FRX4 Custom battery

[dbranko]

Hello from Balkan!
I want to share my battery setup for FRX4.
An electronics engineer made me a battery that has its own charger. It is not necessary to remove the battery for charging. I just remove the cover and plug in the charger. The package includes 6 x 18650 batteries and associated electronics. Something similar or the same as the battery and charger from the Dutch shop.
I know that here on the forum there were controversial opinions about such things, but I still decided to buy this battery three days after buying the accordion.

 

[Ventura]

it is nice to see some of the Drone technology being devloped
by the Ukraine defense forces is filtering back into the private sector

this fpv ubec voltage regulator module seems to be available
and you just do a battery pack that is suitable to the input

looks good.. did you voltmeter test the output to make sure
it is eactly 12 volts or did you just take their word for it ?

 

[dbranko]

I just take their word for it. Accordion doesn't complain.

 

[Ventura]

with the battery packs, the industry sometimes rates the output
generally, based on the maximum charge voltage at full, though the
voltage will drop as the pack is depleted, so the voltage changes through the cycle

power tool batteries are more likely to have fudged ratings, as motors don't
care as nuch about perfect voltage levels

an advertized 12 volt pack can be actually 11.1 as the typical nominal voltage
where 3 batteries in series are the power source

but some battery packs use 4 cells so the voltage is well over 12 volts, then the
regulator circuit drops it down to 12 volts, which is then a very steady voltage,
and is a much more reliable and safe type of pack to use, as a sensitive
device is better protected with the controlled voltage

if you ever want to know, meter the pack at full charge, then check it again
after an hour of use, then again when you go to recharge it.
if the voltage is 12 volts each time you check, you have the better design.

 

[dbranko]

I will do that measurement. You are right. He put in 6 x 18650. It should be 2x parallel (3 x serial)?! Or something else.
There is one more part wrapped with batteries but i think that is power charging balancer.

 

[Airy]

but some battery packs use 4 cells so the voltage is well over 12 volts, then the
regulator circuit drops it down to 12 volts, which is then a very steady voltage,
and is a much more reliable and safe type of pack to use, as a sensitive
device is better protected with the controlled voltage

To me it looks like there is a 12V step down regulator between the battery pack an the FR4x DC input jack. Wouldn‘t that ensure that no over-voltage is applied to the accordion? And I never heard of damage because of under-current. Just curious….!?!

 

[dbranko]

Just measured. 12.2V after 5-6 hours playing.

 

[Ventura]

no damage from undervoltage, but the rolands have a threshold voltage
below which they turn themselves off, so it can be annoying

anecdotal evidence over time from owners of various models
including the 4x suggest that there are shutdown issues that can
cause problems and these have been associated with storage and
battery packs that became depleted and other odd happenings

so i conclude that it is rather important that these things shut down
in a correct and controlled manner, and that roland designed the
low-voltage cutoff in to protect against this, though some of us
have inadvertantly found our way around this anyhow !

usually a factory reset clears the gremlins, but i think 'Sharks had to
send his back for repair once

 

[Airy]

Just measured. 12.2V after 5-6 hours playing.

I don‘t want to criticize or pretend that I have deep knowledge but wouldn‘t it be necessary to measure the voltage with realistic load e.g. with the FR4x connected and running?

 

[Ventura]

12.2 is very good after an hour

seems like a good system

a few of us have been trying the Li-ion AA virtual batteries,
but i think your pack will give a longer run-time

 

[Airy]

so i conclude that it is rather important that these things shut down
in a correct and controlled manner, and that roland designed the
low-voltage cutoff in to protect against this, though some of us
have inadvertantly found our way around this anyhow !

usually a factory reset clears the gremlins, but i think 'Sharks had to
send his back for repair once

Thanks Ventura for that reminder. I think I now remember the discussion about this issue.

 

[Ventura]

I don‘t want to criticize or pretend that I have deep knowledge but wouldn‘t it be necessary to measure the voltage with realistic load e.g. with the FR4x connected and running?

it depends what you are measuring for i think

i just want to know the status of the charge at various levels of depletion,
which are known and can be compared to give a clue

 

[dbranko]

I don‘t want to criticize or pretend that I have deep knowledge but wouldn‘t it be necessary to measure the voltage with realistic load e.g. with the FR4x connected and running?

I don't think it will drop voltage significantly.
I will charge them tonight so will get that data tomorrow.
Didn't test them to shutting down cause guy who made this batteries told me to never do that. Assuming it's better for cells lifetime.

 

[dbranko]

Did full charge. 12.26V. Only weird thing is I've got only "O O". Yesterday was "O O O". I suppose it's some calibration glitch.

 

[Ventura]

next question is, does your battery wizard want to make a dozen of these for sale to
your friends ?

lol

but seriously, we have plenty of FR4 FR3 owners in here to get him some sales

 

[cestjeffici]

I'm wondering what problem this new battery solved. And what new problems it introduces.

 

[Ventura]

NiMh AA battery technology has proven itself dissapointing
for me in professional use. I require predictable reliability
and reasonable return on investment. For an application like the
FR3 and FR4 where the battery compartment is severely limited
i consider NiMh unacceptable in practical terms

my original work-around for the FR3 were flat pack battery packs
slipped under the backpad and plugged in to a jumper from the compartment

Li-Ion and LiPo have a tremendous advantage over NiMh
for the amount of energy they can hold in the same amount
of physical space

as soon as ways are figured out to tame the wrinkles
the new battery technology presents, it then becomes
a far more desirable option to people who require
Pro level performance because their gigs depend upon it

people who do not need that level of performance may also
prefer it because they like to push the boundaries

the rest of you can keep using NiMh and be happy,
and that's fine too

 

[cestjeffici]

"NiMh AA battery technology has proven itself disappointing
for me in professional use"

What aspect of the batteries disappointed you?
In what way were they unacceptable?

 

[Ventura]

premature individual failure of identical batteries purchased in sets, then
unequal individual aging of identical batteries purchased as sets
causing battery packs to drop below threshold voltage quickly
and causing frequent battery changes on gigs, and forcing far too
many redundant sets of batteries needing to be carried on Gigs

then how to identify the weak cell.. how to replace one..
the need to buy 12 packs instead of 10 so there are spares
of similar age and chemistry, adding more cost/loss to the equation

 

[Alan Sharkis]

no damage from undervoltage, but the rolands have a threshold voltage
below which they turn themselves off, so it can be annoying

anecdotal evidence over time from owners of various models
including the 4x suggest that there are shutdown issues that can
cause problems and these have been associated with storage and
battery packs that became depleted and other odd happenings

so i conclude that it is rather important that these things shut down
in a correct and controlled manner, and that roland designed the
low-voltage cutoff in to protect against this, though some of us
have inadvertantly found our way around this anyhow !

usually a factory reset clears the gremlins, but i think 'Sharks had to
send his back for repair once

I had a freeze, or lockup, or whatever you want to call it. Since the symptoms after this happens vary widely, and mine were more weird than usual, my dealer asvised me to send it to Roland for service. On the way to Roland, the capacitors must have finally discharged completely, because because when Roland got the accordion and powered it up, it behaved normally and none of what I had added to it was lost.

Since then, I learned a few things:

1. I checked the batteries that were in it. Two of the ten would not charge completely. That explained the lockup. It turns out that the power button on the FR-4x is not a simple switch. It’s what is referred to as a ‘soft power switch,’ meaning that it needs power to power up the accordion. I didn’t know the two batteries were bad, and I left them in the accordion for a couple of weeks without playing it. So, booting up the accordion thereafter, produced the lockup, and removing all power from the accordion cures the lockup.

2. After a lockup, the time it takes to recover from the lockup can vary from a few minutes to days.

3. It is important not to leave batteries in the accordion if you’re not going to use it for a while.

4. It’s just as important to buy a new set of batteries every six months and charge them fully before putting them in the accordion.

I’m a believer in sticking with the batteries suggested by the manufacturer. Anyway, since the accordion doesn’t leave the house anymore, I use the AC adaptor and no longer put batteries in the accordion.