Charge Controller Setting for battery

[Matrix]

To the OP, I do not know if this helps, but I did just find this on another forum

Hard to find, but I got Info on...DEKA GC15 batteries from MFG...recommended charge info (bulk/absorb/equalize) for GC15 6volt 230AH wet cells that lots of us use.

1. BULK STAGE = 30% of C20 (or 30% of 230Ah)
- 69 amps (max.current) per series string.
- Multiple the 69 amps x the parallel strings, if applicable.

2. ABSORPTION STAGE = 2.40 - 2.45 vpc (x 3 cells) = 7.32 v x the # of batteries in your string

3. FLOAT STAGE = 2.30 - 2.35 vpc (x 3 cells) = 6.96 v x the # of batteries in your string

4. EQUALIZE STAGE = 2.50 x 2.55 vpc (x 3 cells) = 7.59 v x the # of batteries in your string

NOTE: TEMPERATURE COEFFICIENT IS -3mV / Cell

[Sunking]

To the OP, I do not know if this helps, but I did just find this on another forum

FWIW and clarification so no one misunderstands when you see a voltage setting like Bulk = 2.4 to 2.45 volts per cell is a window or range of voltages. Example for a 6 volt battery is 7.2 to 7.35 volts at 77 degree F.

However the Temperature Compensation recommendation is incomplete making it gibberish.

NOTE: TEMPERATURE COEFFICIENT IS -3mV / Cell

Should read something like this:

Add 3 mv for each degree below 77 F
Subtract 3 mv each degree above 77 F

[monogram]

Hello All,

Received the Hydrometer on Saturday, below are the readings:

On Saturday:

• At 5PM, the batteries at Float mode, MPPT display battery at 27.4V, SG reading at around 1240 (the needle about 3/7 between 1225 & 1250) (Load OFF)
• At 11PM, 25.0V with SG=1245 (with LOAD)

On Sunday:

• At 7:30AM, 24.6V with SG=1240 (with LOAD)
• At 10PM, 25.1V with SG=1240 (with LOAD)

On Monday:

• At 7AM, 24.6V with SG=1240 (with LOAD)

Does my reading look normal?

Do I need to increase the voltage to get SG to 1270?


Here is my MPPT settings:

SETTING	User setting
Over Voltage Disconnect Voltage	33
Charging Limit Voltage	32.5
Over Voltage Reconnect Voltage	32.5
Equalize Charging Voltage	32.4
Boost Charging Voltage (Bulk)	29.7
Float Charging Voltage	27.4
Boost Reconnect Charging Voltage	26.4
Low Voltage Reconnect Voltage	25.2
Under Voltage Warning Reconnect Voltage	24.4
Under Volt. Warning Volt.	24.1
Low Volt. Disconnect Volt.	24
Discharging Limit Voltage	23.8
Equalize Duration (min.)	120
Boost Duration (min.)	120

[Matrix]

did you read and look at the Temperature Compensation? Depending on the Temp, you either add or subtract point based on the temp. There is a temp thermometer on the hydrometer. So is the value of 1.240 a temperature compensated value? IF that is the Temp Comp value, I would think it is low. The chart I sent posted here indicates 1.240 is just over 80%. Too Low.

[monogram]

I did not get the one with temperature (glass) as I broke one last time.

This is the one I got:

2018-04-09_112630.jpg


Can I take the temperature by using this:

2018-04-09_112921.jpg

What adjustment do I need to make to bring it up to 100%

[Mike90250]

Adding time is one method, but there is seldom enough sun hours, so try going up in voltage a bit, try adding half a volt, and increase Absorb time by an hour. Let that run a couple days and then see if you need more of either

[monogram]

Adding time is one method, but there is seldom enough sun hours, so try going up in voltage a bit, try adding half a volt, and increase Absorb time by an hour. Let that run a couple days and then see if you need more of either

Am I adding the voltage to Float or BOOST?

On my Epever MPPT, it does not have Absorb mode, are there any different term for it? (please see above for my setting)

[Matrix]

Boost

[littleharbor]

The Boost voltage number is the point where your controller will transition to absorb. Until your battery reaches the set voltage point it is in boost mode. when it hits that voltage it should hold the voltage at that point until it determines the battery is full. That would be the absorb stage. If you can watch your controller you should see this. Hopefully it doesn't go straight to float as soon as it reaches the boost voltage set point.

[monogram]

According to MPPT manual, this controller has 3 stages battery charging algorithm:
Untitled.jpg


My current setting for Boost voltage is already at 29.7V which is little high compared with MPPT default setting at 29.2V.

• Should I continue increase the Boost voltage? If yes, then to What value?

What about the Boost Duration, as it currently set at 120 mins (default value)

• Should I increase it or leave it as is?

I also noticed the last few days that my Gas Monitor Alarm went off when all doors in the house were closed, could it be the gas coming out from those batteries?

Please let me know the correct setting as I don't want to explode my batteries.

Regards,
Key

[littleharbor]

I see they refer to the constant voltage, absorb stage as boost. Different mfg. have different words for these phases of charging. .

Bulk, phase is where your controller allows all available power through to your batteries.

The set point , 29.7 in your case, to transition from bulk to absorb (constant voltage) is where your controller holds the voltage steady and allows the current to slowly finish charging your batteries. If you have the ability to use % of ah. rating you can ensure your batteries are getting closer to full before you run out of sun for the day. Sunking has a much better explanation of this battery charging stuff. Have you already read the stickies at the top of the category list? I believe he has authored most of them.

As far as your gas alarm, What kind of gas is it detecting? Aggressively charging batteries produce hydrogen gas, which is lighter than air. propane is heavier than air so the sniffer should be down low for propane. Not sure if a carbon monoxide alarm would detect Hydrogen gas. If your batteries are indoors they need to have some form of ventilation to the outdoors.

[Matrix]

If your Boost voltage is 29.7 volts and you did not reach a full charge, you either have the option of increasing the Boost time, or the Boost voltage. There is no other option. And since the sun doesn't give you enough time, you can only increase the voltage. As has already been stated why don't you try one half a volt increase to. 30.2 volts boost for a few days and check SG again?

your manual is telling you that according to your manufacturer boost is what other people here are commenting as absorb.

Right now at 1.240, IMHO, your SG is too low for a fully charged battery

[Sunking]

My current setting for Boost voltage is already at 29.7V which is little high compared with MPPT default setting at 29.2V.

• Should I continue increase the Boost voltage? If yes, then to What value?

What about the Boost Duration, as it currently set at 120 mins (default value)

• Should I increase it or leave it as is?

I also noticed the last few days that my Gas Monitor Alarm went off when all doors in the house were closed, could it be the gas coming out from those batteries?

Please let me know the correct setting as I don't want to explode my batteries.

Regards,
Key

Your questions have been answered. Your battery hydrometer will tell you what the voltage should be. Go back and read the answers.

[littleharbor]

One other question. How far is your controller from your battery bank and what size wire are you running between the two? You could have enough voltage drop between the two that your controller thinks the voltage is higher at the batteries than it really is. Keep the controller as close as practical and use the largest wire it will accept. This will eliminate any issues there.

[monogram]

Hi Matrix,
Thank you for your advise.

• If I set the Boost voltage to 30.2V, will it be too high for 24V batteries bank?
• If I have enough sun time, does increase Boost Time is a better option for the batteries?
• How to know if I have enough sun time?

Hi Littleharbor,

If you have the ability to use % of ah. rating you can ensure your batteries are getting closer to full before you run out of sun for the day

• Would you please explain for me on this "ability to use % of ah."?
• For the gas monitor, I use this device mainly for Combustible Natural Gas and just noticed it also detect the gas coming off from batteries too (https://www.amazon.com/Yeezou-Combus...nitor+detector )
• The batteries are about 2ft below the controller. I don't remember the wire size but I think it's small wire. What is the correct gauge size for controller to 215A batteries?