Hello Stuart,Hello all
I've Just joined the forum and see we have a few DIY battery enthusiasts here.
Glad to meet and to see I'm not the only one who likes to tinker.
I hope you don't mind me trying to use your experience...
I have a question about the Roland FR7 battery I hope one of you can answer...
My original battery still works ok for 2 hours or more so I don't want to mutilate it yet but would like to build a copy before I have to replace it.
I would like to stay with NiMH.
There is a 3 wire connection from the battery pack to the instrument.
Does anyone know what is inside the pack apart from the NiMH batteries?
Pentaprism mentions a 10k thermistor, would that be all (and how is it wired) or is there a more complex circuit?
Perhaps one of you can help me out here.
Best wishes to all
That spot welder seems nice to have with this project. Makes a good connection…I just received enough materials to assemble a Li-Ion battery pack (the prices below include tax + shipping):
spot welder - $66
I plan to rebuild a bunch of battery packs for my power tools. Instead of buying batteries with tab (thus limiting the sources), I can just buy flat top battery cells and add the tab myselfbatteries - 8 cells - $42
need 7, but bought 1 extra just in case....charger - $10
don't want to use the NiCad-NiMH chargers I currently have.
battery protection board - $7
connectors - $11
thermal protector (metal, 5A, 70 degrees C) - $10
I'm still waiting for the delivery of the heat shrink tube - $8.
Instead, I could buy these:
Custom NiMH Battery Pack: 24V 4500mAh (108Wh, 20x4/3AF, Sanyo) - $185
Thermistor - $2
Or have one built by batteryspace.com, probably about $200. That would be still $50 less than a "used, very good" battery pack from Amazon Warehouse.
But to me, putting the battery pack together is most of the fun.
Wish me luck.
Not only you get what you pay for but much more --
Washington — OSHA has released a Safety and Health Information Bulletin warning employers and workers of potential fire and explosion hazards stemming from lithium batteries used to power small or wearable electronic devices.www.safetyandhealthmagazine.com
Crushed or opened lithium batteries have caused sudden and massive fires at recycling plants and in garbage trucks. They're also all over your house.www.pressconnects.com
I think these should not even be labeled as a "battery" because they are capacitors! Like most rechargeable cells.
A lithium-ion capacitor is a hybrid electrochemical energy storage device which combines the intercalation mechanism of a lithium-ion battery anode with the double-layer mechanism of the cathode of an electric double-layer capacitor (EDLC). The combination of a negative battery-type LTO electrode and a positive capacitor type activated carbon (AC) resulted in an energy density of ca. 20 Wh/kg which is about 4–5 times that of a standard Electric Double Layer Capacitor (EDLC). The power density, however, has been shown to match that of EDLCs, as it is able to completely discharge in seconds.