hello! does anyone have any idea if you need another special charger to charge batteries over 2500mha to Ni-Mh 1.2v rechargeable batteries? I use Ever Activ UC-800 and with 2500mha batteries it charges perfectly. I tried to get one with a higher mha (3000,3900,4900) and it seems to charge in a maximum of an hour and when I put them on and turn the volume up, it doesn't last more than 10 minutes.
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baterry roland fr4x
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Ventura
Been here for ages!
a charger is a charger.. a battery with higher capacity just
takes longer to charge
the power rating of a charger may indicate if it can do
more batteries at once, or faster, or uses a switching system
to charge faster safely as opposed to steady voltage/current
the problem you are having can have a number of reasons
1: some battery companies lie about rated capacity
you can have one bad cell in a bunch of good ones so
it drops the total voltage of the pack below the Roland's threshold
and it assumes the battery pack is depleted and shuts off
takes longer to charge
the power rating of a charger may indicate if it can do
more batteries at once, or faster, or uses a switching system
to charge faster safely as opposed to steady voltage/current
the problem you are having can have a number of reasons
1: some battery companies lie about rated capacity
you can have one bad cell in a bunch of good ones so
it drops the total voltage of the pack below the Roland's threshold
and it assumes the battery pack is depleted and shuts off
The problem is that I bought 3 sets of batteries as I said, 3000, 4900 and 5500 1.2v Ni-Mh and the same thing, I thought it was the charger's fault, but with Batmax 2500mAh batteries it charges perfectly and the batteries last about 4-5 hours, but I wanted some with a higher capacity and longer lasting
Ventura
Been here for ages!
borrow an old charger for niCad batteries..
these old ones are just trickle charge type
and try that on the new batteries overnight
also, after the the pack stops working, test each battery
with a meter to see if they are all really depleted
personally i have never heard of or seen NiMh AA size
in 4900 and 5500 or even close to it.. too good to be true ?
these old ones are just trickle charge type
and try that on the new batteries overnight
also, after the the pack stops working, test each battery
with a meter to see if they are all really depleted
personally i have never heard of or seen NiMh AA size
in 4900 and 5500 or even close to it.. too good to be true ?
I use the batmax ones and I go on the charger.
Attachments
The problem is the batteries. There are very few AA batteries that reach 2800mAh, much less some of the highly suspect mAh rated batteries you mention.
Stick to known good names like PowerEX or Eneloop.
Stick to known good names like PowerEX or Eneloop.
Batmax batteries are low quality batteries that generally never come close to their ratings. Do a Google on them as I have. 
For anything more than normal durations a custom battery will serve best.
For anything more than normal durations a custom battery will serve best.
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cestjeffici
Active member
I timed it. It takes about two minutes to change the batteries in my FR4. Taking a two minute break every 4 hours kind of relaxes me. If I think the set in my FR4 won't last until I'm done playing I change them before I start to play. I have 4 sets of batteries and my charger can easily keep up with me. I enjoy the extra playing time instead of messing around with my equipment.
I
I envy you Jeff if you can play 4 hours without taking a break, and then going on after a two minute break. Even playing at home in my practice room I couldn’t do that. No way at a gig.
cestjeffici
Active member
Caps
Active member
Ratings over 2800 Mah are highly suspect. i would test each cell separately. I suspect you got some bad ones in there.
Known good ones are enelope, EBL and tenergy. There may be others but i know these are good.
Known good ones are enelope, EBL and tenergy. There may be others but i know these are good.
Those are not ratings that seem compatible with NiMH battery chemistry in AA format. Smart chargers will not be able to properly detect the end of charging. Dumb chargers (which provide a fixed low current for a fixed time that is known not to damage an already full battery) will stop too soon, but you could try using a dumb charger twice.
The most likely explanation, however, is not a different battery chemistry but a marketing hoax. Of course there are ways to achieve higher capacity at the cost of durability. Such a battery might deliver its stated capacity, if at all, just for a few times before significantly deteriorating and hitting lower capacities than quality batteries within a dozen charge cycles. In addition, such fast deteriorating batteries will not be properly monitored by smart chargers, leading to phenomena like you describe above where the charger declares the battery full long before it reaches its stated or at least feasible capacity.
Squeezeplay
Active member
I use 2800 mah batteries, they last for a full evening…..never had issue, so why you would actually NEED more capacity is beyond me. Buy good quality batteries as Jerry said, and do not mix different brands or capacities. Ie, don’t use nine Of one capacity with one of another. Don’t use mostly one brand, and some of another in a pack. Battery care is critical to good results. And a four hour session with no breaks is possible, I do it in my studio fairly often. On occasion I will use a full set of batteries in one session. AND a good quality charger is essential to good battery performance. Something that runs on 12 volts from a wall wart won’t cut it.
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Caps
Active member
What is wrong with a 12 volt wall wart? or even a 9 or 5 volt one? As long as they can provide the proper current and voltage per cell they are fine.
Ventura
Been here for ages!
there are switching type wall wart PS now outputting 2 amps, and lightweight,
while the biggest heaviest transformer ones topped out at about 1 amp
and could melt the plastic cover under some circumstances
while the biggest heaviest transformer ones topped out at about 1 amp
and could melt the plastic cover under some circumstances
Squeezeplay
Active member
What I’m getting at is that generally , most “wall warts” that you purchase from Amazon, are not good quality…the charger is the very heart of your battery system. I have been using battery power for large model airplanes, and boats for many years, and have learned the hard way about “ in expensive “ chargers. You will get much longer battery life with a good charger…the killer part of charging is charging at the same rate from start to finish…the last part is what kills the battery…as it can not absorb the charge at the same rate as a depleted one, without causing itself some damage. A good charger will detect when this starts to happen, and react by reducing the current so as not to damage the battery. To actually get the longest battery life, never charge to more than ninety percent of capacity, never discharge more than ninety five percent. This has served me well, as I have some batteries more than fifteen years old that still have ninety five percent capacity.
Regarding Ventura’s comment, my charger for my accordion is capable of putting out fifteen amps at twenty volts, BUT, it wasn’t the amperage output I wanted when I purchased , it was the temperature sensing, and the internal battery resistance detection. IR goes up when the charge nears completion, and that’s when the damage is done with a CC charger.
Regarding Ventura’s comment, my charger for my accordion is capable of putting out fifteen amps at twenty volts, BUT, it wasn’t the amperage output I wanted when I purchased , it was the temperature sensing, and the internal battery resistance detection. IR goes up when the charge nears completion, and that’s when the damage is done with a CC charger.
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Ventura
Been here for ages!
LoL 20 amps.. you can jump start your Lawn tractor with that thing
to be fair, the wall wart isn't the problem, it's the
charging unit it is powering being sophisticated vs primitive
yes any decent modern charger should do those things you refer to..
and i have some and use them for the Lithium stuff, actually i still
prefer my old trickle chargers that can sit on batteries for a week
if i forget to go out to the barn and pop them out
having said that, i still hate NiMh.. while larger sized c and d
NiMh have performed well for me, frankly AAA and AA cells
have been nothing but a disappointment
to be fair, the wall wart isn't the problem, it's the
charging unit it is powering being sophisticated vs primitive
yes any decent modern charger should do those things you refer to..
and i have some and use them for the Lithium stuff, actually i still
prefer my old trickle chargers that can sit on batteries for a week
if i forget to go out to the barn and pop them out
having said that, i still hate NiMh.. while larger sized c and d
NiMh have performed well for me, frankly AAA and AA cells
have been nothing but a disappointment
Squeezeplay
Active member
It is a conundrum for sure….one day they might make a lithium based battery that will replace all these others. Lithium polymer isn’t really the answer for us. They react very badly to improper use. ( can you spell smoke ? ). Or worse yet a fire. You need to baby sit them while being charged…. Nimh….like nicads, can be left pretty much un attended without worrying about burning down the house. I have seen a couple of results from lipo batteries going wild. It ain’t pretty.
Caps
Active member
I agree! I bought a set because of their high claimed capacity. They did not perform as well as the EBL or Tenergy. I tested them ( I have a solid state variable load that measures voltage and current up to 10 amp). At a one amp discharge rate, the 10 cell 12 volt pack was down to 9 volts in less than an hour and 30 minutes. And not all of the cells discharged at the same rate. Clearly junk. I tossed them away and chalked it up to experience. I would be wary of any AA cell claiming more than 2800 MahBatmax batteries are low quality batteries that generally never come close to their ratings. Do a Google on them as I have.
For anything more than normal durations a custom battery will serve best.
