OK so here's the story - skip to the end if you just just want the punchline
For ages I've been looking for a good balance charging solution. Yeah, everyone uses RC chargers but they're a bit dumb in the way that most charge up to pack voltage and then bleed back the high cells. This prompted me to go down several routes to make my own, using individual DC converters and finally small 5v meanwell SMPSs. The DC converters didn't really work sufficiently, none I tried had enough guys to be feasible without adding multiple in parallel and finding isolated gutsier ones proved difficult or expensive. Then I tried 5a 5v meanwells tuned to 4.2v which did work but was quite bulky and messy to set up and due to the low delta V between flat and fully charged at the single cell level using a dumb meanwell meant it didn't deliver much current for long before dropping to CV mode.
I also tried a few other dedicated lipo charging boards after discussion with a few chinese manufacturers and wholesalers without much luck. Until now.
Enter my current beasty - no DIY fiddling required - it's a neat commercially produced product that you can just plug in and use.
As per the teaser info I posted in my build thread it's an isolated 6S balance charger that charges each cell individually - through the balance taps.
And it does so at up to 8 amps! It also discharges at up to 1 amp. If charging a single 6S pack your balance tap wires might get a bit warm but the silicon wires on mine didn't get anywhere near hot enough to be concerned about them melting. If yours do get hot just turn the current down a little. It'd be unlikely anyone would use them to charge a single pack in an ebike application anyway, you'd be charging multiple packs in parallel which is no issue for it.
For all out speed you could bulk charge to 4.1v/cell or there abouts and then finish off with this charger if you're worried about overcharging, or just let this charge at 8 amps from the get go if you don't need a super rapid recharge. And because it's so quick to balance at the top end, if you did want to bulk charge at full pack voltage you could leave the pack permanantly in series connection and top it up/balance each sub pack through the balance connector (come back 5 minutes later and swap to the next balance tap, and then the next)
Or do what I do with a multipin centronics plug (or similar) and charge all through that.
As an example it balanced up a slightly out of balance (10mv difference) 5ah pack in about 3 minutes and one that was seriously out of balance (2 cells at 3.9v while the others were at 4.16) big 15ah pack in 20 minutes. It basically topped up the 4 nearly charged cells and then belted 8 amps into the other 2 until they were full. See how long your average powerful RC charger takes to sort that one out!
In the below pic I have it set to charge to 4.18v. You can see cells 3, 5 and 6 are already there and have tailed right off before stopping. The others which are slightly behind still charge with max current or are tapering off too. This can balance a slightly out of balance pack in literally only a few minutes.
It doesn't have all the advanced features of some RC chargers but it does what's necessary - set the charge voltage, current, charge time and also has a temp probe. Physically it's relatively large (around the size of a 350w meanwell but about an inch shorter) - alot bigger than my icharger 1010b (which is now largely of use only to calibrate controller shunts
) It has 2 fans in the opposite end to pictured below and runs barely above ambient at max power. It needs a 20 amp + 12v PSU to power it. A 350w meanwell would be ideal - I use cheap server power supply.
So, I had to buy 10 of these as "samples" which was a bit of a risk as they were much more expensive than all my other attempts at a good balance charger and I wasn't sure how good they'd be but it looks like they are indeed the goods so it was worth the gamble. I only had 1 shipped to me initially for testing but the rest are now on the way. So, the deal is I have 7 left to share with everyone and then if there's interest in more I'll drop ship them from china to keep the postage costs to a minimum for everyone.
OK enough dribble
Price is $120 delivered for Aussies and for now international orders will be $130. But once these 7 are gone I'm hoping to have them for $120 delivered world wide. But get in early just incase
- 8 amp balance charger of doom
- Bal-charge1.jpg (56.86 KiB) Viewed 14965 times
- Input power: 250W
- Charge Power: 200W (33W x 6 cells)
- Discharge Power: 25.2W (4.2W x 6 cells)
- Charge Voltage Precision: +/- 0.001V (claimed - resolution of LCD is only x.xx V - which is good enough!)
- Discharge Voltage Precision: +/- 0.001V (claimed - as above)
- Accessories:
- 1 x Balance cable (8cm)
- 1 x Temperature sensor cable (25cm)
- 1 x Adapter board
Cliffnotes: Awesome isolated balance charger that charges individual cells through the balance taps at 8 amps.
Price:
$120 delivered (Australia)
$130 delivered (worldwide)
[moderator edit to add part number to title]
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Suzuki SP200, Mars Brushless, 300 Amp Kelly Controller,(18S12P) 
