Battery Medic - how to ID the REAL vs FAKE

[Scruffoid]

Hey i think i can see my One in that picture of yours there Jay!

Please Mr Methods PM has been sent

Scruff

[methods]

Lol..... I will get to my PM's but just FYI

Sorry guys - I dont sell these

We wanted to make them available to folks but it is just too expensive and risky. Take the information here and do more research. Find a way to make them reliably available to all of us at a good price

-methods

[miro13car]

[quote="Hyena"]Nice work methods. Another way to potentially tell them apart is some say "made" instead of "mode" on the bottom left button.
I'll have to start checking my sources, I've used several and noted that some come in a plain white cardboard box, some in a nicer looking blue and black coloured cardbox box with a picture on the frontand some in a clear hard plastic case - that almost always arrives cracked from postage![/quote]

there are ones with red boards on eBay with MADE word on the front
So it is rather mix and match

[methods]

I have had a few members bring some new flavors to my attention that really look promising. At this point (and it is a moving target) my personal belief is that the best solution would be:

Bulk charge to a comfortable level on a daily basis
Once a week/month/year use a cell level charger like the one Hyena is selling.

Pushing the cells up to 4.2V is a hell of a lot easier than trying to pull them down to 4.2V - especially as our packs get bigger and there is more and more energy to dissipate.

I got out of bed last night and finally finished the design for my new Battery Breaker. It is an aluminum box that gets built into your battery and interfaces with my LVC/HVC boards. It can flow 100A+ to the controller and 50A+ from the charger. If any cell level trips (high or low) the box disconnects your battery completely. No more tapping into the throttle, no more worrying about leaving a controller on. This will be a "real" hardware implemented cell level protection. Ironically - it is almost identical to my HVC Breaker design but with one more set of mosfets hooked up Source to Source. We are going to go with a TO-247 this time around and shoot for 200V+ capability. Going to try and do it by spring time - but the way I have been going... could be spring after next

Anyway back on topic
I would be interested to hear results from anyone who has tried out the newer flavors of this Medic. They are still super small and simple for what they are.

-methods

[Arlo1]

I have had a few members bring some new flavors to my attention that really look promising. At this point (and it is a moving target) my personal belief is that the best solution would be:

Bulk charge to a comfortable level on a daily basis
Once a week/month/year use a cell level charger like the one Hyena is selling.

Pushing the cells up to 4.2V is a hell of a lot easier than trying to pull them down to 4.2V - especially as our packs get bigger and there is more and more energy to dissipate.

I got out of bed last night and finally finished the design for my new Battery Breaker. It is an aluminum box that gets built into your battery and interfaces with my LVC/HVC boards. It can flow 100A+ to the controller and 50A+ from the charger. If any cell level trips (high or low) the box disconnects your battery completely. No more tapping into the throttle, no more worrying about leaving a controller on. This will be a "real" hardware implemented cell level protection. Ironically - it is almost identical to my HVC Breaker design but with one more set of mosfets hooked up Source to Source. We are going to go with a TO-247 this time around and shoot for 200V+ capability. Going to try and do it by spring time - but the way I have been going... could be spring after next

Anyway back on topic
I would be interested to hear results from anyone who has tried out the newer flavors of this Medic. They are still super small and simple for what they are.

-methods

Very cool methods.
Do you think that people can just run this as a first line of defense then balance charge every so often??

[methods]

I am biased - but this is how I see it

If a pack has cell level HVC and LVC protection then the balance state of the cells does not matter. The only thing the state of balance affects is the usable capacity of the pack (and of course the associated sag as cells drop in charge). I dont sweat balancing at all. If I am going on a camping trip, or a long ride then I take the time to top everything off to 4.2V - otherwise - I just ride my bike and bulk charge every chance I get. I never pass up an opportunity to charge and I never let battery management get in the way of a good ride.

We harp on balancing a lot here because most people dont have cell level protection - not because it makes a pack perform appreciably better. If a user is dependent on pack level LVC or charger level HVC then an out of balance pack is just a time-bomb waiting to destroy itself. I have ran more packs into the ground - and seen more people run packs into the ground. It is just ignorance - and totally avoidable.

-methods

EDIT: PS. If given the choice to run a full featured and well designed BMS I would always take that over the solution I described above. I just dont have the energy to make one and nobody else seems to either. They are nasty buggers - I have designed 4 of them and they are no fun.

[Hyena]

Bulk charge to a comfortable level on a daily basis
Once a week/month/year use a cell level charger like the one Hyena is selling

Yep, this is what I've been recommending to people for the best part of a year since finding those chargers. I don't want to harp on about it because it probably comes across as a lame sales pitch but it really isn't. I used battery medics for a year or 2, and recommended them to others too. If I built a lipo battery for someone it would always come with a medic. But not any more. As methods said medics are slow and if you get a really out of balance pack it's going to take a month of sundays to sort out. These 168 chargers are the shizzle and make short work of any imbalanced lipo pack. And if you're not in a hurry or paranoid you can use them as your sole/primary charger. I've always bulk charged with little regard for balance but for noobs it's a case of 'do as I say and not as I do'. In reality unless your pack is old and tired balance charging every time is just not necessary. I normally check the balance on my bikes about once a month and have never seen a difference between cells of more than 0.04v. This alone is balanced enough for routine use IMO.
I've said this before elsewhere but I'll say it again here because it's relevant. After using these 168 chargers it gives you a better appreciation for how trivial balancing to the nearest nanovolt really is. These chargers whack 8 amps into the cells through the balance taps which makes topping up lazy cells a snack. One thing that surprised me is how quickly a cell tops up from say 4.17v to 4.20v
Those with lipo OCD might get up tight about that sort of delta V but in the real world in makes little to no difference. To top up such a cell to 4.2v it takes around 1 minute at 8 amps. So that means if you had of left it the discharge would have been 1 minute less if you were drawing 8 amps. Most of us would be drawing double that sort of power at any give time - so that time is cut in half to 30 seconds. So but having an "imbalance" of that order you short changing yourself by 30 seconds of ride time. And that's only if you're discharging right down to LVC which is not recommend for longevity of the pack anyway. So really, big deal.


Anyway back on the topic of the new medics, I haven't bought one in probably 6 months but the last time I did I got the blue "150w" ones. I was curious as to how they were claiming such powerful balancing power but it turns out it's only a bulk discharge. It uses 3 x 50w halogen globes which runs through a circuit which must pulse more juice into them because they pull nearly double that power happily. I use them just for cycling packs now and it's handy because it'll sit there pulling 10 amps through the main discharge leads but when any cell hits the programmed discharge cut off it'll cut the power. So you can walk off any leave the packs discharging safely without the risk of forgetting about it killing them (as is likely with other DIY high current loads)
I think I posted a bit of a review about these a while back, I'll go dig it up

edit: here it is
http://endless-sphere.com/forums/viewto ... 15#p617708

[Ypedal]

These chargers whack 8 amps into the cells through the balance taps

Seriously ? the ballance leads and JST connectors can take this much without melting ?

conservative me was keeping it to 2 amps or less.

[Hyena]

Yeah man it defies logic but they can! I was skeptical at first but did alot of testing and it is true.
It must pulse the power to prevent them heating up, plus the internal fans blow alot of air over the output where the balance wires connect which I'm sure is intentional. This post has a video where I tested temps etc.
http://endless-sphere.com/forums/viewto ... 15#p601267

edit: and yeah in the old days if I needed to pull up individual cells I used a 5v 5a power supply through the balance taps and the wires got super hot so 8 amps straight up would definately be melted insulation territory.

[Arlo1]

These chargers whack 8 amps into the cells through the balance taps

Seriously ? the ballance leads and JST connectors can take this much without melting ?

conservative me was keeping it to 2 amps or less.

Ive charged everything at 8 amps a cell and never a problem even little 1ah pacs.

[methods]

Ok - I just deleted 4 posts that I had. They contained incorrect information so I thought it better to just make them disappear. Here is factual information.

First off - I totally agree with Hyena's statements above on battery care

So I got feedback from two of my associates on how well this charger works. I have one in my possession - but i never tested it myself. Here is what I found.

The charger kicks ass.
Puts out a solid 7A into 4.0V 16Ah emoli pack
Still puts out 7A into 4.1V (contrary to what I had heard)

my 22awg wires did not get hot
My JST-XH-5 connectors got only slightly warm
I hooked up a crappy Hobby King Extension and even at that point it only got warm.

That charger totally does what it says it does - I should have tested it earlier instead of listening to what other people said.

-methods

[methods]

These chargers whack 8 amps into the cells through the balance taps

Seriously ? the ballance leads and JST connectors can take this much without melting ?
conservative me was keeping it to 2 amps or less.

I just did a test and confirmed that you can easily run the full current through the standard taps. Silicone, PVC, real JST's, fake JST's. Tried it with a ghetto-extension and even that hardly got warm. This was 22AWG so I think you should hook yours up and give it a try at full blast. I think you will be very happy with the results.

I liked these chargers just in principle but now that I actually tested mine ( ) I am really impressed. I have been suggesting them to people who ask but I think I am going to redouble my efforts as this really is a one stop solution. Only thing that needs doing is isolation - and that is easy

-methods

[methods]

So to make a pack charger out of these tap chargers all one needs to do is supply an isolated 12V supply for each one. That is a pretty easy thing to do - no doubt someone else has already done it?

Tons of isolated (switching) aftermarket supplies in the 12Vish range. Many that have 4 or 8 isolated 12V outlets in one box.

I am totally side-tracked right now... but if folks are landing on this Medic thread (a thread I cooked up) then it is probably the right place. I still like the Medics and they are and easy solution - but I can no longer recommend them over this charger. This is the superior solution.

Topic officially changed
Bait and switch!
Come to read about medics... get an ear full of balance charger talk

-methods

[Scruffoid]

While I do agree that there isnt a real need for balance charging every time you charge. With this charger i am just like Why not?

If i was short of time then my bulk charger is heaps faster. But the shortest shift i do at work is 6 hours and i can easily charge my 22s 15Ah pack in that time.

Best part is that you can plug in multiple battery types. So i charge my 9 6S and 3 4s batteries all at the same time using the included parralleling board.

[methods]

We are trying to find a good isolated modular 12V supply to point people toward so that folks can build up 12S and 18S versions of this balance charger.

I am a bit concerned about the insertion cycles on the balance taps... I HIGHLY SUGGEST using a sacrificial jumper if folks plan to balance charge every time. This is a small extension that you plug into your balance taps. That way for every one insertion on your actual balance taps you get 20 or 50 insertions on the extension.... so by the time your balance tap sees 100 insertions it is actually 5000.

When balance tap sockets get loose and worn out all sorts of irritating things start to happen

-methods

[Scruffoid]

I am a bit concerned about the insertion cycles on the balance taps...
-methods

For this exact reason I have a large stock of spares JST-XH connectors and regularly test for continuity of my balance plugs and replace as required.

In my case I am not actually using the balance taps on my Packs but rather I have a 3 to 1 parrallel harness which is being used to plug into the chargers Parrellel board.

[methods]

sacrificial connector - that is how I do it. Assume it will wear out and swap it every 20 cycles. Measuring is very hard.... first off just taking the measurement affects the measurement. It also does not tell you anything about how it will respond in cold weather, hot weather, direct sunlight, vibration, etc. I have seen the JST-XH fail in so many weird and inconsistent ways.

I used to work on high reliability components that were in the harshest earth environments imaginable - one of the hardest tasks we had was figuring out how to test if something will work without without our test affecting the test (so to speak). To truly test a dynamic system one must build in the diagnostics at birth and monitor them always.

Anyway - that is another subject all together


-methods