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Harvo · 12-15-2008, 11:09 PM

I have an Onyx 230 charger. I set one of the presets for a 2200mah Lipo. Based on the mah, the charger is supposed to select the correct current to charge at. The first time I charged the battery it charged at 2.2 amps for like 120 minutes.

The second time I connected the battery and started the charge, my settings were still there, but it started charging the battery at 3.4 amps. It was really putting a charge on the battery fast. (that's how I noticed). So I reset the current for 2.2 amps again.

If the Charge rate for lipos is automatic based on the mah of the battery, why did my charger start throwing like a 1.5 C charge on it?

If I had left it, would that have been safe? Was the charger doing what it is supposed to? I'm sure it is smarter than me about it's functions, but that just made me panic a little.

JohnRobHolmes · 12-15-2008, 11:14 PM

Sounds like a bad charger. Did it taper off the amps when it gave the 120 minute charge? That is how my triton ruined many packs. It wouldn't terminate the CV portion of the charge.

Harvo · 12-15-2008, 11:31 PM

I didn't let it go long enough to reach the constant voltage stage. I panicked when I saw the 3.4 AMPs going to the battery and stopped it. I changed the setting manually to 2.2 Amps and strated again. I'll check it later to see if the Amps drop off.

It times out after 30 minutes, so I can either up the time or go restart it every 30 minutes. Which do you think is better?

I felt the pack after it had charged at 3.4 amps for about 900 mah worth and it was cool and not swollen at all. I assume all is still well.

This lipo charing thing is freaking me out. I guess because I have heard so many warnings.

Harvo · 12-15-2008, 11:34 PM

OK... I just checked and it must be up to the point where it switches to CV charge because it is down to 1.6 amps of current going in.

Sound about right?

JohnRobHolmes · 12-15-2008, 11:40 PM

yep.

I wouldn't trust a charger that changed settings on me. While it may be ok on a smaller pack, the surface area to volume ratio of a larger pack could cause thermal runaway. Basically the ability of the battery to dissapate heat will determine how fast you can charge it. Some tiny lipos can charge at 3c no problem, because they get rid of heat so well.

12-15-2008, 11:09 PM	#1
Harvo I wanna be Dave Join Date: Mar 2008 Location: In the Dark Edges of your Mind Posts: 6,386	Lipo Charging Question I have an Onyx 230 charger. I set one of the presets for a 2200mah Lipo. Based on the mah, the charger is supposed to select the correct current to charge at. The first time I charged the battery it charged at 2.2 amps for like 120 minutes. The second time I connected the battery and started the charge, my settings were still there, but it started charging the battery at 3.4 amps. It was really putting a charge on the battery fast. (that's how I noticed). So I reset the current for 2.2 amps again. If the Charge rate for lipos is automatic based on the mah of the battery, why did my charger start throwing like a 1.5 C charge on it? If I had left it, would that have been safe? Was the charger doing what it is supposed to? I'm sure it is smarter than me about it's functions, but that just made me panic a little.

12-15-2008, 11:14 PM	#2
JohnRobHolmes owner, Holmes Hobbies LLC Join Date: Nov 2004 Location: Volt up! Gear down! Posts: 20,290	Sounds like a bad charger. Did it taper off the amps when it gave the 120 minute charge? That is how my triton ruined many packs. It wouldn't terminate the CV portion of the charge.

12-15-2008, 11:31 PM	#3
Harvo I wanna be Dave Join Date: Mar 2008 Location: In the Dark Edges of your Mind Posts: 6,386	I didn't let it go long enough to reach the constant voltage stage. I panicked when I saw the 3.4 AMPs going to the battery and stopped it. I changed the setting manually to 2.2 Amps and strated again. I'll check it later to see if the Amps drop off. It times out after 30 minutes, so I can either up the time or go restart it every 30 minutes. Which do you think is better? I felt the pack after it had charged at 3.4 amps for about 900 mah worth and it was cool and not swollen at all. I assume all is still well. This lipo charing thing is freaking me out. I guess because I have heard so many warnings.

12-15-2008, 11:34 PM	#4
Harvo I wanna be Dave Join Date: Mar 2008 Location: In the Dark Edges of your Mind Posts: 6,386	OK... I just checked and it must be up to the point where it switches to CV charge because it is down to 1.6 amps of current going in. Sound about right?

12-15-2008, 11:40 PM	#5
JohnRobHolmes owner, Holmes Hobbies LLC Join Date: Nov 2004 Location: Volt up! Gear down! Posts: 20,290	yep. I wouldn't trust a charger that changed settings on me. While it may be ok on a smaller pack, the surface area to volume ratio of a larger pack could cause thermal runaway. Basically the ability of the battery to dissapate heat will determine how fast you can charge it. Some tiny lipos can charge at 3c no problem, because they get rid of heat so well.

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