Topic: Double A batteries to power MT2496 (fun hack)

[dunebug81]

what kind a run times do you get from that?  I just picked up the new RH1 MD and it doesnt have an external AA like my RH10 does and this thing would be pretty sweet for doing a long show.

This very cool kit seems to output up to 200 milliamperes at 5 volts.  So some higher power devices (like Microtrack deck especially with internal battery still charging) are not going to work very well, and/or very long. 

Suggest using highest capacity 2500+ma capacity NiMH AA cells over regular alkaline, or maybe try newer 'OXY' type alkaline from Sony or Panasonic for longest possible operating times.

I was going to put some Monster 2300mAh NIMH rechargables in there.  perhaps I could find a lithium cell to put in there.  Does a MT consume more juice then the MD does?

Quite a bit more; likely 2-4x more than MD. 

Measured 6 C alkaline battery milliamperes power draw from external BC-MT power sled connected to Microtrack with and without the battery charging and posted the chart of the results at near bottom of page: www.sonicstudios.com/mt2496rv.htm

Actual current going into Microtrack deck's 5 volt USB connection is more or less same as measured pack battery drain as BC-MT USB input.  BC-MT internal switching voltage converter is 75-95% efficient depending on capacity remaining in the sled's 6 C cells. 

Chart is based on near full capacity (9 volt max) sled batteries, and switching regulator is bucking 9 volts) down to needed 5 volts, so measured draw LESS than what deck is drawing by ~20-30%.    So if chart says sled battery draw is 200 milliamperes, likely deck is needing ~300 milliamperes at 5 volts USB input to operate

If I made chart of sled battery draw when alkaline sled batteries were near end (4.8 volts; batteries at nearly half rated voltage), then converter is less efficient and slightly boosting battery voltage to needed 5 volts, and measured current would be higher than actual current draw of MT deck.

Bottom line is MT deck is going to draw at least ~225 milliamperes with already fully charged internal battery (minimum current draw for deck to operate), so 2 AA cell boost converter kit seems not a good fit.

But what about for the MD?  I use a MD not a MT.  I would think that a MD would use more power since it has moving parts and all.

[guysonic]

But what about for the MD?  I use a MD not a MT.  I would think that a MD would use more power since it has moving parts and all.

You'd think, but actually MD decks draw a lot less. Flash card recording takes up a lot more power than most suspect, like at least double that of full featured MD. 

Quick look at the small size of some internal MD batteries and the 8-14 hour record time ratings should give good clue MD decks are way less power hungry than flash types.

[dunebug81]

I WiSH I got 8-14 of record time on my internal batteries.  If recording in PCM Ill get just over 2 hours with a 1350mah nimh gumstick and about 6 hours on at 380mah lithium.  Thats assuming that the display is off and everything is running at optimal conditions.

[guysonic]

I WiSH I got 8-14 of record time on my internal batteries.  If recording in PCM Ill get just over 2 hours with a 1350mah nimh gumstick and about 6 hours on at 380mah lithium.  Thats assuming that the display is off and everything is running at optimal conditions.

If I didn't know better, I'd say your 1350 mah gumstick is in sore need of replacement; at < 50% original capacity? 

Suggest taking a look in your owners manual specification for record run times with fresh gumstick battery. Stated spec times are usually fairly accurate with new battery and good working deck. 

[dunebug81]

According to the manual recording on a 1GB disc using PCM setting will do 5.5 hours of continous recording.  I call bullshit on that.  Even when this thing was brand new I never got more then 3 hours of record time.  I do charge the battery off of the USB port which doesnt fully charge the battery, I guess I should charge it off the wall more often.  I'm sure that battery life has gone down a little in the year that Ive been using this unit but I cant say for sure what the true recording time is because I always have the AA side car attached.

I still might order this thing just to try it out.  Even if it doesnt work I can always give it to someone or charge my ipod.

[guysonic]

I still might order this thing just to try it out.  Even if it doesnt work I can always give it to someone or charge my ipod.

That's the spirit! 

It never hurts to try something fun and inexpensive like this to see what happens. 
Suggest fully charging the MT battery shortly before the trial run and I hope to read about how this cutie works.

Recent (fun) project here has all components acquired for building a new external pack using 4 C and 4 D alkaline battery sled (7 and 14+ amps @ 3.2-6.0 pack volts) into advanced 5 volt step-up switcher good for over 1000 milliamperes for Microtrack and other 5 volt portables requiring up to 5 regulated watts.

Hoping for MT running a solid 15+ and 30+ hours with these 'pocket size' power sleds. 

[dunebug81]

lol, I dont know how "pocket sized" a battery pack containing 4 D cells would be. 

For all the effort going into this I might as well spend the $60 and buy a 2nd battery...or use my old recorder and bring along some AA cells for a long festival show.

[willndmb]

when i had a sony md the gumstick got shot pretty fast, within a yr it really needed to be replaced
lucky mine had a add on AA pack

originally i could get like 12 hrs on the gumstick and aa pack at the end i could get 3.5 if i was lucky