I'm ready to go lipo, but need advice

[mud2005]

Hi all, I hate to do this with all the lipo topics on this board, but I've been reading for hours and am getting confused.

I'm finally ready to get a lipo pack, but have no clue because I'm a lipo virgin.

I want a 48V 10AH lipo pack. choosing the cells is easy, but choosing a charger...

what is the best way to charge 4 6s packs? I have no problem spending some $$ on a good charger, but not sure if I should get one charger or one for each pack or what.

I see hyperion makes a 12s charger, would that be best to charge the pack as a whole? or would it be better to charge the 6s packs seperately each time (seems like a pain)

what other bits do I need???? I don't want to place an order to china, wait a month to get it and realize I forgot a crucial piece.

thanks for reading

edit: forgot to ask... why do y'all buy the DC chargers when they make AC/DC? seems like the AC/DC would be more conveinent

 

[liveforphysics]

A 48v pack would mean 13S with LiPo. Do you want 44.4v pack or 48v pack?

If you want to charge from AC to DC directly, use a meanwell.

When you build your pack, parallel the cells at the discharge leads and the balance taps. Now it doesn't matter if you've got 40x 6s packs or 2x 6s packs, you only need 1x 12s charger or a pair of 6s chargers to charge the pack.

I've not personally found a 12s charger that really floated my boat (my hyperion and mega-charger both suck and don't get used). The badass chargers seem to stop at 8S or 10S.
For your needs, I would go with a pair of the iCharger 208b(+) series. They will balance charge up to 8s each, and charge up to 20amps.

Then just run your combined balance tap and charge leads to some handing to plug-into point on your bike. Have a meanwell for each iCharger so everything is isolated. Then just plug-in, hit charge on each charger, and it will start charging your pack at 20amps, and leave it all balanced charged.
This would be the fancy pants way to make a setup that balance charges everytime.

The way I would do it if it were my own setup, is to just build the pack, leave the paralleled balance tap leads exposed, and charge it with a meanwell. Then check it every few charge cycles by plugging in a battery medic to the tap leads, and hit the balance button if something gets out of wack.

 

[mud2005]

A 48v pack would mean 13S with LiPo. Do you want 44.4v pack or 48v pack?

44.4V

thanks Luke, that sounds like a great solution for charging. couple questions, where to get a meanwell and which model? and what did you mean by this...

The way I would do it if it were my own setup, is to just build the pack, leave the paralleled balance tap leads exposed, and charge it with a meanwell. Then check it every few charge cycles by plugging in a battery medic to the tap leads, and hit the balance button if something gets out of wack.

could you elaborate? I don't quite get it. no charger just a power supply? or am I missing something

edit: looks like HK is out of the icharger 208b, looks like the 106b+ would do the job? and its cheaper

 

[mud2005]

ok, It's starting to make sense I think. I could use a meanwell power supply as a charger. it looks like the s-350-48 and adjust it to the correct voltage (4.1V/cell?) and when the amperage starts to drop the pack is done charging?

I need more info this, much reading to do, sleep now.

 

[dogman dan]

Hard to say if they will last, but I just recieved two Turnigy, accucel 150 chargers last night. They seem pretty ok, and charge at 7amps. Not too expensive and may be in stock. This page takes you to links where I ask a lot of dumb questions and smart folks answer.http://endless-sphere.com/forums/viewtopic.php?f=14&t=19956

12s is a nice convenient way to go lipo for a street legal-ish bike. It's just about halfway between 12s lifepo4 and 16s lifepo4 voltage. two pair of paralelled 5 ah lipo won't be hard to disconnect and reconnect, and two chargers can top it up fast. An Imax B6 AC could be carried around to charge out on the road, but slowly though. You could also just charge with a simple power supply out on the road too of course, especially if just charging for 15 min at a time while in a store or something.

You can run 15s through a 48v controller, but it's risky. I like to use 14s lipo for my 48v bikes. That is nearly identical to 48v ping voltage.

 

[mud2005]

ok, I'm going to try a meanwell s-350-48 for a charger. it looks like it doesn't need modding for a 44V pack.? also I'm going to try dogman's suggestion of using a kill-a-watt while charging to help check for errors.

now the battery medic. I'm wondering If I can use these while discharging as a cell level low voltage alarm. I'm imagining 4 of these mounted to the top of a battery box so I can visually check the voltage of each cell and hear an alarm if any cell drops below the cutoff.

hows that sound for a plan? can I use the medics in that way?

if so I'm ordering 4 6s packs, 4 medics, and a meanwell, and a kill-a-watt right away

 

[E-racer]

Im trying to build the same pack you are 12s2p im a lipo noob as well so watching this thread close. I don't think the cell medics have a lvc or hvc alarm. The cell monitors 8s do have programmable alarms and they log but dont balance. Im looking for the best way to charge my pack aswell. I really want a complete system in the bike I can just hook 120AC to and it takes care of itself.

I found this charger MEGA POWER INFINITY-930SR 12S http://cgi.ebay.com/ws/eBayISAPI.dl...f883108&itemid=280538874726&ff4=263602_304652 looks like it could be the ticket...

 

[mud2005]

I just ordered a meanwell... so it begins

 

[liveforphysics]

Im trying to build the same pack you are 12s2p im a lipo noob as well so watching this thread close. I don't think the cell medics have a lvc or hvc alarm. The cell monitors 8s do have programmable alarms and they log but dont balance. Im looking for the best way to charge my pack aswell. I really want a complete system in the bike I can just hook 120AC to and it takes care of itself.

I found this charger MEGA POWER INFINITY-930SR 12S http://cgi.ebay.com/ws/eBayISAPI.dl...f883108&itemid=280538874726&ff4=263602_304652 looks like it could be the ticket...

The mega-power charger line sucks. It's a clone of some german charger that sucked badly that I can't remember the name of.
The Hyperion chargers also suck IMO, but not nearly as bad as the mega-power. I used mine about 3 times before shelfing it indefinitely.

Chargery makes the iCharger line, which absolutely kicks ass.
FMA makes the cell pro 10, which is also a good charger.

 

[liveforphysics]

edit: looks like HK is out of the icharger 208b, looks like the 106b+ would do the job? and its cheaper

Yeah, you could get the 106, but the first 2 digits represent the charge current, so a 106 is only going to charge at 10amps max. The 20x series charges at 20amps, and the 30x series charges at 30amps (the chargery icharger 3010b is currently my favorite battery charger ever to grace planet earth for any price, but you don't need 30amp charging on just a 10ah pack).

So, if you don't mind waiting an hour to charge rather than a half-hour, the 106's would be fine. I personally like to be able to charge in well under an hour, but it's a personal preference thing.

 

[mud2005]

just ordered 5 cell-log 8m from progressiverc (one extra)

so..... how many battery medics will I need to balance the pack? do I just use one and switch it between the 4 packs or do I need four cause one takes too long? I have no idea how long it takes to balance a pack.

"they" should combine the medic and cell-log, would make a great product having an alarm feature and balancing all in one.

 

[liveforphysics]

Remember, you combine the balance taps...

This means, it doesn't matter if you have 400 packs, or 2 packs, you only need to handle 12s. This means just 2 cell logs and/or battery medics is all you would ever need.

When you parallel cells at the balance tap level, they become like 1 cell for all practical aspects.

 

[mud2005]

oops, I was thinking one cell log per pack I forgot about paralleled connectors

looks like I'm going to have a couple extra cell-logs

thanks for the heads up Luke

 

[mud2005]

ok, I'm thinking about this more and trying to wrap my head around some concepts.
hypothetical question: so if I have 2 6s packs wired in parallel and say the voltage on cell 4 is low because cell 4 is going bad, will cell 4 on the other pack also have low voltage even if it's not going bad? I mean will the cells auto balance themselves and always have the same voltage
the reason I ask is because I am wondering if there is any situation where not paralleling the balance leads and using one cell-log per 6s pack would make it easier to locate a bad cell? or balance the cells.
in other words, in a situation where a cell is going bad, if I'm using the cell-logs as an alarm for low voltage on a single cell and the leads are paralleled how will I know which of the paralleled cells is the problem?
maybe I should be asking if it's possible for 2 cells in parallel to go out of balance?

 

[MrKang]

oops, I was thinking one cell log per pack I forgot about paralleled connectors

looks like I'm going to have a couple extra cell-logs

thanks for the heads up Luke

When you have all the stuff and are ready to build be carefully with connecting the balance connectors.

First charge all packs individually with the icharger. Then when combining first connect the main leads and then the balance taps.

 

[mud2005]

I decided I'm going to try charging with a meanwell directly instead of going with the icharger. that's why I was asking previous questions about paralleling leads and whatnot ^ ^ ^ ^

edit: crap, my questions are now on the previous page so I'm going to repost them

ok, I'm thinking about this more and trying to wrap my head around some concepts.
hypothetical question: so if I have 2 6s packs wired in parallel and say the voltage on cell 4 is low because cell 4 is going bad, will cell 4 on the other pack also have low voltage even if it's not going bad? I mean will the cells auto balance themselves and always have the same voltage
the reason I ask is because I am wondering if there is any situation where not paralleling the balance leads and using one cell-log per 6s pack would make it easier to locate a bad cell? or balance the cells.
in other words, in a situation where a cell is going bad, if I'm using the cell-logs as an alarm for low voltage on a single cell and the leads are paralleled how will I know which of the paralleled cells is the problem?
maybe I should be asking if it's possible for 2 cells in parallel to go out of balance?

 

[MrKang]

But still buy a cheap 6S or 8S charger at Hobbyking. you have to make sure your packs are balanced while combining.
it's an essential thing to have when you use Lipo...

 

[mud2005]

But still buy a cheap 6S or 8S charger at Hobbyking. you have to make sure your packs are balanced while combining.
it's an essential thing to have when you use Lipo...

isn't that what the battery medic is for? I was planning on getting a couple battery medics to balance, is there another reason I may need a charger?

 

[Ykick]

But still buy a cheap 6S or 8S charger at Hobbyking. you have to make sure your packs are balanced while combining.
it's an essential thing to have when you use Lipo...

isn't that what the battery medic is for? I was planning on getting a couple battery medics to balance, is there another reason I may need a charger?

I don't think the battery medic will be able to correct large dfferences in balance. As I understand it's simply bleeding off higher voltage cells to lower voltage cells. What's to prevent your Meanwell from overcharging the higher voltage cells in the 1st place?

'recently blew-up an iCharger 106B+ (my fault) and thought maybe I'd get along without it - but no, I suffered withdrawl and ordered a replacement ($99 shipped) from epbuddy.com. Just too damn handy of an item to have around in this day and age of battery powered electronics.

While I rarely use it for my eBike packs anymore I've scavenged many a cellphone/laptop/tool battery cell(s) - assembled them into very useful battery packs for lighting and various home applications. Wouldn't have been possible without the RC charger at my disposal.

Maybe consider an RC charger tuition into battery school? I have never considered it a waste of money - quite the opposite!

 

[mud2005]

you guys are right, I'm going to buy an icharger when I order my batteries, sure couldn't hurt to have one around

 

[MitchJi]

Hi Mud,

If you don't want to blow the Meanwell you need to mod it (see this 37 page thread - its discussed in detail some pages in):
http://endless-sphere.com/forums/viewtopic.php?f=14&t=4125

The problem is:
http://endless-sphere.com/forums/viewtopic.php?f=14&t=4125&p=259132

...
The whole reason for this thread in the first place is that we found many really inexpensive supplies, that could be used as chargers, but they don't have the right sort of current limiting required. Many of these inexpensive supplies do have CC modes, but are used in applications such as audio amplifiers, where they might see high peak currents, but overall the average current stays under the power level the supply is rated for, so the current limit is set to 125-130% of the rated value. This is not good for our charger application, because the unit needs to supply the current continuously at its rated output, so the current limit needs to be set to 100%, not 130%. Several clever folks here figured out relatively simple hacks to these inexpensive Meanwell supplies, to "adjust" the current limit, but it turns out there are many different "flavors" of the PCB layouts for this design, so the hack for one, wouldn't be the same for another. Compounding this issue it was discovered there are several Meanwell models that don't have any sort of secondary current limiting at all. Instead they have what is called a "hiccup" mode on the front-end that cuts power for an overload condition, and then after some period of recovery, restores power. This makes these type of supplies not "hackable".

...

Or use this board by Richard:
http://endless-sphere.com/forums/viewtopic.php?f=31&t=21768

This attaches to most Meanwell and Meanwell clone power supplies to give an adjustable current limit. This prevents overloading the supply at elevated voltages and prevents 'hiccup' mode limiting from kicking in.

Gary has some parts that will make combining the packs easy here:
http://www.tppacks.com/products.asp?cat=26

6-Channel LVC + 4p Parallel Adapter

New Protected Version
6-Channel LiPo/LiFePO4 Low Voltage Protection Circuit + Parallel Adapter.
Provides two functions, individual low voltage protection for each channel, and provides a convenient way to connect the balance plugs for up to four Turnigy/Zippy LiPo packs in parallel. The PCB contains pads for four 7-pin JST-XH connectors. This is a very easy way to build up to 20Ah packs, and provide cell-level low voltage protection at the same time, for either LiPo or LiFePO4-based packs.

This version now includes 5.1V zener diodes on each circuit, to help provide protection from loose connections and wiring errors causing the TC54 voltage detection chips to fail....$10 or $15....

8-Channel LVC + 4p Parallel Adapter

New Protected Version
8-Channel LiPo/LiFePO4 Low Voltage Protection Circuit + Parallel Adapter.

I thought he sold parts for or modified Battery Medic's but I don't see them on his site. He discusses them in this thread:
http://endless-sphere.com/forums/viewtopic.php?f=14&t=17168

In the seemingly endless series of BMS testing I've been doing of late, one thing I've noticed is that these Turnigy and Zippy 6s-5000 packs I'm using, just don't get out of balance very easy, without forcing them out-of-balance. This has made me re-think how to manage these packs. What I really need to do is monitor each cell during charging, but not worry about balancing every time. What I've now done is use combo LVC/HVC-only boards in the pack, in conjunction with the new charge control board. What this does is use the throttling logic to hold each cell from exceeding the set point, which is about 4.16V, in my current setups. The current will drop all the way down to essentially zero, as the high cell gets full. With the cells fairly well balanced, they will all get full.

With all the BMS weirdness we were seeing, the problems were causing the cells to get as much as 100mV delta between the lowest and highest cells. What I used to re-balance the cells was my trusty Hobby City Battery Medics. These units work amazingly well, and will balance the cells to within about 5mV, but it can take quite awhile. They have 10 ohm shunts, so they should be capable of at least 300mA of balance current, but there's no fans inside, so it would be hard to believe they'd really shunt that much. As it turns out, the unit pulses the current, so that all the channels aren't all on at the same time. The duty cycle is roughly 2 seconds on and 1 second off.

I then decided that maybe it was easy enough to come up with a way to boost the shunt current, so that the balance time would be reduced. As it turns out, this was actually pretty simple. What I did was tap into the collector of the shunt transistors, and use this to drive the same KSA473 power transistors and 3.1 ohm shunt resistors we use on the full BMS. I finally am able to make use of some of the earlier version shunt boards, that have been accumulating in a big pile at an alarming rate. It took some experimenting to get the values right, and Richard made some circuit "adjustments", but this works amazingly well. There's just under 3.0V across the shunt resistors, so just about 1A of "boost" current. Here's what the schematic looks like:...

 

[mud2005]

thanks Mitch, I had wondered also about the meanwell and if I needed the adjustable current board so I emailed Fetcher and got a quick reply.

The S-350 limit can be modifed by snipping the shunts inside. It might be OK with the stock current limit, but watch the heating. The S-350 generally behaves well when charging and most don't have the 'hiccup' mode limiter, so can work OK without my limiter circuit. Also watch the max. charge rate the batteries are rated for and it's wise to check the actual current with a meter once at beginning of charge to see what you're actually getting.

 

[mud2005]

just placed my first HK order

1x #iCharger1010B/6609 iCharger 1010B+ 300W 10s Balance/Charger variations = $121.40
4x #Z50006S-15/7639 ZIPPY Flightmax 5000mAh 6S1P 15C variations = $179.96
2x #HKB-Medic/10328 Hobby King Battery Medic System 6S variations = $47.90
1x #TR-Wattmeter/10080 Turnigy Watt Meter and power Analyzer variations = $23.95
6x #B10A1780-06/9672 Turnigy Pure-Silicone Wire 10AWG (1mtr) BLACK variations = $17.94
6x #B12A1062-06/9674 Turnigy Pure-Silicone Wire 12AWG (1mtr) BLACK variations = $14.94

I went with fastest shipping, its crazy expensive but I don't want to wait weeks

now I just need a power supply for the icharger, any suggestions?

edit: this power supply looks good and these guys ship super fast

 

[MitchJi]

Hi,

1x #iCharger1010B/6609 iCharger 1010B+ 300W 10s Balance/Charger variations = $121.40

now I just need a power supply for the icharger, any suggestions?

edit: this power supply looks good and these guys ship super fast

iCharger 1010B
A high powered charger, capable of handling up to 200W or 10A charge rates.
Spec.
Maximum charge power capacity : 300W (@ input voltage > 13.5V)
Charge current range : 0.05¨C10.0A
Input voltage range : 10.0¨C18.0V DC

To take full advantage of the charger you need a PS with a 200W or 300W at (higher wattage with higher voltage I think 18V is better than 13.5V -check with Luke) plus some head room.

The Meanwell you linked to will not do it:

Output power : 10 amps continuous, 150 watts
Output voltage : 15V DC (adjustable +/- 10% = 13.5V-16.5V)

 

[AussieJester]

Remember, you combine the balance taps...

This means, it doesn't matter if you have 400 packs, or 2 packs, you only need to handle 12s. This means just 2 cell logs and/or battery medics is all you would ever need.

Very true...but it would take you 3 weeks to balance a pack only slightly out using a battery medic, heck, one pack alone takes all day and half the night LoL ...been there done that ...GGoodrum Battery Medic Booster FTW...sadly no longer available though

KiM