charge state less than half!! Be warned! Believe I did suggest to you to note the capacities before you left Hungary last time. Whatever - Have Fun😉 Cheers, Doug
Attached Files - Click To View Large
Young at heart - slightly older in other places 😉 Cheers Doug
I don't intend using Lipos when I get back to actually boating and flying as I feel they are too much bother. Lion orABC or similar for me I think.I'll have to think more on it. I have Nimhs and A FEW Nicads .The Nimhs I know for certain are 13 yrs old at least and are showing 11.2v at 82% charge despite not being charged for 4 yrs. The Nicads 9.4v and 42% charge. Not as good; as we might expect but the others really surprised me when I metered them out.8 yrs lying in a blokes planes,boats and boxes and I got them 5 yrs ago.I charged them all and they've not been charged since.We'll have to see what happens under load etc. They might not last 5mins.🤔 John O/T👍 I know some of you won't believe me so tuff. J😎
I'm not tooo surprised at your NiMh results. But I also think that you are correct that they won't last the proverbial 5 minutes on load. I had a similar experience last year when I retired and took stock of everything lying around in boxes and shelves in the so called workshop😲 Some also measured above the 'dead' voltage but collapsed within seconds of applying a load; a 540 motor running offload. They were consigned to the Great Recycling Centre in the sky 🤔 The NiCads had preceded them by a decade or so! Since then I've restocked with LiPos where I have brushless and LiPo safe ESCs and NiMh for the 'brushed ships with older pre Lixx EScs. For heavier jobs like Graf Spee (3 x 600), HMS Belfast (4! x 385), U25 (2 x 385) I've restocked with 6V 4Ah SLAs. Have started compiling an XL spreadsheet to keep track of them; when last used / charged etc.
Oooops! Just discovered that Grauer Burgunder is an excellent cleaner for my inductive mouse pad 😲 Prost allseits! Doug 😎
Young at heart - slightly older in other places 😉 Cheers Doug
Which reminds me, Doug. Any sightings of what to me is the finest wine I ever drank (excepting Chateau d'Ychem..... Erben Merlot Spatbergunder. I bought it for a laughably low price in a little general stores in Sauerlach, a kind of quadrant of shops with a bit of parking available. I have found mention of it on the 'net, but not a supplier. So, if you do happen to see a bottle, would you get me at least three and I'll pay you immediately for the wine and the postage!
Hi Martin, Yeah, you mentioned this about a year ago but as yet I haven't seen any of their wines. I don't get quite as far south for shopping as Sauerlach. The furthest I go south is the relatively new conglomerate of mega stores just outside Unterhaching. Then usually just for the garden centre and electronics store. But I have noticed that there is an 'Up Market' supermarket there. I'll keep me eyes peeled for you. Can you give me a net link for Erben? On reflection I think that one of the finest wines I have ever drunk was the Chablis at dinner in Cherbourg while visiting the CMN shipyard there. Superb fish as well 😋 A good Muscadet comes a close second though😋😋 Prost, Doug 😎
Young at heart - slightly older in other places 😉 Cheers Doug
Thanks John I hope Martin picks up on this. The Spätburgunders are something for him not me! They are 'Lieblich' wines, too sweet for me, cos the grapes are picked as late (spät) as possible and have a higher sugar content. Not all of which is converted to alcohol. BTW: i tried a few links with the result 'Not available at the moment'. Guess the spät crop is a bit limited🤔 Cheers (!) Doug 😎
Young at heart - slightly older in other places 😉 Cheers Doug
That's the one! Even recognise the writing. Very Germanic. I can only find it on a Polish site, so it figures I should go to one of the several Polish shops in out local town (Wisbech) which is very much Eastern Europe in Fenland these days. Many thanks. Let's hope I can get some. It seems mad that I paid 3-50DM for it in Sauerlach back then which was about £1-50, a derisory sum. Now it's about 7 quid if my Polish-Pound sums are right, but it's still well worth it. I hate dry wines, like most French. I see no point in paying through the nose for what I wouldn't even put on my chips! My favourite day to day wine is a Spatleser, although Chateau de Lardilay from Cadillac is rather nice. Sorry if the spellings are awry.
Hi Doug and all. Delay in answering your post as for some reason, my phone was useless on the internet. I did not see your post about checking the capacity percentage until I returned home, so that is why in April my checks were not complete. On my return to Hungary a couple of weeks ago, I checked the batteries and they were both at 3.85 volts per cell and at 51% capacity. When they were new, they were at 31% capacity. My new smaller batteries were also at 30% capacity and when I left on a storage charge, they are also at around 50%. The new, lighter 4S batteries are 1800mAh. On the first full charge they only gave me 89% capacity. I used them both, unfortunately they lasted about 6 minutes each, and recharged. This time they charged to 99% and lasted 10 minutes. Hopefully they get a little better after a few uses. I am now back in England and when I left, all of the batteries were at around 3.86 volts per cell an 50% capacity. I will check again at Christmas but I will have to see if the Danube freezes to see if I can use the boats then or not.😉
Hi Pete, welcome er Home?😉 I'm not too surprised at your results with the new LiPos. That's exactly why it is recommended to put new LiPos through about min 6 max 10 charge / discharge cycles to 'condition' them, i.e. get 'em used to their working life😉
I'm not surprised at the short run times either. I seem to recall you have two hefty motors in your boat! Let's say (for simplicity) the motors draw 1.8A each. Therefore one motor would (theoretically!) run max 1 hour on a fully charged 1800mAh (1.8Ah) battery. Two such motors only half an hour etc etc. If (more realistically) they draw 10A together (probably more!) then they can theoretically run at that current for 0.18h or 10.8 minutes on a fully charged battery. QED. Theoretically cos you don't want to empty the battery and run it into 'Deep Discharge', i.e. less than MINIMUM 2.7V per cell. They don't like that and get stroppy; don't charge properly or worse 😲 You get the drift! 😉
If there's a danger of the river freezing over - you've got 4 months to build an Ice Breaker😁😁So get cracking😉 Cheers, Doug 😎
Young at heart - slightly older in other places 😉 Cheers Doug
5th Apr 2018 22:20
