DIY cheap charger from balance wires

[cwah]

Etriker, please stop spamming this thread... Thanks.

ps: I don't think it's super safe. I think it's safer than bulk charging. Quite different.

 

[etriker]

Make 2 packs out of it and charge with a Hyperion 1420. Watch it the whole time. They mess up too.

Etriker, I agree there are risk in doing that. And I think most members here know there are risk in doing that. In this forum, most member take more risk than other by cycling at indecent speed.

But what we need here isn't someone that said that we shouldn't do it because there is risk, but to propose solutions or alternative solutions to our ebike problem and community.

Yes I recognize it's not the best solution, but rather than trying to stop everything, why don't you help at finding better way to make it safer?

One thing is sure: It is inherently safer than bulk charging. So it's already a step forward for our ebike custom solutions



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Jeremy, really thanks for taking time drawing this. I wouldn't be able to do that by myself.

I tried to add some colours on your drawing to help myself understanding the wiring:

There is the full red stroke which is the red from the battery wire, and the dotted red which is where the red goes to the charger:

Is it good like this? Your drawing is super clear so I think I get it right. Thanks


Also, I've just ordered a set of 3s extension to connect to the charger, but now I'm thinking to completely discard the 3s plug. I'm thinking about removing the 3s plug and directly solder wires to it. Actually, I'd completely remove the charger plastic case and put everything into a bigger plastic case. Good idea?

 

[etriker]

Etriker, please stop spamming this thread... Thanks.

ps: I don't think it's super safe. I think it's safer than bulk charging. Quite different.

You did in your first post. Now you don't. My job is done !

No spam. I don't sell. I buy.

I am a customer that has bought 2 times in the last month from the online sales forum.

Got great deals and am making some real cool ebike friends !

Ya'll need to be nice to the customers !

 

[Ratking]

Etriker, please stop spamming this thread... Thanks.

ps: I don't think it's super safe. I think it's safer than bulk charging. Quite different.

You did in your first post. Now you don't. My job is done !

No spam. I don't sell. I buy.

I am a customer that has bought 2 times in the last month from the online sales forum.

Got great deals and am making some real friends !

Ya'll need to be nice to the customers !

I don't see how a grown man can fail so miserably in understanding such a good explanation from Jeremy. Why do you keep on beating a dead horse?

 

[etriker]

Etriker, please stop spamming this thread... Thanks.

ps: I don't think it's super safe. I think it's safer than bulk charging. Quite different.

You did in your first post. Now you don't. My job is done !

No spam. I don't sell. I buy.

I am a customer that has bought 2 times in the last month from the online sales forum.

Got great deals and am making some real friends !

Ya'll need to be nice to the customers !

I don't see how a grown man can fail so miserably in understanding such a good explanation from Jeremy. Why do you keep on beating a dead horse?

Again, I am a customer that buys stuff on this forum that sells stuff.

I am the customer and I am always right !

Ya'll need to be nice to the customers and question the people that sell.

I believe Jeremy has customers. He has a whole different angle.

Why else in the world would he be pushing such a cheezy charging setup ?

I do not have ebike customers. I have a whole different angle.

Be nice to our customers.

 

[cwah]

Guys guys, can you please stop spamming and just answer on useful way to get a "cheap safer balancer wire charger"??

Half of the thread now is on argument and accusations. Please stop and if admins can remove them that would even be better.

Thanks, please help

 

[etriker]

Guys guys, can you please stop spamming and just answer on useful way to get a "cheap safer balancer wire charger"??

Half of the thread now is on argument and accusations. Please stop and if admins can remove them that would even be better.

Thanks, please help

Hyperion 1420. And watch it the whole time charging.

It will charge fast so you will not need to watch it that long.

I have a pile of cheap chargers that I don't use anymore.

I wish I had known this before I bought them because I will not resell that junk ! They belong in the trash !

 

[cwah]

I already have 2 hyperions 1420i. They are not good for any pack over 14s.

Please try to help on the subject.

 

[etriker]

I already have 2 hyperions 1420i. They are not good for any pack over 14s.

Please try to help on the subject.

You can team them up and charge up to 28 cells. You would have to split the pack to charge it.

Read your Hyperion book.

You could also split them into 2 packs and charge them using one charger one pack at a time.

 

[Alan B]

Has anyone measured the leakage current of these 3 cell chargers? Would they be suitable for an onboard charger that was left connected to the pack when the bike was in active use? I don't mind disconnecting an onboard charger when the bike is being stored (then I don't want anything connected to the pack), but it would be connected the rest of the time, and combined with a timer to shut of AC power after the charging period. So the question is do these chargers leak much from the battery when connected and not AC powered? If so, how much?

 

[dnmun]

there are three resistors across the output capacitor it appears.

in jeremy's picture of the bottom, you can see the schottky diode SS24 and the output cap is across that output trace from the schottky over to the output ground or negative.

there are 3 white brackets of resistors to the left and right of the cap, and if you lift those then the output should not leak down.

 

[cwah]

Ok, I have everything ready in my head now.

Here's what I plan to do:

More pictures coming when I'll go further

 

[auraslip]

Hope this guy doesn't make jermery stay away from the forum again for another 6 months. His posts are literally priceless.

 

[Punx0r]

cwah, go for IMO.

I'm a pessimistic worrier and I don't see a huge problem. Step 1 is ensure that if a battery catches fire it won't cause serious harm or damage. Step 2 is to do your best not to use a charger that will cause a fire.

If the battery is charged in a place where it doesn't matter if it burns up then you don't need to sit and watch it.

Charging it in a dangerous place and relying on a fancy charger instead is backwards.

Just look at how hazardous materials are stored: in isolated facilities where a fire/leak/explosion will cause little harm. No one is employed to sit and watch the stuff 24/7.

 

[cwah]

I started to strip the main wires and there is no red wire? :?

I think that polarity doesn't matter in this case? It seems that I can revert the 2 pins directly on my main socket.

Here's how I plan to parallel the wires:

Hope that everything is fine

ps: Just read your message Puxnor, that's great to have the green light thanks

 

[etriker]

i build my own homemade packs with A123 cells and take a lot of time to test the cells so the pack is easy to balance.

I take all this time to build a pack and I am going to do everything I can to make it last a long time.

I would never hook my homemade packs with A123 cells to a cheap charger.

I don't understand the whole sloooow diy cheap charger from balance wires at all.

Now if it was fast I might because I am not leaving my beloved packs alone on any charger and I am not waiting with it for 10 hours.

I guess some of y'all don't feel the same way about your packs.

I don't want it to burn up even way out in the yard. It took me months to test and build that pack !

cwah, go for IMO.

I'm a pessimistic worrier and I don't see a huge problem. Step 1 is ensure that if a battery catches fire it won't cause serious harm or damage. Step 2 is to do your best not to use a charger that will cause a fire.

If the battery is charged in a place where it doesn't matter if it burns up then you don't need to sit and watch it.

Charging it in a dangerous place and relying on a fancy charger instead is backwards.

Just look at how hazardous materials are stored: in isolated facilities where a fire/leak/explosion will cause little harm. No one is employed to sit and watch the stuff 24/7.

 

[torqueon]

Dam'it ! I skim these treads, often, based on topic of interest. WTF happened here! There is aways some drivel, but this take the cake Man!

 

[torqueon]

Oh yeah this is about balancing solutions.

 

[Jeremy Harris]

I believe Jeremy has customers. He has a whole different angle.

For the record I've never sold anything for profit via this forum and I have no "angle" as you put it.

Your only contribution seems to be to spread negativity and to troll this topic that you have no interest in. If you don't like the topic of this thread then don't read it. Simple.

 

[Jeremy Harris]

cwah, go for IMO.

I'm a pessimistic worrier and I don't see a huge problem. Step 1 is ensure that if a battery catches fire it won't cause serious harm or damage. Step 2 is to do your best not to use a charger that will cause a fire.

If the battery is charged in a place where it doesn't matter if it burns up then you don't need to sit and watch it.

Charging it in a dangerous place and relying on a fancy charger instead is backwards.

Just look at how hazardous materials are stored: in isolated facilities where a fire/leak/explosion will cause little harm. No one is employed to sit and watch the stuff 24/7.

Exactly. Couldn't have put it better myself.

I'm frankly amazed that people get risk so massively out of proportion. A quick look around this forum will show that there are many members using RC LiPo packs, many using ready made Chinese packs of often unknown build quality and many using packs they've built themselves from cells of varying kinds.

How often do we see major problems? So far, most problems seem to be with packs made from cells, in fact recently I think we've seen more fire issues with LiFePO4 cells than with LiCoO2 cells, which is interesting.

Charging at a low current is inherently safer for several reasons. The chances of a wire or connector heating up is lower and the chance of a cell heating up very quickly before it has time to vent safely is reduced. The other charging risks are all still there, the primary one being a failure of the charger to stop delivering current when a cell reaches the maximum allowable terminal voltage.

However, these charging risks exist for every lithium secondary cell in every bit of equipment we own. I've just counted the lithium cells around here, excluding my bikes and the boat. We have two 'phones, 3 netbook PCs, a laptop, two cordless drills, a car GPS, a handheld GPS, two cameras (but 5 battery packs for them) and a portable wireless hub. All told we have a total of 11 LiPo chargers for this little lot. Some of those items above have a long recharge time. The newer of the two cameras actually recommends "overnight charging" when you first charge the battery!

I doubt the above collection is that unusual, most homes are probably going to have at least a handful of LiPo powered items around, many will have a lot more. As another example, my neighbour has a Chinese made ebike, with a big LiPo battery. Judging from the fact that it uses a Euro style kettle lead for the DC charge connection (which is just asking for someone to plug the battery directly in to the mains!) I'd suggest the design if the charger may not be that great. His bike takes around 6 hours to charge and I know he charges it in his garage, next to his car. The garage is attached to his house.

Why should a well-designed and used charging solution like the one in this thread be any less safe? At least here on ES we are generally aware of the hazards associated with charging these cells. The vast majority of people who use and abuse them every day are blissfully unaware of the potential risk. Thankfully LiPo fires are remarkably rare, given the many hundreds of millions of cells being used around the world every day.

 

[Jeremy Harris]

cwah,

I'm going to do the same, I think, take the units out of their cases and wire directly to the boards.

The mains inputs are double insulated when in the case, so the live and neutral are interchangeable. If you fit the boards to another case then you either need to ensure it's plastic (with ventilation - these boards will run a bit warm when charging) or, if you choose to use a metal box then ensure the boards are mounted on insulating pillars and that the metal box is connected to earth, using a three core mains cable. Standard nylon pillars like these: http://www.rapidonline.com/Tools-Equipment/Standard-PCB-pillars-64769/?sid=c2dbc273-fe19-46f8-95df-5c52b4810d56 seem to fit the holes in the board OK, although the components are a little close in one corner and the pillar may need trimming slightly to get a good fit.

I will probably fit a fan to mine, as my experience with the other charger was that it ran a bit warm to the touch without it. I'm not sure that a fan is really needed, if the case has plenty of ventilation then it would probably be OK without one.

 

[Jeremy Harris]

i build my own homemade packs with A123 cells and take a lot of time to test the cells so the pack is easy to balance.

I take all this time to build a pack and I am going to do everything I can to make it last a long time.

I would never hook my homemade packs with A123 cells to a cheap charger.

I don't understand the whole sloooow diy cheap charger from balance wires at all.

Now if it was fast I might because I am not leaving my beloved packs alone on any charger and I am not waiting with it for 10 hours.

I guess some of y'all don't feel the same way about your packs.

I don't want it to burn up even way out in the yard. It took me months to test and build that pack !

OK, just so we all understand where you're coming from here, and how you've assessed the relative risk from the known charging failure modes, please educate us all by explaining exactly how and why watching a pack charge quickly stops your pack burning up.

I've only had one major charging failure (http://endless-sphere.com/forums/viewtopic.php?f=14&t=3241&p=47328#p47328) and I was lucky enough to be able to carry the pack outside before it caused a house fire. If I'd been sat in the room watching it the outcome would have been exactly the same, as once a cell has started to fail it's failed and the pack is likely seriously damaged. This isn't unique to any particular cell chemistry, it's really just a function of the stored energy being released in an unwanted way.

There's almost always a chain reaction from a cell failure in a pack during charging, one that turning the charger off or disconnecting the wires won't stop, as it'll almost certainly be due to interactions between adjacent cells, either electrically or thermally. Once a cell starts to go, then it will either just vent and cool down, leaving perhaps minor damage to one or more cells, or it'll get hot enough from internal breakdown to cook its neighbours and cause them to fail. No amount of watching it is going to change that, or allow you to save the pack, much as it might give you false comfort to believe that.

 

[etriker]

I have not had a battery fire. Except on the grill.

Made biodiesel for over 5 years and no fires.

Same with the biodiesel processor. Stayed with it the whole time processing.

You have failed to sell the sloooo diy cheap charger from balance wires idea to me the customer.

I don't buy your idea.

If I wanted to go slow charging I would have used SLA batteries because on the trike the extra lbs would not have made much difference.

A big feature of the A123s and rc lipo for that matter is to charge them fast.

There is a lot of info on the Hobby King forum and rc forum where the kids suggest to stay with the charger.

If I only need to stay with it for 45 mins there is less chance I will be distracted away from what I was doing.

10 hours. Get real.

 

[Jeremy Harris]

You have failed to sell the sloooo diy cheap charger from balance wires idea to me the customer.

I don't buy your idea.

1. You're not my customer.

2. I'm not selling anything at all.

3. It's not my idea.

10 hours. Get real.

Why not just bugger off from this thread then?

 

[etriker]

If it is ok for you to use this forum to suggest using cheap chargers to charge cheap rc li ion then it is ok for me to question your logic.

If I am not messing with your money or business then why are you taking it so hard ?

Feel free to question my posts and logic all day long if you want.

And I don't think you are a foe at all.

I like you. Seem like a nice person. Just some strange charging ideas.