As a charger? Powerjack lf3000 with 50amp charger

[Mickfromperth]

Hi guys I am new around here.  I recently purchased a boat wich has two battery banks and a dual bank charger.  After a few months of ownership the charger has died.  I Was also in the market for a pure sine inverter before the charger died and that is how I discovered this forum - I was saving my pennies and seriously considering the power jack units for bang for buck.  I don't need much just a coffee machine (pod) and a microwave.....  Hehe.

I'm hoping for some advice from users of the power jack inverters.  The thing I'm most not sure about is if the charger could be used to charge 2 banks (starter is a single n150 and house is 2xn200's).

I also can see an issue with a power loop - the way the boat is wired, if the charger and the inverter are both set to on then the inverter would be feeding the charger which i presume would make fire?

[oztules]

Provided you shut the inverter down at charging start from shore power, and then trun it off again before you shut down the shore power as in your user manual, then it will charge anything connected to it's battery inputs.

But:

if you charge from a second charger from the inverter 240v output, it will create a loop... but it will just discharge you battery according to the losses in the  system... ie use batteries to make 240v, use that 240v to charge the batteries from a seperate 240v charger connected to the inverter... will just do what you would expect... ie charge the battery  at a slower rate than you are pulling the charge out of them.... I don't envisage fire.... just flatter batteries than when you started.

I think thats what you explained... if not..... try to explain exactly what it is you want to achieve.... and with what.



.......oztules

[Mickfromperth]

Firstly - thankyou for any input / coaching you have on the topic!

The boat has / should have
1 x inverter (2kw modified sine is in situ - disconnected but works)
1 x dual bank battery charger
- bank 1: single n150 Bosch less than 2 months old.  Used only for starting engine 1 and for boosting bank 2 if not enough power to start engine 2.
- bank 2: dual no-brand n200 deep cycle less than 2 months old.  Used for running fridge (beer & candy), lights, inverter, and importantly starting engine 2.

The inverter works but I disconnected it early on to troubleshoot other issues (tacho was not working reliably when engine was running) - I was just up to the stage of reconnecting the inverter when the charger died.

The battery charger recently stopped working - its a xantec true charge 40 amp tc40i - when I opened the cover there was no obvious sign of burn / damage.  This was dis pointing as I can solder and I can shop so replacing a burnt part is a skill I have - but troubleshooting such a complex device is not a skills I have :-).  My electrical experience really is whatever I learnt playing with dick smith kits 20 years ago!

Right last thing first:

- inverter / charger loop:
This could never really be clear without seeing the control panel / master switch panel in the boat...  Basically it is a switchboard that any occupant (ie wife, kids) can turn things on and off.  I am / was concerned that the naive users might turn switches on or leave switches on that might have a disaterous effect - right now I don't have this concern because my inverter was disconnected when I purchased the boat.
I suspect the shore power input, the inverter output, and the battery charger input are on the same circuit.  Shore power feeds the battery charger - this I know.  Shore power also feeds appliances like the microwave - the appliances are also fed by the inverter when it's on.
On the plus side all this is wired up to a central switchboard which means right now things are in the users hands.  I suspect users should just know what not to do.  But we are novices so trial and error learning as we go.
I wasn't sure how much damage a user could do but I get a sense from your comment that really all they are going to do is to waste power while a charger gets fed from the inverter which is getting fed from the battery..  Ideal I would hope fuses etc to kick in before any real damage was caused but wasn't sure..

- Second last thing was: is the power jack system good bang for buck pure sine inverter - I've read enough posts on this forum to answer this question so I was planning on replacing my modified sine inverter with a powerjack LF unit of around 3000w.  Just not until I had a real reason to dispose of the modified sine inverter!

- But the main show for me is now that my charger has stopped - can I use the powerjack as a full time "top up charger" - I think the technical term is float charger (Ie to keep the system ready to go while on shore power and the fridge is still draining 12v),  part time dual bank charger - Ie to recharge either bank when they drain (after a week "at sea").  I don't have a choice but to buy a charger so if the charger just happens to come with a pure sine inverter I am a very happy camper..

My research has led me to the following stumbling block around this
- is the "dual bank" something that can be replicated with ease?  the charger that died has 2 positive terminals and one negative.  Havnt buzzed the positives to see if they are actually a single terminal with two connectors - I only just thought of that.
- is a dedicated / branded charger going keep the batteries healthier that the powerjack tack-on to their inverters?
- can the charger switch and / or the inverter switch be wired to a control panel?  Having them as seperate hardware (current setup) means as an appliance they are left on and the control panel is really a power switchboard - delivering power to each appliance.  I am thinking that - when offshore and I turn the power feed to the inverter on - that would power an appliance which is also a battery charger which creates this battery drain issue (?).  And vice versa when on shore power turning the (240v) circuit that feeds the battery charger on - my head can't think of something that might go wrong here - I suspect the biggest issue would be having the inverter on being fed from the 12v system and them turning the shore power on it would see me injecting my battery power into the grid??
 

[oztules]

Ok, It needs to be designed so that "things" can't happen.
I note that others will be playing with the system.... you may be able to train the kids... but I have yet to have had success in training the wife... so it must be fail safe.

To that end i think.....

1. A double throw double pole changeover switch is mandatory, so that the inverter output and shore input cannot ever be connected at the same time.... that solves all your AC problems.

2. The inverter  is integral to the charger. The charger is not an add on, but a consequence of the H bridge switching of the fets. Once a N channel is turned on, it is a bidirectional switch... so power will go into the transformer, and out of the transformer to and from the battery depending on the emf at each end.

So charging is a result of a separate 240v input, relay isolated internally... then the chip matches the frequency of the shore and itself, then closes the relay... then power flows backwards through the transformer, and gets synchronously rectified by the fet switches, and then back to the battery. This is also the basis of the reverse grid tie function... not designed for it, but does it anyway, only the grid tie meets the inverter frequency, not the other way around in this case.

The charger is a multi stage charger, and should run the banks fine... provided they are switched together for charging, and floating.

3. I would treat the banks as one bank  while in port, and  separate entities at sea. This will solve all your synchronizing problems, and the switch is there already for you to use. I would direct the inverter to the house bank ( hardwired but for fuse?), and if you chose to connect the starter battery to it, well and good, it can piggyback on it.

So it is really simple if you chose that direction. The ac input to the pj inverter will be upstream  ( shore side) of the dpdt isolator, so it can see shore power at all times it is connected. If the shore isolator is off ( shore disconnected from loads but the  PJ shore input is still hard wired to it on the shore side of the dpdt switch), the pj will charge the batts, and run the loads.

If the shore isolator is closed, the PJ looses the loads, so now shore will run the loads, but the pj will still charge the batterie/s


The one proviso is ........ until proven otherwise, (and a few have actually had success... not me), always shut down inverter before changing the isolator from shore to off-shore. Never seen a problem going across to shore power and charging... very smooth, but disconnection from shore power without shutdown MAY blow up the inverter... others have had no problem with this, but it is in big red letters on the sellers site too.... my experience is .... listen to the seller.... it seems to revert to 50hz from whatever the shore power was... instantly, and this may put the magnetics in the transformer at odds with the incoming wave form, and blow things up.


Somehow the trainees need to shut down the inverter BEFORE reverting back to  inverter power.

 If you have separate charger  (best option, as no chance to blow up PJ.....), then it can go on the shore side of the dpdt switch, and there is no need to turn inverter off before switching back and forth with the dpdt switch. The pj will cop full loads in this case instantly. Only time it is important to shut down inverter is if you are charging with it, and want to stop charging, and revert to just running.... just don't hook up the PJ ac input .


Clear as mud I suspect



.........oztules

[Mickfromperth]

Thanks oztules - very thorough response.  Yes clear as mud!  Will try to follow your order below - I think I'm getting there but have some questions!

1.  The boat has a double pole switch - for shore power vs ships power, they cannot both be on.  I will have to check wiring but looks like the boat has already been wired for this issue..

2. I don't understand the engineering but yeah what I was trying to say was that if I was buying a charger that did the job I needed, also fit my budget; that just so happened to be a device that could upgrade my modified sine inverter to a pure sine inverter would make me pretty happy.

I will do some googling to understand what an N channel and a H bridge are!

Re: Multi stage: any pointers to help me confirm just how smart the charger is?  I see some now are 5 stage vs the three stage that I am replacing?

I agree that there would be very little impost to have the charger "mainly" servicing the house bank "bank 2" - the switches are all in place (I forget the name of them? Anderson?) - they are there to allow either bank 1 to start engine 2 or to allows bank 2 to start engine 1 - so when under shore power (ie charger available) I could join the banks (or not!) - my choice - good idea!

So is the charger and the inverter one and same?  Ie if I choose to enable the charge function of the inverter then there are no other controls?

3. Ok so what your saying is that using the pj as both and inverter and a charger puts me into a "high risk" position that isn't there for most users who would be using the inverter just as an inverter?

The "problem" is when the charger is running off mains / shore power, and shore power is disconnected??  is it that simple?  You've got me worried as mains power is not highly available (it is good and reliable though) on the dock - so if there is a mains power outage would this be that same as switching the mains power off??  Can you point me to the words in the manual - powerjack888.com doesn't have the unit we are discussing nor does it have manuals published!

So I would need a way to stop power from failing or being switched off - could a relay of some sort work that switches the unit off as soon as mains is off - I would also want said relay to turn the unit back on when mains was available as the whole idea is to keep the fridge running 12v & fed from bank 2) for a week or two without having the visit the boat...

Otherwise the double pole switch - forces the mains to off before allowing shore to switch on - which means if the charger was on (ie the inverter was on but being fed mains power) - switching mains off (ie shore off) would occur milli seconds before ships power on - which would then put the inverter into the mode where it is on, being fed by 12v only.  I hope I'm keeping up here - if the unit survived the change it would still have the charger enabled - but as shore power isn't being fed now the charger will no longer be functioning - so it would be feeding (or taking) the load of any ships appliances (coffee machine!!).

How did I go?

Mick

[oztules]

For all intents and purpose thats close enough.

I would not recommend the pj as a charger.. good inverter, but they have not addressed the charger issues... so I would not rely on it.
For a big boost charger, then fine, so long as it is supervised for shut down.

I would probably go for a small intelligent (trickle ?) charger for your purposes. You don't need to run the fridge with the charger, there is plenty of time to replace fridge power usage between uses.... so a big charger is of little value. If the 2 weeks between likely use is so, then plenty of time for the small charger to get the bank back up.

If you chose to replace the current inverter, then the pj may be useful, but if you can find a sealed unit, it would be better for this purpose. Marine environment is not really the place for fan forced electronics. If you were to spray the boards with lubricant like WD40 or that lanolin spray stuff, then probably that would be enough.


.........oztules

[Mickfromperth]

Oztules thanks for your advice.  How can I find out more about this charger issue - is it documented elsewhere? So just to be 100% clear - your suggesting that in a mains fed environment, this unit has an engineering floor - that might see if fail if mains power is cut while the charger is in operation.  Given the risk of catastrophic failure the idea to use it as a full time charger and part-time inverter is not looking promising!!!

PS: I do need to restock bank 2 all the time as it runs the fridge non-stop :-)

Does this change your advice at all?  I suspect not.

20amp chargers are soooo much cheaper than 40amp chargers (a cheap 20amp is 1/10th of the price of a decent 40amp) I am thinking it might be better to treat the charger as a throw away device, and have 2 (1 for each bank).

I am probably over stepping the boundaries on free advice but I'll ask anyway: bank 1 and bank 2 share the negative - like what a think a bus is.  Here is a link to a wiring document, mine is wired like this only with 2 banks not 3:

http://www.xantrex.com/documents/Discontinued-Products/tech-notes/976-0117-01-01_Rev-A(artwork).pdf

I can't see how I could rewire things to avoid this shared bus model - as I suspect the alternators use it also for charging.

Do you foresee any issues having two seperate chargers feeding each bank on a shared negative bus??  Is it safe to suggest that given the alternators don't have an issue, that neither should multiple chargers?

[oztules]

"How can I find out more about this charger issue - is it documented elsewhere"... yes in your manual, and most sellers have big red writing on their advertisements to this effect.

here is a cut and paste of one from the second in the list from  ebay today... http://www.ebay.com.au/itm/3000w-120000w-LF-pure-sine-wave-Power-Inverter-DC-24v-to-AC-240v-converter-H5-/261920139035?pt=LH_DefaultDomain_15&hash=item3cfba8271b


"  PLEASE NOTE: for battery charge mode: before charge the battery, please turn off the inverter first, connect the AC power cord with home AC source and inverter, then turn on the inverter to start the function. When finished, need to turn off inverter first, then disconnect the AC power cord. Otherwise the PCB board might be damage due to high voltage spark."

You will note in the same advert, that they claim that is fine as a ups.... ... don't believe them, they cut and paste bits of each others ads from the look and have no concrete idea what they actually have for sale sometimes... guess they are only salesmen/women, and have never used one.

So very good inverter as an inverter only, or supervised charging.

So I don't want to see you running a PJ as a ups for that reason.... regardless of what they don't say in some adverts.... until they claim to have solved this problem explicitly with next years model blurb eg.

So you can use either one or two chargers, banks connected together or separate... in the end it won't make much difference if your only using it every few weeks. Two gives you redundancy.... which I like. Common earth is fine.

Yes the alternator is only a charger, so if it has no problems with however you set  your isolator switch, nor will the charger/s. The alternator is after all only a charger ......diode isolated from the batterie/s anyway. via that isolator....

So you can connect as many chargers as you please to a single battery, or a single charger to several batteries without disaster. The 20a charger is technically big for the starter battery as it exceeds the C10 rate... but won't ,matter as the battery will likely be full when you get port anyway, so will go straight to float in minutes... and the house bank is technically under done with 20A, but won't matter either, because the long recovery time, so it won't get to C10 rate...... but so what........ really, you have time on your side which is even better for it.

I suspect the fridge is only light  % duty, so the 20A will be fine.

So I would be happy with the two chargers, however they were configured, so long as they were a little smart... ie had at least two stages, bulk/absorb and float.

The PJ
It is from the reversion to default frequency from the mains frequency. If they differ in waveform/phase/timing call it what you will, the surge current into the transformer can be huge. These boards were designed with E I (normal) transformers in mind, and work perfectly with them, as their leakage is high enough to absorb the surge, torroids are very stiff comparatively, so start currents can be up to 60 times the idle currents... so it won't blow every time, maybe 20 percent of the time...so plugging in the shore is not a problem ( power jack advert wants shut down in each direction to be safe), as the device syncs to the mains before changeover, it is the turning off and reverting to default 50hz thats the problem, there is no smooth transition programming.


..................oztules

[Mickfromperth]

Oztules I was convinced to give up on the pipe dream and started shopping for plain old chargers and somehow I stumbles across this:

http://www.ebay.com.au/itm/2000W-Peak-6000W-DC-12V-Pure-Sine-Wave-Inverter-With-Charger-65-AMP-LCD-25KG-/201302205995

I suspect this is similar gizzards to the PJ - just wanted to get a sense from you if this is looking like a "newer" or and "older" model - obviously it's different I'm just not sure in what direction. 

Feeling a little excited that this might be the newer unit and it appears to be not havethe charger issue p.  I will contact seller so see if I can get a copy of the manual.

[oztules]

Thats a perfect unit for you, as it is the same gizzards almost resistor for resistor, but the programming is for realistic watts, as the the Transformers are nice and big.

They re of the E I type, and with their high leakage, transfer back to battery power from shore power without incident.
I have the 6000w version as my first unit some years back , and still do.... very tough work horse with a true 6kw/18kw surge, they are generically knows as W7 power star.

Thats the good news, and if it stopped there I would never have used the PJ

The downside is....... the very transformers, that give them this huge performance will gobble up over 5kw hours/day... before they drive anything  They gobble up huge amounts of energy just to magnetize the e cores.... that is why I started to modify them with torroid transformers in the first place, otherwise they are perfect.

PJ had the same cards, but also had torroids... so thats why I bought my first one of those. The torroids get the kwh down to about .5kwh/day... 10 times less loss.

story here http://www.anotherpower.com/board/index.php/topic,780.0.html

picture here:




very powerful and reliable unit apart from that.

Now, where were those cheap chargers........

.................oztules

[Mickfromperth]

Hmm.  Bugger. 200w for idle is costly - especially as I cannot replenish my power (project 2 is a genset for the boat).

Can I trust the 25w "idle watch mode" figure?

I am not comfortable with the "super cheap" chargers - there doesn't apear to be any way to permanently mount them.  Non-mountable, permanent chargers ;-)

$40
http://m.ebay.com.au/itm/121440885022?nav=SEARCH

Mountable start at 40amp, and can be landed for about $150:
http://www.ebay.com.au/itm/40-AMP-Battery-Charger-3-Stage-Charger-Boat-Caravan-Workshop-12-V-/161741860011?pt=LH_DefaultDomain_15&hash=item25a890ecab

But then marine ones say they are "ignition safe" from $350:
http://www.ebay.com.au/itm/12V-SMART-BATTERY-CHARGER-4-STAGE-40AMP-AUTO-AGM-GEL-CALCIUM-4WD-MARINE-CARAVAN-/221792155441?pt=LH_DefaultDomain_15&hash=item33a3d7b731

And then I can get the replacement of my current unit for $500:
http://www.ebay.com.au/itm/XANTREX-TRUECHARGE2-40-Amp-12v-Marine-Boat-3-BANK-BATTERY-CHARGER-804-1240-02/380866753718?_trksid=p2045573.c100033.m2042&_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20131017132637%26meid%3D023e357247864d90bdccd38c513b7d27%26pid%3D100033%26rk%3D2%26rkt%3D4%26sd%3D221792155441

I'm off to get my head around "ignition safe" now..

M

[oztules]

Idle watch is about right.... that means it comes to life and pulses every 2-3 seconds only for a part of a second,, and looks for a load..... and still uses 25w average... imagine what it uses when it actually turns on..... and you cant charge in that mode...... so a very good but hungry inverter.

Rule number 1..............If your not comfortable with something... don't use it.

It is unattended, so if your not totally comfortable with it............... you don't need that on your mind as well.

The $500 dollar one failed too....... so not much good either..... what to do.


...............oztules

[Mickfromperth]

The xantrax unit was old - its 2 models behind so insuspect 10years old.  I could probably confirm exact age by sifting through invoices as I have a pretty solid stack!!

So I "trust" that brand right now based on my 3 month experience in "boating" :-).

Ignition safe sounds like a pretty good idea - I'm not sure its required but it sound like damn fine insurance!  Given I think the previous unit lasted I would go for that over any other marine / ignition safe charger.

However I can source a 40amp, permanently mountable charger, which will do the job, for under 1/3rd the xantrrax - and I'm not toooooo worried about about the chances of ignition - it sounds a lot like smoking at a fuel station to me!!  The charger will only ever be on after the engine has run me home post fling up from a depo so if I was to be at risk of ignitable gas the engines would have tested out that theory well before I get plugged into mains power and srtart charging..  Still I wouldn't want to explode because I applied the 80/20 rule to ignitable gas scenarious!!!! 

I suspect I've read about the W7 in a previous lifetime back when I was researching "just"  inverters.

One last question on the w7 - if the unit is switched off or in low power mode - can it charge the batteries? No am actually more interested in the oxy-moron of this - ie if the unit is charging batteries from mains power  and the power is cut - is it possible to have the unit (ie inverter) feeding off battery power in either a) off (this would be preferred) with another switch to enable the inverter or b) idle watch? 

(Just in case you know the answer oztules??)

M

[oztules]

Can't charge in sleep mode, as the H bridge us inactive.
The W7 will behave as a normal UPS.

If you want it to shut off when you lose shore it will need another ac sensing relay upstream of the inverter to turn it off when there is no ac power.

Then it will behave as a normal charger if thats what your angling for.


.....oztules

[Mickfromperth]

I ended up sourcing one of these:

http://enerdrive.com.au/product/epower-battery-charger/

I chose to roll with mountable as the primary feature; multiple bank as the secondary; and ignition safe as the tertiary requirement.

Will install it this weekend - fun fun.

Thanks for your help oztules!