OK here's the low down
I meant to post about these months back when I first came across them but got side tracked with other projects (namely the isolated balance chargers which kinda made these a bit redundant)
OK, so they're essentially a standard battery medic with an additonal port that connects up to this external board that has either 1,2 or 3 50w 12v halogen globes connected. One might logically assume that they discharge at 150w with these connected but infact they discharge much higher than that - like 250w. They're an interesting circuit actually, you can hear a high pitch whine as they power up and the bulbs get brighter and brighter. I assume it's high frequency pulsing the power to the globes to get the higher power output without popping them. As stated they can't balance discharge, only bulk discharge. The internal circuitry continues to slowly leech away at the individual cells (as per a normal battery medic) while this external circuit connected up to the main discharge leads pulls bulk amps. And when I say bulk amps I mean around 10a. Which is quite a bit for a little unit like this.
So it whacks this heavy lead onto the discharge leads while still keeping an eye on the individual cell levels and trivially bleeding them down in addition with the SMD resistors. When any cell level gets close to the target discharge voltage the circuit dials the power back, dropping the brightness of one bulb first, then switching it off leaving just 2 running, then switching those off as well until all globes are off and just the internal SMD resistors are left sipping away at each cell. As is usually the case which ever is the runt cell will cut out first and in the case of the bulk discharge when that cell hits the programmed LVC off go the lights. If this is at say 3.3v many of the others are still around 3.5v or what ever and the medic will keep trying to pull those down to the same level.
So in short they're good for rapidly discharging or cycling packs but not for fast balancing as such. I was using them to cycle new packs with a watts up meter in series with the battery. With a 10a discharge on single 5ah packs (ie 2C) you could get a close to a real world discharge for lipo packs in ebike use.
motomech wrote:I don't think the bulbs can get that hot.
WRONG! these get stupidly hot - like 160c (I measured with my IR thermometre). Within seconds of powering up they were burning into my MDF work bench top. They're also very bright - think of a 200w flood light laying on your bench top. I tried putting them in a biscuit tin but after a minute or so the tin was at close to 100C and started smoking. I'll post pics of my modified set up with these when I get home, but yes these do get VERY hot.
Nope, I made a quick and dirty adapter and hooked it up to a 6S brick,...it promptly blew the bulbs
Maybe up to 3 cells > 13.8V.
Yep, they're 12v globes and connecting up 24v+ will pop them instantly. You'll need to run 2 in series on a 6S pack.