A little electric help here
05-07-2010, 04:56 PM
#1
A little electric help here
Need a little help please.. I just got my hands on a E Revo with the Novac hv pro 7.5 conversion and it has two 7.2 5000 nimh batteries. Now I have no real idea what I got myself into I always ran nitro before this... But I hear that Brushless is the new best thing so help me understand how to make this thing go more than 15 miles an hour for 5 mins.... whats the matter here?? I have changed the pinion gear from a 17 to a 16 and the runtime and hp still blows, i also checked the programing on the esc and had to turn off the lipo auto shutoff thing, and even that gained me another 45 seconds. Please school the new electric guy? Im not trying to be a racer or break 60 miles an hour, just wanna keep up with the stock 3.3. This is just pretty pathetic.
Thankx in Advance
Thankx in Advance
05-07-2010, 06:49 PM
#5
I'd be suspicious of the batts. How old are they when you got them, how long had they been sitting unused? Were the stored fully charged or not? NiMh doesn't like to be left sitting for anything over a month without some kind of maintenance. It can take some cycles to get them back to the best they'll run if they're going to recover.
How are you charging them? You are using a peak stype charger? Are the both getting equally hot when they peak? You shoulkd be charging somewhere around 5amps with a peak setting of 3 to 5mv/cell and they should be getting to 120-130F when they peak. What is the charger putting back into them after running?
Sorry for all the ques, but need to know whats going on with the batts and how they're being handled since they're what makes this go (or not).
The key to the brushless thing is lipo. Even the best NiMhs have a hard time supplying the amp demand of a good BL setup.
How are you charging them? You are using a peak stype charger? Are the both getting equally hot when they peak? You shoulkd be charging somewhere around 5amps with a peak setting of 3 to 5mv/cell and they should be getting to 120-130F when they peak. What is the charger putting back into them after running?
Sorry for all the ques, but need to know whats going on with the batts and how they're being handled since they're what makes this go (or not).
The key to the brushless thing is lipo. Even the best NiMhs have a hard time supplying the amp demand of a good BL setup.
05-07-2010, 07:17 PM
#6
I'd be suspicious of the batts. How old are they when you got them, how long had they been sitting unused? Were the stored fully charged or not? NiMh doesn't like to be left sitting for anything over a month without some kind of maintenance. It can take some cycles to get them back to the best they'll run if they're going to recover.
How are you charging them? You are using a peak stype charger? Are the both getting equally hot when they peak? You shoulkd be charging somewhere around 5amps with a peak setting of 3 to 5mv/cell and they should be getting to 120-130F when they peak. What is the charger putting back into them after running?
Sorry for all the ques, but need to know whats going on with the batts and how they're being handled since they're what makes this go (or not).
The key to the brushless thing is lipo. Even the best NiMhs have a hard time supplying the amp demand of a good BL setup.
How are you charging them? You are using a peak stype charger? Are the both getting equally hot when they peak? You shoulkd be charging somewhere around 5amps with a peak setting of 3 to 5mv/cell and they should be getting to 120-130F when they peak. What is the charger putting back into them after running?
Sorry for all the ques, but need to know whats going on with the batts and how they're being handled since they're what makes this go (or not).
The key to the brushless thing is lipo. Even the best NiMhs have a hard time supplying the amp demand of a good BL setup.
Im starting to agree I have charged them a total of 5 times now today and there may be some improvement... Dont apologize this is exactly what I looking for "info" ill tell you what i know. I know nothing about these batteries before 3 pm yesterday but they look beat up and old. They look way older than the Truck. Im charging them with a purple charger called the brain something.. and im charging them at 3amps as for the mv's i have never adjusted this. there no way, getting that hot when i charge them and it only takes about 15 mins each... but they get super hot when being used. and one gets more hot then the other when running in the truck. The charger is supplying them with almost half a volt or better they seem to be about 7.3ish when empty and between 8.01 and 8.10 when charged, hope this doesnt sound too too dumb. anyway your right about the lithium polymer, thats the way im sure. but i just blew my load on a new special order spectrum trans/receiv set today. the traxxas one is junky i think. As long as this motor isnt junk then i will invest in the lipo's, that was my big concern. sorry for the run on and on but thanks for the help.
05-07-2010, 07:35 PM
#7
[QUOTE=07d675cm2;7375905] but i just blew my load on a new special order spectrum trans/receiv set today. the traxxas one is junky i think. QUOTE]
HAHAHA!!!
Anyway, the batteries are surely garbage. the reason one is getting hotter than the other is because one of the batteries is also supplying your BEC (battery eliminator circuit) with power so you can use your receiver and servos without a separate power source. It draws more juice from one side hence the heat issue.
First you need to dump the brushless setup. The HVs are crap. Not trying to insult your ride at all because Revos are awesome but that thing will either burn up internally or blow up your truck. I've had both happen and it cost me $500 to learn that lesson.
And definitley get some better batteries. They are dirt cheap these days.
HAHAHA!!!
Anyway, the batteries are surely garbage. the reason one is getting hotter than the other is because one of the batteries is also supplying your BEC (battery eliminator circuit) with power so you can use your receiver and servos without a separate power source. It draws more juice from one side hence the heat issue.
First you need to dump the brushless setup. The HVs are crap. Not trying to insult your ride at all because Revos are awesome but that thing will either burn up internally or blow up your truck. I've had both happen and it cost me $500 to learn that lesson.
And definitley get some better batteries. They are dirt cheap these days.
05-07-2010, 07:39 PM
#8
[QUOTE=Neu_Racer;7375958]
dump the brushless system for what... a brushed one like the stock one? are all brushless systems crap?? should i have stayed with nitro? lol
but i just blew my load on a new special order spectrum trans/receiv set today. the traxxas one is junky i think. QUOTE]
HAHAHA!!!
Anyway, the batteries are surely garbage. the reason one is getting hotter than the other is because one of the batteries is also supplying your BEC (battery eliminator circuit) with power so you can use your receiver and servos without a separate power source. It draws more juice from one side hence the heat issue.
First you need to dump the brushless setup. The HVs are crap. Not trying to insult your ride at all because Revos are awesome but that thing will either burn up internally or blow up your truck. I've had both happen and it cost me $500 to learn that lesson.
And definitley get some better batteries. They are dirt cheap these days.
HAHAHA!!!
Anyway, the batteries are surely garbage. the reason one is getting hotter than the other is because one of the batteries is also supplying your BEC (battery eliminator circuit) with power so you can use your receiver and servos without a separate power source. It draws more juice from one side hence the heat issue.
First you need to dump the brushless setup. The HVs are crap. Not trying to insult your ride at all because Revos are awesome but that thing will either burn up internally or blow up your truck. I've had both happen and it cost me $500 to learn that lesson.
And definitley get some better batteries. They are dirt cheap these days.
dump the brushless system for what... a brushed one like the stock one? are all brushless systems crap?? should i have stayed with nitro? lol
Last edited by 07d675cm2; 05-07-2010 at 07:41 PM. Reason: added something
05-07-2010, 07:46 PM
#9
No, absolutely not. The Novaks are just particularly horrible for 1/8 scale. Their 1/10 stuff works but after I had an HV system destroy a 1/8e buggy with $500 + worth of electronics and batteries in it I swore it off.
I would suggest the Castle 2200kv system or a Hobbywing setup. Castle is definitely better but you're looking at another $250 or so and considering you "blew your load on a Spektrum system" may not be in the cards now.
Hobbywing 80A motor/ESCs can be had for about 1/2 that and work ok. Motors get a bit hot but fans help.
I would suggest the Castle 2200kv system or a Hobbywing setup. Castle is definitely better but you're looking at another $250 or so and considering you "blew your load on a Spektrum system" may not be in the cards now.
Hobbywing 80A motor/ESCs can be had for about 1/2 that and work ok. Motors get a bit hot but fans help.
05-07-2010, 08:00 PM
#10
No, absolutely not. The Novaks are just particularly horrible for 1/8 scale. Their 1/10 stuff works but after I had an HV system destroy a 1/8e buggy with $500 + worth of electronics and batteries in it I swore it off.
I would suggest the Castle 2200kv system or a Hobbywing setup. Castle is definitely better but you're looking at another $250 or so and considering you "blew your load on a Spektrum system" may not be in the cards now.
Hobbywing 80A motor/ESCs can be had for about 1/2 that and work ok. Motors get a bit hot but fans help.
I would suggest the Castle 2200kv system or a Hobbywing setup. Castle is definitely better but you're looking at another $250 or so and considering you "blew your load on a Spektrum system" may not be in the cards now.
Hobbywing 80A motor/ESCs can be had for about 1/2 that and work ok. Motors get a bit hot but fans help.
OK thanks so much for the info... I just traded a jato 3.3 and a revo 3.3 and a ton of parts for this thing, im beginning to wonder if I got the short end.
05-07-2010, 08:33 PM
#11
Im starting to agree I have charged them a total of 5 times now today and there may be some improvement... Dont apologize this is exactly what I looking for "info" ill tell you what i know. I know nothing about these batteries before 3 pm yesterday but they look beat up and old. They look way older than the Truck. Im charging them with a purple charger called the brain something.. and im charging them at 3amps as for the mv's i have never adjusted this. there no way, getting that hot when i charge them and it only takes about 15 mins each... but they get super hot when being used. and one gets more hot then the other when running in the truck. The charger is supplying them with almost half a volt or better they seem to be about 7.3ish when empty and between 8.01 and 8.10 when charged, hope this doesnt sound too too dumb. anyway your right about the lithium polymer, thats the way im sure. but i just blew my load on a new special order spectrum trans/receiv set today. the traxxas one is junky i think. As long as this motor isnt junk then i will invest in the lipo's, that was my big concern. sorry for the run on and on but thanks for the help.
These should be taking about 45min to charge fully, so part of the prob is the charger. The reason they're getting hot when used is they can't supply the current that they're being asked to. Do you have any access to another charger? Your RC would run differently (better) if the batts were really getting a full charge. These cells should be +/-1.5v off the charger so a 6 cell pac should get up there close to 9v or maybe a little better. These might not be trashed, but its going to be hard without a good charger to get them to the best that they can do.
05-07-2010, 08:51 PM
#12
Well i want to thank you all for your help i was thinking about busting out the credit card tomorrow and getting some lipo's and a Charger. Does anyone know what the max battery size I can put on this little hv 7.5 without burning it out? and what is a good brand?
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