smkettner wrote:
Now we are getting somewhere. For float service set the supply at 13.30 volt in normal conditions and let it sit. For fast charge set to 14.8 volts and give the timer a twist from 30 to 180 minutes depending on level of discharge. (about 10% to 50% discharged respectively)
I am not an expert on Megawatt so now everyone can jump on me with corrections. :B
Not sure how the meter fits in.
SMK, I came to you in the beginning for advice. It was good advice. And as I grew in knowledge and experience, I chipped in my observations. I think that what you have chipped in above matches my observations with my 30 Amp MegaWatt, so your contribution is based on solid experience. Something also tells me that you are an EE by education or trade. That you've had a Nissan Leaf all electric car adds further to your credentials on experience in charging electric batteries. Your suggestions and time settings are spot on, only minor detail would be state of charge when the OP starts charging his batteries, and ambient temperatures, to fine tune things a bit. That will come with time and experience.
Meter comes in in telling you your current amperage charge rate, and voltage at the charger, for setting the voltage before you start charging. DMM will tell you voltage at the terminals, as the variance between the two will give you a clue as to the take of charge the battery is in. Current amps will also tell you the take rate. Cumulative amps will tell you how far down you ran your battery, with the understanding that you have to add back in 5 to 10% more amps than you took out of the batteries, lost in resistance to charge in the batteries.
Of course, the hydrometer has final say on state of charge of every single cell, the meters are just a cumulative of each cell in series for 12V, it will not tell you which cell might be going bad.
Just tools, used in parallel, or in conjunction , to remove doubt, to assist in knowing exactly what the battery is doing while charging.
The smart person that wants to know for certain logs all the parameters the first 2 or 3 hours that the meter puts out on display.
Do this logging a couple of times, and decisions can be made, smart decisions, about how much time to set for, based on previous experience, saving time and fuel.
I will also add that at this stage of the game, for those that do NOT feel comfortable with this homegrown setup, for bulk charging, hands down, serious bulk charging, the closest you can get to this set up that is "near enough" is a Iota DLS series with the cheat wire installed, that will get you 14.7V, but only up to 106F, beyond that, the unit shuts off maintaining charge.
smkettner steered me that way, it's solid advice if you are not a more hand on person, or is satisfied with "good enough".
