LiPo Charger (6S Turnigy $33 7-Amp) info for noobs

spinningmagnets

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WARNING: The default "LiPo" charge setting on this charger will end with 4.2V per cell (25.2V for a 6S pack). The "LiIo" setting will end with 4.1V per cell (24.6V for a 6S pack). LiIo is short for Lithium-Ion

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=11341

T7A80W.jpg


Edit: read this LiPo break-in thread for new batteries before you charge or discharge any NEW LiPo battery (reading is free, and it couldn't hurt, right?). Your LiPo will have more capacity and will live longer if they are "broken in" properly. Several shallow and light charge-discharge cycles before attempting full power and longest range. For a 5Ah brick, I am charging at 2A until broken in. (slightly less than 1/2-C)
http://endless-sphere.com/forums/viewtopic.php?f=14&t=22949&start=0


I am a LiPo newbie, so take everything I post here with caution. I will edit-in corrections and good suggestions in the near future, as soon as they are sent to me. After the first day of use I have found changes I wished I'd made (listed below) and parts where I wish I'd payed a few dollars more for a better/bigger component. This is intended to show an affordable beginners system that has the bare minimum of the important features, while avoiding you paying for extra features that you may never use.

All the charger options below will only charge 6S or below (3.7V-22.2V), and they DO have cell-balancing, and auto-shut-off when finished. They will only charge one pack at a time, so if your research suggests that you will likely want to charge several packs at the same time, or may upgrade to 8S/10S/12S. you should investigate other upgradable charging-system options.

I have read about others bulk-charging two or more packs at the same time using Y-connector-cables. I have no experience with this, and if you do that, you should occasionally balance-charge each pack individually (once a month?). The balancing feature can only be used on one pack at a a time.

Here is Ypedal's excellent "multi-pack" charging thread. Much useful info, even if only charging one pack:
http://endless-sphere.com/forums/viewtopic.php?f=14&t=23551&start=0

This is the first charger for LiPo batteries that I have ever used. I do not mean to imply that I think it is the best choice for someone, or even a good choice for anyone. The posted specs suggest that it may be a good value of features for the modest price, and is perhaps one step up from the most basic Lithium-Polymer (LiPo) 6S-chargers. “6S” refers to Six 3.7V cells connected in Series for a pack voltage of 22.2V.

This unit is rated as a low-speed 7-amp max charger providing a modest 80-Watts, so it will not charge a LiPo pack as fast as they are possible to charge. It has an individual cell balancing-during-charge option that is an important feature. I found that the cooling fan is very quiet during charging.

When it senses that the pack is fully charged, it automatically shuts off the charging cycle, which is a VITAL feature for LiPo battery packs. It also displays the amount of time taken to complete the charge, which will be very useful information, as you will see. Once you know how how much time a normal re-charge takes, you can add an inexpensive power-timer to cut power to the charger as an extra layer of safety.

This is because if a charger malfunctions and continues charging after a pack is full, the pack may catch on fire. LiPo fires have happened most often to ill-informed owners who left the pack charging too long using only a very cheap and 'dumb' 24V lead-acid battery charger. A 'smart' charger will sense the State-Of-Charge (SOC) and will stop at the proper voltage.

This charger is also capable of charging Sealed-Lead-Acid (SLA) up to 20V, and also Nickel-Metal-Hydride (NiMH), and Nickel-Cadmium (NiCD) battery packs up to 15S.

It also has a cycling feature that allows it to drain and then charge a pack, in order to help evaluate a battery of unknown capability. Also, the cycling feature can be used to "break in" a new LiPo pack with several low-amp shallow cycles. This removes a chemical inhibitor that helps the packs shelf-life, but hurts capacity if cycled heavily when new.
 
The “power in” and “power out” leads that this charger comes with are terminated with alligator clips, and I recommend that you cut these off, and properly solder on any one if the several appropriate styles of connectors, then properly insulate the new joint.

Here is a pic of my DIY soldering station. A small-tipped soldering iron is useful for working on tiny components that are spaced closely together. But for this work, I recommend a 100W (or higher) soldering iron with a fat tip. A thin tip will cool off too fast when touching larger subjects. I found this 100W soldering iron for less than $20 at a local hobby & crafts store in the stained-glass building section. I built this station from scrap-wood and a wire coat-hangar in order to meet my personal preferences.
View attachment SolderStation.JPG

Once you have decided which connectors you like, determine how much wire insulation must be removed from each wire tip to get full penetration into the connector, so you will have a very solid bond. Then, it is useful for the bare wire tips to be “tinned”, which is to apply some solder to them before inserting them into the connector. Once the wire tip has been stripped and tinned, slide over a suitable length of “Heat-Shrink” insulation (HS), and you are ready to solder the wire to the connector.
View attachment 1
 
This charger accepts a range of input voltages from 10V to 18V of DC power only. You can charge your pack from 120VAC house-current by adding a power-supply. The one shown is very similar to a laptop computer battery charger. Some laptop chargers provide more than 18V, so exercise caution. The unit pictured provides 15V at a max 5-Amps, and even adjusting the charge down to a modest 2-Amps of current, the power supply got quite hot during charging, and I do not expect it to last long.

I have recently read in the customer feedback section of the Hobby-King power-supply that I selected, that some customers were disappointed. I suspect these power-supplies are often used beyond their actual capabilities, and for this charger, I recommend sourcing a more robust power supply.

The 10V-18V input voltage range was determined by customer requests, because RC-model enthusiasts like having the option to charge their packs in the field from a 12V car system. If charging system bulk is not a concern, a very robust and affordable 12V “dumb” car-battery charger can be used. If you use a car-battery charger that is “smart”, it may cycle and vary the voltage and current, which will cause the LiPo charger to reset.

I purchased an inexpensive socket for a laptop battery charger from Radio Shack (since this is only a low-amp charger), and unscrewed the two pieces. (I cut off the alligator clips and left some wire on these clips for later use. I now wish that when I had cut the charger input leads, I would have left them as long as possible) Slide the socket shell onto the wires before soldering.

Separate a couple inches of the red/black wires, and strip the tips, then slide on a section of HS over the red wire. Open the CENTER post mounting hole with a small drill bit if it is not big enough, and/or thin the wire tip, until it can be inserted. Then bend the wire tip into a “J”, and tin the tip. Insert, crimp, and solder the RED (POSITIVE) tip to the CENTER post of the socket. I find it helps the start-up heat transfer if you first dab a tiny spot of solder onto the iron tip on the spot where the wire will touch it.
View attachment 7A_input1.JPG

Once soldered and then cooled, slip the HS section over the finished solder joint, and heat it until it shrinks enough. Repeat the previous steps to solder the BLACK (NEGATIVE) wire onto the OUTER SHELL mount.
View attachment 7A_input2.JPG


Another option for the input is a cars “cigarette lighter” accessory extension cable (as long as the wire gauge is thick enough). It is simply a long two-wire cable with a male plug on one end and a female on the other. Cut the extension cable in half, and with the male plug end properly attached onto the chargers input, It can be plugged in directly to a cars 12V (dumb) accessory socket, and the female socket with leads can then be attached to any other power supply output that you might get.
12-volt-extension-cord.jpg


Ebikes.ca uses 3-pin XLR connectors (a male-female set, of course) on their battery packs and chargers. The rubber fill inside the socket makes these more splash and weather-resistant.
Dmx3pin.jpg


Some builders like Anderson-Power-Poles (APP)
http://endless-sphere.com/forums/viewtopic.php?f=14&t=24666
powerpoles_45_xlrg.jpg


I have no experienced opinion to give, other than to say that it is VERY important to put the FEMALE socket on the BATTERY pack to reduce the probability of a short, from exposed male prongs touching something metal by accident (put the male plug on the charger output). LiPo packs are capable of unusually high and sudden amp discharges when shorted, and this can start a fire. Also, a short can immediately ruin your expensive pack in only a moment of distraction.

Also, it is VITAL that for any connectors used, they must be physically polarized in some way to prevent them from being accidentally plugged in backwards. Some chargers and controllers are diode-protected, but do not count on this to save your system from damage. APPs are symmetrical, so I would recommend to mount them in a "T" orientation. Either that, or the chargers APPs should be back-to back, and the batteries APPs should be face-to-face. Several builders have relied on the red/black color to protect them, and have plugged them in backwards (when red/black are oriented the same), when in dim light or when distracted.
 
The stock output cables use 4mm male bullets (sometimes called "banana" plugs), and it also came with a set of male/female yellow connectors that are XT60's (XT-style, 60A). In the pic I have cut off the output alligator clips and added male 45A Deans. Heres Hobby-Kings connectors section:
http://www.hobbyking.com/hobbyking/store/uh_listCategoriesAndProducts.asp?idCategory=121


On the power-output side, I have chosen 45A Deans “T-prong” connectors. My friction-drive should draw around 40A peak during acceleration, and around 10A continuous during cruise.
View attachment Deans45A_12AWG.JPG

For this modest power level, a single 5-Ah pack with a 25C rate of discharge capability will be adequate to prevent voltage sag, which would cause the controllers Low-Voltage-Cutoff (LVC) to disconnect power. It would do this to prevent damage to your pack, as it would think that the low voltage reading meant that the pack is very low (rather than a temporary high-Amp demand sag).

For added range (or to prevent voltage sag in a high-Amp system), I have seen others add more packs in parallel. I have no experience doing this, so exercise caution, and do your homework before attempting that.

Using the same techniques from the previous soldering post above (stripping, tinning, HS), I connected the female Deans socket to the battery, and male Deans plugs to the charger and also the ESC. ONLY expose one battery cable tip at a time, and then COMPLETE that connection before exposing the other cable tip. A split second of the bare cable tips accidentally touching will be expensive and/or painful.

If you are buying LiPo packs from hobbyking.com, the popular 6S/5000mAh/25C packs use medium 12-AWG wire and 4mm bullet connectors (5000 mili-Amp-hours is the same as 5Ah).

If you get any 30C (or higher C-rate) packs, they use fat 8-AWG wire and 5.5mm bullet connectors. If you buy any 5800mAh pack size (or larger) it will also use the 8AWG and 5.5mm connectors regardless of C-rate.

I am listing this because it may affect the connectors you choose to use. Calculate your systems constant-draw amp-loads, and also the peak amp-loads (during hard acceleration from a stop, and also during a steep hill-climb). Use a wire gauge and connector size big enough, so that they will not get too hot.

View attachment 5.5mm_8AWG.JPG
 
View attachment 7A_LiPo_Charger.JPG

edit: my charging system died. I had cycled the LiPo brick a few times to break it in (shallow cycle, low 2A charge) and the power supply was getting very warm. When I adjusted the charger to charge up my battery using a higher 5A rate, something died halfway to the battery being charged. The PS was VERY hot (the black box in the foreground, thats labeled "AC adapter 15V"). After it cooled down, it still didn't work.

[two hours later] Back again: I hooked it up a 12V car charger, the Turnigy 7A LiPo charger is still working, the cheap power supply died when I tried to use it at its labeled rate of 5A. I will likely buy this $60 fan-cooled Meanwell, 23A (15V/350W)
http://epbuddy.com/index.php?main_page=product_info&cPath=5&products_id=28
or this $40 Hobby King 25A :
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9205

This is my first LiPo charging set-up. It ‘works’, but I recommend a more robust power-supply, and also to keep the input leads as long as possible when removing the stock alligator clips. Also, consider a more substantial type of connector type if your bike has a high-power system. I will be searching for an affordable but simple "dumb" 12V power supply providing a minimum of 15A/180W. I already have a power timer.

The chemistry of a LiPo battery has a high-amp/FAST-charge capability that is a desirable feature for many enthusiasts. So, consider if you would like that, and if your budget allows for a charging system with a higher-rate than 7-Amps.

Here is a simple $37 "6S/LiPo-only" smart-charger (from a supplier thats warehoused in the US) that requires no programming, and may prove to be less ‘fussy’ to use. Be aware it uses a very slow 1.5A charge-rate. This price includes an integrated 120VAC power supply, but cannot directly charge from a 12V car system.
http://www.batteryspace.com/smartcharger15afor222vli-ionpolymerrechargeablebatterypack.aspx

For $39 you can get the same model as the one featured in the pic above, but at the faster 10A charge rate. Be aware you must also use an even larger power supply (I recommend around 15A/120W or larger so this part will run reasonably cool at 10A).
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=11444

Heres the $80 version of the same model, and it can charge at a very fast 20A
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=11340

Here is a highly regarded $90 10A "iCharger", which is known to balance individual cells more precisely than the more affordable chargers.
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=6792

Ohio distributor of $99 10A iChargers, 6S, 3-chemistries, Model 106B+, $10 more than HK, but located in USA. Shipping may be cheaper.
http://epbuddy.com/index.php?main_page=product_info&cPath=1&products_id=1

Concerning power supplies, here is a $60 Meanwell that will charge at 23A (15V 350W), pricey, but well-regarded. Fan-cooled.
http://epbuddy.com/index.php?main_page=product_info&cPath=5&products_id=28
 
A 6S pack is made from six cells connected in series. Each cell is selected for that pack to have very similar characteristics. But due to minor manufacturing variations, one cell may charge slightly faster, or may not hold quite as much voltage as the other cells. For best pack life and performance, you should regularly "balance charge" the pack. (perhaps one out of ten charges?)

By connecting the multi-colored wire balance plug, a charger with the balancing capability will ensure that all the cells are topped off in a way so that they are all at the same voltage. If all the cells receive the same discharge loads and the same charging, over time the minor individual cell variations will become more prominent. The lowest cell will hit LVC before the others, and the charger will stop when the highest cell reaches the top before the others.

This chargers operations manual can be downloaded in PDF format for free from the "files" link on the original Hobby-King web-catalogue page link at the top of the first post. Just to help you get started, I will now present here a simple checklist to perform a balance charge of a 6S LiPo pack using this charger. Go to the PDF if you want any other details of the other optional functions and capabilities.

Standard charge menu: (to be added)
Balance charge menu (to be added)
 
I have just recieved my $40 25A Power-Supply, and will be testing it soon. It has a metal case and is fan-cooled.

http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=9205
A30.jpg


This $39 10A charger just arrived:
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=11444
T-200W-0.jpg


edit: I have used this set-up several times and I like it a lot. The power-supply can feed two of these chargers at one time, so for an additional $40, I can cut my occasional balance-charging time in half. (One PS, two chargers)

The Charger inputs are a one foot length of red/black wire, and alligator clips (which I cut off). The PS output can accept a bare wire in its shank-hole (with the plastic red/black nuts clamping down on it), or, the plastic nut is located around a round cylinder that will accept a 4mm male bullet. I may eventually solder a few inches of wire onto one of the two output pairs which I wil terminate with a polarised connector (XT60 probably), but for now I just slapped on two 4mm male bullets.

Since I was temporarily using bare bullets, I made the two leads different lengths so they wouldn't naturally touch

PSinput 001.JPG

Many are performing small modifications to Meanwell power supplies, and using them instead of a charger. Here are some threads about (since this is becoming popular once LiPo users gain experience). The listed thread has info on how to make a very cheap 18V-58V charger at 10A (5S up to 14S), and also a more expensive charging set-up for a max 84V (16S up to 20S when charging to a max 4.1V per cell)
How-To: Meanwell 63-84V CV/CC Charger
http://endless-sphere.com/forums/viewtopic.php?f=14&t=20118
 
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