How to stop false 100% battery status

[colemj]

I probably wouldn’t turn the charged voltage up any higher, since you’re already above Victron’s recommendation of being the float voltage.

I don't think this is correct. Victron's recommendation is to set the "charge voltage" 0.2-0.3V less than the absorption voltage. It is how I have ours configured.

Mark

 

[Davidasailor26]

I don't think this is correct. Victron's recommendation is to set the "charge voltage" 0.2-0.3V less than the absorption voltage. It is how I have ours configured.

Mark

I was going by section 5.7.1 of the manual at https://www.victronenergy.com/upload/documents/SmartShunt/9172-Manual_BMV_and_SmartShunt-pdf-en.pdf, saying it should be the float voltage. Section 4.3.2 of the same manual says to set it to 13.2V. Mine is set to 13.1 and works fine.

Looking at the algorithm it seems like the important things are that it’s not so low that the battery reads as “charged” when there is no charging source at all, and that it’s not so high that the charger doesn’t get there when absorbing. That suggests that anything around the float voltage to a bit less that absorption should be fine. The tail current is probably the more important part of the trigger.

 

[Elysium_Van_Isl]

Well here's an interesting development!! From Costco today:

Hello Mike,

In response to your email,

• the manufacturer of this battery is Trojan.
• Charge Efficiency is 91%
• Peukert coefficient (exponent) is 1.179

Thank you for contacting Costco,

 

[jssailem]

WOW

 

[Johnb]

Notwithstanding all the foregoing if you want your batteries to live long and prosper you need to

1 Make sure that they get fully charged and not left in a partial state of charge (PSOC)
2 Make sure the water does not get low. Check them regularly and develop a sense for what is needed.

Those flooded Trojans are robust. Mine are in their 7th year including 5 years of live aboard with solar power, and when they die I will almost certainly replace with like and go sailing.

 

[Maine Sail]

Those batts are not 91% efficient more like 80%. Peukert is closer to 1.3..

Making Your Battery Monitor More Accurate - Marine How To

Program The Ah Capacity This article features the older Victron BMV-602. The 602 has been replaced by the BMV-7oo series (700, 702 & 712). Everything in this article is still relevant to the current series of BMV-7xx battery monitors. WARNING: This article

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