Do rechargeable nimh batteries improve with age?

[Wobblers]

Good advice (and I should have read more of the came-to-late thread before posting above) but doesn't that somewhat depend on the charger? I thought quality chargers such as the Technoline

http://www.batterylogic.co.uk/technoline/technoline-BL700.asp

reduced charging once full to a tiny trickle.

By the by, does anyone have any opinion on Lidl low self-discharge batteries?

I think they tend to have a green stripe/somewhat green logo/marking or whatever.

I have the impression that they are not half bad.

Tend to be sold a couple of times a year or so.

Yes, absolutely, a good battery charger is essential. The charger you link to is good - and can also be found rebadged as the 7 Day Shop Smart Charger, and the Uniross Smart Charger. Another good charger is the Opus BT-C3100 (or Fluxeon BT-C3100, same charger, different label) which also can recharge lithium ion cells. The Maha C9000 is very good - it should be, it's the most expensive one here - but slightly undercharges batteries. I've used all these chargers, and any one will do a perfectly good job of things. I would, however, advise you avoid the Technoline BL900 as it has a design fault which can cause it to overheat and damage any cells on charge.

The LSD batteries from Lidl or Aldi are okay-ish, but not up to the quality of Eneloops. I found my Aldi cells lost a fair amount of capacity after a couple of years of fairly light use. I don't recharge my NiMH cells after each use and haven't noticed any adverse affects - as I say, my 10 year old Eneloops have suffered little capacity loss. It is a good idea to occasionally fully cycle your batteries (once a year is quite sufficient): this prevents recrystallisation of the nickel oxy-hydroxide anode. All the chargers I've listed above have a facility to test the battery capacity which is perfect for the task.

 

[slowmotion]

Yes, absolutely, a good battery charger is essential. The charger you link to is good - and can also be found rebadged as the 7 Day Shop Smart Charger, and the Uniross Smart Charger. Another good charger is the Opus BT-C3100 (or Fluxeon BT-C3100, same charger, different label) which also can recharge lithium ion cells. The Maha C9000 is very good - it should be, it's the most expensive one here - but slightly undercharges batteries. I've used all these chargers, and any one will do a perfectly good job of things. I would, however, advise you avoid the Technoline BL900 as it has a design fault which can cause it to overheat and damage any cells on charge.

The LSD batteries from Lidl or Aldi are okay-ish, but not up to the quality of Eneloops. I found my Aldi cells lost a fair amount of capacity after a couple of years of fairly light use. I don't recharge my NiMH cells after each use and haven't noticed any adverse affects - as I say, my 10 year old Eneloops have suffered little capacity loss. It is a good idea to occasionally fully cycle your batteries (once a year is quite sufficient): this prevents recrystallisation of the nickel oxy-hydroxide anode. All the chargers I've listed above have a facility to test the battery capacity which is perfect for the task.

Is the Technoline BL700 OK or am I going to be cremated in my bed tonight?

 

[albion]

Some people are describing personal experiences, ignoring the chacteristics of the 1000+ of blends of NiMh.

All of us can only guess from experience/knowledge. It could be that a different charger is now used resulting in better full charge detection and/or the 2 batteries are now matched so that a 'in pairs' charger does not overcharge or cut out early. Also, I suspect that if a GPS has better line of sight, less computation is needed resulting in longer battery life.

Regarding batteries, my Eneloop NiMh light packs must have been charged 100+++ times, run down to 0% 50+ times and still seem to perform to 100% original capacity.


I can't really find fault with anything said on this journey, though it is worth noting that a refresh often does a full charge/discharge loop until capacity increase has stopped.

View: https://m.youtube.com/watch?v=JslHWoXpnEw

 

[Blue Hills]

On eneloops, which ones do folk use?

My.AAs are relatively low capacity, 1800 assured i seem to remember. Higher capacity ones are available (up to 2500?) But i seem to recall that they have less claimed recharge cycles.

I have four 7day shop 2900s (not low self discharge) which seem very good but they haven't been used a lot yet so I don't know how well they will last. Tend to use them for intensive use where they have no time to self discharge as I'll be too busy discharging them.

 

[Wobblers]

Is the Technoline BL700 OK or am I going to be cremated in my bed tonight?

You might want to reconsider taking your battery charger to bed then. Oh... and take a look at @Blue Hills' charger link - there's even a BIG hint in the URL...

 

[Wobblers]

On eneloops, which ones do folk use?

My.AAs are relatively low capacity, 1800 assured i seem to remember. Higher capacity ones are available (up to 2500?) But i seem to recall that they have less claimed recharge cycles.

I have four 7day shop 2900s (not low self discharge) which seem very good but they haven't been used a lot yet so I don't know how well they will last. Tend to use them for intensive use where they have no time to self discharge as I'll be too busy discharging them.

The problem with high capacity cells like those 2900 mAh 7day shop ones is that, to increase the capacity means less room is made for essential things such as current collectors and seperators. This makes them rather fragile things, and they soon lose their extra capacity. There are a few good high capacity low self discharge batteries - Eneloop Pro, Duracell 2450 mAh precharged and Fujitsu 2450 mAh ready to use. They all come from the same Japanese factory, so if the packaging says "Made in Japan" and some thing like "Ready to Use" you're probably good. I've used these cells for a couple of years, and they're holding up very well so far: I certrainly haven't seen any capacity fade.

 

[Blue Hills]

Thanks mcwobble for confirming that the Fujitsus and Eneloops are one and the same. I had long suspected it.

Just looked at unopened pack of Lidl 2300 low self discharge (75 per cent capacity left after a year it says) - has a German address but doesn't say where they are made. I thought that was illegal?