I finally got around to testing one of the new Hyperion 14s balancing chargers
I got last week. This is the one Doc first reported about in this thread
. I had to make a special balancing harness, and put Andersons on the main charge wires, but that was pretty easy.
I just used two 7-pin pigtails and crimped some VAL-U-LOK socket connectors on the ends, and stuffed them into a 14-pin VAL-U-LOK 4.2mm PE Series plug that matches up with the connector coming from the LVC boards in my 12s3p packs. To power the 1420, I used two unmodified S-350-24 MeanWell supplies, wired in parallel:
I maxed out both at about 27.25V. I'm still trying to learn all the various charging/balancing options, but the basic operation is pretty intuitive, especially if you've ever used RC chargers before. The instructions weren't completely clear on connections for large packs, made from smaller sub-packs, so I was pleasantly surprised to learn that even though the pigtails I used only made use of 7 of the 8 available pins in the two balancer inputs, the unit simply ignored the two "empty" inputs and correctly identified the pack as a 12s configuration. I was worried I'd have to do a funny harness, that remapped the two 6s3p "chunks" into a 7/5-channel configuration.
I bought two of these chargers, so that I can do both 12s3p packs on my Townie at the same time, but for these first series of tests I'm only using one. As shown below, my 24s3p setup is split into two 12s3p packs that are connected in series. Each has 10-gauge discharge wires, with the large 75A Andersons, and each has a separate 12-gauge charge pigtail, with "normal" Andersons. Each pack also has two LVC/parallel adapter boards that provide the cell-level parallel connections and each have a 7-wire set of 18-gauge wires for balancing. These two sets terminate outside the pack in a VAL-U-LOK free-hanging plug.
The connections between the 1420 and the pack are simply the matching 14-pin VAL-U-LOK connector and the two wire main charge leads, with the Andersons.
First I tried straight balancing, which works quite well, simply pulling the high cells down to the level of the lowest cell. With 1/2A of balance current, it didn't take long (about 45 minutes...) to balance all 12 cells to within 5mV from an initial max delta of around 65mV. Actually, I think it could be even closer, as there is a setting somewhere for what is considered "balanced". There's several different monitoring screens, which is handy. One shows the average cell voltage, and the max delta. Then there's two more screens that shows all the individual cell voltages. On these last two, the decimal points change to small squares to indicate which cells are being drained. Finally, there is another screen that lets you select an individual cell, and see the voltage to three decimal places.
Next, I tried a regular charge. There are 20 memory slots available, and setting the various parameters is straightforward. You set the number of cells (1-14), the max charge rate (up to 20A) and the pack capacity. I'm not sure what the maximum capacity that you can enter, but it had no problem with my 15,000 mAh (i.e. -- 15Ah...) 3p pack. If the balancer connections are not present, the charger will default to a charge-only mode. With the balancer plug(s) connected, it will automatically select the balance charge mode. Holding the "Enter" button down for two seconds initiates the charge/balance process, after first confirming the number of cells.
Since the pack in this first test was already 90% full, it didn't start out at a max charge rate. It ramped up and stopped at about 8.5A. What was interesting was watching the screens. All of the aforementioned balancing screens were available, as were a bunch of "Data Display" screens. There's a "Quick View" screen which I mostly used, which shows the total pack voltage, the input voltage (from the MWs...), the charge current and the total mAh going into the pack. What was interesting was seeing that the mAh calculation is smart enough to not get skewed by the balancing that is going on at the same time. Unlike most RC balancers and/or balancing chargers, this one uses 12-bit A/D conversions for better accuracy. The unit also "pauses" occasionally, shutting off the charge current, I'm guessing to get better voltage measurements. At the end, the unit plays a littly diddy, to indicate that charging and balancing is complete. I watched closely at the end, wondering how far down the current would drop, and what affect the balancing would have. The current dropped down to about .3A and stayed there awhile, as the cells continued to balance. When the max delta got down to 5mV, the current was down to about .21A. Amazingly, they will both get to their appointed "minimums", at the same time.
I used the default settings, for most everything, but there is lots of user adjustments that can be selected to change things like the charge to voltage, max "C" charge rates, max balance deltas, charge time limits, and a host of other settings. As I said, I will need to explore these further. There's also a USB port, with a supplied cable and a PC app for monitoring/logging. I still have to try this as well.
What I will do first is figure out how to lower the charge-to voltage, from the current 4.20V, down to about 4.15V. There's also the option of simply selecting Li-Ion instead of LiPo, which uses a slightly lower voltage setting. I'm also going to look at redoing the pack connections/charge harness a bit. I'm thinking if I use an 18-pin VAL-U-LOK connector, instead of the 14-pin version, I can dedicate 3 pins each for the two main charge wires, and end up with a single charge plug. Doesn't get much simpler than that.
I also need to do a set of harnesses for the 18s2p packs I use on the folding bikes. For this scenario, I will need to use both chargers, if I want to charge the whole pack at once. One would charge the first two 6s2p blocks, so 12s, and the second one will charge the remaining 6s2p sub-pack. This is pretty straightforward. I also have a 16s2p pack made from 8s-5800 Turnigy packs. Fr this I'll simply have a harness that lets each charger do one 8s section. I'll just spit the 8s connections so that it looks like two 4s packs. I now know that the charger will simply ignore the unused channels.
Anyway, I really haven't found anything that I don't like about these units, including the price. One of these, plus a MeanWell, or two, are all that's needed to do safe charging and balancing of a 12s LiPo or LiFePO4 "commuter" setup. I'm going to go ahead and add them to my site, and will offer E-S members enough of a discount to cover the "typical" eBay cost of a MeanWell.
I'll also provide options for some pre-made harnesses. The 1420s also come with a couple balancing adapters, for most popular RC pack brands. When I get the site updated, I'll start a thread in the "For Sale" section, which will include a way to get the discount coupon.