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Author Topic: Don't feel guilty about using Lithium Ion over NiMH, Eneloops are no better.  (Read 5861 times)

freax

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*Censored*
« Last Edit: March 11, 2015, 02:00:48 AM by freax »

Luigi

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Make sure you have a smart charger such as a Powerex Maha mh-c9000. THe charger allows you to set the recharge rate. Individual cells can be charged. This is vital to allow for cell capacity matching. If you have an underperforming cell, it will ruin the others. With a smart charger, you can check cell capacity. The charger that I mention can run off 12 volts. That is good when all you have is a solar charger (with or without battery storage) or a running car for power.

Other rapid battery charger will cook the batteries that you have an reduce them to garbage in no time. DO not trust chargers that can charge under an hour.

Luigi

cockpitbob

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We have a Powerex smart charger and love it.  If I suspect a battery I have it analyze the battery and it tells me the mAH capacity.  We have 2 boys and have a lot of Eneloop AA NiMH and it's very rare that I have to throw one away.

For my QRP radios I've been using the AA size (14500) 3.2V LiFePO4 batteries.  It gives me 12V with just 4 cells, or for my MTR_V2 I use 3 cells for around 10V.  They are only 600mAH, but that's all I need.  So far they've been very reliable even though I've over-discharged them several times.

Luigi

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I am glad others are using the MAHA charger. It is nice.

I recommend everyone toss their 15,30 and 60 minute chargers in the trash or give them away. The money spent on a smart charger pays off in the long run.

Luigi

KG7LZD

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I'm going to diversify between Alkaline, NiCD and Li-Ion/Li-Poly, I'm not going to keep on buying NiMH if they don't last as long as the last Eneloop batch did, and they are by-design a high-cycle count battery, can be discharged at high current and recharged at high currents, Can be left in a discharge state for long periods of time, Etc.

Hello all, this is my first post on this forum.

I must say that you have an interesting point freax.  I have used Tenergy, Sanyo Eneloop (white, Japanese 1900mAh), and normal Energizer batteries in my KX3.  While the alkalines lasted a long time when receiving, they were quickly drained when transmitting (even using the low-draw 3w and below mode).  The Tenergy and Eneloop batteries seem to do better when transmitting, though the Tenergy brand batteries are inferior.  I also have used an Antigravity XP-3, which works really well and can be recharged off 12v power which is a plus.

I never thought of using Ni-Cads but it makes sense.  I was looking at some of the larger cells and it seems feasible to build a large pack of them to give me 12v power, and place them at the bottom of the pack.  They are certainly light enough and they do provide two of the more essential prepper requirements in my mind - low self discharge and extra long cycle count.

I will buy a set of Ni-Cad AAs and compare them to the Eneloops and ordinary alkaline AAs in my KX3 pretty soon.  My plan is to do a mix of transmitting and receiving (easy enough with the KX3's message memories) until the cells are at a certain minimum voltage.

Anyway I have to say I have lurked here for a while, and I enjoy the site a lot.  While I do operate with up to 100w some of the time, I am mainly into QRP and I am trying to improve my CW all the time.

KG7LZD

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If the only choices are super-heavy (they must put lead in these things) Eneloop or NiMH and Duracell Coppertop alkalines then why not go the lightweight version of NiCD? I can certianly buy them cheaply enough. Everytime I go to the hardware store I buy 2 packs of four of them! I would advise caution as you need to understand that they DO have lower capacity than NiMH. However during high current draws the advantage of NiMH may not actually be an advantage anymore.

I do need to do further testing. That is buy a smarter charger with a discharge feature so that I can do a high current discharge with NiCD and Eneloop NiMH and see who comes out best. I only used my camera last time.

I am interested in seeing how well the NiMH batteries perform vs NiCad in my KX3 specifically.  If it turns out that they have a decent life then the next step is to build a D cell pack so I can operate for a long time with them.

I will probably do a test that involves transmitting for 6 seconds and listening for 54 seconds, and repeating this sequence until the batteries are too depleted to run the KX3 reliably.  It's probably true that the NiMHs will be damaged if I run them until the KX3 shuts off but this might be a worthwhile test even if I sacrifice some AAs.

I am not too excited about the lithium battery technology.  While these batteries offer much greater energy density, they are too easy to damage and I have had one lithium pack catch fire on me before while charging.

I own a Goal Zero solar panel which I like a lot, and I have the lead-acid charger unit for it.  I think it would probably charge a 12v NiCad pack just fine as well.  This will be the next step provided that I like the NiCad AAs inside the KX3.

Thanks again for your interesting post.  I haven't seen NiCads in a very long time (or hadn't looked for them) and they kind of just fell off my radar.