Re: [AH] Does mAh value matter on a memory backup battery?

From Steve Lenham
Sent Fri, Jan 24th 2014, 12:38

I have never encountered a synth with a NiCd/NiMH memory backup battery 
that does not simply trickle charge it with a small current - in that 
situation, you can use NiCd and NiMH interchangeably, and I do so 
regularly. It's only if you want to rapid-charge them that it matters.

The OP wrote that it is a memory backup battery, so the current drain is 
negligible and the capacity uncritical - the battery is probably 
self-discharging faster than it being drained by the CMOS RAM device 
that it maintains.

So the answer to the original question is that either would be OK, but 
if the larger capacity device will physically still fit then there is no 
reason not to go for that one.

Cheers,

Steve L.

Benden Sound Technology
www.bendensound.co.uk


On 23/01/2014 19:47, Peter Mörck wrote:
> OK, get another NiMH then, should be no problem :)
> Old synths usually have NiCad and the recharging circuit probably isn't
> designed to handle NiMH (which has different charging characteristics).
>
>
>
> On 23 January 2014 20:42, M V <mv_synths@hotmail.com
> <mailto:mv_synths@hotmail.com>> wrote:
>
>     Yes, it's an NIMH battery... on a pretty small synth.
>
>
>
>
>     ------------------------------------------------------------------------
>     Date: Thu, 23 Jan 2014 20:40:24 +0100
>     Subject: Re: [AH] Does mAh value matter on a memory backup battery?
>     From: peter.morck@gmail.com <mailto:peter.morck@gmail.com>
>     To: mv_synths@hotmail.com <mailto:mv_synths@hotmail.com>
>     CC: analogue@hyperreal.org <mailto:analogue@hyperreal.org>
>
>
>     The big question is: Is it a rechargeable battery?
>     100mAh sounds awfully low though, so I'm guessing no.
>     Is it a toy? :P
>
>     Capacity is a measure of how much charge the battery has.
>     100mAh will last for 100 hours if the synth drains 1mA from it, 1000
>     hours if it drains 0.1mA from it, and so on... (in theory)
>     So, bigger is better as it will last longer.
>
>     /Peter
>
>
>
>
>
>     On 23 January 2014 20:33, M V <mv_synths@hotmail.com
>     <mailto:mv_synths@hotmail.com>> wrote:
>
>         I'm looking to replace a memory backup battery on a synth. The
>         original was a 3.6V 100mAh battery, but the available mAh values
>         for new ones are 80 and 150. I'm guessing that such a small
>         difference won't matter, but am unsure whether it's better to
>         shoot high or low.
>
>         thanks,
>
>         Matt
>
>
>
>