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        Question Rapid-charging the Venom 5000mah (7 cell)

#1 enoctis Jun 06, 2008 04:11 AM

Rapid-charging the Venom 5000mah (7 cell)
 
The Venom 5000mah batteries I have don't even get warm during the entire charging process @ 5 amps each, which lasts slightly over an hour. Does this mean that I can charge them faster using more amps?

They get quite warm (not too hot to handle) during discharge and that doesn't seem to hinder them at all. It would seem to me that it's possible to charge them just as quickly as they discharge. Is this incorrect?

Recap:
1. Can I charge my Venom 5000mah faster using more amps (1.25hr @ 5amps)?

2. Can you charge them as quickly as you discharge them without causing any damage?

#2 thomanie Jun 06, 2008 04:26 AM

I'm assuming these are the 5000 lipopack, and not A123s, NiMH or NiCds:

Quote:

Originally Posted by enoctis
1. Can I charge my Venom 5000mah faster using more amps (1.25hr @ 5amps)?

No - not necessarily.

I strongly suggest you follow the mfgrs recommended charge rate (typically 1C; 5000 mA for a 5000mAh pack). Some will tell you to go ahead and charge at 2C or 3C, but as you will operate (well) outside the spec - be prepared to pay the price...

I should note that I haven't checked the C-rating on the Venom packs.

Quote:

Originally Posted by enoctis
2. Can you charge them as quickly as you discharge them without causing any damage?

Most likely NO!

Some of todays lipos can be discharged up to 30C and above. They do NOT stand such a high charge current. 1C is the generally accepted max charge current - a few exceptions do exist though.

If you only draw 1C at discharge, then the answer is yes. Otherwise NO.

I'm not aware that even A123/K2s can stand similar charge amp to discharge amps. But can't remember seeing any reports of them don't handling it either...

T

#3 thomanie Jun 06, 2008 05:02 AM

Now - as I see Venom doesn't have any big cell count Lipo packs, but a mass of 7 cell NiMHs, I guess you were asking about the Venom 5000 NiMHs packs.

The 1C fast charge still applies to NiMHs as a general rule, but they are a lot more forgiving at higher charge rates. I still suggest you follow the mfgr recommendation when it comes to charge current. I tried, but could not find any specs on the packs either at the Venom site, nor at TowerHobbies. Specs or recommendations ought to be included with the packs.

I've used my automatic charger on my old NiMHs so I haven't payed a lot of attention to the exact chargerate, nor time to complete.

T


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