Battery charger recommendations

I’m going to get a battery charger primarily for charging AA and AAA batteries, but I would also like it to be able to revive a dead LiFePO4 cell if one of my Reform’s batteries ever dies (knock on wood, so far it’s recovered from 0% every time I forgot to charge it). I’ve seen the Nitecore i2 recommended in the forum, but that can only do two batteries at a time. I see that Nitecore has a few options that can charge four batteries at a time, but they have mixed reviews and there are other brands with chargers that can do eight at a time.

Has anyone used a higher-capacity charger with the batteries in the Reform?

I left the laptop without a charger for about a month and 2 batteries died. Used this charger, and it brought them back to life. I have the feeling that they drain faster, but I have no way to prove since I don’t know which are the ones that originally failed, but it’s just perception.

I have A nitecore D4, but it is really annoying to use with LiFePo4 batteries, because it assumes they are 4.7v cells, which would damage them if you are not paying attention… you have to manually set it with each and every cell by holding a button for a second or two at the right moment to get it to charge them as LiFePo4 batteries. If the power goes out while you’re charging and comes back, it will reset and charge at 4.7v, killing your batteries.

Most multi-chemistry chargers are like this, as I understand it, probably because people using higher voltage cells would otherwise complain about incomplete charging…

I would recommend getting one that only does LiFePo4, or has hardware switches to select the appropriate voltage (e.g. 3.2v). I have a two-cell charger by XTAR which has this, and am pretty happy with it.

Which one from XTAR do you have? I saw the VP2 has a mechanical switch to select the voltage but it’s discontinued:

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That definitely looks like the two-cell XTAR charger I have. I cannot find a model number on mine anywhere.

I ordered the Nitecore SC4 after @mauro’s post, and unfortunately it has this same issue. Otherwise, seems to work great.

Not sure if discussion is more about EU or USA situation (available hardware differs, despite globalization).
For EU (Germany to be precise) I used Voltcraft IPC4, bought last year in Conrad (German electronics-related shop). It can charge 4 AA batteries or 2 18650 at one time, and allows for choosing charging parameters (LiFePO, LiIon, NiCd, etc.).
It can also show statistics, like current during charging, detected capacity, and so on. Nice tool, was able to resurrect one discharged battery - although I have less need for it since recent firmware upgrade :smile:

I’m currently resurrecting my batteries with a Nitecore VP2, thanks to @josch for mentioning it. It was a bit of a pain to get, since it’s discontinued, but I appreciate the hardware switches.

Taking a battery from around zero to the standard min for that battery takes ages. I haven’t attempted to time it, but we’re talking many days, maybe 4 days straight or more.

It’s worth noting that it can only resurrect one battery at a time, and just in the right battery bay. It can do a standard charge at the same time in the left bay though.

Often you can revive batteries with even the most basic charger by “jump-starting” them. If you have a two slot charger then put a good battery in one slot and the bad battery in the other slot. The charger should start charing the good one. Then you can use a cable and bridge the “hot” contact (+) from the good battery with the hot contact (+) from the bad battery (I use breadboard jumper cables) . The negative / ground side (-) is normally the same for all the batteries.
Now the charger sees the voltage from the good battery and will apply a charging voltage to the bad battery.
It’s like jump starting a car battery. It works for me in almost all cases (if the battery is not completely dead (chemically)

Update on the SC4: I had my first chance to test it tonight since my Reform has refused to run on battery power the last couple of times I tried to use it. Turns out I got too confident in how long it could last while turned off and in a drawer - I resurrected individual cells just by plugging the Reform in to AC power several times, but my luck ran out.

Every cell was dead, but the SC4 has been able to recover two of them. The others are either so dead the SC4 doesn’t recognize them at all, or it allows me to try to recover the cell. For the ones it allows me to recover, some can’t be recovered at all, some are “recovered” but at a voltage so low the charger thinks they’re NiMH and refuses to let me manually select LiFePO4 charging, and the two I mentioned before were recovered and recognized as Li-ion, which allowed me to manually select LiFePO4 charging. I considered using @pandora’s jump-starting trick, but I figure if 6/8 are this far gone, it’s probably better just to buy new cells.

I have to say, I’m a little disappointed in the lack of control on the Nitecore SC4 (and what little control there is is very unintuitive - there are only “C” and “V” buttons and the letters don’t obviously mean anything). That said, I’ve been happy with its general-purpose performance charging other household batteries.

Edit: I’ve been able to get the recharging process started on two more cells. The process to start the “IMR battery recovery” mode is to press the C and V buttons at the same time, but the instructions only say you can do that when the cell shows up as reversed polarity. I tried that after removing and reinserting the “NiMH” cells, and it changed to Li-ion mode which enables LiFePO4 charging. Of the remaining four, three aren’t even recognized by the charger and one has the IMR recovery attempt fail every time.

You should be able to jump start all of the batteries tho I wouldn’t recommend using batteries that had its polarity reversed.
I made a little comment here:
If u had a battery with reversed polarity that normally means that the capacities were not matched in the first place or some cells degraded a lot quicker than other cells. Before you install new cells u should measure them and rematch them.

Over the years I accumulated a bunch of dead batteries. So upon seeing this thread, I bought the Nitecore Digicharger D4(4EU). Unfortunately, I have found that it was not able to revive all of my batteries.

I should mention that I do have the protected battery board installed now and some of the cells I tested with died after that, so chances are they were killed by something other than low voltage.

When I insert one of these cells, nothing happens. It’s as if the charger didn’t even notice that something has happened. When I insert a healthy cell, it works as documented.

I’ve found this charger (amazon link) works well for me. I’ve only used it a few times on the reform cells but successfully brought them back to life.