Going solar

[Covo71]

I have been looking around and have decided to leave fridge in the car and mount the arkpak permantly as well. I have been looking ideas of what to do. I am thinking of getting a redarc bcdc1225, http://www.ebay.com.au/itm/REDARC-BC...3D262464932603.
Is the price good for the kit or worth still looking around? Or is there a different direction I could or should be looking at?
Cheers for any input.

[GQtdauto]

I'm a cheap barstard but I really like this unit over my elcheapo , I have a 40 watt solar panel which is regulated by a cheap regulator sending power to crank battery side of dual battery solenoid .
While mine works ok and can keep fridge running and cold I need more solar now that I run two gel cell spare batteries and I like the specs on this unit only I do have a battery isolator already .
IMG_7271.JPG

[GQtdauto]

As for price a good Mppt controller and a dual battery solenoid will cost about that , but this unit has a lot more functions and is pretty shmick imo.

[stevemc181]

I'd be going for the latest model from Redarc called the BCDC1225D

The REDARC BCDC1225D is a 12V 25A In-vehicle DC to DC battery charger. It features the next generation in REDARC In-vehicle charging technology, charging from Solar and DC inputs simultaneously. Featuring a Maximum Power Point Tracking (MPPT) solar regulator, the BCDC1225D will charge from both solar and the alternator simultaneously. And, with built in 'Green Power Priority' it will select solar charging first, meaning less load on the alternator.

I have discussed this unit with Redarc as I am chasing similar, but in their 40 amp version (BCDC1240D), which is due for release sometime in the 2nd quarter 2017. There is no need for the changeover relay with this unit, so wiring is also much easier. These units also have a lithium charging profile available which is not available on the BCDC1225.

http://www.ebay.com.au/itm/REDARC-BC...-/302153822444

Details on the unit can be found here:
https://www.redarc.com.au/dual-input...attery-charger

[threedogs]

Where is the Arkpak being fitted, shorten one of the drawers or recess into the Qrt panel.
You could use 50amp anderson plugs for the Battery pack so it can be used elsewhere
around the camp or down by the river if need be.
I think 80 amps may be to big,,happy to be wrong though,,lol

Just reading the stats and says its good for temps to 80C
so perfect for under bonner installation.???
How hot does under bonnet temps get to has anyone measured this @MB

[GQtdauto]

I think the unit that will do lithium batteries as well would be the way to go .

[Cuppa]

The Dual seems to be a small step toward what Redarc should have produced in the first place, i.e. a charger which can accept input from both sources at the same time without needing a separate relay to switch between them. The ‘Green power priority’ is imho a piece of marketing hype.What is disappointing is that they have persisted with not including battery temperature compensation, & as a result continue with what I consider to be a rather crude form of protection by limiting float voltage to 13.3v, when most battery manufacturers recommend 13.6v to 13.8v.

I’m also unsure what to think about the suitability of the charger for LiFePo4 batteries based on the understanding I’ve gained from a mate who has been experimenting with lithiums for in vehicle/rv use for longer than Redarc, & who has now established a design & installation business for in vehicle lithium set ups.

Redarc state in their brochure
"When the lithium profile commences charging the auxiliary battery it will charge in a constant current stage, this stage maintains a constant current until the battery voltage reaches its
set point. The lithium profile will then move to constant voltage stage which keeps the battery at 100% charge”. There remains a great deal of debate in ‘lithium circles’ as to what the cut off set point should be, & how it should be monitored. Most agree that monitoring individual cell voltages is the wisest method. Redarc fail to say what their set point for cut off is & there is no mention of the unit having any adjustability for this, & their connection diagrams show no individual cell monitoring, in fact no monitoring at all other than total battery voltage. This leaves the possibility for charging to continue if/when cells get out of balance, which as I believe is bad news for lithiums. Furthermore, Lithiums which are not being regularly cycled are apparently bed kept at around 60% state of charge. Unlike Lead acid batteries (wet/AGM/Gel) keeping them constantly at 100% when not in regular use apparently reduces their lifespan. Most folk would not be using them 365 days a year & thus lithium charger set ups need some user adjustability.

Don’t get me wrong, I’d buy one, but not for lithiums & I would be surprised if any lithium installers would recommend these chargers.

My AGM batteries, on a BCDC1240 are now about 5.5 years old & looking good, but have not been worked hard yet. The next 5 years will tell whether the low float voltage & lack of temp compensation has had an impact or not. When they do eventually need replacing I’ll look at Lithiums, but there is a good chance there will be a newer battery technology by then.

[stevemc181]

I've been running a LifeP04 dual battery for 3 years using a Redarc BCDC1225-LV as the only charger. Obviously redarc refused to support the charger being run in this way due to no lifepo4 profile, but I decided to experiment early on as the charge profile is close enough for what I need. The only issue I've had is the fact that I need to disconnect the charger every few days to force it into boost mode as the voltage doesn't run low enough for it to detect boost mode is required so I need to force it manually. (Typically my battery is still at 12.9volts or so when it is 90% discharged) I am now looking at either getting rid of the current Redarc altogether and just charging using an Isolator type set-up or moving to the BCDC-1240D when it's released. 25amps is just too slow at times for me to get a fully charged battery. 40 amps with simultaneous solar would suit me fine, there is nothing in the new Redarcs Lithium charging profile that would concern me.

Still early days for my 100a/h LifePo4 at 3 years, but she is still as good as the day I bought it, time will tell I guess. I don't know of any charger that has individual cell monitoring. My battery has it's own BMS attached for cell monitoring and I also use a backup LV/HV shut-off, I also use a Victron BMV-702 to give me an idea of whats going on with the battery, this has an option for temp monitoring, but I've never felt the need to be bothered with it. There is a lot of scare mongering out there regarding LifePo4, that's why I decided to investigate it myself.

[GQtdauto]

Changed my mind about lithium batteries now and will stick with gel cell , bound to get cheaper as lithium takes off .

[Cuppa]

there is nothing in the new Redarcs Lithium charging profile that would concern me.

Can you point me to where Redarc spell out what their charging profile actually is please?

Still early days for my 100a/h LifePo4 at 3 years, but she is still as good as the day I bought it, time will tell I guess. I don't know of any charger that has individual cell monitoring. My battery has it's own BMS attached for cell monitoring and I also use a backup LV/HV shut-off, I also use a Victron BMV-702 to give me an idea of whats going on with the battery, this has an option for temp monitoring, but I've never felt the need to be bothered with it. There is a lot of scare mongering out there regarding LifePo4, that's why I decided to investigate it myself.

I agree that there has been a great deal of scaremongering, unnecessarily so. I haven’t gone to LiFePo4 yet, but hold no qualms about doing so when my current batteries have served their time.
Don’t know what BMS you are using or how you have your LV/HV shut off set, but you do have them. Redarc appear (to me) to be marketing their charger as being for lithium charging without mentioning any BMS or other battery protection. As I understand it pretty much any ‘dumb’ charger could be used to do the actual charging provided there was a BMS & HV/LV disconnect, settable by the user? The Victron monitor is certainly popular, especially because of Victron’s willingness to be open about their product’s connectivity. Another friend is reasonably advanced in his efforts to use Arduino technology in conjunction with the Victron to manage his lithiums.

Re. Temperature monitoring - can’t see any real need for that either, but I am very much in favour of temperature compensated charging at least for lead acid’s. I believe it to be important for maximising battery lifespan