Hitec H4

It's been pretty quiet on the charger front for the last few years. There were a glut of cheap and reliable new units on offer a while back, all in similar vein - anodised blue metal body, four programming buttons, 50W output, comparable software - it seemed like they'd all come from the same sausage machine!

My first good charger was a Hitec CG335, but that was last century, and Hitec didn't have anything to offer when Li-Pos came to re-shape my flying activities. Well, they're back, and have just pushed through the saloon doors with one of the nicest-looking chargers you'll find; it even manages to kick sand at Graupner's blingy units.
I've never invested in a big charger, simply because the 50 – 100W units I've accumulated over the years have worked well enough, although I now find an increasingly regular need for a more powerful charge output, especially as I tend to be using mostly 5s and 6s Li-Pos nowadays, sometimes hooked in series for larger models. My solution has been to spread the work across my charger fleet, but a small, cluttered charge bench and the need to remember the slightly different programmes across the four machines is a constant reminder that I really should simplify the set-up.

HUMBLY YOURS
The unassumingly-named H4 has four charging ports and, unlike many quad chargers that manage only 50W per channel, it'll push out 120W and 8A through each, with an ability to link the two channels on each side to create 2 x 240W, 16A outputs – a feature that Hitec refer to as ‘Channel Bridge’.
It's beautifully made and incredibly good looking, too, thanks to an all-metal body that relegates plastics to the screen and push-input buttons. Two charge outputs, balance and temperature ports are on either side, with cooling fans to the side and rear, where a power input lead enters. The H4 requires an 11 – 18V, 30 - 40A power supply, although a smaller (say 20A) PSU is fine for more modest charging requirements.
Supplied with an array of charge lead types (albeit without a temperature sensor) and three balance boards - one each for FP, JST-XH and JST-EH plugs - there's also a support bar that clips to the underside and raises the rear to improve the flow of cooling air whilst making the screen easier to read. You won't find four sets of leads and boards, “please contact your local hobby shop…”, but, like me, no doubt you'll have acquired plenty over the years; my multi-plug balance boards work fine.

IN USE
Although modestly sized, the back-lit 1.2 x 2.75”, 128 x 64 pixel screen is easy to read. I had some initial concerns, centred around whether four outputs should really have four screens, but having used the H4 I'd say that one screen is better. How so? Well, Hitec's software is darn good, much in the same way that Graupner's behemoth Ultra Duo Plus 60 isn't. The single screen allows the software to bring data together for easy comparison and makes bridging channels easy.
Each of the charge outputs (A – D) has a quadrant button, a press of which takes you to that output's individual screen. Programming is a simple case of using the arrow keys to scroll the cursor followed by the + / - keys adjust the data settings. Press the start / stop key when you're ready to go, press it again to confirm the cell count, and you're away.
The H4 is nicely quiet in operation; in fact you'll probably find that the noise from your chosen PSU will drown the quiet hum from the four cooling fans.
Moving between packs is just a case of pressing the relevant channel select buttons that take you to an excellently informative charge monitor screen. All the data you'd expect is displayed here: charge current, pack voltage, individual cell voltages, input capacity, time elapsed and a neat graphic showing the pack's charged status as a percentage. Scrolling (using the arrow keys) brings more information such as temperature and parameter reminders, plus a handy surveillance screen that brings the unit's four outputs together, showing each pack's charge status, i.e. voltage and charge current – handy if you want to check that your PSU isn't being thrashed.
The manual is very good, although the software’s so intuitive that I think the vast majority of users won't reach for the blurb very often. Many chargers ask the user to find the parameter set-up screen (System screen on the H4) to change from Li-Po to Li-Fe or Li-Ion, but not here - the H4 allows the battery type to be selected from the normal charge-start screen. There isn't a programme memory facility, although from a normal charge screen, pressing the ‘up’ arrow takes you to the recent history list, where each output's last activity can be selected and re-used.

BRIDGING
As mention above, the Channel Bridge facility hooks two channels together for doubling the output power, and two bridge plugs are included for the purpose. You can join two channels on one side while still using two separate channels on the other, or double up on both sides.
Channel Bridge is activated by entering the System menu (pressing both arrow keys at the same time) and scrolling to the Output Set option before selecting A + B and / or C + D. The software makes the process very easy, and the monitor screen neatly reflects the merged outputs. I did initially wonder whether this facility should be a little more obvious, accessible perhaps from a normal charge set-up screen, but it's really quite easy to find and its less obvious path probably prevents users making unwanted errors along the way.
Whilst the majority of users probably won't be using this facility, those graduating to larger models, competition pilots requiring a fast charge at higher ‘C’ ratings, and anyone who needs to replenish a large pack quickly will be grateful –and the fact that it’s easy to negotiate is a real bonus.

OTHER BITS
The H4 provides all the warning and error message screens you’d expect – PSU reverse polarity, short circuit detection and auto-cell counts. You can use it to measure lithium pack status and cell voltages just by plugging the pack's balance plug into a port and pressing the channel's relevant select key. There's a storage facility, too, where Lithium cells can be discharged to a safe level if they're not likely to be used for a while.
The NiCad and NiMH screen differ a little as you'd expect, and I like the way the final monitor screen shows what's been taken and added when a pack’s been cycled.
So, is there a downside to H4 ownership? Not that I can see; Hitec have a reputation for releasing well-tested products and they've not made a slip here. Perhaps the H4's only disadvantage is that some may consider it too nice to take down to the flying field, where finding a leisure battery big enough to cope with fast charging demands may prove a problem.

COOL
Hitec users will be familiar with the HPP-22 PC programming device used to update software for radios, modules and receivers, and here it can be employed to update the H4's firmware and provide a PC screen interface (although to be honest that's really not necessary, given the H4's abilities).
Well, that's it. What a relief - I had concerns that Hitec would make this unit far more complex than it needs to be, a temptation that, sadly, some manufacturers haven't managed to resist over the last few years. But Hitec have, and the result is best charger I've used. It's a wonderful bit of kit, well made, powerful and easy to operate, so your head won't be in the manual very often. There's everything here in a charger that the electric flight enthusiast will need for many years to come.

FOOTNOTE
A problem with this charger cropped up after the review and, I'm told, an issue that affected the first batch in the UK. Some channels completed a charge process when the battery level was in the region of 80-90%. The problem was intermittent but clearly something was wrong. It turned out to be a hardware issue according to distributor J.Perkins who fixed mine promptly.

DATAFILE
Name:  H4
Product type:  Multi-function battery charger
Manufactured by:  Hitec     
UK distributor:  J. Perkins Distribution,  www.jperkinsdistribution.co.uk
Charging ports:  4 x 120W (2 x 240W with Channel Bridge)
Battery chemistry:  1 – 6 Li-Po, Li-Fe, Li-Ion; 1 – 15 NiMH / NiCd, 1 – 12 Pb
Input voltage:  11 – 18V
RRP:  £199.99
Supplied with:  Charge leads, balance boards, manual

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