Very Inexpensive Battery Maintenance Charger
1.0 ampere output. 13.8 volts regulated charge limit. This unit is good for 100 amp hours worth of batteries. IMO the voltage is a tad high for a high antimony RV battery with temps 60F or higher but ...
Forum Discussion
pnichols, you have proven yourself to have never been in the least sarcastic with your questions never mind have been insulting. It is a pleasure to answer your questions...
Evaporation loss in a flooded battery is addressed by surface area of the electrolyte being minimized first by the small area of the filler hole then secondly by the miniscule area of the filler cap breather.
We all know the warmer water or water solution gets the higher the evaporation loss. But few RV batteries are exposed to 50C temperatures for prolonged periods of time. Therefore in a sense of priority evaporative loss is considered minor in the scheme of things.
Electrolytic water loss due to evolvement of hydrogen and oxygen is a horse of a different color. Even the larger of the two, oxygen, migrates through the cell cap with the greatest of ease. It is order of magnitudes smaller than water vapor. And along with hydrogen atoms it is accumulated under pressure which water vapor does not have by itself.
Chemical action and reaction increases with temperature. What may be a minor event at say 10C may become uncontrollable at say 50C
Plastic is a less than ideal conductor of heat. Heat radiation is such a concern of some auto manufacturers that they install a plastic shell over an underhood battery at an attempt to mitigate radiation effects.
Using a sensitive IR instrument with temperature resolution to one-tenth degree is yet another tool an individual can use to find and diagnose battery problems. When I am trouble-shooting a large off grid system or cruising sailboat battery bank issue it is the first instrument I use. Temperature variation is an alarm to delve deeper into the cell to find out what's up. The bank of course should be biased with a high amount of regulated charging amperage for this to be valid.
RV'ers who live in environments of extreme summer-winter temperature variation need to adjust bulk charging and float voltage limits appropriate for their ambient temperature. I manually adjust for 5C variations. Each 5C lost or gained warrants temperature compensation.
I do it manually, some thermistor systems do it automatically, the best kind of course measures interior battery temperature (or tries to).
The used WFCO I have, has a "working" voltage setpoint of 13.75. When temperatures climb above 30C, the output voltage is going to get routed through a 300 amp rated Schottky rectifier. This will render output voltage .4 volt less or a finish voltage of 13.35 If temperature climbs above 40C I'll move (it would be an all-time record). After have used the unit for almost a month, the factory 13.2 volts float event seems to be unobtainable. I attribute this to unavoidable frequent shore power glitches.
With a VRB example an AGM, an amp hour (better yet a kWh) meter is invaluable. In float mode the amount of energy gained in an indispensable tool for determining whether a voltage set point is valid. I do not have one here and I grumble about it. A kWh meter is high on the list of "must get".
Evaporation loss in a flooded battery is addressed by surface area of the electrolyte being minimized first by the small area of the filler hole then secondly by the miniscule area of the filler cap breather.
We all know the warmer water or water solution gets the higher the evaporation loss. But few RV batteries are exposed to 50C temperatures for prolonged periods of time. Therefore in a sense of priority evaporative loss is considered minor in the scheme of things.
Electrolytic water loss due to evolvement of hydrogen and oxygen is a horse of a different color. Even the larger of the two, oxygen, migrates through the cell cap with the greatest of ease. It is order of magnitudes smaller than water vapor. And along with hydrogen atoms it is accumulated under pressure which water vapor does not have by itself.
Chemical action and reaction increases with temperature. What may be a minor event at say 10C may become uncontrollable at say 50C
Plastic is a less than ideal conductor of heat. Heat radiation is such a concern of some auto manufacturers that they install a plastic shell over an underhood battery at an attempt to mitigate radiation effects.
Using a sensitive IR instrument with temperature resolution to one-tenth degree is yet another tool an individual can use to find and diagnose battery problems. When I am trouble-shooting a large off grid system or cruising sailboat battery bank issue it is the first instrument I use. Temperature variation is an alarm to delve deeper into the cell to find out what's up. The bank of course should be biased with a high amount of regulated charging amperage for this to be valid.
RV'ers who live in environments of extreme summer-winter temperature variation need to adjust bulk charging and float voltage limits appropriate for their ambient temperature. I manually adjust for 5C variations. Each 5C lost or gained warrants temperature compensation.
I do it manually, some thermistor systems do it automatically, the best kind of course measures interior battery temperature (or tries to).
The used WFCO I have, has a "working" voltage setpoint of 13.75. When temperatures climb above 30C, the output voltage is going to get routed through a 300 amp rated Schottky rectifier. This will render output voltage .4 volt less or a finish voltage of 13.35 If temperature climbs above 40C I'll move (it would be an all-time record). After have used the unit for almost a month, the factory 13.2 volts float event seems to be unobtainable. I attribute this to unavoidable frequent shore power glitches.
With a VRB example an AGM, an amp hour (better yet a kWh) meter is invaluable. In float mode the amount of energy gained in an indispensable tool for determining whether a voltage set point is valid. I do not have one here and I grumble about it. A kWh meter is high on the list of "must get".
