Projecta IDC25 DCDC charger review (it’s not good)

Nearly 5 years ago, we purchased an Isuzu Dmax and set it up for touring Australia. The focus on the build was to get something reliable, reasonably capable, functional and that would double as a touring vehicle and the family car around the city.

However, there was one more major consideration that we factored in, and that was cost. 

Every single component that I added, or had added to the Dmax was done with that in the back of my mind. I didn’t want to buy rubbish, but at the same time wasn’t going to buy all the best gear out there and deck it out.

That’s why when it came to setting up the electrical system, I went with a Projecta IDC25 DCDC charger.

Not the cream of the crop, but certainly not the worst product out there either. Something that I thought would be value for money, and still reliable.

We’ve had a pretty good run with Projecta gear over the years, and I was happy to give their DCDC a whirl. If you want a Projecta IDC25 review, you’ve come to the right place!

Our reviews are completely non biased, and we paid full retail for the product with zero commercial gain.

EDIT – This has been replaced by a Renogy DCDC, which we are much happier with.

Projecta DCDC
The Projecta DCDC installed in our Electrical Box
Dmax build and DCDC
Our Isuzu Dmax, built for touring this great country

Dmax electrical system

I designed our electrical system to be reliable, cost effective, to comfortably run the appliances we needed, and to have some redundancy.

We went with a 200W Low Energy Developments panel that is fixed to the Bull Motor Bodies Canopy. From there, I installed a 150aH Bosch deep cycle battery right up against the front of the canopy.

There’s an electrical box above it which houses our breakers, Projecta IDC25, switches and a few Anderson plugs to move things around as required. 

Projecta IDC25 in our Dmax
Projecta IDC25 in our Isuzu Dmax

The canopy came with a PWM controller that had seen its fair share of use, and I kept this on Andersons, so that in the event of a failure from the DCDC charger I could still charge the rear battery. The DCDC takes charge from the front battery (via the alternator) or from the solar panel.

We run a 55L Evakool Fridge and or Freezer, a fair bit of lighting, a Projecta 350W pure sine wave inverter and charge a laptop, drone batteries, DSLR batteries, Go Pro batteries, Ryobi 18V batteries (mainly for our Ryobi 18V Chainsaw) and occasionally run a 240V fan and other bits and pieces.

Nothing overly power hungry, and the system was designed to run off solar only, so the car can be parked up for weeks at a time and we have no issue maintaining charge.

Dmax build
The Dmax, all set up for living out of

What is a DCDC charger?

There are lots of DCDC battery chargers on the market (or BCDC chargers as Redarc calls them). If you aren’t familiar with what a DCDC battery charger does, in layman’s terms it takes 12V power (usually from the alternator) and charges a second (or several battery) in stages, until it reaches 100%.

They have the ability to bump the voltage up, to ensure that your battery gets full charge. They overcome voltage drop issues, battery isolation requirements and charging two different batteries in the same setup.

If you have a second battery in the vehicle, or in a trailer behind, it is very difficult to get the voltage required to that battery to charge it in the right stages, right to 100% charged without the use of a DCDC.

Of course, most of them today also have a solar input, which allows them to replace your normal, often poor quality regulators on solar panels.

12V solar regulator
A lot of the cheap panels come with poor quality regulators that are better off swapped out

About the Projecta IDC25

The Projecta IDC25 has been out for a number of years now, and they’ve released a 40 amp version too. The 25 means 25 amps, which is its maximum output.

It will take charge from the alternator and solar simultaneously, has the usual 3 stage charging process and can take power between 9 and 32V.

They are quite compact, IP67 (dust and splash proof) and can operate in environments up to 80 degrees. They also have a number of programs to allow you to charge different batteries – Wet, Calcium, AGM and Gel. It is important to note that they are not setup for a 12V Lithium battery!

The Projecta IDC25 price is around $300 – $330, depending on where you get it from.

Projecta DCDC charger review

So, onto the nitty gritty, of the IDC25 review. We’ve had our Projecta IDC25 for nearly 2.5 years, and up until about 2 months ago I’d almost forgotten that it was running. I never looked at it, I never worried about running out of battery capacity even when it wasn’t sunny, as it just did its job. 

We also run the Projecta dual battery monitor, so I do keep an eye on the battery voltages, and up until then I don’t think I’d ever seen it under 12.4 volts at rest, so the battery has had a good life.

However, on a recent run down south, I became suspicious that the unit wasn’t doing what it was supposed to. It was hard to tell, as I was only running the fridge and the ambient temperatures were quite low.

It was obvious after some investigation that the charger wasn’t taking charge from the alternator anymore, as the light wasn’t lit up, and at night time (when there’s no solar) I could never get the battery voltage to go up higher than about 12.8, when it would normally hit 14.2 with the vehicle running.

Cloud down south
With lots of cloud about down south having a working DCDC battery charger is important

The solar seemed to still be working, but I bypassed the whole unit for the rest of the trip and just used the second PWM regulator. As we got further into the trip though, the battery started to struggle with limited solar input due to cloud, and I had to get creative.

I carry a 10 metre Anderson extension which is pretty heavy duty, and worked out that I could plug the lead onto the rear Anderson (which is powered from the main battery) and run it up the back of the canopy, around the roof rack and then squash it in the door, where it connected to a normal output from the rear battery.

This essentially joined the batteries together, which I had to do manually every time once the car was started (to avoid a starting load on the dual, deep cycle battery) but it kept charging slowly this way.

Fixing the IDC25

When I got back to Perth, I rang our good mobile auto electrician, and arranged for him to come around and take a look at our Projecta DCDC charger. We’d lost a solar panel on the camper trailer, and needed some other work done anyway, so it was good timing.

Stephen had previously commented that the Projecta units are OK, but not top of the range and certainly not as reliable as the Redarc ones.

However, at $600 for a Redarc replacement, I wasn’t feeling too pleased! I was told that the chances of getting it repaired or replaced were slim to none, being outside of the 2 year warranty period.

He did some investigations, and found a dry joint inside the IDC25, and re-soldered it, and its been working perfectly fine ever since (roughly 3 months later).

Projecta DCDC review
We’ve spent 2 weeks on the Ningaloo Coast since and it hasn’t missed a beat

EDIT January 22

I think its time to ditch the Projecta DCDC, and move to something a bit more dependable.

If you’ve been through this review already, you’ll know that we had issues with the alternator charge and the DCDC some time ago, which our sparky diagnosed as a poor internal connection, and got it going again after re-soldering the joint.

The other day though, I walked past our canopy at 2PM in the afternoon, and saw the battery voltage sitting at 12.3, despite having been in full sun for days with a 200W solar panel on the roof, and no additional draw. By this time in the afternoon, it’d normally be at 13V or higher, so something was up.

Lucky for us, I’d installed a cheap PWM regulator that was set up to take solar charge too, and with everything on Andersons you can literally unplug the solar input to the DCDC, and run it to the Itech solar controller, which then charges the battery.

Immediately after swapping, the voltage jumped up 0.2V, and was pumping a healthy 10 amps in.

I tried the following morning swapping back to the Projecta DCDC, and it went from 13.1 volts down to 12.9, and stayed there.

Clearly the IDC25 is still doing something, but its doing a very bad job of it. Now, you might wonder if its related to temperature, and I wondered the same thing, but on the second test the unit had sat overnight, and was as cool as it was going to get.

With a new DIY lithium battery coming anyway, its time to look for something better quality, that isn’t going to take away from our family holidays fault finding and mucking around. Want to know about Projecta DCDC problems? That’s two we’ve had, which is rather disappointing.

That’s nearly 5 years out of the Projecta IDC25, and knowing what I know now, I wouldn’t get another one. I can’t say they are rubbish, but there’s certainly better products out there. I’d really love an Enerdrive DCDC in the Dmax, but they are massive, and it won’t fit in my electrical box. Such is life!

Is the Projecta IDC25 worth buying?

These are quite popular little chargers, and a lot of people swear by them. That said, I have read a number of complaints from owners who’ve had issues, and given what we’ve been through it seems to reflect the same.

They are a reasonable unit, but not built to the quality of Redarc, Victron or Enerdrive. My opinion only, of course. 

So, is it worth buying, and what’s the final Projecta DCDC review? Only you can answer that. I hate to buy things twice, and I like the idea of supporting fully Australian made gear (like Redarc), but still went with the IDC25 purely to save some money.

I’d probably have been better off buying a higher end DCDC; a poor man buys twice rings true!

I don’t think I’ll be getting any more Projecta products, but that’s just me.

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  1. Hey Mike,

    Sounds like you’ve been very thorough, and its a shame you’ve had these issues. I’ll have to do some more digging on my end

    All the best

  2. Mike Clarke says:

    Hi Aaron.
    I certainly have been in touch with Enerdrive as my one blew up. Of course it was my fault, I’d supposedly wired it up wrongly. They went into total denial, after which I decided I had nothing to lose, and decided to buy a Victron unit. I dismantled the device to find power mofsets blown off the circuit board. I sent Michael Sullivan photos of this, and Enerdrive finally agreed to a replacement through Advance Trident here in NZ. However, Advance Trident were required to re-flash all their stocks – a sure sign there are problems, and after being told by Michael that there was no firmware update. After again advising Michael to find a programmer that knew what he was doing, I have a new unit fitted, that charges my lithium house battery at 50 amps, hasn’t blown up yet, but still pulls 35 amps from the truck battery when supposedly off. We’ve been touring for over 2 months now and haven’t needed the DC2DC charger, but 2 days ago observed a truck battery too low to start the vehicle at 24°C. Connected my 15A mains battery charger and noticed 20A of charge across my house battery shunt, turned off charger, 5A solar coming in. I’ve now installed a 100A battery isolation switch to the supply lead, and control it manually. Problem solved but…
    DO NOT PURCHASE ONE OF THESE UNITS – THEY ARE FAULTY, and the Company, Enerdrive are not being forthcoming, or transparent in their dealings with this product.

  3. Hey Mike,

    Very interesting. Mine does the same thing, and I always thought it was due to not being wired up correctly. It was actually to the stage that I’d unplug the anderson if we pulled up for an extended period as I didn’t want a flat starter battery.

    These days I rarely plug it in as our solar system keeps up, but its interesting to know I’m not the only one who’s experienced this, and its not a great fault.

    If I read the manual correctly its supposed to continue charging for 3 minutes, then verify its not under 12.8V, and then disconnect if it is.

    Have you consulted Enerdrive to further query this? They have a pretty good reputation for customer support

    All the best

  4. Mike Clarke says:

    Regards your comment about Enerdrive DC2Dc chargers being a great unit. Be wary of these units. They continue to pull current from the truck battery after the key is turned off, even with the sense wire connected. They don’t drop out until truck battery voltage drops to around 12.3 volts. Current draw can be up to 35 amps.
    Buy a Victron.

  5. Hey Col,

    They are two different products. If you only need solar input, I’d go for a quality MPPT any day of the week.

    If you need alternator charge with the DC step up (like for lithium batteries etc) and also the isolation between two batteries then a DCDC is a good compromise, as long as its solar side works well.

    I went with a DCDC as I needed the lithium profile, alternator and solar charge, and isolation between our starter battery and the house battery in the rear.

    Some people even run a DCDC with a separate solar MPPT for some redundancy. We have a cheap PWM regulator wired up that I can swap to for solar charge if I really needed to

    All the best

  6. Col Tranter says:

    Hi Aaron.
    It was a very interesting read you story, and I’m wondering whether to go a MPPT or a dc2dc charger.
    What are the pros and cons of both?
    Would be interesting to hear your opinion.

    Regards. Col.

  7. Hey Tim,

    Good to hear you’ve had a great run from them. Maybe I got a dud one, but I’m not going to try again.

    I have just bought a whole heap of Renogy gear; I hope they are better and do well!

    I agree with the pricing; I think some products just have better marketing and rely on a brand name. That’s not to say they are bad products, but just maybe over priced.

    All the best

  8. Hi Aaron, I have installed a couple of these units in my vehicle (under bonnet) and caravan and they have been running flawlessly since 2016 through some very extreme temperatures and conditions. I have also installed another couple in other friends vehicles at the same time as we all travelled together and they are all working well also. I think Projecta is generally a good product however it has become more expensive in recent years. In the last couple of years I have now moved to Renogy products and I believe they represent excellent value and have proven to be reliable. I dont know that price necessarily dictates better quality these days as nearly all products are manufactured in China and while the very low cost products are less reliable there are excellent products around without the crazy price tags from the “brand name” suppliers.
    Cheers Tim

  9. Hi Geoff,

    Are you planning on running one DCDC to charge the two batteries? I’m not sure if that will create any issues if they are a reasonable distance apart.

    Regardless, if you look up the battery model, you’ll get the specifications for the recommended charge rates. For 260 aH of batteries that are close together though, you’d probably get away with somewhere between 10 – 20% of the total capacity (around 20 – 40 amps going in).

    If I was to get another unit, I’d get an Enerdrive DC2DC – they are great units and you can adjust the charge rate, and they are lithium compatible.

    All the best

  10. Hi Aaron
    Can you advise what amperage dc dc charger to run two agm 130ah batteries one in the tray of the triton for the fridge and another in the camper trailer for lights etc .The fridge will stay in the triton when not connected to camper
    Thanks Geoff

  11. Hey Brenton,

    I can’t really comment on the specifics mate. If you’ve been through the manual and still aren’t sure, I would just message Projecta.

    I can’t see the lights on mine as its mounted upside down and close to another piece of timber.

    All the best

  12. Hi Jason,
    I have just finished installing my IDC25 into my 4×4.
    While vehicle is turned off there is a solid green light for alternator, solid green light for solar and solid blue for AGM (solid green which would mean fully charged).

    Is alternator light on all the time even when solar is present??
    If vehicle is off would thought alternator light would not light up.
    Whats your thoughts on the charging lights when they should be on or off flashing and solid. Thank

  13. Hey Jason,

    It’s 2 B and S to the junction box under the canopy. I reckon maybe 3.5 – 4 metres long?

    All the best

  14. Hio Aaron,

    May I know the wire size you have from the battery at the engine bay to the back? How long is the cable?

  15. Hey Sharon,

    You are very welcome. Let me know if you want any further information; what’s it going on?

    Hope you are well!

    All the best

  16. With ‘himself’ just starting to talk about installing a DCDC charger, this review couldn’t have come out with better timing. Thanks for giving us something more to chew over 🙂