Risking a fire with these batteries?

[MT-Tank]

Another newbie question:

I have been using three different pairs of 7.4V 4000mAh 10C battery packs with about ten runs on each pair so far. They always get run and balanced as pairs. They are fairly hot when removed immediately after a run. Haven't measured temp and they are more than warm but not too hot to hold. Perhaps a slight increase in thickness of the pack when hot.
I thought 10C would be sufficient since the ESC is rated for 40A. Then I read this in another thread:

Ha, now that I know more about these things...I can see I SHOULD have seen it coming! I miss read the spec that said 7.4v lipo 3600 mah 20 c or better to mean MORE IS BETTER! So went for 2 x 11.1v 2200 mah 25c - result = KABOOM! Others on the forum say they are running 6cells without a problem - any one care to chime in and tell me what I have done wrong??? Unlucky or stupid?

... The primary cause (other than using 6S) was that your packs were clearly underpowered - they only accept a 55 amp draw while the manufacturer suggested 72 amps minimum - so they overheated, couldn't supply enough power to the ESC, the ESC burned up from the ripple current and shorted the cells......

So am I risking trouble with these?
I am pretty sure I am OK with some Tenergy 5200mAh, 25C cells I also run. They are always cool.

Paul

[ozzie-crawl]

your 7.4v 4000mah 10c batteries have a constant amp draw of 40 amps of wich you shouldnt pull anymore of 70-80%, so you are pushing there limits
the other thread you posted is saying the guy ran on 6s not 4s and his packs couldnt supplie the amps needed
your tenergy cells will be good as they have a constant draw of 130 amps but once again you only want to pull no more than 70-80% of this (91-104amps)

[Ub Hauled]

If they are not too hot to hold you should be fine....
But Tenergy packs are not exactly top of the line and I doubt they give out 25C, don't abuse them, they can and do give, sometimes they just puff up and some times they actually catch on fire. I spoke to a Castle Creation tech guy once and he told me that if the cells can't supply the ESC with enough juice, the ESC will burn up (like the quote above)... if you are really unlucky things can get worst, the cells and motor may burn up.

[ozzie-crawl]

yea you have to be carful of the c rating on some cheaper packs.
i remeber awhile back i got some cells for my 25" mono they said 25c 4000
i was only pulling 45 amps max even ran in parallel they couldnt last more than 30 sec with out dropping rite off and the packs were really hot

[Tony]

I'm running my boats with ZippyFlightmax packs. So far,these packs are running as well as my other Thunder Power packs, and a whole lot cheaper.