SP140 battery discharge for storage/transport

I was wondering how long should we wait before charging the battery after a flight?

I don’t know how it is with the sp 140. but basically the bms says when the battery can be charged because the bms is programmed to a temperature from when the charging process can be started. it is no problem if the battery is below 30 degrees celsius, 20 degrees celsius is better.

normally everything is described in detail in the operating instructions for the devices and batteries that are used.

Is this information something OpenPPG includes for the at least the supported batteries? I had been assuming the docs were a weak point if I couldn’t find them online.

Right now the setting are baked in and can not be changed, but from batch 3 battery’s and forward, all setting can be set by the end user if they want (even if most dont wont wana touch it).

A Bluetooth module will be built into the pack so you could set the temp and under where charging is allowed to whatever you want. Defaults are good for most but this will be an extra option going forward.

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We’re pretty excited about some of the BMS’ Paul has been testing and look forward to making everything a bit “smarter”.

I’m proud that we were able to get a great custom yet affordable battery pack created for the SP140 (the X4 didnt come with a battery or any BMS) but we still have lots to improve on.

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For 15 years I’ve prematurely killed my rc flight lipos by keeping them fully charged to be ready for the next flight, which sometimes came after weeks. Needless to say, after 20-30 cycles my lipos started to swollen and loose power becoming unusable. And thought this is normal I guess.
One day I’ve read people getting 250-300 cycles…what?! Being the caring for their stuff type I was broken a few days realized what I’ve lost in terms of flight performance all those 15 years.
So…I was told that for an 86v battery an 1500w 230vAC infrared heating radiator could work by drawing about 500w, this could be good by drawing 1kw in two hours, not too fast to count as a lost cycle and not too long to be annoying.
But since I’m building my pack it would be nice to be able to test it at a power draw of around 4kw to simulate at least level flying and see if something gets hot because turning the prop in the apartment is counter productive to say at least…
I’m making the pack from three 8s8p packs so I can balance charge them with my hobby charger. So I have packs of 30v(8s) and about 900w. The question is how can I draw a few kw from these with an infrared radiator? Because using the same math as above gets me at just 195w draw at 30v (if at 230v draws 1500w, at 30v draws only 195w)…is this correct? What could I use then to simulate a 3-5kw out of the whole 24s(86v) pack or 1-2kw out of individual 8s(30v) packs?

Crap, mine have been fully charged that long. Weather changed and didn’t get to fly. Might be windy in my trailer tonight.

A simple toaster will do or a heat gun.
Here drawing roughly 1kW or 11Amps

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Wait, a regular 110V AC toaster without any inverters? I guess it’s just resistive 1K-2KW, but I never considered using that :slight_smile: Thanks!

I thought I had posted mine here but I don’t see it, so here it goes:

96->12V DC converter, 12V->120 AC inverter, and a 63A 250VDC breaker for a switch, plus some XT90 plugs that I also use with my 48V ebike batteries when camping, etc.
I hate wasting electrons so I actually use this contraption for transferring power to my ebike batteries (~100W charger works OK, but I do plug in a small USB fan to the inverter’s port in order to cool down the DC converter as it gets toasty)

https://www.amazon.com/gp/product/B07DW1PSRH/
https://www.amazon.com/gp/product/B07B6B6HQZ/
https://www.amazon.com/gp/product/B0746DLP7S/
https://www.amazon.com/gp/product/B0886HB9V3/

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I liked your idea…so I made one too. Thanks! The breaker I used is the 15amp version. I did not have a spare Anderson, but that should be here tomorrow. I knew it was not going to be fast, but that’s fine…sometimes “slow” is better.

The weak link here is the DC-DC converter. I was hoping to find a heavier duty version, but this one is the only one I could find. It is marginal for charging my e-bikes. If you run across a heavy duty converter that covers the same voltage range, please let me know. :+1:
Bill

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I continue to use my low-power (120W) inverter via 12V that I posted earlier, but I’m tempted for an upgrade that could handle my ebike or other chargers more reliably, or even a 110V mini-split heat pump for a day or two.

Has anybody tried this inverter? Amazon.com

It says 5000W peak, rated for 2250W for $260; they have stronger versions too (up to 10K peak/5000W rated for $453), and this is one of the few ones that comes in 96VDC variety. Can I realistically expect it to be reliable to around 1KW…?

See if you can find a MPPT controller that can take a 100V battery as well. That way you can use it for charging the battery as well using a solar panel.

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How is it working for you? Worth it?

It works great! It is absolutely worth it to maintain the health of my batteries.
Bill

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