Projecta IDC25 DC DC charger

Submitted: Tuesday, Jan 14, 2020 at 18:10
ThreadID: 139557 Views:1420 Replies:11 FollowUps:35
Hi, thinking of getting one of these to charge my 2 120ah AGM house batteries. Going to get power from the alternator and a 250W solar panel. Ive read pretty good feedback but would like to hear from actual users of this brand, thanks.
Back Reply Expand Un-Read 0 Moderator

Reply By: IvanTheTerrible - Tuesday, Jan 14, 2020 at 19:03

Tuesday, Jan 14, 2020 at 19:03
We have fitted a few with no problems so far. Have also fitted a few Redarc but not having the same success with them.
AnswerID: 629522

Follow Up By: Member - David M (SA) - Tuesday, Jan 14, 2020 at 20:07

Tuesday, Jan 14, 2020 at 20:07
G'day Ivan. Just setting up my batteries for the new van and had almost settled on a Redarc unit Would be good to know of any problems I might encounter with it. Might have to think again.
Dave.
0
FollowupID: 904476

Follow Up By: IvanTheTerrible - Tuesday, Jan 14, 2020 at 21:33

Tuesday, Jan 14, 2020 at 21:33
Not sure why they failed. Both were on dual batteries mounted in the vehicle, one was mounted in the engine bay next to the second battery the other in the cab with the battery under the tray. I only installed the first one as per Redarcs guide but I wasn't happy installing it in the engine bay.
1
FollowupID: 904477

Follow Up By: Member - David M (SA) - Tuesday, Jan 14, 2020 at 22:12

Tuesday, Jan 14, 2020 at 22:12
Cheers Ivan. Their factories just down the road from me so I might call in for a chat.
Dave.
0
FollowupID: 904480

Follow Up By: Bushranger1 - Tuesday, Jan 14, 2020 at 23:10

Tuesday, Jan 14, 2020 at 23:10
G'day Dave,
I have the 40 amp Redarc BCDC1240 charger installed in my Dmax ute charging 2 off 120 AH AGM batteries.
Been working just fine for 18 months.
Mate had some issues with a Redarc brake controller & he was happy with how Redarc resolved his problems. That was the reason I bought that brand.

Cheers Stu.
1
FollowupID: 904481

Follow Up By: Batt's - Friday, Jan 17, 2020 at 21:30

Friday, Jan 17, 2020 at 21:30
Got the same charger as Bushranger around 4yrs ago charging 2 x 105ah agm's mounted in the canopy next to the batteries no problems. I would go with something larger like these to get the power into the batteries.
0
FollowupID: 904555

Reply By: RMD - Tuesday, Jan 14, 2020 at 19:06

Tuesday, Jan 14, 2020 at 19:06
Trevor.
I have one of those, just not the latest version. It charges from the engine alt, via a heavy constant duty solenoid which can be selected to be ON when desired, or off. That function of supply is either the solenoid/relay or a battery isolator switch which locks the battery to the Projecta if need be. I fitted 3 Anderson plugs to it's cables for easy removal or alternate connections as I require sometimes. The Solar has a dual (4th) Anderson to it so I can connect a portable panel to the solar input when needed.

If you can possibly avoid it, don't fit it in the engine bay. Radiant heat and general high ambient will see the Projecta already at elevated temp inside and it will derate itself so it doesn't burn up. That means a limited output although good inputs are connected. Think Cool, and if cool it can put out it's intended current as required. I have measure mine with 8amps of solar input and high panel voltage and slightly more than 10 amps going to the battery from it's output. That means it IS taking advantage of the solar panel ability and using the MPPT feature of it's design. Mine is on a 100ah with an additional 40ah attached sometimes.

There are other good brands too, I also have a Enerdrive 40 amp unit if needed, just more $$$$'s.
If you buy a panel which has a maximum OC voltage near to the max solar voltage input, that unit will then take maximum advantage of the amps and peak loaded voltage of the panel to provide it's maximum performance. Doesn't sound like much difference but a couple of solar volts higher at it's input than a lesser panel, will equate to more energy to battery and shorter charge times to float voltage. Just a bit of matching.
AnswerID: 629523

Follow Up By: Trevor G5 - Wednesday, Jan 15, 2020 at 07:10

Wednesday, Jan 15, 2020 at 07:10
Thanks for the information. It’s going in the van behind the front seat in a “battery area”. I’ve got an Iveco daily.
0
FollowupID: 904484

Follow Up By: RMD - Wednesday, Jan 15, 2020 at 09:09

Wednesday, Jan 15, 2020 at 09:09
Even so, if the place the DC unit is in doesn't allow full cooling air supply, when charging a large AH battery bank will mean the IDC25 will create it's own heat internally and if it can't get rid of the internal heat while working hard, then it will also derate it's output to some degree which lengthens the charge time as mentioned below.

COOL is good. Some add a switchable computer fan to gently blow airflow over the unit. A very small milliamp draw keeps it cool. Works for fridges and most electrical gear subject to elevated temps.
1
FollowupID: 904487

Reply By: Gbc.. - Tuesday, Jan 14, 2020 at 20:16

Tuesday, Jan 14, 2020 at 20:16
I have had one in the camper since 2016. It charges 360ah no problem. It has been faultless.
They will draw mid 40a’s odd so run good quality cable.
AnswerID: 629524

Reply By: Phil G - Tuesday, Jan 14, 2020 at 23:32

Tuesday, Jan 14, 2020 at 23:32
I have two of the IDC25 - one for the 130Ah caravan battery and one for the 105Ah second battery in the Troopy. They both work well and I've used them for a couple of years. I selected the Projecta because it takes the solar power first and because it has a probe you stick to the battery for temperature compensation. At the time i bought, Redarc did not have those features but I think they may have caught up.

But you have 240Ah of batteries which is a lot for a 25A charger if you are likely to cycle them heavily - it will take all day to do a recharge. Projecta have a 45A version called the IDC45 which might be a better option for you but you would need to run nice thick cable in both vehicle and caravan.
AnswerID: 629525

Follow Up By: Trevor G5 - Wednesday, Jan 15, 2020 at 07:08

Wednesday, Jan 15, 2020 at 07:08
The main drain will be the fridge which is an Engel 40ltr eclipse. I have 3 lights, a fan, a laptop and will probably be charging a couple of phones. I’m in an Iveco daily van. 2 batteries were suggested as I like to stay remotely. Thanks for your information.
0
FollowupID: 904483

Follow Up By: Phil G - Wednesday, Jan 15, 2020 at 09:31

Wednesday, Jan 15, 2020 at 09:31
Trevor, OK that's a bit different to what I was thinking.
240Ah of storage and 250W of solar is heaps for what you are running in the Daily. IDC25 will be fine because I don't believe you'll be running down the battery much at all. In fact you could easily get by with a single battery but its nice to have plenty of power in reserve.
1
FollowupID: 904489

Reply By: Matthew G3 - Wednesday, Jan 15, 2020 at 08:50

Wednesday, Jan 15, 2020 at 08:50
Hi Trevor
If you do go for IDC25 make sure you don't get an old version 3, solar input is max 23v which can trip the IDC. From version 4 on they up it to 26v. The Projecta web page is really out of date, when searching they have the latest info on the boxes they come in. I put a V4 in my Tvan 18 months ago.

Matt
AnswerID: 629527

Reply By: Member - Racey - Wednesday, Jan 15, 2020 at 09:39

Wednesday, Jan 15, 2020 at 09:39
Trevor, have a look at the Enerdrive 40amp units. I have one in caravan and another in the Cruiser. Both work well.

Cheers
Jon
AnswerID: 629528

Reply By: swampy - Wednesday, Jan 15, 2020 at 20:29

Wednesday, Jan 15, 2020 at 20:29
hi
Theory
available capacity to us =120ah [50%DOD]
Peak Sun Hours 5.5hrs per day [mainland ozzy in spring summer and autumn] . PSH is solar at 100%
200watts generates 48ah per day
400watt gen. 96ah per day
Mppt and sun out side of PSH is unreliable to measure . Although in reality both of these contribute to power production .

Reality
MAX input is 40amp to charger with max 25 amp output to battery
200watts max output is approx. 11 amps. With mppt 14amps
400watts 22amps and mppt is 28amps

NB
remember to wire alternator to DC2DC with 25mmsq /3 B&S cable
25mmsq over 9mtrs 36amps at .4 volt drop …..This is ideal
13mm sq over 9mtrs 18amps at.4 volt drop Using this will starve the dctodc and may run hotter
AnswerID: 629537

Follow Up By: Trevor G5 - Wednesday, Jan 15, 2020 at 21:08

Wednesday, Jan 15, 2020 at 21:08
thanks for the information but I don’t really understand much of what you have written. I’m not being disrespectful but I have very little technical knowledge on this. Thanks anyway.
0
FollowupID: 904504

Reply By: Idler Chris - Wednesday, Jan 15, 2020 at 21:54

Wednesday, Jan 15, 2020 at 21:54
Hi Trevor. If you have an Iveco Daily and 240ah of batteries your have a serious setup. I would suggest a 25ah charger to be to small. In ideal conditions it would be fine but you have to cover when conditions are not ideal. I have a 100ah lithium battery and an Enerdrive 40amp charger which I have had for 15 months now and I would never go back to a smaller charger. The Enerdrive charger is simply just great and I would highly recommend it. I would assume that Projecta and Redarc are good chargers too, best to go off recommendations. Chris
What other people think of me is none of my business.
Do unto others what you would have them do unto you.

Lifetime Member
My Profile  My Blog  My Position  Send Message

AnswerID: 629538

Reply By: Trevor G5 - Thursday, Jan 16, 2020 at 06:49

Thursday, Jan 16, 2020 at 06:49
Thanks for sharing your thoughts. It seems like a 40ah charger may be a better option! Can someone explain why? Also does this mean that you have to upgrade other things when setting the system up. Thanks
AnswerID: 629543

Follow Up By: Gbc.. - Thursday, Jan 16, 2020 at 07:23

Thursday, Jan 16, 2020 at 07:23
In addition to the projecta I mentioned I have above I also have a ctec 250/smartpass setup in the Ute. This gives up to 120a charging when the battery can handle it which isn’t very often. If you aren’t deeply discharging your batteries while off grid, larger chargers are a waste of effort. If you run a 24v cpap all night through an inverter such as my old man does for example, you want the fastest recharge money can buy. The system you first mentioned, wired correctly, is an excellent choice for most people. 25a is quite a solid charge rate and is right on the commonly recommended 10% of your rated AH capacity so you’ll have no issue with it. As I also mentioned, I’ve been using one on my 360ah bank in the camper since 2016 with no issue at all.
Yes, a 40a charger will require heavier cabling, and yes it will charge a deeply discharged battery quicker than a 25a charger, but that all depends on what the battery will accept, not which charger you bought, and batteries don’t accept monstrous current for very long.
1
FollowupID: 904505

Follow Up By: Member - shane r1 - Thursday, Jan 16, 2020 at 08:04

Thursday, Jan 16, 2020 at 08:04
Hi Trevor
If your usage stays low as you indicated on Wednesday, your existing setup should do it easy IMO . I have been running various solar plus vehicle charging for a few years. I haven’t got very technical about it , but with trial and error (and information gleaned from forums, google etc ) it works. Not everyone is into having all the monitoring equipment ( and it’s not absolutely necessary).
Pretty simple really , if your running out of battery power you probably need more charge , panels are cheaper than ever so if you’ve got space to put them , use more. all you need is a regulator to handle the amount of panels. One thing is on an overcast day you can hook in more solar to the same regulator, ie using a portable to add on panel capacity.
Hope this makes sense to you.
Cheers
Shane
1
FollowupID: 904507

Follow Up By: RMD - Thursday, Jan 16, 2020 at 13:24

Thursday, Jan 16, 2020 at 13:24
Trevor,
It all depends on how low you discharge the batteries as to what current/time factor is required to replace the charge. The 25A DC DC unit coupled with sufficient solar input will charge the batteries ok for normal discharge amounts. In the event you sometimes DO have a lower SOC, then catering for that can be done if engine running by having what Gbc mentioned. As an alternative to that and cost effective, is to fit a heavy constant duty solenoid to link vehicle battery/alternator to your battery bank. Yes cable size has to be sufficient, but as mentioned above, the batteries only take a heavy current for a short while. Most alt charge volt readings indicate that is so. Your alternator 180 amp I believe, will surely recharge via sufficient cable size, a high current which then reduces quite quickly and settles as a normal charge rate which the two batteries require. This solenoid when activated can be done after startup and used to provide the majority of charge and then switched off to leave the DC DC unit to complete the absorb and float as it sees fit to do for a finish to the charge. Having healthy sized cable, not the lowest resistance super large cable size, between main and aux of this solenoid system will cause some advantageous voltage drop while heavy current demand is happening, but healthy current flow all the same and the alt/aux batt voltage will have risen and self limited the bulk charge to the aux batteries. This replaces faster, IF needed, the state of charge if solar time factors or DC DC ability versus time are an issue.
Some may scoff at this idea but I am still using a Full River 105 ah AGM which I bought in 2009, it now only holds about 50% Capacity but has been charged all it's life from the above type of setup. I think it works and cost of it all was a distinct factor for me.
1
FollowupID: 904508

Follow Up By: Zippo - Thursday, Jan 16, 2020 at 15:43

Thursday, Jan 16, 2020 at 15:43
I'd be hesitant to have a solenoid effectively bridging the input-output of any DC-DC charger without the explicit sanction from the MANUFACTURER.
0
FollowupID: 904509

Follow Up By: HKB Electronics - Thursday, Jan 16, 2020 at 16:23

Thursday, Jan 16, 2020 at 16:23
Connecting the input to the output should not cause any problem as the DCDC will just remain in constant current mode, not very efficient though as a 40A charger for instance could be pulling 60A if the charge voltage from the alternator is low and the charger providing no voltage gain in that situation. Think of it this way, the alternator is running at 13.8V, the charger on the other hand is drawing 60A trying to raise its output voltage but can't as it is bypassed and has the cars electrics connected to it. If it does manage to raise the "system" voltage ie car is using less then 40A then the alternator will back of its charge to maintain 13.8V and the charger will be effectively providing the difference. You could end up drawing 60A through the charger just trying to run the cars electrics. You could be just converting 20A to heat, granted you only wasting 20A but 20A is 20A.

Would be more efficient to turn off the charger when its bypassed.
HKB Electronics

Business Member
My Profile  Send Message

1
FollowupID: 904511

Follow Up By: RMD - Thursday, Jan 16, 2020 at 16:43

Thursday, Jan 16, 2020 at 16:43
Zippo
Good point raised there. Yes one or the other not both. I don't mean having the DCDC input also connected to the alt system while the alt is doing it's major bulk run though. Maybe I should have been clearer. Yes, DON'T have the DC DC input active while the engine alt is doing the bulk pump up of charge. I didn't intend it that way. Simple changeover of solenoid/ and DC DC input. Maybe the solenoid select switch DPDT, would switch off/break the sense lead of a VSR which supplies the DCDC. I will not have it connected all the time.

0
FollowupID: 904513

Follow Up By: Gbc.. - Thursday, Jan 16, 2020 at 17:00

Thursday, Jan 16, 2020 at 17:00
Pretty much the same as a smart pass but cheaper. Sounds good.
0
FollowupID: 904515

Follow Up By: Zippo - Thursday, Jan 16, 2020 at 18:05

Thursday, Jan 16, 2020 at 18:05
HKB/RMD I asked Redarc that very question, more than once. The first reply was "we'll need to check and get back to you". A follow-up email some time later quoting the previous exchange was met with silence.

It may well be OK, but if it lets the magic smoke out then you are out both the charger function and a pile of $$.
0
FollowupID: 904516

Follow Up By: Allan B (Sunshine Coast) - Thursday, Jan 16, 2020 at 18:24

Thursday, Jan 16, 2020 at 18:24
.
No no no HKB. You have it all wrong!
What will actually happen if you connect the output to the input of a dc-dc charger is that the charger will raise the output above the input voltage which will then feed directly back to the alternator. The alternator will begin to behave as a motor and add drive to the engine via its belts. This drive will cause the vehicle to increase its speed and go racing up the highway straight past a cop waving you down.

At least that's the story I'm going to put to the cop if I get pulled up for speeding!

Cheers
Allan

Member
My Profile  My Blog  Send Message

2
FollowupID: 904518

Follow Up By: HKB Electronics - Thursday, Jan 16, 2020 at 19:45

Thursday, Jan 16, 2020 at 19:45
"It may well be OK, but if it lets the magic smoke out then you are out both the charger function and a pile of $$."

The input is isolated from the output internally. Nothing untoward will happen apart from wasting power.
HKB Electronics

Business Member
My Profile  Send Message

1
FollowupID: 904519

Follow Up By: HKB Electronics - Thursday, Jan 16, 2020 at 19:46

Thursday, Jan 16, 2020 at 19:46
Perpetual motion Alan, if only I could achieve that.
HKB Electronics

Business Member
My Profile  Send Message

1
FollowupID: 904520

Follow Up By: Allan B (Sunshine Coast) - Thursday, Jan 16, 2020 at 19:54

Thursday, Jan 16, 2020 at 19:54
.
There are days Leigh, when I feel that I am in perpetual motion. lol

Cheers
Allan

Member
My Profile  My Blog  Send Message

0
FollowupID: 904521

Follow Up By: RMD - Thursday, Jan 16, 2020 at 20:05

Thursday, Jan 16, 2020 at 20:05
Allan.
When traveling with the solar feeding my DC DC unit ,when the sun comes out I do feel the alternator add power to the system as it gets a surge. To compensate, I have fitted a row of large dia driving lights to the roof to act as an airbrake and to keep below the highway limit. Seems to calm it down ok.
2
FollowupID: 904522

Follow Up By: Zippo - Thursday, Jan 16, 2020 at 21:18

Thursday, Jan 16, 2020 at 21:18
"The input is isolated from the output internally. Nothing untoward will happen apart from wasting power."

There you have it folks, the warranty statement that I couldn't even elicit from the manufacturer. So go for it, Leigh will provide the warranty replacements ...
0
FollowupID: 904523

Follow Up By: HKB Electronics - Thursday, Jan 16, 2020 at 21:37

Thursday, Jan 16, 2020 at 21:37
Been inadvertently done by novices in the past with no damage to the charger.

This setup exists in many vehicles where they have installed a jump start bypass solenoid and have a DCDC charger.

Rather surprised that Redarc could not answer your question.
HKB Electronics

Business Member
My Profile  Send Message

0
FollowupID: 904524

Follow Up By: HKB Electronics - Thursday, Jan 16, 2020 at 21:41

Thursday, Jan 16, 2020 at 21:41
Actually it appears they do know the answer Zippo, well their engineering section anyway, you must have been asking the wrong person:

Redacr diagram showing jump Start
HKB Electronics

Business Member
My Profile  Send Message

1
FollowupID: 904525

Follow Up By: RMD - Friday, Jan 17, 2020 at 14:11

Friday, Jan 17, 2020 at 14:11
Zippo.
HBK didn't give a warranty statement at all and didn't announce it as such, but to claim he did is not correct. He simply stated what the unit will do because it is a switchmode device with separate, isolated, input and output.

These devices are VERY different to a PWM regulator which is toast if incorrectly used. I scrape of the burnt bits on toast, it doesn't work with PWM regs though. Lightning or some hidden force zapped one of my cheap PWM units.
0
FollowupID: 904539

Follow Up By: Zippo - Friday, Jan 17, 2020 at 14:19

Friday, Jan 17, 2020 at 14:19
Leigh, it was exactly that diagram which I queried - and which they were unable (or unwilling) to back up or qualify in any way.

RMD - I have been designing in power electronics for decades, so I do know the odd bit about magic smoke.
0
FollowupID: 904540

Follow Up By: HKB Electronics - Friday, Jan 17, 2020 at 16:43

Friday, Jan 17, 2020 at 16:43
It would seem to be a lack of communication between the Redarc engineering section and their technical support staff.

As they have published a document stating the unit can be wired in such a way then they would have no case to deny a warranty claim if doing so was to cause the unit fail, but then it shouldn't anyway.

HKB Electronics

Business Member
My Profile  Send Message

0
FollowupID: 904543

Follow Up By: Allan B (Sunshine Coast) - Friday, Jan 17, 2020 at 17:55

Friday, Jan 17, 2020 at 17:55
.
Note that the Redarc diagram shows a pushbutton activating the solenoid. On that basis it would not be expected to be closed for long..... only a brief cranking. Closed for lengthy periods could be another 'kettle of fish'.
Redarc may recognise this but not wish to get into debate over it.

Bear in mind that the charger differential voltage, that is the difference between the input (say 12v) and the output (say 14v), being only a couple of volts limits the power being dissipated in the charger loop.
And also, maybe Redarc has some crafty circuit magic that effectively shuts the charger off in this configuration, but I doubt it.
Me? I have trouble getting my head around it. It is not what I would design.
Cheers
Allan

Member
My Profile  My Blog  Send Message

0
FollowupID: 904546

Follow Up By: Allan B (Sunshine Coast) - Friday, Jan 17, 2020 at 17:59

Friday, Jan 17, 2020 at 17:59
.
I think that the Redarc technical support staff IS the engineering section.
At least that is the impression I gained when I have spoken to them.
Cheers
Allan

Member
My Profile  My Blog  Send Message

0
FollowupID: 904547

Follow Up By: HKB Electronics - Friday, Jan 17, 2020 at 18:38

Friday, Jan 17, 2020 at 18:38
Allan if there was an issue they would have some warnings ie don't use override for extended periods etc. From memory the start assist has an on duration of 10 seconds once triggered.

To raise the terminal voltage of a battery you need to apply a charging current. The charger is not 100% effiecient therefore its output power will always be less then its input power. Therefore if we connect the output of the charger to the input it will try to raise the voltage it 14.4V which it can never achieve as it can't supply more power than it is drawing. The charger will therefore go into current limiting mode ie 20A. It will be supplying 20A to the battery but drawing more than 20A from the battery o the battery will naturally be discharging. How much discharge current will be flowing will be dependent s on the conversion loses within the charger.

This is exactly the same thing as would occur when connecting the charger to a discharged battery .

This reminds me of the good old days when a trainee seriously asked if you could use a generator to power an electric motor and then use the electric motor to turn the generator, wonder why no one else ever came up with that idea!
HKB Electronics

Business Member
My Profile  Send Message

0
FollowupID: 904549

Follow Up By: Allan B (Sunshine Coast) - Friday, Jan 17, 2020 at 19:11

Friday, Jan 17, 2020 at 19:11
.
Leigh,
You didn't grasp my point which related to the power being dissipated within the charger.
There is only a couple of volts differential between charger input and output therefore at your nominated 20A the charger would be dissipating about 40W or so which is of not much concern.
Cheers
Allan

Member
My Profile  My Blog  Send Message

0
FollowupID: 904550

Follow Up By: HKB Electronics - Friday, Jan 17, 2020 at 19:46

Friday, Jan 17, 2020 at 19:46
Alan switch mode power supply and this got thinking also, if we look at the case where the supply is 14V and the aux at 11.5V. The Redarc wants to raise the voltage to 14.4V but it can't as the battery terminal voltage is 11.5 at 20A so it current limits at 20A. One would hope theRedarc is around 95% efficiency but they don't say, the Enerdrive unit is 95% so will use that figure, therefore 11.5V at 20A gives 230W. Allowing for a 5% loss, around 13W.

So I'm revising my initial statement of 20A being wasted.

HKB Electronics

Business Member
My Profile  Send Message

0
FollowupID: 904551

Follow Up By: Allan B (Sunshine Coast) - Friday, Jan 17, 2020 at 20:40

Friday, Jan 17, 2020 at 20:40
.
I give up!
Cheers
Allan

Member
My Profile  My Blog  Send Message

2
FollowupID: 904554

Reply By: Sigmund - Saturday, Jan 18, 2020 at 12:54

Saturday, Jan 18, 2020 at 12:54
Trevor, I put one in the CT beside the batteries - initially just for solar (up to 350w) and in case the Redarc 40a in the wagon died. It's been there for 3 years and it works well.

Last trip the Redarc looked like it had died and I spoke to an auto sparky who said that that unit was more prone to failing than their 25. In the event it turned out just to be a failing earth.
AnswerID: 629574

Reply By: Trevor G5 - Sunday, Jan 19, 2020 at 07:35

Sunday, Jan 19, 2020 at 07:35
Thanks for all the information.
AnswerID: 629587

Popular Content

Popular Products (13)