Eneloop Charge / Discharge rates ?  - Page 1
Forum section: electronics / general

author: Flump
author_rank: Frequent Contributor
timestamp: August 13, 2015, 12:19:30 pm
content: I just bought some EneloopsAnd wondered what the best Charge rate for prolonged battery life is and a sensible Discharge rate is for them,I want to do a few Cycles to get them off to a good start.AA BK-3MCCE/4BEhttp://www.amazon.co.uk/Panasonic-BK-3MCCE-4BE-Eneloop-Rechargeable-White/dp/B00IWS52MIAAA BK4MCCE/4BEhttp://www.amazon.co.uk/Panasonic-BK-4MCCE-4BE-Eneloop-Rechargeable/dp/B00JVV8PS8/ref=pd_bxgy_23_img_ymy Charger is Accupower IQ-328http://www.accupower.at/iq328_en.php

author: ion
author_rank: Regular Contributor
timestamp: August 13, 2015, 02:00:38 pm
content: 0.5C is usually a good charging rate that's gentle on NiMH batteries, although I've read that Eneloops can safely handle up to 1C.1 Amp for the AA and 400 mA for the AAA should be sensible values for charging.Your charger can't discharge at more than 500mA, which shouldn't be a problem for any of the cells. Lower currents will drain more energy out of the cell but the cycles will take longer.However if you want to check the capacity of the cells, you'll get a more accurate result if you can match the current draw of the device you will be using them in. If they're not going in any specific device, I'd normally discharge at 200mA.

author: Flump
author_rank: Frequent Contributor
timestamp: August 13, 2015, 05:04:32 pm
content: Ok so Charge and Discharge at 500mAhThanks very much both of you

author: BillW50
author_rank: Contributor
timestamp: August 13, 2015, 08:19:24 pm
content: I am not knowledgeable about your charger. But it might show capacity when charged. Is that true? If true, the capacity varies for many reasons but the most important is how long you drain them down to. The lower you drain them, the more capacity it will show when recharged. But this capacity isn't as important as the state you normally recharge them at. Say you recharge them when they are 50% empty, it should show about 50% of the rated capacity. As long as what you are doing isn't changing the capacity, you are doing fine.Eneloop batteries are really tough. I wouldn't be surprised if Eneloop can be charged at 2 to 3C without any damage. As far as I know (AFAIK), Eneloop only comes in AA (around 2000mah) and AAA (750mah) sizes. If anybody knows of other sizes, I would love to know. I don't know about your battery charger, but most NiMH battery chargers will heat up the battery near the end of the charge. And I am very surprised how cool the XTAR VC4 runs at. One of the coolest chargers I ever used. Hell even the vent slots are fake and there isn't any really. Heat is the big thing to worry about with battery care.

author: retiredcaps
author_rank: Super Contributor
timestamp: August 13, 2015, 08:22:39 pm
content: Quote from: BillW50 on August 13, 2015, 08:19:24 pmSeehttp://www.candlepowerforums.com/vb/showthread.php?364607-Overview-All-eneloop-batteries-2005-2015

author: BillW50
author_rank: Contributor
timestamp: August 13, 2015, 08:40:05 pm
content: I never found any C or D size Eneloop batteries. I would love to find AAAA size Eneloop as well. Has anybody else?

author: IanB
author_rank: Super Contributor
timestamp: August 14, 2015, 12:07:42 am
content: I have an IQ-328. I was not impressed. At low charge rates it can miss the end of charge condition and over charge one or more cells. At 1000 mA or higher it tends to overheat and cook the batteries. If you stick to 700 mA you might get a successful charge.Also, regardless of the data sheet, do not charge Eneloops at 2A. When brand new they might tolerate it, but older cells I have tested popped the seal and started venting. It's safest to keep the charge rate at 1A or lower. For best results you could buy one of the Panasonic chargers sold in a bundle witH Eneloops. Those chargers seem like they are designed well.

author: Flump
author_rank: Frequent Contributor
timestamp: August 14, 2015, 01:14:23 am
content: Quote from: IanB on August 14, 2015, 12:07:42 amI have not been able to find any information on the net about this, is it a known problem or just your experience Ian ?

author: IanB
author_rank: Super Contributor
timestamp: August 14, 2015, 01:31:19 am
content: Quote from: Flump on August 14, 2015, 01:14:23 amYou will probably find the most relevant discussions on Candle Power Forums.However, you can test it yourself. Just charge four empty batteries at, say, 500 mA and see what is reported as the end of charge total for each cell. All four values should be about equal and none should be more than 2300 mAh or so. Or try charging at 1000 mA and see if the charge can finish without the batteries getting hot and the charger's thermal management cutting in.

author: Flump
author_rank: Frequent Contributor
timestamp: August 14, 2015, 02:03:14 am
content: I discharged them @ 500mAh and charged them at the same ratethis is how much they each took1762 | 1952 | 1959 | 1941I have set them on another self discharge/charge cycle and will report back in a few hourshow much they took this time.The batteries are in the same charge bay (not been removed)so should be consistent readings.

author: IanB
author_rank: Super Contributor
timestamp: August 14, 2015, 02:11:23 am
content: The three at about 1950 are balanced, if a little undercharged, which is OK. However, the one at 1750 is unbalanced, which is not good.

author: retiredcaps
author_rank: Super Contributor
timestamp: August 14, 2015, 05:04:43 am
content: Quote from: Flump on August 14, 2015, 01:14:23 amIQ-328 = Opus BT-C700 or Opus BM100?http://lygte-info.dk/review/Review%20Charger%20Opus%20BT-C700%20UK.htmlhttp://lygte-info.dk/review/Review%20Charger%20Opus%20BM100%20UK.htmlhttp://www.accupower.at/iq328_en.php