Opus BT C3100 charger problem

I’ve had the c3100 for a few years without any problem. Recently I’ve been unable to change the charging current from the standard 500 mAh. This is fine for lithium batteries but not for NiMH and other cells. The button still works, since the backlight comes on when I press it, it just won’t change the mAh. Also the whole thing freezes sometimes when putting a battery in. Anyone experienced the same issues? There’s no obvious damage to the electronics inside. Is it bricked and should I get a new one?

Welcome to BLF! :sunglasses:

I’ve been using several Opus BT-C3100 for several years without a single issue except the noisy fan. Sorry i can’t help on this. It may be time to replace it…

I’ve recently retired a BT-C3100 that would stall when charging NiMH in slot 4 (and occasionally slot 3 too). It would report ‘Full’ after adding only 2-300MAh to an empty cell. The problem seemed to be independent of both the cell age and the cleanliness of the sliders and contacts (the two things that were suggested to me for checking).

With it malfunctioning, I was reluctant to use it with Li-ions.

Welcome to BLF. :slight_smile:
I have used one for 2 yrs, not heavy use, with no problems. I will get another charger when it malfunctions. No need to risk a fire. :wink:

Thanks for the replies everone. Time to retire this charger it seems. Any recommendations for a 18650/AA/AAA charger?

Edit: preferably with discharge test too

For the money, around $30 US the Zanflare C4 checked all my boxes for a charger. I haven’t found one yet that does all this so well yet. Has 4 independent slots, discharge testing, Ir test (actually works well), adjustable current 300mah to 1A on all 4 slots, can change current on the fly (no auto current selection) and charge modes while charging also. Doesn’t overcharge cells either and handles my nimh well too. It doesnt do li-ion HV, lifep04 though. It doesn’t have a dedicated discharge mode either, but that’s okay. Only other I’d recommend is the SkyRc MC3000 (expensive) or MiBoxer C12-4. If you don’t want the testing or discharge function, the Enova Gyrfalcon All-44 is great too.

Trying checking HKJ’s charger reviews:


“Analyzer” on the table refers to Discharge Capacity Test

For 2-slots, I suggest the AllMaybe/Xtar TC2.
For 4-slots, there are many choices, some might have “pros” and “cons” (eg. does it do “trickle charging” for NiMh, etc).

Thanks, they’re very helpfull, but somewhat overwhelming if you don’t know what you’re looking for.

Based on my local availability, I might go for the Gyrfalcon :slight_smile:

@JoachimH: Might as well still get a new generation analyzing charger for someone who already has been accustomed to the Opus BT-C3100.

Had this charger since June 2016. Has been in use nearly every single day and has seen tens of thousands of watt hours go through it. It has had it’s quirks but yesterday evening I noticed it was overcharging an AAA NiMH, so much so that I couldn’t touch it and the battery casing became swollen. It seemed that slot 1 kept on charging past the cutoff; even when I took the battery out it showed that it was still delivering a fluctuating charge of 30 to 40 mA. Very off.

Slot 4 is being very temperamental and appears not work unless the battery is put in at an angle. Slot 2 and 3 are fine. I guess a new charger is long overdue.