I was wondering what is the going recommendation for a battery charger and power supply for Lifep04 batteries. Any thoughts are welcome. USSNH
I highly recommend the I-Charger. It does all battery types, has built-in balance plugs and several other nice features like measuring battery internal resistance. At $80 it's an investment, but it will cover all of your charging needs.
RCENGER, Thanks for the info Tugboat, This is what I found, http://www.progressiverc.com/chargers/battery-chargers http://epbuddy.com/index.php?main_page=index&cPath=17_1&zenid=h1h22659ofhk4l806ggjdjvbm3 http://www.hobbyking.com/hobbyking/store/__216__408__Battery_Chargers_Acc_-Battery_Chargers.html
I'd recommend something with an AC input, personally I find having to lug around a DC power supply to run my chargers off of a hassle. It also depends on how you have your batteries setup for charging. I charge the Bismarck's battereries as 4 cell packs just like they are used in the boat, some people charge each cell individually. I only need one charger to charge both 4 cell packs in an evening, if I charged each cell individually I'd need to buy more chargers or I'd need to spend a lot more time monitoring the charger so I could swap cells and less time working on the boat or hanging out with the crew. (I've done both methods and I personally think my current setup is a lot easier and makes evenings less hectic/more enjoyable.)
For a simple yet effective charging, quite a few of us are using single cell chargers for overnight and lunchtime charging. www.batteryspace.com/Smart-Charger-...AC-CE.aspx These are automatic types that only requiring plugging into the cell and plugging into a wall outlet. We buy two, one for each cell of a 6.4v battery. They do not have a display, nor require setting up. Just plug and charge. An added benefit to single cell charging is that both cells will charge to the same voltage and stay in balance when conencted in series. There is no requirement for cell balancers or battery management systems. There is also LiFE chargers for 6.4v, 12.8v, and higher voltages located at: www.batteryspace.com/smartchargersf...packs.aspx If electing to charge two or more cells in series, I highly suggest using a balancer to keep the voltage across each cell in step with the other cells in the battery pack. Balancing will prevent one cell's voltage from running lower than the other cell and any damage that could result from drawing the voltage too low. Although I have not researched a balancer for other LiFE cells such as the Headway cylindrical cell, there are a very nice per cell balancer available that would let a person charge multi-cel 20ah and 40ah and larger prismatic (plastic case) batteries with a single charger. www.batteryspace.com/Smart-LED-Bala...rrent.aspx www.batteryspace.com/Smart-LED-Bala...for-L.aspx
I use the Hyperion 720 and individual chargers. I initially used 2 cells at a time and didnt make packs as they had to be seperated in the boat. I tried charging it with the Hyperion and with a balancing board and while it may be knitpicking.. one of the cells would never charge to full and during balancing it would discharge the cell with the higher charge until they were both equal.. and not at full charge. Its an even bigger problem with 4 cells. How much impact would that have on a battle? I dont know for sure but in the end when charging with 2 or 4 cells and the first cell hit 3.65v and the least charged cell was at 3.3v and it would balance by dragging all the cells down to 3.3V.. I didnt like it. So I bought 4 individual chargers which would have been cheaper than the Hyperion charger (I do use it for other things now) and the process is the same as Snipehunter describes.. I plug in 4 cells before dinner, and swap in the second set before I go to bed. So, yes I am sure the next argument is do you really need to keep the cells at 3.65v.. I dont know as I dont have a Battery management system and I dont want to find out where the cells reach 'empty' in a battle. I did a rough calculation on how much current the ship uses so I know roughly how long I can run pumps and drive around at full stream before I get in the danger zone. However as I DO run dual Titan 12T pumps (successfully I might add), I want every tiny tiny bit of voltage I can get out of those batteries so that I dont damage and dont run out of current on the water. So to me it makes a difference.. how valid.. I dont know. It seems either method works right but at least with the indivual chargers.. I know that all cells will be at 3.6v before I put them in the boat. Redundancy was another reason I got the individual chargers.. If my Hyperion failed on the weekend.. then I was DONE for the weekend .. AND I had to shell out another 130 bucks when I got home. The individual chargers were 26 bucks each and if one went bad.. well the cost to replace it was cheap AND its affordable to keep a spare. So now I have both types of chargers and a padded case to carry them in so I dont worry as much about the hyperion breaking as I used to. And YES A/C is KING! J
My icharger works great. The only time the fan has kicked on to cool it down is when I was charging in direct sunlight on a hot day. I just converted a 500w computer power supply for my power source. Easy day. There are youtube videos.
I do have two chargers, my second charger being a Orbit Pocketlader which is very good charger and very reliable. I have never had a charger fail, so if I pack the second one, it's only so I can charge my transmitter and ship at the same time. No need for overnight charging. I didn't charge my LiFe cells in my cruiser for the first two days of my last battle. At the end of day two I threw it on the charger and 30 minutes later they were full and ready to go - I had only used 50% of the charge in 8 sorties. The discharge curve on the LiFe batteries is so flat I never noticed any difference in performance.
It is interesting to see the different approaches to charging and why you took that approach. 1. I would be interested to know what make and model charger and what your average charge times are. 2. Do you charge individual cells or as a pack? 3. Do you charge multi cells or packs in parallel? 4. Have you ever had a charger fail on you? If so which one? Cheers! USSNH
1. Make and model is listed in my previous post. The links will take a person directly to the web page with the single cell chargers. 2. I charge individual cells versus a pack namely to ensure the cells are balanced before putting them back into the ship. IMO it does away with needing balance bars and/or a battery management system and the costs/complexity associated with them. 3. Nope. Sure don't. Don't have any packs or cells in parallel. No reason to with the high amp hours cells have. 4. Nope. Not a single charger has failed. Those single cell chargers are robust and well built in a strong plastic case.
Good question. I can only estimate since the single cell chargers do not have a timer (or even a display for that matter, heh). Also, I tend to plug in the batteries in the evening and forget about them until the morning. If we do the math though we find that to charge a discharged 20ah cell with a 6 amp charger, it would take at the most around 3 hours. In actual use, the time is less because we rarely discharge a battery fully. The 20ah prismatic LiFE cells seem to be some of the most popular cells in our ships. At 1.65 pounds each, a two cell series pack gives 20ah @ 6.4v and only weighs 3.3 pounds. That is enough amp hours to satisfy even the most power hungry ship on the water for a two sortie battle. At that light weight, they will fit into most ships. Most captains will have four cells built into two battery packs, one for the morning battle and one for the afternoon battle (if doing fast gun). With two battery packs that will power a ship all day, some captains will not charge while at the pond. Instead, they charge in the evening after the battling is done. I rarely take the chargers to the pond and leave them in the hotel room instead. After unloading the ship into the hotel, I plug in the first set before heading out for dinner. After dinner, the first set is usually done charging and I put the second set on to charge for the rest of the night. A couple of Florida guys like to keep the same battery in the ship all day and simply top them off over the 1.5 to 2 hr lunch break. They haven't run out of power yet during the afternoon battle. Hope this was good info for you.
1. For the Bismarck (4s LiFePO4 @ 20A/hr) I use this charger (http://www.batteryspace.com/Smart-C...se-CE.aspx), charge time is less than an hour. (But the bismarck carries far more power than it ever uses so you'd expect shorter charge times.) For my VDT (3 x 7.2 V NiMh @ 10A/hr in parallel) I use this charger and two older DC only input chargers like it. (http://www.electrifly.com/chargers/gpmm3155.html) Charge time there is generally around an hour, which is why I have three chargers vs only needing one fro the Bismarck. 2. I charge as packs. All 4 LiFePO4 go on the charger at the same time (they have balanceing bars installed which makes it dirt simple http://www.batteryspace.com/Smart-L...rrent.aspx). Each 7.2V NiMh pack gets charged on its own but even that is a pack itself. 3. No and charging in parallel is probably a bad idea if the cells/packs arent all identical (which they arent) and have identical amounts of charge remaining (which they wont). You can charge in series obvisouly but you get back to the balanceing issue. (Then again I used to charge my gel cells in series without issue.) 4. I've had a charger break, but I think that was because it was dropped or otherwise physically damaged. Something inside it started to rattle around and it stopped working. I don't remember exactly what type of charger it was, something for NiMh packs.
I have a Duratrax Onyx 235 AC/DC Advanced Charger w/Balancing LC . Will not charge the 4s LiPo will charge the 3s LiPo though.
