What Lipo's Are Most Using?

[mporlier]

Lipos are much easier to live with than NiMh batteries.
NiMh batteries must be discharged after each use otherwise the capacity drops away rapidly (memory effect).

If you are using a 5cell NiMh pack you would still need a stepdown for the tail servo.

Mick

I am not certain but I think NiMh have no memory. Only NiCd suffer from this problem?

[jbock24]

correct nimh has no memory, I agree if that means anything

[aussiemick]

NiMh DO have memory effect

read from the fifth paragraph
http://www.buchmann.ca/Article10-Page1.asp

Mick

[mporlier]

NiMh DO have memory effect

read from the fifth paragraph
http://www.buchmann.ca/Article10-Page1.asp

Mick

Thank you for this info!

[aussiemick]

Here is an excert from schulze in one of their charger manuals page 6 of the hyper link.
http://www.schulze-elektronik-gmbh.de/index_uk.htm

"If cells are repeatedly stored partially discharged, or are recharged from a half-discharged state,
what is known as the memory effect sets in. The cells note that their full capacity is not required,
and react by refusing to make it available.
One aspect of this is that the crystalline chemical structure inside the cell changes; the cell‘s
resistance rises and its voltage collapses under load, with the result that “full capacity” can no
longer be exploited at normal discharge currents.
Even if reflex charging were to eliminate the memory effect, there is no denying the necessity to
store your cells in the discharged state; this applies to Ni-Cd cells and also to Ni-MH cells.
A characteristic fact of these cells is that they self-discharge - and the rate of self-discharge is
different for each individual cell in a battery pack! If a fully charged pack is left for a considerable
time, it will eventually consist of cells of widely varying states of charge.
If at this point you ...
a) ... give the pack a full charge: the cell with the highest charge will be overcharged, heat up and
be ruined, while the cell with the least charge will still not be full after the same period of charging.
b) ... discharge the pack: the cell with the least charge will be completely flat first, then reverse
polarity and often suffer an internal short-circuit. At the point when this happens, the cell with the
most charge is still not yet completely discharged.
This is a reliable method of wrecking your most valuable packs - and rest assured that reflex
charging will make absolutely no difference. However, there is one method of avoiding the
problem: discharge cells after use, and recharge them just before use!"

MIck

[jbock24]

I'm not being the argument guy here but your first example is 7year old informaton
the cells basic design has changed since then the insulator inside the cell has been changed
to eliminate exchange. Also NIMH does have a higher discharge rate when not being used
than do Nicad's, however you always have the option to run doubles and I personally have never had any formation charging problems or memory problems with NIMH systems. And if you take into account the impedence differences between the two I think if your not using lipo's NIMH is the best choice. I have two friend with over eight thousand in jets and they trust them to. I think like everything in this hobby information is biased depending on who's
providing it and how up to date it is. Kinda like California is Futaba central they say JR and Spektrum is junk, you know as well as I do chances are real good they all come from some overseas factory. Just IMO..... Take all info with a grain of salt.

[aussiemick]

I use Nimh in all of my gliders and in my Tx.

I know for a fact that the capacity is nowhere near as good now as when they were new. I never used to discharge after a days flying and the capacity dropped away after about 6 months of abuse. I now discharge witha very smart charger (NextGeneration schulze) and the batteries are getting better but still only about 65% of new capacity.

I never said dont trust them I just said Lipos are more user friendly.

Mick

[TheBum]

I'm using the Align 1900 that came with the 2-in-1. I actually ended up with two of them after I burned up my first 2-in-1, so I have enough capacity to last me for awhile and I can always charge one while I'm flying the other.

[slo_dave]

I actually ended up with two of them after I burned up my first 2-in-1

Can you elaborate...I was considering the Align 2in1 but a friends fried also. Was it the unit or something else that caused it.

Thanks,

Dave[

[TheBum]

Can you elaborate...I was considering the Align 2in1 but a friends fried also. Was it the unit or something else that caused it.
Something else, namely my stupidity. :oops:

I accidentally got one of the connectors on my Multigov skewed by one pin. Nothing else fried, luckily.