What Charger

[John Mc]

After many years of IC flying I am finally starting to get into Electric flying for my smaller models using 3S and 4S Lipos. I am also enviously eyeing club mate’s models which use 5S.

I have two Lipo chargers, one is a 50 watt Fusion Elysium plus a 90 watt Eclipse which I bought last year. Both chargers are simple to use and can charge both battery sizes no problem.

If I could stay on the right side of Father Christmas I could buy another Eclipse for £100 which I am very pleased with so I can charge three batteries at once using three separate chargers.

So what’s my problem?

I now am seeing quad chargers becoming more available but the ones I am interested in - AC/DC with a built in PSU have four outputs of 50 watts each totalling 200 watts. I see the Lipro Quad 6 for £190 and am strongly tempted to get one rather than another Eclipse.

So what option should I take? Another 90 watt charger or a Quad 50watt one?

Opinions and advice would be appreciated

John

[MattyB]

Sorry, but my vote is for neither. Chargers with integrated PSUs are generally very limited in power, and if the integrated PSU dies the whole charger is history.

Instead gget yourself a decent 250-350W charger (an iCharger 106/206b or one of the HK Turnigy Reaktor clones based on them). Add a matching DC PSU of 250/350W (500W server PSUs can be sourced on eBay for ~£20 and concerted in an hour or so) and a parallel charge board and you have much more flexibility to fast charge a single pack at high C ratings or multiple packs of the same cell count in parallel at 1-2C. It will also be a better solution if you do choose to move up to bigger pack sizes and cell counts.

Edited By MattyB on 18/10/2016 20:14:09

[Steve Hargreaves - Moderator]

50W doesn't sound very much when it comes to charging John...even if there are 4 of them. On a 3S battery that equates to around 4A max charge current on a 6S only 2A. Many Lipos now can be charged at 2C & if you move towards bigger batteries I can see you wanting another bigger charger soon.

As far as the PSU for your charger is concerned there are interesting threads on the forum about converting an Xbox PSU (200Watts) & even a computer server PSU (500watts) to power our chargers & these PSUs can be obtained very cheaply....

[Former Member]

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[Geoff S]

Yes, what Matty says. I have a Graupner Ultramat 16 which has a built-in power supply but with the option for an external 12 volt DC input. It's OK on mains and that's how I usually use it but it works better with the external supply.

I also have an iCharger 308 duo which is effectively 2 x 30 amp chargers in one package. That only works with an external supply.

At the field I use an old lead acid battery that came out of our 2.5l diesel engined campervan when it didn't prove man enough to start the engine after a few days rest without a hook-up. At home I have a an old server PSU like Matty's which can deliver up to 47 amps at 12 volts! I've never actually tried it at that but it works well and they're very cheap on eBay and are easy to convert.

Geoff

Edited By Geoff Sleath on 18/10/2016 20:30:38

[Former Member]

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[Adrian Smith 1]

Like Percy I have just ventured into electric after a long time in IC (still doing IC of course). After a discussion with George at 4-Max on chargers and wanting to keep to a modest budget he advised me, for what I wanted, to have the GT Power A612-D for my lipos. They are 6S and after some maths over the phone he suggested a 200W output model charger. Admittedly, I can only do one Lipo at a time which is fine by me. One thing he did mention that mains only chargers were less powerful which I don't quite understand. However, this charger does either mains or battery. Obviously, if I wanted to move on to 8S or 10S lipos I would need a different charger. However, this one is fine for now.

[Geoff S]

It's just that the mains powered supply built into the charger would have to be very expensive to be able to source a lot of current. They in-built power supply is fine on my Graupner for charging 2200 mA 3S LiPos at 1C (2.2 amps) but won't push out 5 amps to charge a 5000mAh 4S at 1C. It'll charge the bigger battery OK but at a lower rate. It works fine if I connect it to either a good 12v battery or, better, the server power supply.

A mains powered charger without the external option (if there are any?) limits its use. You couldn't use it away from either.

Geoff

[Former Member]

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[Bob Cotsford]

Server power supplies are very cheap and supply a regulated output that will be more than enough for a quad charger or two. They are also compact! I bought mine of the BMFA classified ready fitted with 4mm connections and modified for variable fan speed for around £35 and it's a 47A unit. They are available from ebay for around £15 unmodified.

I'm thinking of getting a quad charger for home use but ideally I want something capable of 4 * 6S at around 4A - any suggestions that won't break the bank?

[John Mc]

Thanks for the advice all.

I agree a 4 X 50 watt charger is not future proof. I will shelve that idea and do the maths - plus research some of the ideas you have given me. I think I need to up my budge a bit.

[John Lee]

Posted by Bob Cotsford on 19/10/2016 10:50:51:

I'm thinking of getting a quad charger for home use but ideally I want something capable of 4 * 6S at around 4A - any suggestions that won't break the bank?

Hitec H4 does just that Bob. Mine's 3 years old now & has been very reliable. It's 120 watt per channel but you can bridge 2 channels for 240 watt. All the outputs are independent so you can mix & match battery capacities & chemistries. Typically at the end of a day's flying I may have used 1300Mah 3 cell, 2200, 3 cell 2700 4 cell, 5000Mah 6 cell and I can have any mixture of these of these charging simultaneously.

[Geoff S]

I'm not sure the capabilities of a charger should be expressed in watts.

As an example: my icharger (308 duo) is capable of delivering 30 amps into an 8 cell LiPo on each side (it's 2 identical chargers in one case). So that's 30 amps at (say) 30 volts or 30 x 30 = 900 watts? Not really. Ideally the source resistance is zero so the charger itself dissipates zero watts and delivers 30 amps into the battery. It's just a current source (actually a voltage limited current source for the LiPo so the current gradually reduces as the target 4.2v/cell is reached.)

Perhaps the power rating is used as a shorthand but it's not an accurate figure. Of course to use both sides of the charger at its nominal full capacity would need a better power supply than my 47 amp 12v server supply but I think it's more than I'll ever need.

Geoff

[Former Member]

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[Bob Cotsford]

Thanks chaps, I've ordered the Hitec from Slough Models for £179. It's not exactly cheap but hopefully it will see me through the next few years. The only thing is that it doesn't list what leads it comes with, some other options for quad chargers are only supplied with one output lead and balance connector - where's the sense in that?

[IanN]

Posted by Geoff Sleath on 19/10/2016 23:53:55:

I'm not sure the capabilities of a charger should be expressed in watts.

Geoff

Funnily enough, I'm just asking myself that same question.

My battery needs to date have been relatively modest - 2 and 3s up to 2200 - and two of these have been absolutely brilliant for that, have provided sterling service and will continue to do so

However, I've now moved up a little and have 4 x 5000 4s to play with for a project. As just one of those at 1c will take 84 watts (16.8v x 5a, yes?), and I'm (a) a fan of parallel charging and (b) would like to go to 2c sometimes, it's clear the B6AC won't cut the mustard

I've been looking at the icharger 306B, and the equivalent HK clone Turnigy Reaktor. Both claim 1000w (albeit at 23v input - although that's not a problem as I have a couple of PSUs that will deliver that) or 500w at 12v input.

That sounds all well and good as to put my 4 batteries on at 1c will need 84 x 4 = 336w, and at 2c 168 x 4 = 672w. So, easily within the wattage the charger is claimed to deliver. However, both chargers quote a charging current range of up to 30a, which surely limits me to a max of 7.5a per battery if charging all 4, so 1.5c max?

So, maybe the wattage isn't the whole story - not all it's cracked up to be?

Don't get me wrong, I still think these chargers look like very capable choices and will probably suit my needs. In reality I probably wouldn't have the need to charge all 4 at 2c very often, However, I've never been totally confident at working out the electric side of things and just want to be sure that my numbers above are correct.

Am I barking up the right tree - even if it's at the wrong cats?

[John Lee]

Posted by Bob Cotsford on 20/10/2016 10:11:09:

Thanks chaps, I've ordered the Hitec from Slough Models for £179. It's not exactly cheap but hopefully it will see me through the next few years. The only thing is that it doesn't list what leads it comes with, some other options for quad chargers are only supplied with one output lead and balance connector - where's the sense in that?

My H4 came with a couple of the Bridge connectors for joining the two to one outputs and a handful of leads, most of which are still in their sealed packs as they included Tamiya, Traxxas and Deans none of which I use. There were no EC5 or XT60 when I bought mine, so had to buy/make these up subsequently. The outputs are standard 6 cell balance ports & 4mm banana sockets. Hope it works out well for you Bob.

[Bob Cotsford]

I just read the email from Slough and that showed just £79. Well, I thought, am I on a winner or have they packed the wrong charger? I phoned them up and unfortunately it was a mistake on the email notification. It really is £179.

At least it's in the post and due for delivery tomorrow. A lack of XT60s is a pain in the rear but easily fixed via HK - if they are in stock!

As for watts output, I guess I like it as I can convert to estimated amps in required regardless of battery size so I know whether my 47A power supply can cope. Specifying a different amp rating and watts output capability isn't so clever though.

[Former Member]

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[Bob Cotsford]

Yes Brian, the last one in stock at Slough. Other places were listing them at anything up to £220! I've order some multi-adaptors and balance boards from HK so that I can keep my existing leads for non-volatile (ie NiMh, Pb and LiFe) charging in the garage. I'll have to change the supplied Deans connectors to XT which is odd as HK batteries seem to come mainly with XT these days.

[Former Member]

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[Bob Cotsford]

I've just about eliminated Deans from my life now so I'll solder XT sockets in place of the supplied Deans, I do have some adaptors but prefer not to use them unless it's a temporary fix. I have a couple of the HK multi-plug leads in use on my existing chargers and find them excellent value and good quality.

I'm suitably impressed with Slough's service, they tell me the charger is due for delivery between 14:00 and 15:00 this afternoon.

[Former Member]

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[Bob Cotsford]

The H4 has been delivered, unpacked and is being put through it's paces with various battery types and sizes. It is a nice unit, bulky but what can you expect for a quad, and once you work out the control logic (read the manual? - I'm a bloke, don't go there!) it's quick and easy to configure. One feature I like is that you can tell it how much power your power supply can deliver so that the charger won't try to overload it. It also has 10 memories on each output for commonly used batteries. The only issue is that the memories are easy to overwrite by accident.

XT60s can also be a pain to separate but to date I've had no dodgy connections, something I did suffer with Deans when the spring tongues became flatter with use.

So, initial impressions - easy to use, very well specified and it feels solidly constructed which always makes you feel warm and cosy.

However - why do they only supply one set of connectors and why must the battery and balance leads be made so short? Also, the memory function needs a way to lock it once a setup is defined.

[Eagle 899]

Posted by Bob Cotsford on 21/10/2016 15:24:08:

XT60s can also be a pain to separate.

I experienced that with XTs, then I read about a very good solution:-

Carefully drill very small holes in each side of the XT and use outside circlip pliers to separate, works a treat.