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#1
17-01-2008
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WHAT CHARGER FOR LiPO?????????
So what charger are people using to charge there LiPO cells and what advantages and disadvantages are there using the chargers??? Also would like to know more about balancing of the cell's
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#3
17-01-2008
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We have been looking at Lipo, seem to be lots of chargers on the market, the flyers have been into them for a while, less weight in your heli etc.... but the Bantam BC6 looks interesting, I am thinking the price may come down as these things become more common. Try a google for Lipo charger.
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#4
17-01-2008
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I use an cheapo Ansmann thingy that cost £45 - it doesn't even have a discharge function (bizarrely the one that costs £35 does but doesn't do lipo) but its been reliable so far and it'll charge all my stuff. Max output is only 5A though. My lipo's are both Trakpower gold bricks (as reviewed on oople) and I use a Trakpower balancer - no problems so far.
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#5
17-01-2008
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Orion avionics .. Hyperion Eos 5 .. Swallow Advanced Charger. All have similar form and specs .(lipo cc/cv up to 5A) . which leads me to believe that they MAY be from the same factory?
Robitronics overloader <- similar to SJ Supernova Competition charger. This is the one I’m currently using. A one-size-fits-all charger. Got it at a price that was too good to resist. It is my main charger for lipo & nimh now. Other lipo capable chargersin the market – checkpoint 1030, lrp pulsar 3, duratrax ICE, Orion Advantage carbon edition.
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#7
18-01-2008
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So how is everyone looking after there LiPO's, do you repeak them after every race (if you use only 1 pack)or do you discharge them then recharge (if you have more then 1 pack) How about balancing when do you do this ? What Amps do you charge at or is this dependent on the spec of the cells ? Sorry for all the questions
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#8
18-01-2008
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There is a range of lipo chargers from FMA Cellpro that are absolutely brilliant (http://www.aurorra.com/shop/product....cat=258&page=1). From all the research I have done it's the best possible lipo specific charger due the algorithms they use. Lipo batteries should be charged at or below 1C (that is if you have a 3000mah pack = 3amps or a 5000mah pack = 5amps). The charger will look at the number of cells and ramp up the charge current according to cell feedback, then as soon as the cell get's close to 4.2v it will slow the charge rate down automatically so that the cell never reaches to more than 4.2v.
Lipo specific chargers automatically balance all the cells in the pack through balance taps. It monitors and charges each cell in the pack individually. Lipo packs are made up of 3.7v cells in series (and sometimes packs of series are paralleled together to increase capacity) so it is very important to charge all cells in the packs individually because if a cell is over charged it could become a fire hazard. Lipo packs do not heat up, they stay cool as does the chargers so there are no need for fans etc. Currently there are no international lipo balance tap standard so you need to make sure your batteries come with the right balance taps to fit your charger or you will need a converter lead. The great thing with lipo's are that they can be recharged and recharged and recharged in the same day so what I do is swap packs and top up after every race. So every packs races every second race. But by no means do you need to, you could do several races and then do a big charge or just use one pack and charge after every race. My big 5500mah saddle pack charges from empty to full (at a maximum of 4amp charge rate) in about 35-40mins.
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#10
18-01-2008
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Sorry, have to add. In some circumstances it is possible for the lipo pack to warm up (just a little usually). This happens in cases where the current draw from the lipo pack is very high, near the pack's maximum power delivery limits.
Lipo batteries have a direct relationship between capacity and power delivery so you packs come with a stated C number on it for example 15C continuous\20C burst. That means that a 5000mah pack x 15C = 75amps power delivery continuous. If your motor and ESC draw more than that for prolonged periods (for example with high gearing or drive train issues) the pack can become warm. In such cases it is advisable to let the pack cool to room temperature before charging. In extreme cases the pack might bloat up and in such cases it is advisable to dispose of the pack. (I have seen some people still charge and use bloated packs I would definitely NOT recommend doing it!) So the idea is get lipo packs with the highest C rating possible and don't think you are going to be saving weight by buying the smallest capacity lipo that will get you through a 5min race as it will very likely be under powered and not last long. Lipo packs can actually be charged at higher rates but it yields no increase in performance and significantly reduces the life of the pack.
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#12
18-01-2008
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Quote:
2) I charge between heats and use 1 pack (have done since Feb07) 3) Charge rate = 1C no more. On the Trakpower 4900 this means that I charge at 4.9amps 4) I've not had the pack go out of balance yet, but I use the Trakpower balancer which lets you charge through it. 5) As for a charger, I used an el cheapo £16 charger that did lipo only before I got a Checkpoint 1030. Both of them work without any problems.
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