Is 13.9v OK as a PWR Supply voltage?

darb

Well-Known Member
My projecta AC/DC charger has a PWR Supply mode which provides power to loads whilst my vehicle is parked up in car port (solar not in sun). It’s plugged into the circuit at one of my Anderson connections at rear of vehicle.

I’ve noticed it sits at 13.88 - 13.90v , is this voltage too high for it to be on days or weeks on end ? Wet cell lead acid btw

Note : it’s not on a charge or float mode (I put her away fully charged) so it won’t be delivering any current unless load requires it (fridges , various electronic chargers, led lighting and such - no huge loads)
 

mac_man_luke

Well-Known Member
best way is to run it in charge mode then it wont over charge if its a smart charger - what model charger?

Supply mode will be constantly feeding power into the battery and effectively charging it.
Its more for powering something without a battery in circuit or keeping power while swapping a battery
 

darb

Well-Known Member
best way is to run it in charge mode then it wont over charge if its a smart charger - what model charger?

Supply mode will be constantly feeding power into the battery and effectively charging it.
Its more for powering something without a battery in circuit or keeping power while swapping a battery
PWR Supply mode doesn't work without a battery source.

The charging mode floats at 13.7v (set to Wet Lead Acid) whereas PWR Supply is independant of any chemistry type and only provides current if something demands it? I thought that was the whole point of PWR supply mode?

I don't want to use charging modes for this scenario because it is often left for days or weeks un-monitored - with loads on, and critically it's also plugged in at a connection at rear of vehicle where volt drop underload becomes an issue (meaning : the charger will not charge correctly) ... don't want it frequently dipping into charging < I have seen loads confuse this particular unit in the past and causing it to over-charge.

The actual charging of battery is all sorted, and she's parked up with a 100% SOC every time - this is simply I want to do "shore power" as such and leave fridge and a few other slow draw accessories lit up (but i just wasn't sure if a 13.9v - current-on-demand-only source would be OK)

Given its a wet cell i guess i can just keep an eye on levels anyway

To be fair, the most damage my batteries get is the 80c engine bay where they live!
 
Last edited:

darb

Well-Known Member
ps its a projecta 7 stage, IC1500 (I think)

the spec sheet says 13.8v - but this one runs at 13.9v for some reason (maybe because its plugged in at a remote spot instead of at the battery)

spec sheet also says it can be used without a battery, but never works for us (supplies zero volts)

Capture.JPG
 

Bigfish1

Well-Known Member
It should be connected to a battery that has an appliance running off it. The 25 amp models and above cannot be used without a battery. Projecta says the 15 amp models can....13.9 wont hurt
 

dabbler

Active Member
If your AC charger is configured to supply a constant voltage, you might be shortening your battery life. That's because you're not using the smart charging profile and it's operating as an old school charger.

That voltage shouldn't harm the things you have mentioned as 12v is a nominal description really not a specification.
 

darb

Well-Known Member
Yeh it’s connected to the circuit via Anderson plug (with 60 amp wiring to the battery in engine bay). Not for charging , just for power supply - so when fridge pulls amps, or my lighting is on, or any of the various USB chargers are in use, they get juice.
 

darb

Well-Known Member
If your AC charger is configured to supply a constant voltage, you might be shortening your battery life. That's because you're not using the smart charging profile and it's operating as an old school charger.

That voltage shouldn't harm the things you have mentioned as 12v is a nominal description really not a specification.
is that different to it sitting on float for weeks at 13.7v ?
 

mac_man_luke

Well-Known Member
interesting must behave differently to my ctek which is perfectly fine to leave hooked up in charging profile and power supply mode works great with no battery
 

darb

Well-Known Member
interesting must behave differently to my ctek which is perfectly fine to leave hooked up in charging profile and power supply mode works great with no battery
It could have been operator error ! Haha

All I’m really wanting to achieve is a “shore power” scenario. My projecta is mounted in the vehicle , into the circuit. I simply plug in 240v lead when parked up in the garage - and my fridge / freezer and various other shit that draws power can continue to be provided without draining

When vehicle is in use it’s fine as I am driving and also have pemanent solar panel on canopy roof with mppt
 

mac_man_luke

Well-Known Member
If you have loads running your not likely to have overcharging anyway being in float or supply, if your worried looks like you can drop the charge current down to as low as 2amps which would probably be less than your using? probably don't want it pumping the full 15 amps in constantly

Does say on the website "Fully charged and maintaining, no need to turn the charger off"

Looks like the projecta floats for 21days then restarts where ctek floats for 10 days then goes into pulse mode keeping it between 95 and 100%
 

darb

Well-Known Member
Yeah there's a few static loads - Ironically my Victron MPPT charger with Blue Tooth module has a slow current draw, Dash mounted ipad draws USB, dvd head rests pull a small amount, extensive LED lighting in the canopy when i open and close (which i do alot in the weeks before a trip), a hidden onboard ipod 128gb full of music and offline spotify-cache also has a slow current draw, handheld camp lights / torches / etc I will often chuck on charge in between camping trips (all of which pull from auxillary circuit) ... and of course my fridge pulls around 4amps whenever the compressor demands it.

my understanding of "power supply mode" is that it doesn't force-feed any amps at all ... only if load demands it (i don't really understand how that all works but presumably the device senses it? like any charger does).

Judging by the screeny below ... the charge modes do pump amps in (regardless of load), whereas float just says it sits at a voltage ... 13.7 instead of 13.9 I’m seeing on PSU

On PSU mode , it says ;

POWER SUPPLY
When Power Supply mode is selected, you can safely run an appliance or load from
your battery. An appliance can also be run directly from the battery clamps if required,
for example using the charger as a memory saver when disconnecting the battery
from the vehicle.


Q. Can I use the charger as a power supply
A. Yes, by selecting Power Supply mode you are able to use the charger as a power supply
to run an appliance. Ensure the appliance being run is not greater than the charger’s
output current and where possible connect the charger to a battery, and the battery
to the appliance.
The charger may also be used to connect to a vehicle while changing the battery
to maintain the vehicles computer and radio settings.


POWER SUPPLY (CONSTANT VOLTAGE OF 13.8 VOLTS)
This sets the charger in power supply mode giving a constant voltage of 13.8VDC.
This mode is best used where appliances are drawing power from the battery, for
example like a Fridge. Although the charger is designed to work with a battery
connected, it can also work without a battery.


GEL (MAX VOLTAGE OF 14.1 VOLTS)

This charge mode is designed for GEL batteries and has a maximum charge voltage
of 14.1V. Note that some GEL batteries require a higher charge voltage such as 14.4V.
The AGM mode can be used if this is required.


AGM (MAX VOLTAGE OF 14.4 VOLTS)
This charge mode is designed for AGM batteries and has a maximum charge voltage
of 14.4V.


WET (BULK AND ABSORPTION 14.7 VOLTS, RECONDITION UP TO 16 VOLTS)
This charge mode is designed for WET batteries and has a maximum charge voltage
of 14.7V during Bulk and Absorption stages and 16.0V during the Recondition stage.


CALCIUM (BULK AND ABSORPTION 14.7 VOLTS, EQUALIZATION AND
RECONDITION UP TO 16 VOLTS)


This charge mode is best suited for Calcium batteries that have been deeply discharged
and require an equalization charge to restore a full electrolyte reading. If the battery
requires a simple ‘top-up’, the WET charge mode can be used.



Capture.JPG
 
Last edited:

dabbler

Active Member
is that different to it sitting on float for weeks at 13.7v ?
If it sits on float for weeks, why use the AC charger ?

Where are you measure voltage and how ?

I guess my point is, why use supply mode when charging mode is more appropriate if a battery is involved.
 

darb

Well-Known Member
If it sits on float for weeks, why use the AC charger ?

Where are you measure voltage and how ?

I guess my point is, why use supply mode when charging mode is more appropriate if a battery is involved.
I’m not saying it does sit on float in perpetuity , we were comparing difference between sitting on float vs psu modes on the unit - and whether there a difference in amperage delivered/forced (load aside) in a float vs PSU comparison.

Whether it would sit on float or not I’m not sure , which is actually the whole point I suspect it will / does. When I leave it parked up for weeks on end (or even just days) , unattended, I don’t want the projecta to be tricked by load demand into engaging any “charging” at all (especially bulk or absorption modes) ... not when I’m not around to keep eye on it.

The manual does warn that charging with loads connected will confuse algorithms - so when I’m on shore power I just want power and not charging

I just want “shore power” to supply my demand ... which the PSU mode seems perfect for except the 13.9v (13.88 - 13.92) threw me off a bit as it seems a smidge high (hence the thread).

As to reading voltages, both my batteries are monitored by in car volt meterss direct to the terminals with good wiring - so what I see on my dash volt meters is always identical to what you’d see with multi meter on the terminals.

Obviously to correctly read a voltage for SOC purposes , we would remove all load and allow rest

Where the projecta is plugged in is down stream at an Anderson plug in the rear - I suspect it would suffer 0.2v - 0.3v of volt drop.

So just to round out - I don’t want the projecta entering a charge cycle of any sort (in this scenario) but was just a bit wondering if the 13.9 was a tad high

It’s probably all a bees dick of difference - but slow week and not camping leads to tinkering
 
Last edited:

dabbler

Active Member
Unless you isolate your battery and load then you are using drawing from battery not "shore" power.

I'd be using the charger's smart function not supply mode. It's how every camper, caravan and motorhome is configured.
 

boobook

Well-Known Member
If there is a battery, then use charge mode, NOT Power Supply mode.
If there is no battery use Power Supply mode, NOT Charge mode.

In Charge mode the charger expects to see a battery load and varies the voltage on that basis. That could damage electronics or at least move the voltage around given no battery - when it is expected.

In PS mode it gives a fixed 13.8 voltage. Full load or no load.
 

darb

Well-Known Member
Thanks fellas

Ended up speaking to an auto sparky and battery supplier

So the chargers when in a charge mode floating apparently will detect house load amp draw more than 2 amps as battery needing charge and flick back into absorption mode from float (as high as 15v)) - and so risk having the system regularly put in and out unnecessarily overcharging.

This same risk occurs all the time when driving anyway with my DCDC because my load and battery aren’t isolated - so there’s no free lunch here. Charging modes are more aggressive with the current/amps whereas PSU mode wont try and push amps

Perfect world I should actually be isolating my load and battery from each other.

Going to stick with PSU mode and keep an eye on battery fluids (as above - the battery probably cops more stress from hot engine bay charging and heavy use camping , than some PSU or floating at home in a nice cool garage!)

Ps my dcdc charger is routinely up to 14.5 volts when charging with battery and loads. (Same problem can occur - it can be confused by 2 heavy loads and a battery and risk overcharging)

Either option has variable risks - any time you mix loads with charging this is a risk of confusing the charging algorithms (so the past 10 years for me then!)
 
Last edited:

dno67

Well-Known Member
I've got the same projector charger and have it fry a battery. In a similar situation, maintenance charge while pulling a light load from the battery. I don't use it as anything more than a charger now, l don't think there any where nears as smart as there advertising suggests. Not a piece of equipment l trust at all.
 

boobook

Well-Known Member
Charging modes are more aggressive with the current/amps whereas PSU mode wont try and push amps
Amps never get pushed, they get drawn. Sorry for being pedantic, but there is a lot of misunderstanding on forums. The amp rating of any power source is the 'available' current that can be drawn. The amp rating of a device ( load) is the amount of current that device will draw given its rated voltage.

Amps are like flow in a tap, voltage is like pressure, and the tap or valve is like the resistance.
 

darb

Well-Known Member
I've got the same projector charger and have it fry a battery. In a similar situation, maintenance charge while pulling a light load from the battery. I don't use it as anything more than a charger now, l don't think there any where nears as smart as there advertising suggests. Not a piece of equipment l trust at all.
Yeh that’s the back channel thought I have

To be fair I had a serious issue with my early model dcdc charger whereby it never ever entered float - ever! It would sit on on absorption for a full tank of fuel drive : long drive. It boiled a battery and shortened life of another.

In the end we worked out why - my two stereo amplifiers which pull a decent constant/static draw even when turned on with volume low we’re causing the dcdc to be confused and never enter float even though battery was fully charged from the start.

I moved the amps back over to the normal starter circuit and problem solved it enters float almost immediately (if battery is charged)

None of its perfect - with load and battery sharing the same circuit but is what it is
 
Top