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wintersdawn

Newbie Lipo Question

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Just started using Lipo batteries and have done quite a bit of research to try and avoid pitfalls.

I ordered a new Gens Ace 2S 5500 mah lipo from Amazon but it doesn't seem to be taking much charge.

My other Floureon 5200 mah 2S takes 3494 mah charge from storage to balance charge in 55 mins

The new Gens Ace takes 1877 mah charge from storage to balance charge in 33 mins

Both were 3.8 v storage voltage in each cell before doing the balance charge.

Do new lipo's take a while to get to full capacity or have I got a dud?

Cheers

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That sounds duff to me try a discharge from full to see how much capacity it has from full. Is it puffed at all. (Keep an eye on it).

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Charging from the same starting point, they should both take the same amount of time to charge at 1C (assuming you've a charger that'll charge at 5.2 and 5.5amps?). Is it fully charged, with both cells at 4.2v?

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Cheap lipos can take an absolute age to balance charge, you will find it’ll reach the 8.4v in good time, but can sit there trying to balance the last bit for a very long time. 
generally in the past I’ve left these for a while then as long as it’s at 8.4v just given up and unplugged it. 
the main key with lipos is to not leave them fully charged and ideally ok storage charge. The other rule is don’t completely discharge them. 
 

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Just now, catman79 said:

Cheap lipos can take an absolute age to balance charge, you will find it’ll reach the 8.4v in good time, but can sit there trying to balance the last bit for a very long time. 
generally in the past I’ve left these for a while then as long as it’s at 8.4v just given up and unplugged it. 
the main key with lipos is to not leave them fully charged and ideally  storage charge them after use. The other rule is don’t completely discharge them. 
 

 

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Cheers for the advice.

Once charged the battery shows 4.2 volts for each cell. Just gets there so quick. I have used the battery gently twice so far to break it in. No puffing that I can see to the hard case.

I plugged the battery into my battery checker and at storage charge it reported it was 38% charged so I did a calculation and 38% of 5500 is 2090 leaving 3410 needed to balance charge to 5500. The floureon from storage to balance charge added 3494 mah, so it seems that the gens ace battery should add about the same mah from storage to balance charge.

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Just trying to storage charge the gens ace battery again from balance charge and it's over two hours now and the voltage is still 8.13, needing to get down to 7.6v but taking so long. When going from storage to balance it takes only 30 minutes.

My charge rate for balance and storage is 5 amps, the maximum of my charger (skyrc t100). It doesn't have a separate discharge function so the lowest I can discharge is 3.8v per cell using storage charge.

I'm also using my existing xt60 charge lead but it works fine for my floureon.

Gonna wait for the gens ace to finally storage charge and send it back to Amazon.

Can anyone recommend a good 2s/3s lipo manufacturer? Seems floureon are ok as I've had no problems with the one I've got but be good to know other options. Cheers

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15 minutes ago, wintersdawn said:

Just trying to storage charge the gens ace battery again from balance charge and it's over two hours now and the voltage is still 8.13, needing to get down to 7.6v but taking so long. When going from storage to balance it takes only 30 minutes.

My charge rate for balance and storage is 5 amps, the maximum of my charger (skyrc t100). It doesn't have a separate discharge function so the lowest I can discharge is 3.8v per cell using storage charge.

I'm also using my existing xt60 charge lead but it works fine for my floureon.

Gonna wait for the gens ace to finally storage charge and send it back to Amazon.

Can anyone recommend a good 2s/3s lipo manufacturer? Seems floureon are ok as I've had no problems with the one I've got but be good to know other options. Cheers

Don't forget your charger only has 0.3a current for balancing 2.0a for discharging. It only charges at 5 amps. If there is a lot of balancing being done it will take much longer.

It does sound as if it hasn't got as much capacity as it should but it can be hard to tell sometimes. The difference simply between 3.80 and 3.89 can be 20% of the overall pack capacity.

I've had good luck with Floureon too for a budget brand but if anything, Gensace have a better reputation so if you do have a bad one, it might be worth trying to exchange it.

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Cheers. After 8 hours trying to storage charge my new gens ace, it's still at 7.65 volts but low enough to send back to Amazon.

Would be great to hear of any other lipo battery recommendations, cheers.

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It doesn’t seem to me that your LiPo is having problems. I think your over analysing it by monitoring the mah.  If your getting 8.4 v at full charge you’re in good shape 

I have two chargers, Polaron 1400ex capable of 20 amp charging / 10 amp discharge and ICharger X6, capable of 30 amp charge and 10 amp discharge. I’ve charged 5000 mah batteries and it’s ended up way over 5000. So the mah displayed on chargers is not exact.

Also your charger is not very powerful, 5A for charging and 2A for discharging is very low for 5000 mah battery. You can discharge much quicker if you use it in your car.

My recommendation before you send it back  is as follows. Charge it fully to 8.4 volts. Use it in your car for 30min or so , until you hit the low voltage cut off. Then fully charge it at 5A to see how many mah you get.  
 

GensAce makes good batteries. I used to use them.  They aren’t readily available in the US anymore so I’ve switched to SMC-Racing. I’ve been using them for past 5 years, great batteries at half the price of name brands like Reedy etc

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1 hour ago, Raman36 said:

It doesn’t seem to me that your LiPo is having problems. I think your over analysing it by monitoring the mah.  If your getting 8.4 v at full charge you’re in good shape 

I have two chargers, Polaron 1400ex capable of 20 amp charging / 10 amp discharge and ICharger X6, capable of 30 amp charge and 10 amp discharge. I’ve charged 5000 mah batteries and it’s ended up way over 5000. So the mah displayed on chargers is not exact.

Also your charger is not very powerful, 5A for charging and 2A for discharging is very low for 5000 mah battery. You can discharge much quicker if you use it in your car.

My recommendation before you send it back  is as follows. Charge it fully to 8.4 volts. Use it in your car for 30min or so , until you hit the low voltage cut off. Then fully charge it at 5A to see how many mah you get.  
 

GensAce makes good batteries. I used to use them.  They aren’t readily available in the US anymore so I’ve switched to SMC-Racing. I’ve been using them for past 5 years, great batteries at half the price of name brands like Reedy etc

Thanks, I will do as you advise and balance charge the new gens ace battery and run it in my r/c until the ESC cuts power and balance charge and note the mah.  My floureon 5200 mah lasts 35 minutes, so I have something to compare with. 

Lipo is new to me, having only used nimh before so I am glad to learn more and I have also read good things about Gens Ace batteries and have a nimh one that is very good.  I did get 8.4 volts at full balance charge on the gens ace so hopefully you are right and the battery is fine.

I've done some research and surprised to find that chargers a lot more expensive than mine still only discharge at a low rate, I guess its because the manufacturers assume the battery will be discharged through being used in an r/c vehicle.  The problem is, after balance charging a lipo, if something comes up and I can't run my r/c for sometime, I like to discharge it back to storage charge to avoid damage/puffing etc.

 

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Balance charged the new gens ace 5500 mah 2s battery (reached 8.4 v) and it ran my RC for 30 minutes when the ESC low voltage cut off activated. Towards the end, acceleration was erratic, sometimes normal, sometimes slower, then back to normal again, then the cut off, is this normal when the battery is nearly gone? 

The battery charger and tester reported 4% capacity/charge left at the end and both cells were 3.4 volts.

I balance charged the battery again and the charger put 4628 mah back in out of a total of 5500 mah.

Does this sound normal? Cheers

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4 hours ago, wintersdawn said:

Balance charged the new gens ace 5500 mah 2s battery (reached 8.4 v) and it ran my RC for 30 minutes when the ESC low voltage cut off activated. Towards the end, acceleration was erratic, sometimes normal, sometimes slower, then back to normal again, then the cut off, is this normal when the battery is nearly gone? 

The battery charger and tester reported 4% capacity/charge left at the end and both cells were 3.4 volts.

I balance charged the battery again and the charger put 4628 mah back in out of a total of 5500 mah.

Does this sound normal? Cheers

That behavior sound more like your ESC than the battery itself . Some ESCs low voltage detection acts differently than others.most will go into a low power mode once they hit a a determined voltage. 
it sound like yours was going into low voltage cutoff when it reached a certain threshold under load then was going back to full power when the battery recover a few seconds later. It under load.

some ESC will act this way when they go into thermal protection as well 

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On 5/3/2021 at 6:38 AM, wintersdawn said:

Just trying to storage charge the gens ace battery again from balance charge and it's over two hours now and the voltage is still 8.13, needing to get down to 7.6v but taking so long. When going from storage to balance it takes only 30 minutes.

My charge rate for balance and storage is 5 amps, the maximum of my charger (skyrc t100). It doesn't have a separate discharge function so the lowest I can discharge is 3.8v per cell using storage charge.

I'm also using my existing xt60 charge lead but it works fine for my floureon.

Gonna wait for the gens ace to finally storage charge and send it back to Amazon.

Can anyone recommend a good 2s/3s lipo manufacturer? Seems floureon are ok as I've had no problems with the one I've got but be good to know other options. Cheers

I use Venom. Whatever you like just don't cheap out on Lipos bro. 

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4 hours ago, Dakratfink said:

That behavior sound more like your ESC than the battery itself . Some ESCs low voltage detection acts differently than others.most will go into a low power mode once they hit a a determined voltage. 
it sound like yours was going into low voltage cutoff when it reached a certain threshold under load then was going back to full power when the battery recover a few seconds later. It under load.

some ESC will act this way when they go into thermal protection as well 

That matches what was happening, cheers. I thought maybe the ESC was faulty but probably just speed fluctuations due to the battery level/ESC low voltage cut off.

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18 hours ago, wintersdawn said:

I thought maybe the ESC was faulty but probably just speed fluctuations due to the battery level/ESC low voltage cut off.

I know the 1060 esc goes into half speed when nearing voltage cut off, kind of gives you a heads up and try drive back.

As stated, a high demand motor, sucks the volts down under acceleration, so the likes of the 1060 go half speed thinking the battery is almost flat, then the volts go back up, so it resets itself.

In the almost decade of using lipos, I don't think I've ever checked the chargers Mah battery level. I tend to go off the balance , especially after a run. As the esc only sees a full voltage from the 2 cells, say 6v before cut off, if one of the cells is a bit duff, one could be 2.8v and the other 3.2v.

Discharging takes effort, I think they use resistors, but that produces heat, so you need cooling fans and heat sinks etc etc. If you look at the price of the chargers with 5A + discharge rates, they're usually double the price (but usually brilliant chargers, so not just discharge parts)

 

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