Solar charge controllers that can absorb at 14.8v. Let's make a list?

[Mwilliamshs]

I'm looking for a solar charge controller. Needs to handle 15 amps input (2 100w panels at <6a each) and absorb charge at 14.8v with temperature compensation. Running flooded batteries and NEED the voltage.

The Morningstar Tristar 45 is the current front runner but at 45 amps rated input capacity, it's overkill. At about $160 though, it's not ridiculously priced IMO.

The MorningStar ProStar PS-15 has a 15a rating and is ~$115 but absorption is fixed at 14.4v for flooded batteries so it's a no go.

The MorningStar SunSaver has a 15a rating but an absorb voltage of only 14.4v. So it's out of the running.

Any suggestions?

 

[Mwilliamshs]

The MidNite Solar Brat (~$125) has an absorb voltage of only 14.4v. So it's a no go.

The MidNite Solar Kid at ~$440 is too expensive for me but it does feature an adjustable absorb voltage range that appears to include 14.8v.

The MidNite Classic series, which start at $750 (!!!) are too expensive for me. The cheapest model is hugely overkill for my system in terms of amp rating but it's only applicable charging profiles are:

Profile # Absorb Float Equalize
Flooded 1 14.6v 13.5v 15.3v
Flooded 2 14.7v 13.5v 15.4v
Flooded 3 15.4v 13.4v 16.0v

So Flooded 2 is the highest-voltage option that wouldn't constantly overcharge (14.8 is the battery mfg recommended rate, not to exceed 15v) but it's still too low and as I said, $750 is WAY WAY out of my range.

 

[IdaSHO]

I'm looking for a solar charge controller. Needs to handle 15 amps @ 12v input and absorb charge at 14.8v with temperature compensation. Running flooded batteries and NEED the voltage.

Care to explain why?

What batteries, specifically?

Traditionally voltage is reduced during the absorption for good reason.

14.8-15V BULK
14.2-14.4 ABSORB
13.4-13.6 FLOAT

 

[Mwilliamshs]

Care to explain why?

No, not really. Here's some reading material: http://www.trojanbattery.com/BatteryMaintenance/Charging.aspx http://www.trojanbattery.com/pdf/datasheets/T105_Trojan_Data_Sheets.pdf

What batteries, specifically?

Trojan T-105

 

[Mwilliamshs]

The Renogy Adventurer has a 30 amp capacity but a fixed absorption rate of 14.6v. So it's out. Note: for $90 it includes the remote temperature sensor and the remote voltage sensor so it seems like a great deal if 14.6v will work for you.

The Renogy ViewStar has a 30 amp capacity and adjustable absorption rate of 9-17v. At ~$140 it seems priced right too. Note: Renogy calls absortpion "boost" but defines it as "Boost Charge: When the battery has charged to the Boost voltage set-point, it undergoes an absorption stage" so I'm good with that.

The EP Solar ViewStar is the same unit as the Renogy above. EP manufacturers the unit and Renogy is a re-seller. The unit sells for $125.90 on Amazon and other than longevity and accuracy concerns based on having never heard of the brand and limited reviews available, I think it'd be a great fit for me. Certainly like the price. Whether or not the $ difference between this and the Bogart SC2030 would pay off is a big question. The SC2030 itself is cheaper (like 5-10 bucks cheaper) but to match capabilities the SC2030 NEEDS the TM2030 and that package is $275. The $126 ViewStar and this $36 monitor can supposedly match capabilities for about $115 less. HMM. The EP Solar ViewStar 20A technically meets my specs and costs only $71.90 from Amazon. That plus the Elite Element monitor gets me what I want (with quality a remaining question) for less than $110. DOUBLE HMM.

 

[Mwilliamshs]

The BlueSky SunCharger 30 has a 30 amp rating and an adjustable absorption charge rate of 12-17.0v. At ~$160 it's priced about right too.

The BlueSky Solar Boost 3000i has a 30 amp rating and an adjustable absorption charge rate of 12-17.0v. At ~$280 it's priced about right if you want MPPT.

 

[Mwilliamshs]

The Outback FLEXMax 60 has a 60 amp rating, so it's overkill but it does have an adjustable voltage regulation setpoint for all stages of charging with a range of 13 to 80v. At ~$475 though, it's outside my range.

The Outback FLEXMax Extreme has similar capabilities but is over $1,000 so I'm not even digging into the specifics.

 

[Mwilliamshs]

The ZAMP Solar Digital Deluxe 5 Stage 15 Amp PWM Solar Charge Controller – ZS-15AW has a 15 amp rating but absorption is capped at 14.7v so it's a no go. At ~$120 it looks like a rip-off too.

The Samlex Steca PR-15 has a 15a rating but absorption is capped at 13.9v. Yes, really. At ~$140 it's also a big loser.

The Victron Blue Solar PWM 12v 24v 20a has a 20a rating but absorption is capped at 14.6v. I couldn't find what I consider reliable pricing for this unit, but c'mon, who cares?

The Victron Blue Solar PWM-Pro 20A has a 20a rating and a default absorption rate of 14.4v. It is programmable from 9-17v. For $72.00, it seems too good to be true.

 

[IdaSHO]

No, not really. Here's some reading material: http://www.trojanbattery.com/BatteryMaintenance/Charging.aspx http://www.trojanbattery.com/pdf/datasheets/T105_Trojan_Data_Sheets.pdf

Trojan T-105

Looks to be a simple nomenclature error.

Nowhere does those sheets mention BULK charging, nor does it discern the difference between bulk and absorption.

If I had to guess, they are using the same figures for what they call "DAILY CHARGE", as what others call BULK.



I really think you are worrying about something you should not.

Carry on.


Edit:

My suspicions are confirmed:

Regardless of chargers, and profiles, Trojan treats BULK and ABSORPTION the same with regards to voltages.

Both stages are spec'd (at least on this sheet) the same, at 14.4V

http://www.trojanbattery.com/pdf/U.S. Battery Charge Profile Full 11-12-13.pdf

 

[Mwilliamshs]

If I'd made the title of this thread "Vehicles that can get 50mpg. Let's make a list?" would you be in here asking me why I want to get 50mpg? If I'd said "Bowling balls that weigh 13lbs" would you be giving me advice on why I should be bowling with a 12.6lb ball? ********

...Regardless of chargers, and profiles, Trojan treats BULK and ABSORPTION the same with regards to voltages.

Both stages are spec'd (at least on this sheet) the same, at 14.4V

http://www.trojanbattery.com/pdf/U.S. Battery Charge Profile Full 11-12-13.pdf

Study the graph on the last page of the document you linked. I really don't care what you think anyway. I'm looking for a charger, not looking for an opportunity to explain WHY I'm looking for a charger. Handy Bob is not the only reason I want to charge my batteries at 14.8v but read his words here if you want an in-depth explanation.

Trojan T-105 batteries have a 20-Hr rating of 225ah and each contains 3 cells of 2v (nominal).

The document you linked states:
"1. Bulk Charge Constant Current @~10% of C/20 Ah in amps to 2.40 +/- 0.05 volts per cell"
That's a suggestion of pushing ~22.5 amps into a bank of 2 batteries until its voltage reaches 14.1-14.7v. (.1v loss from charger isn't unreasonable)

"2. Absorption Charge Constant voltage (2.40 +/- 0.05 vpc) to 3% of C/20 Ah in amps"
That's a suggestion of pushing 14.1-14.7v into a bank of 2 batteries until amperage acceptance falls to 6.75a. (.1v loss from charger isn't unreasonable)

"3. Finish Charge Constant current at 3% of C/20 Ah to 2.55 +/- 0.05 volts per cell (e.g. 7.65 volts +/- 0.15 volts per 6 volt battery)
That's a suggestion of pushing 6.75a into a bank of 2 batteries until its voltage reaches 14.4-16.2v. I have no idea why their tolerance increases at this stage from .05 to .15 but if we hold the tolerance as close as here as in other stages, that range is 15.0-15.6v.

The tighter tolerance (.05v) is used for Equalization Charge so it's especially odd they'd slacken the reigns for this single stage. This "Finish Charge" is what I've been getting at all along. I referred to it as absorption before (sorry for what "looks to be a simple nomenclature error" on my part). These terms are all interchanged by different manufacturers so it's likely different customers might do the same.

"Charge termination can be my maximum time (2-4 Hr) or dV/dt (4 mv/cell per hour)"
For simplicity, I stick with 2 hours and if voltage falls off, charging will start again. Haven't studied a 3-stage charger yet that didn't have this 2hr timer.

 

[IdaSHO]

Your not hearing me.


You have made the distinction between bulk and absorption, yet you refer to Handy Bob

Do note that he does NOT make the distinction between the two. You should be wondering as to WHY.

 

[herm]

I think you need to meditate or do yoga or something. stress is a killer.


Go with the view star or the suncharger. you wont get much more out of mppt unless you are using higher voltage panels. PWM will be just fine.


ida: he is not interested in learning. no reason to add stress to his life.

 

[LeishaShannon]

Victron MPPTs are programmable to those voltages (and higher)

 

[mikekey]

Bluesky Solarboost 3024il & the Bluesky Solarboost 2512iX with the IPN pro can hit those numbers and has the temp compensation. I run both of them with my lithium battery setup. Used to have lead acid. And they'll handle the power you want to throw at them.

 

[loonwheeler]

I also believe the Bogart Engineering SC-2030 can also be programmed for high(er) voltages.