Ok, so I'm new

Old 05-10-2017, 05:40 PM
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Default Ok, so I'm new

So I'm returning to the hobby after a few years or more.

When I left I ran TC with matched cell NIMH and was turning my own motors..... TIMES HAVE CHANGED!

While I understand that most principles are the same, the numbers expected from a good Lipo race pack escape me.

I'm running a Hitec X1 at present. No, no, no I won't be able to discharge or charge at 40 amps. However I think it was a decent little charger for the money.

I can charge up to 17amps however have only done 14 and end up with a voltage of about 8.65. This is with a 6000 mah saddle pack. However I can't seem to get a discharge of more than 4.2 amps on the charger even with it set at the max 8.0 draw.

I'm wondering if I were to go old school, and smack these things a little, will I see more amperage?

I'm interested in any an all advice on the numbers of the lipos and advice with the brushless system. Can I still zap a can lol?
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Old 05-10-2017, 06:55 PM
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First off have you read the warning label on the lipo's?? And chances are the charger will have its limits, so if your charging your 2s lipos above the recommended 8.40 volts your looking for a good old fashioned fire, so if your planning on wacking them for more amperage, I will bring the marshmallows, not to sound rude, but times have changed and now the biggest thing to look at in lipo batteries is the C rating, that's my opinion as you get what you pay for, same goes for motors and chargers.
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Old 05-11-2017, 03:28 AM
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They are 80c. I guess I'm trying to rap my head around what I'm supposed to expect from the battery.
They don't even get warm at 14.0 v. They hit 83 degrees and that was after a 8 minute romp.

I'm really not sure if the charger is noting 4.2 per cell or a 4.2 cumlitive amperage. The literature is vague. Though the set up in the menus notes it as a 2 cell 7.4 Lipo.

You didn't sound rude at all. I'm just thinking back and remembering what my NIMH were doing..... this battery doesn't seem too much more powerful... maybe just a longer mode consistent run time.

Originally Posted by Troubles Dad
First off have you read the warning label on the lipo's?? And chances are the charger will have its limits, so if your charging your 2s lipos above the recommended 8.40 volts your looking for a good old fashioned fire, so if your planning on wacking them for more amperage, I will bring the marshmallows, not to sound rude, but times have changed and now the biggest thing to look at in lipo batteries is the C rating, that's my opinion as you get what you pay for, same goes for motors and chargers.
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Old 05-11-2017, 04:33 AM
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Originally Posted by Stareyedirish
They are 80c. I guess I'm trying to rap my head around what I'm supposed to expect from the battery.
They don't even get warm at 14.0 v. They hit 83 degrees and that was after a 8 minute romp.

I'm really not sure if the charger is noting 4.2 per cell or a 4.2 cumlitive amperage. The literature is vague. Though the set up in the menus notes it as a 2 cell 7.4 Lipo.

You didn't sound rude at all. I'm just thinking back and remembering what my NIMH were doing..... this battery doesn't seem too much more powerful... maybe just a longer mode consistent run time.
Grab a old Nimh pack and compare, so who made the battery, what are you running it in, as some manufacturers will give you 2 numbers, like a 40-80c rating, also note how long you ran, the old packs you could make 6-7 minutes and now I in stock 17.5 buggy we race for 15 minute mains, and practice upwards of 25 minutes on a battery, also note that hitec gives you what appears to be the correct voltage, as I had a couple of them chargers, and had issues, then bought better and now feel confident that my packs are fully charged, as they are 8.40 volts when done.
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Old 05-11-2017, 07:41 AM
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It's a JP saddle pack.

I'm running it in a mod 4wd buggy.

I'll run what I've got for the season. Maybe I can get one of the icharger guys to slap it on and see what he get.
Originally Posted by Troubles Dad
Grab a old Nimh pack and compare, so who made the battery, what are you running it in, as some manufacturers will give you 2 numbers, like a 40-80c rating, also note how long you ran, the old packs you could make 6-7 minutes and now I in stock 17.5 buggy we race for 15 minute mains, and practice upwards of 25 minutes on a battery, also note that hitec gives you what appears to be the correct voltage, as I had a couple of them chargers, and had issues, then bought better and now feel confident that my packs are fully charged, as they are 8.40 volts when done.
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Old 05-13-2017, 03:45 AM
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DO NOT try to compare or relate any of the newer RC technology to the old. With both the brushless motor and LiPo batteries the technology is totally different. There's no reason nowadays to Zap your packs or zap the motor cans on the brushless motors. If you wanted to zap anything, I think you'd probably have to zap the rotor (That would be BAD!). You'll probably notice that when pricing out batteries now that the higher the C rating usually (not always though) dictates the price, along of course the the Capacity (Mah).
Bottom line is this, just set your charger to not charge to more than 8.4 volts on a regular 2s pack or 8.6 volts on a new High Voltage pack (which aren't legal for racing yet anyway)
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Old 05-14-2017, 01:56 AM
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With greater power comes greater responsibility Also the battery is going to get warm from current draw, not voltage

But seriously if you are new to lipo the biggest thing you need to know is that they are significantly more powerful than nimh and failures can be much more catastrophic then their predecessors.

The C (Coulombs) rating of the battery is a representation of the internal resistance of the battery, which is the limiting factor to how much current (amps) can move in or out of the battery at a time.

The mAh (Milli-Ampre*Hour) is pretty much the same, as stated earlier its the storage capacity of the cells and voltage is the same as well, its just the potential energy across the components.

The cells in a battery is pretty much the same as the nimh and nicd, its just the lipos generate more voltage per cell so the cell count is lower.

Any lipo cell should only ever be charged to 4.2v by a lipo battery charger and you should remain above 3.0v if I recall (I never let mine get that low) It is also important to keep your battery balanced as this can cause issues. Any roar approved lipo should have a hard shell so that the cells cannot be physically damaged. If you notice a faulty cell, swelling in the battery or damaged cell the battery should be immediately retired.

Its also important to keep your batteries at storage voltages until you are about to use them as keeping them at max voltage will limit how long they last.

The nice part about lipo aside from the power gain is that they don't need to be fully discharged each time like ni-cd and seem to retain most of their power throughout their lifespan.

I have ran lipos for years and I've had a few packs fail with some epic abuse. Once I had a strap break free from an rc plane ~300ft up in the air and eject the battery and in the same plane a few years I had the wing fly off and the fuselage and battery (soft pack) crash into asphalt. I have also had two battery's just fail over time without a single battery ever catching fire. afterward ALL packs were tossed.

I just don't want to make the lipo batteries sound like they're a ticking time bomb, but just emphasize the importance of proper battery management and care.

So the short version is the C rating is how much current you can draw from a time while the Volts and Amps are similar to its predecessor. Battery balance and care is paramount in lipos. You need to use a lipo charger/balancer (make sure the balance connectors are compatible) I found that 2 packs were more than enough to keep my T4 on the outdoor track in Arizona during the summer.

Your brushless setup will prolly depend on what class/spec you want to run. I would check out where you want to race at and see what is ran for your chassis type.

Sorry for the shotgun approach and welcome back!
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