charging lipo's without balancers

[holycaveman]

So my balancer quit on me the other day. I have been reading lately on lipo's when they first came out. Also caught a thread by the main thunderpower engineer "Charles Wang".

From what I understand lipos never had balancers. Balancers is kind of a new thing. To be quite honest, it doesn't seem that you really need a balancer, but it does make it easier.

So I put it to the test. I now have many charges on this old lipo from who knows where 3200mah 3s. And I am keeping it in balance within .02 volts. Sometimes its spot on. But its always off after its drained and needs charged/balanced.

Anyways, I still am leery about lipos. And I want to be safe about it.


But according to "Charles" your charger can be used to balance the pack, and should be used to balance it.

He goes into detail, but there is too much to post right now.

I Check each individual cells voltage before, during and at the end of the charge. Depending on the condition of the pack, decides what rate I charge it at. This is what in turn balances the pack.

Also when at max charge rate and the charger peaks and tells you its done. I then check each cells voltage, usually its under actual peak. So I re-charge it at a lower rate. This method has produced better balanced cells, and longer run times, as well as more power.

Pretty cool, and seems to be spot on. My pack now when peaked is reading .01 vlts difference or less. No different than when I was using a balancer.

Thoughts on this? I am very new to lipos, so I could be missing something.

Thanks

[EeePee]

No thoughts, cause you don't pay me to think, but if you want, you can put my Blinky balancer on your battery next time you see me.

[JohnRobHolmes]

The tighter tolerances on some packs allow you to charge and recharge many times with no balancing. Some packs need it every recharge. Brand quality and construction have a lot to do with it, as well as cell matching (or lack of).

I have packs that stay in balance no problem, and I have had packs that will not stay in balance at all.

[holycaveman]

Originally Posted by EeePee

No thoughts, cause you don't pay me to think, but if you want, you can put my Blinky balancer on your battery next time you see me.

Thanks for the blinky option

The tighter tolerances on some packs allow you to charge and recharge many times with no balancing. Some packs need it every recharge. Brand quality and construction have a lot to do with it, as well as cell matching (or lack of).

I have packs that stay in balance no problem, and I have had packs that will not stay in balance at all.

Yep, I know what you mean John.

This pack I have, happens to have a problem with staying in balance compared to the other pack I have charged.

My new pack stays in balance, and easily charges. The 3200mah pack I am talking about is always out of balance, just about every cycle.

by the way that Charles Wang of thunderpower explains, and I have tested. Surprisingly the pack balances back to normal, even though sometimes way out of balance(.06vlts to .2vlts) with his charging methods and no balancer.

As of yet, a balancer is not needed at all. Not saying balancers are a gimick, but from what I have seen, I am not convinced that they help, except for maybe peace of mind.

The verdict is still out, and i am still monitering the lipo's using only the charging for balancing.

Todays way of automatically buying a balancer is norm. But so far I am pretty confident of this method of balancing without a balancer.

I will keep on testing, to make sure there is no problems. I charged it twice today. Each time it was about .06 out of balance. And I brought each cell back to within .01 using the charger only.

[BEAU]

well i may just stick with the blinky for my peace of mind..... hobbycity has lipos for real cheap 1350 mil with a 25c for 18 bucks a peace

[holycaveman]

Originally Posted by BEAU

well i may just stick with the blinky for my peace of mind..... hobbycity has lipos for real cheap 1350 mil with a 25c for 18 bucks a peace

Yea, I am not suggesting that anyone not use a balancer. At least untill I know 100 percent this is safe.

Also funny you mentioned hobbycity. That is the new pack I bought. A 1450 3s 30c zippy lipo. And that battery really kicks butt!!

My motor draws 45 continious amps, and that 1450 will run my scaler for 35minutes!! With awesome power! I am totally happy with it so far. I could use alittle higher amp battery, but I set my mamba up at medium start up power, just to be safe.

[Big Bill]

Originally Posted by holycaveman

Yea, I am not suggesting that anyone not use a balancer. At least untill I know 100 percent this is safe.

Also funny you mentioned hobbycity. That is the new pack I bought. A 1450 3s 30c zippy lipo. And that battery really kicks butt!!

My motor draws 45 continious amps, and that 1450 will run my scaler for 35minutes!! With awesome power! I am totally happy with it so far. I could use alittle higher amp battery, but I set my mamba up at medium start up power, just to be safe.

Iam new to Lipos also, what are the safety issues you are talking about. Thanks

[holycaveman]

Originally Posted by Big Bill

Iam new to Lipos also, what are the safety issues you are talking about. Thanks

Lipos are a great battery. But they also require more care than nicads.

Lipos must be charged at a specific rate, and NO more. Lipos must stay in balance, and can not be drained clear down like nicads.

All of these things can damage your lipo battery.

You can NOT over charge a lipo. Fire can result from this.

I am sure someone can chime in and explain more.

[Timothy Hill]

Am new to lipos also just got a new venom pro charger, and new 1500mah 3cell pack. The charger will not let me use the balancer, for charging or for dicharging. Cells are no where close 4.99 2.89 3.99 these numbers are out of chargers perameters? Flusterd guess I will Obama rig it and not use balancer, new toy dead batterie

[Harvo]

Originally Posted by holycaveman

Thanks for the blinky option




Yep, I know what you mean John.

This pack I have, happens to have a problem with staying in balance compared to the other pack I have charged.

My new pack stays in balance, and easily charges. The 3200mah pack I am talking about is always out of balance, just about every cycle.

by the way that Charles Wang of thunderpower explains, and I have tested. Surprisingly the pack balances back to normal, even though sometimes way out of balance(.06vlts to .2vlts) with his charging methods and no balancer.

As of yet, a balancer is not needed at all. Not saying balancers are a gimick, but from what I have seen, I am not convinced that they help, except for maybe peace of mind.

The verdict is still out, and i am still monitering the lipo's using only the charging for balancing.

Todays way of automatically buying a balancer is norm. But so far I am pretty confident of this method of balancing without a balancer.

I will keep on testing, to make sure there is no problems. I charged it twice today. Each time it was about .06 out of balance. And I brought each cell back to within .01 using the charger only.

What is this method of balancing with the charger?

[30percent]

You might be able to get away with not balancing new lipo's, but the older they get the more they will require a good balance. It would be a bad idea to get in the habit of not balancing, then have an older pack burn your house down from an over charged cell.

Remember, a Lipo can start on fire hours after it's been used/charged/etc.
You use it, pack up your pit and take it home. Hours later it bursts into flames. Happens all the time with the sky bashers, crash a plane, pack up the car, driving down the road flames out the back seat. (due to damaged cell) balancing wouldn’t stop a damaged packs from burning, its just an example of how flaky a Lipo can be.

If you ever saw a NiMh cell pop during charge, it was due to under-charged cell (un-balanced pack). The charger reads the over all voltage as low because the unbalanced cell is not putting in it's 1.2 so it keeps charging the cells that are full and Boom! Same concept with Lipo, the chance of a cell drifting from the other is too high to chance.

I'm interested in how this turns out. There has been much discussion at the track about balancing. My stand came down to this... if the engineer designed a balancer lead for a pack, use it, it cant hurt like not using it can.

[30percent]

Originally Posted by Harvo

What is this method of balancing with the charger?

Chargers that have Lipo mode without a balancer will detect the overall voltage and divide it by the number of cells, it's a guess-a-mation, not very acurate. 2-cell 7.2v, 3.6v each cell. It wont know if one cell is 3.8 and the other 3.4, it just assumes they are equal.

If you are charging a 2 cell through the main power plug (deans, banana, etc) its connected to both cells in series, theres no way for the charger to charge one cell at a different rate than the other. That's why those balancer wires are there, It's +/- to each cell individually. That's why it's important to use a balancer. It will burn off over voltage cells to the lower voltage cell.

The more I go over this, the more I just want to recommend how much buring your house down over a R/C battery would suck!

Becareful with that unbalanced pack Holycaveman, keep it in a fire safe box. You never know.

[holycaveman]

Originally Posted by 30percent

You might be able to get away with not balancing new lipo's, but the older they get the more they will require a good balance. It would be a bad idea to get in the habit of not balancing, then have an older pack burn your house down from an over charged cell.

Remember, a Lipo can start on fire hours after it's been used/charged/etc.
You use it, pack up your pit and take it home. Hours later it bursts into flames. Happens all the time with the sky bashers, crash a plane, pack up the car, driving down the road flames out the back seat. (due to damaged cell) balancing wouldn’t stop a damaged packs from burning, its just an example of how flaky a Lipo can be.

If you ever saw a NiMh cell pop during charge, it was due to under-charged cell (un-balanced pack). The charger reads the over all voltage as low because the unbalanced cell is not putting in it's 1.2 so it keeps charging the cells that are full and Boom! Same concept with Lipo, the chance of a cell drifting from the other is too high to chance.

I'm interested in how this turns out. There has been much discussion at the track about balancing. My stand came down to this... if the engineer designed a balancer lead for a pack, use it, it cant hurt like not using it can.

Thanks, your right, a fireproof box is advisable. I am balancing my lipo's. But I am not using a balancer to do so. This is nothing new. This is old, actually its what was done before the blinkers came out.


What method? Well is pretty darn simple really.

I added a port to the balancer tab that allowes me to check each cells voltage with a volt meter.

After I use a pack. I check the voltage difference between cells. IF the cells read no more than .03vlts difference between cells, then I proceed with normal 1c charge.

If voltage is .o3 or greater up to .3vlts(hopfully not!) I start charging at .3-.5 amps. IF your battery is below 2500 mah. I would strongly suggest charging at .3 amps. Charging a lipo at this rate balances the lipo. No need for a balancer

Sometimes if the battery is just barely out of the .03vlt range, I will charge at .5 c and this usually will ballance out the pack by the end of the charge.

I charge lipo that is unballanced at the .3 to .5 untill battery is back to the normal .02-.03 vlt difference, which is acceptable. Once battery is back into balance, I charge at the normal 1c for lipo's


IF for some reason your lipo onece peaked auto. Is out of balance of more than .03vlts between cells. re-charge at .3 amps untill pack is balanced.

Never go above 4.2vlts per cell. And always check with volt meter.
Very simple and works on old worn out unbalanced packs. Because thats what I have LOL


Words of caution! IF you have a lipo that is .3vlts or greater out of balance. Use extreme caution! Try and repair it by charging at .3 amps. Monitor the voltage every 15minutes. Most of the time you can bring the battery back to within specs.

[holycaveman]

For those of you interested. Try this on your (out of balance lipo)

After you use your pack, test the voltage of each cell. Record the difference between cells.

Charge pack @.3 amps for large mah packs use .5 amps. Charge for 15 minutes. Record cells again. See if they are balanced within .02vlts or even .01vlts.

IF not charge for another 15 minutes.

And if you don't see them balanced, then stick to your blinky, and call me a newb. IF they are balanced, then if your blinky goes capow sometime, you have nothing to worry about

NOTE: large mah packs or way out of balanced packs will take longer.




Last night I severly drained my 3s 3200mah pack. The volage drop between cells was .27 volts!! I charged at .5 amps. Fell asleep. Still charging in the morning! Actually about 4 hrs later. And I checked the voltage. There was only .01 vlt difference between cells!! and that is balanced.

[JohnRobHolmes]

Cells are generally not in balance through the entire discharge, just at full capacity. It is no suprise to me that it charged back up to balanced.

[Harvo]

Originally Posted by JohnRobHolmes

Cells are generally not in balance through the entire discharge, just at full capacity. It is no suprise to me that it charged back up to balanced.

So is that an acceptable "balance"? I have the 1300 2S that you sell. I haven't managed to come up with a trinity tap yet. Have you had good luck with those cells staying balanced? Because it might be a while before I can balance that one

[dkingston]

Tom,

I balance my crawler packs every time, its just become a habit.

Now, my race packs are another story. The packs I use for my slash are charged as a NIMH at 2C until 8.8-9 volt. I will top them off that way as well. At the end of the race day I will balance. I haven't had one puff, fail or stop coming right back into balance.

Kind of ironic, overly abuse some packs over others...


- David

[JohnRobHolmes]

Originally Posted by Harvo

So is that an acceptable "balance"? I have the 1300 2S that you sell. I haven't managed to come up with a trinity tap yet. Have you had good luck with those cells staying balanced? Because it might be a while before I can balance that one

It is not an acceptable balance, it is just an effect of having a pack that was assembled and balanced properly. As it is used, the cells can start to stray. Just a bit more every discharge/ charge cycle. Balance it again and the pack will charge back up into a balanced state, even when unbalanced in a discharged state. This is assuming that all cells are in good working order. Basically a pack should always be balanced in a fully charged state, so that no cells get overcharged.

The packs I sell do stay in balance well. They are factory matched. I have put well over ten charges in a row with no balancing, and had great luck. I cannot suggest this as a habit though, as I do check the cells during charging just to keep an eye out. If you have one cell that decided to be bad and resist charging, you can have a fire without a balancer to recognize that some cells are getting overcharged.

My packs use an align tap, fyi.

[JohnRobHolmes]

Originally Posted by dkingston

The packs I use for my slash are charged as a NIMH at 2C until 8.8-9 volt. I will top them off that way as well. At the end of the race day I will balance. I haven't had one puff, fail or stop coming right back into balance.

- David

The termination for lipo is 8.4v for two cell packs. You are certainly pushing your luck and greatly reducing pack life by doing this. A perfect "dont try this at home" sort of thing.

[Harvo]

Originally Posted by JohnRobHolmes

My packs use an align tap, fyi.

Uh... right... that's what I meant ... whoops

Thanks