Lipo discharging options.

[fpvmiller]

Not my pic But I found that pc fans are super easy and reliable as part of the discharge setup.

 

[Shazz4321]

Yeah I like the dual purpose and being an IT guy I have an abundance of them so makes sense.

 

[jkflow]

I did build my own discharger, 4 x10 Ohm 50W in parallel mounted on a big heatsink, added a 5V BEC and some cheap fans for the heatsink.
Small lipo alarm for the Lipo itself. Roughly ~$30, some cursing and ultimate;y works like a charm. You could use old lightbulbs as well, I just don't like the fact that they might shatter when I store them.

The ISDT's look interesting but I like to tinker as well. Discharger is truly just a resistive load with a fan for cooling, not much to it.

 

[Shazz4321]

I did build my own discharger, 4 x10 Ohm 50W in parallel mounted on a big heatsink, added a 5V BEC and some cheap fans for the heatsink.
Small lipo alarm for the Lipo itself. Roughly ~$30, some cursing and ultimate;y works like a charm. You could use old lightbulbs as well, I just don't like the fact that they might shatter when I store them.

The ISDT's look interesting but I like to tinker as well. Discharger is truly just a resistive load with a fan for cooling, not much to it.

I also like to tinker when I have the time... I also don't trust myself to hear the Low Voltage alarm but that is on me mostly...

For the AOKoda system, if I were to swap out the bulbs for 3 50W 10Ohm Resistors with a fan\Heatsink that would be pretty slick...Would these be an easy enough swap out with some soldering\mounting?
https://www.banggood.com/5pcs-RX24-...-p-1537748.html?rmmds=search&cur_warehouse=CN

 

[jkflow]

Yes, those are the resistor types I've used, just from Amazon. Don't be surprised as resistance is not to spec but for this application it's a don't care, mine all came in at 13Ohm. Cheap heatsink and some thermal paste for the resistors as they do heat up quite a bit. I had a BEC laying around but it's powered off the battery that is being discharged.

For reference:
https://www.amazon.com/gp/product/B00VG6WPKK/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B07HL1PY3J/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1
https://www.amazon.com/gp/product/B07H3253TR/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[Vedak]

Man you are making me want to build one

 

[Shazz4321]

I think I will do it for a bit of fun as well as the ISDT as when you breakdown the cost in Aussie Dolleriedoos there is not much difference. Comparing to the ISDT100 to make it fair as there is no Bluetooth.

AOkoda Cellmeter 8 with the bits: $30
5x 50W 10Ohm resistors: $11
Heatsink ~ $10
Fan and voltage regulator (could possibly get away without this) ~ $5
Case to jam it all in ~$15.

This is just bangood pricing. Fleabay may find cheaper.

I will leave out the wiring, time and plugs etc as this is a bit unfair.

Something that would be nice is the ability to have multiple dischargers together as I see myself with a lot of small 2s quad packs in my future.

So for a custom job you’re at around $70 and I can get the ISDT100 for $60.

The ISDT 200 is then $130 with Bluetooth.

 

[jondilly1974]

If I were shopping today I would be thinking about the BD250 from SkyRC. I own the BD200 which is the older, dumber version. The BD250 has the ability to analyze your packs via USB to PC. I can drain my Turnigy Graphene Panther 5.0 6S from 4.0v after a run in a few minutes.

 

[Shazz4321]

If I were shopping today I would be thinking about the BD250 from SkyRC. I own the BD200 which is the older, dumber version. The BD250 has the ability to analyze your packs via USB to PC. I can drain my Turnigy Graphene Panther 5.0 6S from 4.0v after a run in a few minutes.

I did see this in my travels but initially discounted it because of the cost... I'm not a racer so don't think I will use the PC logging and the ISDT is about the same price, notably with 50 less watts, but it has Bluetooth which seems a bit gimmicky but I would probably use it. I do like the look of their Q200 quattro though, if it had better discharge I would probably already have one.

 

[rflx]

Related question, because i parallel-discharge with an ISDT FD-100:
After discharge, the individual cells seem to end up between 3.79 and 3.81. I have stopped storage charging them after that, because it is so close to storage voltage anyways. Is there any advantage to balancing the cells to exactly 3.8 before i store them in the trusty LiPo box?

 

[jkflow]

No benefit, I do this all the time. Balancing is important prior using them under heavy load. Under every other circumstance it's a 'don't care'.

 

[Vedak]

If someone builds another one, please post up the process. Those are always fun to see.