Electric for large Planes

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The reason I ask is because charging parallel Nicad packs is not considered good practice. The LiPoly packs must have very low and consistent internal impedances if they can withstand charging in parallel constantly.

Ed Cregger

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That makes perfect sense. Thanks.

Ed Cregger

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Got it.

Ed Cregger

"Ed Cregger" wrote

From what reading I have done, charging in parallel is a definite no-no. Shoot, even charging them in series is sometimes even a problem, with some cells not getting a full charge, and others over charging. Parallel battery packs are even more difficult to keep balanced.

There has been a move by some to use balancing chargers, which requires that the pack have a separate lead for each cell, and the charger reads each battery individually, and brings each cell to full charge. Some people counter, saying that if you use good packs and not run them at too high of an output level, and don't try to charge them too fast, there is little need for the fancy balancing chargers.

I put a lot of stock in that for series packs, but don't know if I would trust parallel charging packs, in any situation.

What the heck. This all hurts my brain, too. I would rather pour some sticky liquid into a container onboard my planes, and allow a chunk of metal right behind the prop make a bunch of noise and mess. I guess I'll start some kinda' flame war, just for admitting that, though!

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No argument from me, Jim.

I fiddle with some RTF type of electrics, but they don't do enough for me to give up my engines. In fact, when I'm too feeble to fuss with engines, the hobby will be pretty much at an end for me. That won't be for a while yet - I hope.

Ed Cregger

Same old Ed, same old stick up his butt. Now I know why I quit coming here.

A piece of advice to newbies: If you are expecting useful and friendly advice, don't come here.

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I never once pretended to be knowledgeable about electric flight. Especially today's electric flight. I was just making a comment about my own lack of skill in this particular area of modeling. Nothing more, nothing less.

Just turned 62 and signed up for social security. I mention it to say that I've been around a while and have made some observations about people over the years. The main observation is that you can't please everyone, so don't try and don't care. It just ain't gonna happen. Before I left a newsgroup that I enjoy because of another person, I would simply put them in my kill file. No one other than me ever needs to know who those folks are. Kill file me, please.

Lately I've been running into folks that once were pleasant and cordial who are now stressed out and rude. It happens to all of us occasionally. But lately it has been off the chart. Oil prices and our ever declining economy are major causes as far as I'm concerned. It is easy to get used to a raising standard of living. It flat sucks when one has to become acclimated by a tanking standard of living. I'm glad I'm old and in crappy health. I feel sorry for you younger folks. I truly am.

Ed Cregger

Not quite, but close. They have a consistent internal impedance, but most importantly, the voltage rises with charge state unlike nickels, where it FALLS at the peak charge (delta peak)

This means they naturally self balance when cells are in parallel.

You leave it connected in parallel and charge it as though it is the total mAh of the two packs, like I said.

Don't know what you've read, but it's wrong. I have been in the battery business for a long time and charge in parallel all the time. YOU DO NEED TO BALANCE THE PACKS AT LEAST EVERY THIRD CHARGE CYCLE. Not balancing is what causes a lot of packs to fail. I use two Astro Flight Blinky balancers when charging in series or parallel with two packs.

Right on the money!