Opus BT-C3100 problem

9 posts / 0 new
Last post
brewster
Offline
Last seen: 1 day 7 hours ago
Joined: 07/19/2019 - 23:29
Posts: 78
Location: Australia
Opus BT-C3100 problem

My Opus BT-C3100 ver 2.2, which is now a few years old, has developed a problem. When charging NiMH cells, the slot #4 terminates after adding only a few hundred mAh and reports ‘Full’. Restarting the charge proceeds as normal until the cell is actually full, adding another 1000 to 1500 mAh. It seems slot #3 is doing it occasionally now, too.

The cells are AAs of no great quality, but they charge fine in the other slots. I usually charge at 700mA, although a few tries at 1000 mA also failed in the same way.

Anyone experienced the same? Is there anything I can do? Is there any risk from a charger that is failing in this way?

leaftye
Offline
Last seen: 11 months 3 weeks ago
Joined: 07/25/2012 - 17:43
Posts: 4278
Location: San Diego, CA

Yes, there’s risk. There’s always risk with any charger. At least you’re charging nimh batteries. With lithium ion the risk is increased, and to be safe you should never leave those charging unattended. As to this charger, I’ve had two fail. One was sort of my fault. It’s supposed to have reverse polarity protection, but it didn’t work when I inserted a (lion) cell backwards and quickly fried the charger. My second charger overcharged a full bank of (Lion) batteries and showed no signs of slowing by the time I caught it. I have a third one, bnib where it’s probably going to stay because I’ve lost trust in these chargers. There’s other users that report failures on this forum.

The low mode should be lower.

BaronVonEissler
BaronVonEissler's picture
Offline
Last seen: 1 year 4 months ago
Joined: 11/03/2019 - 10:10
Posts: 500
Location: 3rd Stone From The Sun

I have had mine over Three years with no issues as far as failure to work.. I have put Li. Ion in backwards with no consequences.

I did modify it Three years ago with a better fan and SMPS[Power supply] that has eliminated any stoppages during discharge cycles and runs more efficiently[cooler]

You can't hide me from me.

leaftye
Offline
Last seen: 11 months 3 weeks ago
Joined: 07/25/2012 - 17:43
Posts: 4278
Location: San Diego, CA

Their quality is inconsistent. Sometimes in cases like yours, there are no problems for years, while others have failures, even for things that the thing was specifically designed to protect against. Too bad because I’d love this charger if it wasn’t unsafe, but I can’t risk using it in my home again.

The low mode should be lower.

NeutralFan
NeutralFan's picture
Offline
Last seen: 2 days 17 hours ago
Joined: 03/20/2014 - 19:22
Posts: 1588
Location: Wisconsin, USA

That’s interesting how some of the slots charge fine right away and the others don’t. Maybe it’s a mechanical problem. Have you tried cleaning the contact points in slots 3 and 4? Try using some isopropyl alcohol or maybe even some fine grit sandpaper.

My Opus BT-C3100 (version 2.0) has been flawless, including the fan. A couple years ago I started using my LaCrosse BC700 again for charging NiMH batteries. There was nothing wrong with the Opus, but since I had the BC700 before I started using Li-ion batteries, I wanted to lessen the load on the Opus.

I’d rather use my flashlight around the house than turn on the lights.

flydiver
Offline
Last seen: 2 hours 1 min ago
Joined: 06/19/2013 - 19:16
Posts: 1308
Location: Seattle, WA

Termination can be a more difficult problem with NiMh than with Li-on. Older cells with higher IR just exacerbate the problem. Wonder if the resistance on the sliders has gotten worse? Try cleaning the contacts well, both on the charger and the suspect batteries.
Do and IR test. The Opus is not super accurate but if you are getting really high readings (>500) that indicates the cells are not so good.

To Air is Human, to Respire….Divine.

ChrisGarrett
ChrisGarrett's picture
Offline
Last seen: 4 hours 36 min ago
Joined: 02/12/2014 - 22:03
Posts: 1030
Location: Miami, Florida

I’ve had my BT-3400 v. 2.2 for 4 years and it’s still kicking ass.

Last year, I bought the BT-3400 v. 3.1 and it’s been fine.

I’m a fan.

Chris

brewster
Offline
Last seen: 1 day 7 hours ago
Joined: 07/19/2019 - 23:29
Posts: 78
Location: Australia

Thanks for the replies. My concern about safety was mainly with Li-ions.

The internal fan works well, after I gave it a drop of oil about a year ago. I also use an extra USB fan with heavy loads, like charging a full house of Li-ions or discharging. Based on earlier threads here and HKJ’s review, I run the Opus off a larger laptop power supply, although that probably only matters for heavy loads.

I’ll do the maintenance and tests as recommended.

FlashKat
Offline
Last seen: 4 days 1 hour ago
Joined: 11/27/2014 - 20:54
Posts: 194
Location: Anaheim, CA

I had an Opus-3100 that overcharged one 18650 battery to 5.2 volts, and the other did not get charged past 3.6 volts.
I just trashed my Opus-3100 instead of taking any future chances.
Saving your charger may be worth burning down something, but I chose to buy 2 new XTAR SV2 chargers.