Batteries - Bumblebee v Greentec v ReInvolt

[theaveng]

Originally Posted by northrupr

I don't want to sell my Honda Insight (2000).
I'd put $1000 down on the "Better Battery" that everyone on this forum raved about, and it went down some hole on Staten Island that may have been washed out to sea recently. Lucky for them I live 2k miles away.

File a credit card dispute via phonecall. Tell the representative, "I purchased a battery for $1000 that was never delivered." The seller than has a few days to prove the battery was delivered. When he fails, you will get your money back and the seller will lose $1000 from his credit Merchant account.

[IamIan]

Originally Posted by theaveng

One of the photos says "Battery being charged at 151.7 volts and 157.6 mA, using full wave bridge and Variac. This setup needs more attention than constant current setup." That's not really a trickle charge then, because a trickle charge operates at 1/20 C and can be left on the battery indefinitely.

I'd still say it is a trickle charge ... it is fast enough to charge in a day or two ... but slow enough not to be likely to cause significant damage in a day or two ... keep in mind a trickle charge is a bit different from a maintenance charge.

A maintenance charge can be left on for long term Months without any significant damage.... this is the kind of charge you want to be doing as you say , 'indefinitely'

A trickle charge is one that takes a day or two to charge the battery very slowly... but is a faster rate than the maintenance charger ... using a trickle charge as a maintenance charge will result in more degradation to the cell over the course of a year or so than if you had actually used a maintenance level charge.

C/20 for trickle charge is not a hard rule ... it is a general guide line commonly used... it won't hurt the battery to be charged slower at C/25 or C/30 ... or as in the case of ~156mA , about ~C/40... this logic can be continued down to about C/650 or ~10mA ... around there you might not keep ahead of Self Discharge Rate ... depending on temperature and such... and the slower the rate gets you start to move away from trickle charge and into maintenance charge... but it really isn't a hard line , but more of a shades of gray kind of thing... slowly bit by bit transitioning from trickle to maintenance.

[theaveng]

Thanks for clarifying. My NiCad and NiMH cells in AA size charge at C/20. Guess I shouldn't be leaving them on the charger.

[IamIan]

Originally Posted by theaveng

Thanks for clarifying. My NiCad and NiMH cells in AA size charge at C/20. Guess I shouldn't be leaving them on the charger.

If they maintain the C/20 rate even after the cell has reached 100% SoC ... it will in the long run ... many months or years ... reduce the cells effectiveness compared to a charger that either did the whole process at a slower rate or one that at least switched to a slower rate once it reached 100% SoC.

In the short term ... a few days a week or so ... it is not likely to present any significant issues ... C/20 is slow enough for no immediate cell damage.

I have general retail AAA and AA NiCd and NiMH chargers that when I tested them ... some do not maintain the C/20 rate ... some do stay at the C/20 ish rate ... but some I've tested drop back significantly , like C/100 or so once they reach up near the ~99% SoC point.

[theaveng]

Originally Posted by IamIan

If they maintain the C/20 rate even after the cell has reached 100% SoC ... it will in the long run ... many months or years ... reduce the cells effectivenes.

Not even really a "charger". It's just a wallwort with a cable coming out of it. It feeds a constant C/20 charge to whatever is attached to it w/o measuring the cell's SOC. It's what came with the $50 R/C car. (shrug)

Here's what I upgraded to and now use most often (LaCrosse). It has adjustable charge rates downto 200mA, and also a "refresh" mode to revive old NiCd or NiMH cells via deep cycling:

[IamIan]

Originally Posted by theaveng

Here's what I upgraded to and now use most often (LaCrosse). It has adjustable charge rates downto 200mA, and also a "refresh" mode to revive old NiCd or NiMH cells via deep cycling:

I have one of those as well ... it is a reasonably nice unit , better than many retail AAA and AA chargers out there ... and once it reaches the top SoC it does dial the rate way back to help with prolonged stay on the charger.