Aldi Activ Energy Smart Charger for AA/AAA NiMH

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kennybobby
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Location: huntspatch, alabama
Aldi Activ Energy Smart Charger for AA/AAA NiMH

The last time i used this charger it didn’t shut off (so called Smart) and the cells were almost too hot to touch.

i suppose the high temperature is harmful to the cell lifetime.

Opened it up and found a loose solder joint where the trace was lifted from the board. This was on one of the arms that makes the + contact to one of the 4 cells. There is a 14-pin IC but the marking code has been ground or etched off. i can see it has current sense resistors but no temperature sensing device. More reverse engineering needed.

What is a normal temperature increase that might be expected during charging of AA NiMH cells?

Now i used to think that i was cool,
drivin' around on fossil fuel,
until i saw what i was doin',
was drivin' down the road to ruin. --JT

flydiver
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Location: Seattle, WA

Warm > noticeably warm.
Too hot to hold is TOO hot and damaging.
Very old or poor batteries with high internal resistance may not terminate properly in a good charger.

You SURE you even want that charger? Did a bit of searching and does not sound like a great piece of kit, charger or batteries.
You can get decent basic multi-chemistry chargers inexpensively. You can get good ones for not a whole lot more.

To Air is Human, to Respire….Divine.

kennybobby
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Last seen: 16 min 40 sec ago
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Location: huntspatch, alabama

Thanks for confirming my guess—i figured it wasn’t shutting off and trying to overcharge when the cells were not just warm, but hot.

It is a poorly made device with crappy pcb traces. i have other 4x chargers, this is probably not worth trying to repair.

Now i used to think that i was cool,
drivin' around on fossil fuel,
until i saw what i was doin',
was drivin' down the road to ruin. --JT

def_nvar
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Last seen: 10 months 3 weeks ago
Joined: 11/01/2020 - 05:42
Posts: 76

none of the aldi nimh products are worth anything.
cells get 500mohm IR after only 30 cycles.
now IKEA is a completely different story. even their new cheap stenkol charger is good. terminates a bit cooler than my BC700 as it uses 0dV.