Topic: MP-2 / AA Batteries question

[Steve J]

Something I came across today while testing some configurations.

I have an MP-2 that I run off of an SLA all the time; but the need is arising to see how well the unit works off AA batteries. As has been stated in this forum before, many MP-2's need a modification to the spring in the battery compartment in order to use rechargeable batteries (mine apparently is one). So I played around with different types of AA batteres, just to see what happens.

First, I threw in a couple regular Duracel's; and unit worked fine, with the phantom power apparently working fine.

Next, pop in the NIMH's; and as discussed, unit didn't power up.

Next, pop in one NIMH followed by one alkaline: unit didn't power up.

Last: pop in one alkaline followed by one NIMH and the unit fires up & appears to work fine!  

So the question: because of the differing capacities/discharge rates, what would be the pitfalls of using the alkaline-NIMH configuration? Would this be a situation there would be no advantage, as once the alkaline was expended, you'd be in the same situation as if it were just 2 alkaline batteries? Any hazards?

[nickgregory]

http://www.sounddevices.com/tech/nimh.htm

dont know the answer to your discharging question, but at the above site you can tell based on serial number if your unit needs the update.  I just got mine done for $25 plus shipping and they also tightened the knobs...good deal if you ask me...

[Chris K]

my mp-2 is on the way there now...

cant understand why you would want to use one alkaline and one rechargeble? although it may not harm your mp-2, i don't think i would run it like that for an extended period? besides, its not like the sell alkaine AA in single packs..where i come from the come in 2 or four (or more) packs. and i have used a set of aa alkalines for an entire 3.5hr show using 15v phantom power without a problem

unless you bought your mp-2 new from sd, it is worth the $25 to get the mod and have it inspected and calibrated

i got 16 rechargeable AA batteries and a couple chargers for xmas, and i think its time to stop buying and chucking all those alkalines

Nick...how long did it take for sd to do the mod, clean it up, and send it back to you. just curious. linda at sd says it would only take a coupla days to turn it around

[nickgregory]

Nick...how long did it take for sd to do the mod, clean it up, and send it back to you. just curious. linda at sd says it would only take a coupla days to turn it around

I tracked the shipment and saw they got it on Monday, called them on Thursday, just to see when they were going to ship it and they said, oh we sent it Wed morning, and sure enough I had it a couple days later.  They did a great job cleaning it up too...looks like new  

Now I just have to find a show where I would not mind missing some of it to test the expected run times of the rechargeables for my entire rig MP-s->Mod SBM->D100 (yes I know I can calculate it, but I like practical experience)  May give it a shot at Jazz Mandolin Project on Friday...and then make a call as to whether I am confident enough yet to run them for Kid Rock the next night....

[Chris K]

sweet....thanks for the info on mp-2 return time

i ran my d8 on 1800mah rechargables for a new deal/disco biscuits whole show. not sure if the newness of the batteries meant anything, but it didnt go below 3 bars

the sbm-1 is another matter, it was at 3 bars at set break (new deal>biscuits) so i changed them with a fresh pair of rechargables. i think the sbm-1 sucks up more juice...not technical terms, but you know what i mean.

please share your tests on the mp-2 runtimes....

your mics run at 48v right? might reduce a little, but if you promptly turn off the meters you might make some of it up

[Steve J]

Yes, the mod will be done; but it doesn't answer the questions. What I'm looking for is some on-the-fly, in-a-pinch, yeah-you-can-do-this-and-not-ruin-the-unit kind of information. First time I ever had a problem with the SLA (actually turned out to be the charger); and until the mod is done, I'd like to know what options (other than making sure I carry more batteries) are available. There are a number of times where I'm the only taper on hand; so improvisation becomes a necessity.

[Steve J]

Well, in case you are wondering I did find an answer, courtesy of our friends at Eveready:

"Can you mix Energizer® e²™ Photo batteries with Energizer® e²™ batteries?

No, you should never mix different battery chemistries. Different battery chemistries discharge differently in a device, so a stronger battery could end up charging a weaker one.

Do not mix battery types or attempt to recharge alkaline batteries - equipment damage, safety hazard or fire could result."

[nickgregory]

Well, in case you are wondering I did find an answer, courtesy of our friends at Eveready:

"Can you mix Energizer® e²™ Photo batteries with Energizer® e²™ batteries?

No, you should never mix different battery chemistries. Different battery chemistries discharge differently in a device, so a stronger battery could end up charging a weaker one.

Do not mix battery types or attempt to recharge alkaline batteries - equipment damage, safety hazard or fire could result."

good to know....

[zhianosatch]

dude, just buy a big pack of alkalines for a few bucks and don't worry.

[hoobash]

Never mix batteries as a rule. Its my understanding that the mp2 will run for over 3 hrs on a 2 high output rechargables. I will be sending mine back for the upgrade. I am trying to cut down on gear.