Charging ?

MEXICOWANDERER wrote:
SATURATED

The charger achieves a regulated voltage limit instantly.

That is how you defined it in the past, but in this thread you seem to be using "saturation charging" more like in the link above now.

Perhaps it is not such a useful term since its meaning is not clear or well-known.

BTW, to achieve "instant Vabs" on a low battery, you need a very high charging rate (charger amps wrt battery AH) or else start with the battery at a high SOC already.

To achieve the specified minimum 20% charging rate on a bank of two 100AH batts all you need is a 40 amp charger, but that will stay at 40 amps until the batteries reach about 73% SOC. Vabs is then reached and held while amps taper from their "absorption" or "saturation" stage (in the other definitions)

If you start the charge to do "instant Vabs" at above 73% SOC you will be under the 20% charging rate. Now what?

To do "instant Vabs at below 73% you need a higher than 20% charging rate, going higher the lower the initial SOC. This where you run into generator power limiting the size in amps of the charger.

You have to juggle the practical factors in RVing for how big a gen you can have to run how big in amps the charger can be to match the size in AH of the bank your RV can carry and needs for your daily AH use, and what that means for your ability to do a high charging rate.

You also have the notion you don't want to go below say 40% SOC before recharging. That sets the low end of the SOC that you can start with to apply your charger to in hopes of hitting "instant Vabs"

Eg, with the 5er I needed a Honda 3000 to run my chargers at 155 amps with 100 of that PF corrected) on my bank of 584AH (temp corrected). So that was 155/584 = 26.5% charging rate--most I could do. At that, it stayed at 155 constant amps until Vabs was reached at 61% SOC.

Nowadays with the MH, the biggest gen I can carry along is a 2200w that maxes my non-PF corrected 75 amp charger, for my 450AH bank of AGMs. Most I can do.

So that is 75/450 = 16.7% charging rate. I cannot achieve 20% or more while camping. Starting the recharge at 50% SOC, it gets to 72% before Vabs is reached and held, while amps start to taper.

Only way I can do 20% charging rate is at home where I can split the bank and do part of it at a time at 75 amps. One at 250 and the other part at 200. Now 75/250 = 30%