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FR-4 battery (not original) exploded while being charged in the Accordion

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Simon Max

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Hi,
I bought a beat up FR-7xB from some accordion buff. I say beat up because there were alot of physical changes made to the accordion. One of these changes was changing the battery to some custom made battery that is much lighter than the original one and keeps the charge for quite some time.
Last week I called him to shmooze shop and he told me that he had a fire in his home two months ago as a result of a battery (like the one that I have) exploding in his FR-4.

It seems that the one that made the batteries for him gave him a custom charger and connection that enables charging the battery in the FR-4, and the charger didn't shut off when the battery was fully charged. There was nothing left of his FR-4, including the V3 Sound Accordion Master XXL unit that he implanted into his accordion. There was extensive damage to the contents of his home.

We've heard of Bicycle batteries exploding, and I guess these batteries are made of the same substance. So if anyone is considering going this root, I would suggest giving it second thoughts.

Sincerely,
Simon
 
Charging a Lithium /Li-on battery inside of an accordion is only an accident waiting to happen. These battery types have been known to
explode in laptops and other electronic devices causing total damage to the device, fires, & sometimes injury to the user.
Ni-Cd batteries are the only type to charge in an accordion.
 
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I'm glad my accordion needs no electricity, but ... if I were looking for a replacement rechargeable battery, I would do a couple things differently.

First, if it costs more to get a charger that shuts itself off, I'd pay more. That's critically important. Ideally, for the common lithium cobalt chemistry battery, the option to stop charging at your choice of charge levels. You get better long term performance out of this type of battery if you usually charge it to something less than full capacity, like 80%.

With that sorted out, I wouldn't worry at all about recharging. I mean, sure, laptops ... millions of them. You can get struck by lightning, too.

Secondly, rather than that common lithium cobalt chemistry, I'd look for a lithium ferrous phosphate (LiFePO4) battery, which is much more robust in this respect, much harder to set on fire with a rough charge or something. The downside is that the "energy density" is lower, so the same capacity will be bigger, and the discharge curve is pretty flat, so it's harder to gauge how much charge you have. (For this kind of battery I wouldn't worry about charging only to 80%, because it doesn't matter much and because you can't tell when you hit 80% anyway. So you can get a less expensive charger, but you still need one that stops when it's done.) On the positive side, they're harder to set on fire and they last for more recharges. And they don't use cobalt, a toxic pollutant that's extracted under terrible conditions in Chinese-owned African mines. LiFePO4 will probably always be hard to find in a small battery pack that you could fit inside an accordion, I don't know if it's even possible to find it, but of course that isn't my problem - mine doesn't need electricity!

[Note that LiPo is not short for LiFePO4 - LiPo (lithium polymer) is a little more hazardous than average, "charge outdoors" kind of thing.)
 
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Keep your Roland all Roland! The normal circuit configuration does not charge the batteries in the accordion. There is a reason why Roland decided not to have this, and one is the risk of overheating and fire!

If the solution involved using Li-Ion batteries it was a really dumb move. These batteries require electronics to deliver their power, unlike older technology like NiMH. You cannot just plug them into a circuit and expect things to work. I have seen Li-Ion batteries in phones and other equipment swell, explode and bust in flames even when used "normally".

I would not risk destroying my prized instruments (or my house) with a gizmo coming from a guy who thinks he can outsmart Roland with dodgy modifications. When I want to play my V-accordions for extended periods of time I just use the AC adapter! Otherwise I use 2800 MaH AA batteries that give me many hours of cordless playing.
 
I don't know about all the models, but the FR-8X charges the battery in the accordion.

John M.
 
I’m just wondering how a lithium ion replacement for the FR-4x battery pack would work, how, for example they could be prevented from overhearing. I’ve done the math on replacing the ten nickel metal hydride cells with alkaline cells resulting in a 25% over voltage situation that would fry a board. I can only imagine what an exploding lithium ion battery pack would do to the battery compartment and beyond.
 
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you can build a perfectly fine and safe li ion replacement for any decive's battery

li ion generally uses a mechanismen to separate the cells from the charge circuit when certain criteria are met

the circuit prevents both overcharging (heat) and discharging (decreased cell life)

in most consumer products this addition system is simply build into the 'pack'

so if you omit this in your 'custom' solution, only put in the cells, and you don't pay attention to your charging habits...BOOM
 
I’m just wondering how a lithium ion replacement for the FR-4x battery pack would work, how, for example they could be prevented from overhearing. I’ve done the math on replacing the ten nickel metal hydride cells with alkaline cells resulting in a 25% over voltage situation that would fry a board. I can only imagine what an exploding lithium ion battery pack would do to the battery compartment and beyond.
The owner's manual specifically mentions not to use alkaline batteries!
 
all batteries have a "nature"

normal carbon cell (basically the original type) and lead acid batteries
have a natural 1.5 voltage per cell

9 volt batteries originally had 6 small individual cells packed on top of each other
6x1.5=9 volts

rechargeable batteries have a slightly smaller natural voltage per cell, and so
a 9 Volt NiCad (old tech) or NiMh (current formula) would stack 7 cells
to make "9 volts"

Lithium Ion cells are by nature 3.6 volts

so it is impossible to make a 9Volt lithium battery without having an over-voltage situation

then there is the charging issue... NiCad and NiMh can be trickle charged for years safely,
and one only needs to supply a slightly higher Voltage than whatever the cell, or
pack of cells, shows when full

Lead Acid batteries also can be trickle charged for decades with no problem

but if you fast charge a rechargeable battery, they each have different reactions,
including a heat buildup

in a lead acid battery, this usually just results in a meltdown

in a NiCad or rechargeable carbon Cell it results in a dead battery

in a NiMh or rechargeable Alakaline it can rupture and spew caustic juice everywhere

in a Lithium battery it can overheat, rupture, and the RUPTURE itself is what causes the fire
as this is the nature of the cell

you can take even a Lithium battery from your Cell Phone that you replaced with a new one, and
if you put a knife through it, usually it catches fire

or if you drive a Tesla and get in an accident and the battery compartment is pierced...
fugggedabboutit

Roland advises against using Alkaline batteries in their plastic battery holders
BECAUSE
10- 1.2volt rechargeable batteries = 12 volts,
BUT
10- 1.5volt alkaline batteries = 15 Volts

if you buy an 8 cell plastic holder to swap out then you could use Alkaline
8- 1.5volt batteries = 12 Volts (but they actually don't last very long)

Lithium also has a further problem in that if you charge them with a voltage
that is too high, it turns them into doorstops

basically, Voltage is the Level, Current is the Force behind the voltage

a note: fast chargers often use the trick of tiny, short "pulses" of high energy
which can be absorbed by NIMh and rechargeable Alkaline batteries without a problem
however
heat=wasted energy, and you will feel those batteries getting quite warm in the charger,
which means wasted energy/money compared to a typical Trickle Charger (very efficient)

while it may be cool and even longer lasting to make Lithium battery packs for
a ROland or any other old tech device, it is an absolute that any in place charging
be disabled in the original circuitry

and only re-charge them on a table somewhere in a controlled environment

there ARE Li-Ion battery packs available on the market that have Voltage Regulation
built into their enclosed circuits... i slip mine under the chest pad and connect it
to the FR-3 by a wire

also, all the lower series (below FR-5) will shut off when the Voltage falls below
a certain threshold, which is why one weak cell in a Pack can drive you nuts
thinking "hey i just charged this pack and it shows good current on my meter"
except that one weak cell dropped the total Voltage a hair too low
 
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Disclosure: I built a Li-Ion battery pack for my FR-7b, and charge it inside the accordion. I also have a charger to charge the original Roland Ni-MH pack inside the accordion. Each battery pack has its own dedicated charger.

I understand the risk of "custom" batteries. But this blanket statement is just too much for me: "Charging a Lithium /Li-on battery inside of an accordion is only an accident waiting to happen. These battery types have been known to explode in laptops and other electronic devices causing total damage to the device, fires, & sometimes injury to the user. Ni-Cd batteries are the only type to charge in an accordion."

So now what? Not using laptops, tablets, phones because they have Li-Ion batteries and their batteries are charged inside the device?

Since the shelter-in-place started over a year a go, we turned the dinning table in the dinning room (normally unused except for holiday meals) into a working table for my wife, my daughter, and myself. Currently in front of me on that table are 3 MacOS laptops, 2 Windows laptops, 2 12.9" iPad Pros, and 3 iPhones, all having Li-Ion batteries, charged in-device. Should abandon them all?

Beware of "custom" batteries, especially from unknown sources. But Li-Ion battery packs can be built safe to be charged inside the device.
 
I do not understand, we pay thousands on our accordions and go with after market hardware…
I do. The solutions from the original manufacturer, not always, but many times are non-existent, inadequate, or unreasonably costly; of course "unreasonably" is very subjective.

Examples:

Searching for "battery for roland fr-7x": $329.99 from Amazon, $249.00 but out of stock from Liberty Bellows, $128.80 (not Roland) but "No Shipments to USA" from Accordions Asia, and not even listed on Roland's website.

Searching for FC-7: "discontinued" on Roland's website, $249.00 (+$71 shipping) in eBay, $305 (+$44 shipping) from Reverb.

I built the battery for less than $100, and the FC-8 (I called it FC-8 because it has 8 switches, not 7) cost me $50. The runtime of the battery is longer than that from Roland battery, and the FC-8 is more user-friendly than the FC-7 because the switches are arranged in 2 4-switch rows instead of in one long row.

Non-existent solutions from Roland for FR-7/5/7x: built-in MIDI ports, built-in power port for AC-DC adapter.

Same thing for non-accordion items. I ordered the hitch for my truck for $160, and spent 1 hr. installing it. Later one of my co-workers with a similar truck told me he'd paid $1200 to the dealer for the hitch (another dealer didn't even want to install it, citing "void manufacturer's warranty). The "after market hardware" and my installation look a lot better than the dealer-installed hitch.
 
I do. The solutions from the original manufacturer, not always, but many times are non-existent, inadequate, or unreasonably costly; of course "unreasonably" is very subjective.

Examples:

Searching for "battery for roland fr-7x": $329.99 from Amazon, $249.00 but out of stock from Liberty Bellows, $128.80 (not Roland) but "No Shipments to USA" from Accordions Asia, and not even listed on Roland's website.

Searching for FC-7: "discontinued" on Roland's website, $249.00 (+$71 shipping) in eBay, $305 (+$44 shipping) from Reverb.

I built the battery for less than $100, and the FC-8 (I called it FC-8 because it has 8 switches, not 7) cost me $50. The runtime of the battery is longer than that from Roland battery, and the FC-8 is more user-friendly than the FC-7 because the switches are arranged in 2 4-switch rows instead of in one long row.

Non-existent solutions from Roland for FR-7/5/7x: built-in MIDI ports, built-in power port for AC-DC adapter.

Same thing for non-accordion items. I ordered the hitch for my truck for $160, and spent 1 hr. installing it. Later one of my co-workers with a similar truck told me he'd paid $1200 to the dealer for the hitch (another dealer didn't even want to install it, citing "void manufacturer's warranty). The "after market hardware" and my installation look a lot better than the dealer-installed hitch.
I understand you frustration. I too purchased the extra battery then a second one as one failed after many years, fr7. Quite pricy from Roland…those were the days you can purchase internal circuit boards for the accordions too. Not now, just user and external parts. Think the 7 and 8 series maybe the last of the factory made battery packs for any music Industry?…even my gopro7 overheats due to the manufacturer battery. So should I upgrade to a GoPro 9? Maybe same problem? Us consumers are the ones getting hit with failed electronics.
 
"if you want a thing done well, do it yourself!" And it's true for batteries - but I'd say the opposite is true far more often.

There's a lot of knowledge involved, and some skill as well if the component cells are to be connected by "spot welds".
  • types of batteries. Where you see "lithium ion" above, that likely means 18650 lithium cobalt cells, but there are other chemistries and formats.
  • where to get good ones. There's a lot of junk battery production - no kidding, it's a real issue.
  • battery management systems. The big battery pack that powers an electric bicycle has a BMS that balances charge across cells, protects against harmfully heavy discharge, etc. I don't know what a smaller pack with a couple of cells would need, but it seems crazy to me to go without a BMS. You have to know what your battery needs, and where to get it.
  • what you need for a charger. This is where we came in - house fire because of over charging.
I personally am not interested in cultivating that expertise, so I'm just relaying this second hand. Someone who really knows how to build up a good battery would probably have more to say.
 
I agree with you 100%, Donn.

I'm no expert in battery building, just a risk taker. Frankly, when I built the replacement battery for my FR-7b (see AIY (Assemble It Yourself) Li-Ion battery pack for FR-5/7/7x/8x), I considered the risk of frying the accordion, and prepared the fund to buy an FR-4xb as a replacement.

Another point related to "after market hardware," I happen to work for a software company. Our products are used by many big software companies in their products, but about 40% of our revenue comes from companies that use our products only internally as an "after market software" when the solutions they are looking for are "non-existent, inadequate, or unreasonably costly" from their software suppliers.
 
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