Variac For Equalizatiion Of Batteries
Note this is a long post and you might want to cut and paste it to your word program so you can relax and take little bites at a time. USING A VARIAC COUPLED TO A MANUAL BATTERY CHARGER TO EQUALI...
Forum Discussion
wa8yxm wrote:
Easier to push the button on the Prosine, Or just let the PD-9280 sit in float mode for a few days.
With a generator?
There exists a large percentage of flooded lead acid batteries that LAUGH at the attempts of a smart charger to bring the specific gravity of all cells back to OEM density. I recently talked to an individual that has twelve L-16 batteries connected to a generator and he uses the inverter (worth three thousand dollars) to try and equalize the batteries. Fat chance. He told me he gave up after ELEVEN tries. Eleven equalization cycles in a row. The inverter is set to it's maximum setting for equalization. I loaned him both my HF charger and VARIAC. I got a text message on my cellular during the middle of the night. "I'm on battery 4, and the first three are now sitting on 1.275 all three cells. Before I could not get them above 1.260. Hello lobster dinner! My reward.
The 15% boost transformer from SURPLUSCENTER.COM is described to AUGMENT a too small a generator's inability to feed the VARIAC with 120 volts. For straight out battery CHARGING, and NOTHING ELSE, one of these booster transformer can help a generator to CORRECT (not over-boost) AC voltages so a charger acts more "normal" in it's amperage output. If you use your small battery charger at home and when the batteries are discharged it charges at 10 amps but when you are camping, the same charger only gives out 8 amps on a generator despite the fact you checked the generator and it has normal output voltage THEN the booster transformer (this is not concerning the VARIAC) can make the charger's output "normal". OK? Just like "at home".
The booster transformer is used to connect between the generator and VARIAC (to boost the variac) when "120" is dialed in on the VARIAC and you "detect" less than 120 volts on the OUTPUT of the VARIAC. The transformer is used to keep voltage HONEST going into the VARIAC.
DETECT! The charger puts out 10 amps at home. It puts out 2 or 3 amps LESS when used with the generator. You can bet your bippy that when you dial the VARIAC to 120 using the generator the charger is going to act wimpy as well. The booster charger is used to keep things honest. When I dial 120 into the VARIAC I would PREFER that charger output stays the same using shore power or generator power. Got it? I don't need to fight a small generator when trying to get 16 to 20 amps out of a Harbor Freight 10-amp charger. The VARIAC's 13/12 boost by itself CANNOT CORRECT ENOUGH for a small generator's distorted waveform. This is Sooooooo easy to check for: If your TRANSFORMER TYPE battery charger puts out a reasonably predictable amount of amperage at home but puts out LESS amperage with your generator then you can use the nine dollar surpluscenter.com booster transformer. This booster transformer is only to be used to CORRECT inadequate voltage, not to TURBOCHARGE already correct AC voltage.
99% of the worth of a VARIAC is to BUCK voltage for a transformer type charger. To throttle it back. If you do not understand clearly the relationship or meaning or significance of a small generator's clipped sine-wave voltage peaks, and how it degrades the performance of a battery charger then get a knowledgeable friend to help.
Fighting an equalization exercise using a charger and small generator is not fun. Fighting batteries that fail to respond to an INCORRECT equalization using a "smart" charger inverter or whatever is equally unfun. Battery distributors ADORE people who ASSUME pressing the equalize button ASSUMES the battery electrolyte reverts to full rated specific density. KA-CHING!
