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12-10-2006, 01:27 PM
| #1 |
| Keep it real   Join Date: Jun 2006 Location: Yakima,WA
Posts: 6,532
|  Does cold affect Batt performance
I was wondering if cold temps can affect battery performance? At our comp yesterday it was between 35 and 45 degrees and my batts didn't have any punch at all. It was my first comp with a super truck. I'm running a Gmade Spider with 65 turn axiom in front and 75 turn axiom in the rear, 9 tooth pinions, novak super duty, 8 cell 4/5A 2000 mah or 8 cell 2/3A 1400 mah batts. The 4/5A pack didn't have hardly any power when I went to run my truck. I had charged it the night before. My truck just stalled out repeatedly. I changed to the 2/3A pack for the next stage and it was a lot better. When I got home last night I tried the warm batts in the house and they had a lot more punch and wheelspeed than at the comp. Could it just be the cold temps? Thanks |
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12-10-2006, 02:07 PM
| #2 |
| Rock Stacker Join Date: Apr 2005 Location: Des Plaines
Posts: 66
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nope unless you left your batts out side then its possible battery performance doesnt drop i think until its less than 30 deg. i think ?
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12-10-2006, 07:43 PM
| #3 |
| Rock Crawler Join Date: Apr 2004 Location: Longmont, CO
Posts: 901
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I would imagine cold can have a big difference. Batterys are chemical reactions which slow with cold temp. Also, do you like gearbox's packed with grease? Grease can get real thick in the cold, causing drag on the drivetrain. |
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12-10-2006, 07:48 PM
| #4 |
| Quarry Creeper Join Date: Nov 2004 Location: In the saddle...
Posts: 473
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JIA might be your person on this one, but temperatures at either extreme are bad for packs. Heat kills your cells, and extreme low temps will also inhibit pack performance. That being said, I don't think there would be an appreciable notice in pack performance until you dropped a good bit below freezing. |
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12-10-2006, 08:14 PM
| #5 |
| Rock Stacker Join Date: Nov 2006 Location: Winston Salem
Posts: 93
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I havent seen a big drop in life on my packs except for lipos. They REALLY DONT like cold weather. I usually carry them around in my pants pocket or inside jacket pocket. I have on them when its cold been known to put them inside of a sock or a cloth glove to keep them warmed up. You may could experiment with something like that to see if it helps you any. Just my 2 pennys.
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12-10-2006, 08:16 PM
| #6 |
| 06 Super National Champ  Join Date: Jun 2004 Location: Stark Industries Bar and Grill
Posts: 11,361
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Yes...cold temps have an adverse impact on NiMh packs. As the temperature drops the internal pack resistance increases. NiCd batts aren't as sensitive to temps as NiMh. The batteries (NiMh) that come with the Parkzone parkflyers are labled "Keep warm before flying" for this reason. Didn't help when I took a buddy out to fly in 40 degree weather today.  40 degree air temps + wind chill = poor performing packs. Still did plenty of hovering and 3D, and John had a chance to put in a few good flights with his Cub. Even made a few 100+ MPH passes with the Stryker.  NiMh also take a charge better when warm than when cold. My good 1000mAh packs would initially accept only 200 or so mAh in the cold today. Had to hit'm multiple times on the Triton to get'm to behave. Last edited by JasonInAugusta; 12-10-2006 at 08:18 PM. |
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12-10-2006, 08:20 PM
| #7 |
| I wanna be Dave Join Date: Jun 2006 Location: Here
Posts: 2,327
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Well i just returned from snowboarding up in hte sierras about 30 minutes ago and ran my truck it has a 3000mah pack which was full when i left home this morning "did a quick test" well we drove my friends 4wd truck up there and i put the little truck into the toolbox 3 hour or so later we were done and i decided that i wanted to run it in the parking lot. It has G-hawg tires a 65T lathe and a emaxx tranny. Well it ran as if the battery was on it's last volt. slower than crap no opower whatsoever. normal speed in low is walking pace and second is well faster than that.
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12-10-2006, 08:24 PM
| #8 |
| owner, Holmes Hobbies LLC  Join Date: Nov 2004 Location: Volt up! Gear down!
Posts: 20,290
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Good NiMH cells perform best above 140F. The 4/5 A cells have a lot of resistance anyway, so the colder you get the worse the performance. I can tell a pretty big difference between 80F and 60F. When you hit 50F and below you can pretty much kiss the performance of any cell that isnt 2/3A or sub C goodbye. I keep all spare batts in my pockets with no other metal. This way they are warm when I hook them in.
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12-10-2006, 10:17 PM
| #9 |
| Keep it real Join Date: Jun 2006 Location: Yakima,WA
Posts: 6,532
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Thanks alot for the info guys, it just reinforced my guessing. I'm new to anything besides sub c cells, and didn't know the 4/5A's had more resistance right off the bat. That explains why my 2/3A pack did better than the 4/5A. Guess I need to rethink my battery strategy. Thanks again. Nathan |
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12-10-2006, 10:44 PM
| #10 |
| RCC Addict Join Date: Apr 2005 Location: Seattle
Posts: 1,437
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I think it only makes a difference when you need an excuse... LOL
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12-10-2006, 10:45 PM
| #11 | |
| Keep it real Join Date: Jun 2006 Location: Yakima,WA
Posts: 6,532
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12-11-2006, 01:11 AM
| #12 |
| Quarry Creeper Join Date: Nov 2005 Location: Planet Earth
Posts: 350
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Chargeing them up right before you run will heat them up too and make them much better performing. Filling over half full the night before is ok, then charge the rest right before if possible (or as much as possible) like maybe 20% at a high rate will build heat. Some over charge on purpose will also build heat.
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12-11-2006, 04:55 AM
| #13 | |
| Newbie Join Date: Mar 2006 Location: Mount Joy
Posts: 5
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12-11-2006, 08:58 AM
| #14 |
| Rock Crawler  Join Date: Sep 2006 Location: Esco.
Posts: 930
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I just attended a comp yesterday in the snow. The courses went from snow covered rocks to icy water crossings. Truthfully, I did not experience any battery problems or have any power loss. I peak charged them the night before.
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12-11-2006, 09:01 AM
| #15 | |
| 06 Super National Champ Join Date: Jun 2004 Location: Stark Industries Bar and Grill
Posts: 11,361
| Quote:
Take a nitro engine and let it idle in the cold weather...measure the head temp. Now run that engine at speed. Even though the engine should be heating up you've still got 30 degree air blowing over the head at X MPH. I've actually had engines come back cooler than what they were when at idle in the same ambient air temp. So although "wind chill" may not have been the best terminology, 100MPH 40 degree air WILL cool a battery. Last edited by JasonInAugusta; 12-11-2006 at 09:07 AM. | |
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12-11-2006, 07:11 PM
| #16 | |
| Keep it real Join Date: Jun 2006 Location: Yakima,WA
Posts: 6,532
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12-12-2006, 07:47 PM
| #17 |
| Rock Crawler Join Date: Mar 2006 Location: Auburn, WA
Posts: 983
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Tanis - did you re-charge the 4/5 pack at home before you tested it again? If so, the fresh peak would give you additional voltage in addition to the temp difference. I remember from my race days that we would peak off our packs right before running for max performance. I think we'll just have to put some time on those 4/5 packs to see what they do. I know my Clod felt like it had more "punch" with the 6 cell sub C than it did with the 8 cell 4/5. I also didn't notice any problems at all with the 2/3 pack in my 2.2
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12-12-2006, 09:43 PM
| #18 |
| Keep it real Join Date: Jun 2006 Location: Yakima,WA
Posts: 6,532
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No didn't repeak, just put them in the truck and tested them. It's weird. When I turned my truck on for the first course and tested it, it had slower wheel speed than usual and then on the first course it just stalled out anytime the tires got any little bind. On the second course I put my 2/3A pack in and didn't stall out once, even bound up worse than the first course. Of course I did change tires, maybe those Ultracs have that much more traction on the rocks LOL. After the comp I tried them out with the 2/3A pack and I didn't stall out like the first course. That night with the 4/5A's I had the normal wheelspeed back and power, but the batts were warm, not cold. I had the same kind of 4/5A pack in Brit's truck, but since I didn't run it this time, I'm not sure her's were acting the same way. I geared her truck down before this comp so she could control the throttle a little easier, so I couldn't tell just by looking at the wheelspeed if it was the same as usual. I made a custom 8cell 3000mah subc pack last night. I might just have to deal with the extra weight of the sub c's to get the performance I want. I'll test it as soon as the snow melts around here.  Nathan Last edited by Tanis; 12-12-2006 at 09:49 PM. |
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12-13-2006, 09:03 AM
| #19 |
| Rock Crawler Join Date: Sep 2006 Location: Esco.
Posts: 930
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I am currently using 7.2v 6c 1800mah mini packs, like the ones for mini-t's. I did not think they would work well but they continue to prove me wrong.
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12-13-2006, 09:15 AM
| #20 |
| Quarry Creeper Join Date: Jan 2006 Location: Jonesboro, TN
Posts: 442
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Yea, I've noticed that cold weather hurts runtime and punch on my regular cell. My Lipo's don't mind it at all though. They just run the same all the time no matter what.
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