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losiXXXman wrote:So, i've got my first lipo and I'm experiencing some issues. I think the battery is seriously out of balance, so I'm trying to balance charge it... how long might a slow balance take at 1s on a 5000 battery thats fully discharged? I've heard that a lot of guys don't balance, as it takes a lot longer, and so my first couple cycles on the battery, I didn't balance. I'm clueless on this whole Lipo thing, so thanks for any advice...

I'm a little confused..

You say that you are trying to balance charge at 1S.. Does that mean that you are trying to charge each cell individually..? OR do you mean that you are charging at 1C (C= Capacity) meaning at 5000mA or 5Amps..?

Personally I always balance charge my LiPo's.. When a LiPo cell (single cell or 1S) is fully charged its voltage should be 4.2 Volts DC, and the voltage should not exceed that 4.2V limit.. SO, for a 2S (2 cell) LiPo battery the fully charged voltage is 8.4 Volts.

When you are doing a regular or non balanced charge on a LiPo (without the balance lead connected) the only sensing that the charger can do is through the main battery connector.. What can also happen if your pack is out of balance, is that one cell may only charge to 4.0 Volts, and charge the other to 4.4 V, for a Total voltage of 8.4 Volts, meaning that one cell is being charged 0.2 Volts higher than it should be (i.e. overcharged), and this could result in the cell being damaged, or worse, the battery pack catching fire....

ALSO.. As I understand it, most LiPo balancers work by discharging the cell with the greater, or higher voltage at approx. 200 mA or 0.2 Amps throughout the charging process, and this is why that it often takes longer to balance charge..

Getting back to my first question regarding if you are trying to charge each cell individually, I would not recommend trying to charge your LiPo's cells individually through the balance lead, as the connector and cables on the balance lead simply are not rated to charge at much more than 200mAmps (0.2Amps).. The only exception to this statement is if you are using "Saddle" style LiPo batteries, that have 4 or 5mm Corally or banana style connectors..

Yeah, I meant charging at 1C or 5amps (for my 5000mAh pack). Hobbyking has acknowledged that I may have gotten a "bad" pack, so they are sending a new one out. I think I'll put this one a balance charge when I get it, and try to mostly do balanced charging. I probably could afford to do that as I don't get out to run the stuff all that much.

I finally switched to LiPo this week. I already had the charger so it just about $ to buy a lot of new 2S batteries. Lots of reasons pushed me to switch, but the last straw was coming across the box full of a dozen or so NIMHs that I bought over the last couple years that are now dead So I'm off to blast around the yard with the T2 runner on 2S

I got my new pack, and soldered it up... runs great. The power output of these batteries is amazing. I now understand all this stuff about pulling wheelies even when you at half throttle by juicing i too much. (Im using a sensorless reedy setup too.) On that note, when I was using this mtor esc w/ nimhs, i didn't really notinc the "cogging". But now it is awful, sometimes the car stutters for quite a while before getting going, so I may have to upgrade to a better esc/motor combo. Going to try running it in nimh mode with the lipo, and see if that reduces the cogging..

losiXXXman wrote:I got my new pack, and soldered it up... runs great. The power output of these batteries is amazing. I now understand all this stuff about pulling wheelies even when you at half throttle by juicing i too much. (Im using a sensorless reedy setup too.) On that note, when I was using this mtor esc w/ nimhs, i didn't really notinc the "cogging". But now it is awful, sometimes the car stutters for quite a while before getting going, so I may have to upgrade to a better esc/motor combo. Going to try running it in nimh mode with the lipo, and see if that reduces the cogging..

That's odd, usually it's the other way around. Check your settings in program mode, maybe something like the throttle position is set to low? I wouldn't put it in NIMH mode, you need the lipo voltage cut-off when running those batteries.

teman wrote:

losiXXXman wrote:I got my new pack, and soldered it up... runs great. The power output of these batteries is amazing. I now understand all this stuff about pulling wheelies even when you at half throttle by juicing i too much. (Im using a sensorless reedy setup too.) On that note, when I was using this mtor esc w/ nimhs, i didn't really notinc the "cogging". But now it is awful, sometimes the car stutters for quite a while before getting going, so I may have to upgrade to a better esc/motor combo. Going to try running it in nimh mode with the lipo, and see if that reduces the cogging..

That's odd, usually it's the other way around. Check your settings in program mode, maybe something like the throttle position is set to low? I wouldn't put it in NIMH mode, you need the lipo voltage cut-off when running those batteries.

Want to say my Reedy ESC from the RTR SC10 would cog with both LiPo and Nimh. Just at slow speeds though. A decent sensored setup would be a good investment if the cogging really gets in the way. My Reedy setup now sits in one of my pit boxes.

I've got 3 cars now that use 2s and 4s lipos and I will never miss a nicad ever again. I balance every charge and use Team check point TC30 chargers

What are you running with 4S? I have my 8th scale buggy that I can run on a single 4S or two 2S batts, it is crazy fast.

Diamond Dave wrote:What are you running with 4S? I have my 8th scale buggy that I can run on a single 4S or two 2S batts, it is crazy fast.

Associated rc8.2e. 1/8th scale buggy

Must be a blast to drive, blazing fast I am sure.

Diamond Dave wrote:Must be a blast to drive, blazing fast I am sure.

No doubt.. Very fast

Looking to purchase a decent lipo charger for charging 2s 5000-5700MaH saddle packs. I see the charger on the first page of this thread from 2011 but what current chargers are decent currently? Current model's I'm looking at now are the Hyperion EOS720I, Icharger 206B and the Duratrax Onyx 245. Leaning towards the Hyperion at the moment with the 90w output. I'm new to this Lipo thing and looking for a charger that will work well now and in the future if I upgrade to larger packs as well as producing fairly fast charge times and is user friendly.

My Hyperion is pretty old and still works great. I'm not sure you could go wrong with any of those though.

I have three of these. 10 amp charge, 30 a discharge fully automatic. Work great. Gotta find em on ebay and such. Out of production.

http://www.rcuniverse.com/magazine/article_display.cfm?article_id=891