Best charging schedule for LSD 4D Car Light?

[Nubo]

My wife likes to carry a 4D Mag in her vehicles for emergency light plus bludgeon capability. She replaces the cells once a year.

So, to give her something a little snazzier I've built her a 4D with a Malkoff drop-in, and powering it with Accupower Evolution LSD D-cells. The reason for LSD is that I know she won't want to deal with monthly top-off charging, for example. Though I think conditioning the batteries 2 or 3 times a year is something she would accept.

So, what sounds reasonable for a schedule for these batteries? I do know that heat speeds up the self-discharge, and it will get hot in the vehicle during the summer months. I was thinking of a condition/charge cycle every Memorial and Labor Day. Does this sound adequate?

With the long run-time afforded by the Malkoff and this setup, I think a 50% state of discharge would still give a serviceable light superior to her current one.

 

[MorePower]

Why bother with rechargeable cells at all? According to the Malkoff Devices website, you should get "[FONT=verdana,arial,helvetica,sans-serif]8+ hours on 4 D Cells at the rated output." I haven't seen an actual runtime curve posted on CPF (I haven't looked for one, either), but I'd expect she'd get enough runtime without using NiMH cells.

If the cells are replaced yearly anyway, just continuing to use alkaline cells seems like the easiest choice...
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[Burgess]

Though I think conditioning the batteries 2 or 3 times a year is something she would accept.

Sure, provided YOU do it for her !



_

 

[LEDninja]

I was thinking of a condition/charge cycle every Memorial and Labor Day. Does this sound adequate?

After every use and every Memorial and Labor Day.

 

[bguy]

Personally, I wouldn't spend almost $100 for rechargeable batteries in a flash light that is rarely used. If she currently replaces alkalines once a year, then the cost recovery isn't for 25 years.

 

[Nubo]

I appreciate the advice about alkalines.

There are reasons.

For one thing, when it comes time to replace the batteries, we come home from shopping and its "oh shoot, I forgot to get batteries again". This goes on for several weeks, even months! As I've gradually replaced other alkaline-powered gizmos I've found it very satisfying to simply pop cells in a charger instead of having to trot off to a store. Or even better, have some pre-charged. She's benefitted from this already with AA batteries, discovering her "battery drawer" is empty and I say "here, just use these rechargeables; just don't throw them out". Batteries when you need them. That's the great thing about LSD rechargeables. I'm gradually increasing our "stock" so that we'll always have batteries of all types pre-charged and on-hand.

She has two other Mags in the house that get more frequent use. The alkaline discharge curve means those get tossed about halfway used. If she likes the mod, those will be next and we won't be tossing all those unused or under-utilized alkaline D-cells. That just bothers me. Before you ask, the Car Light is first because she can show it off to her work buddies Plus she works somewhere where a good long-duration light could come in handy. But she'll be free to use it as her Home Light instead, of course.

Less chance of leakage (I hope!).


More inclined to use the light instead of "saving the batteries for 'real' emergencies".

 

[Nubo]

Personally, I wouldn't spend almost $100 for rechargeable batteries in a flash light that is rarely used. If she currently replaces alkalines once a year, then the cost recovery isn't for 25 years.

Less than $50 from Thomas Distributing. But yeah, it's not exactly an "economizing" move for this application. :thinking:

 

[WDG]

Less than $50 from Thomas Distributing. But yeah, it's not exactly an "economizing" move for this application. :thinking:

For me, it's not always about the economics. One of the things I love about LSDs is KNOWING that "mission critical" lights and devices are charged, instead of trying to remember how much I've used them, wondering how much usage time is actually available. Those items get charged cells swapped in as soon as practical after every use, so they're always fully ready to go, and LSDs allow standby cells to be charged and waiting when needed.

My EDC, on the other hand, gets a cell swap once a week, as a rule. I typically use about 1/4 of the cell's capacity in that time, so that means it always has a good safety margin, if needed. I'd likely leave a primary cell in there much longer, so never be certain how long I could count on it.