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Cross Charging Methods


The following article attempts to explain the recommended applications, advantages, and disadvantages of the Eliminator, AutoSwitch, Parallel Solenoid, and Schottky Diode.

First point of emphasis is that we focus the most effective charge control on the deeply-cycled house battery bank to charge it fast and full. Then, we treat the non-deep-cycled starting battery bank, bow-thruster battery, or such as a secondary unit. The secondary unit (or battery bank) may or may not require sophisticated charge control. For this we offer the following four levels of charge control for the secondary bank (from most sophisticated to the least):

Eliminator #EL5xx
Recommended Application
- Sailing vessel with one house battery bank and a seperate, dedicated starting battery bank.

Other Notes
- Limited to 5A nominal (12A peak) charge current... Absolutely no loads can be attached to the starting battery except the electric starting motor
- Recharges the starting battery with little or no intervention; only a few Amp-hours are depleted during a normal starting sequence
- Starter battery can be undercharged if engine is started and stopped multiple times per hour (or charge cycle)
But this is uncommon practice for most sailing vessels.

AutoSwitch #ASxx-100, #ASxx-200
Recommended Application
- Cross charging from a house battery bank to a second battery bank that has large duration loads or conditions that exceed the limitations of the EL512

Parallel Solenoid #SOLxx-100, #SOLxx-200
Recommended Application
- R/V cross charging from the main coach battery bank to a second house battery bank
Other Notes
- Secondary battery bank may be overcharged, suggest using Lead-calcium type battery that can tolerate higher voltages for prolonged periods
- Add-on option to the #NEXT or #SARV3

Schottky Diode #1029
Recommended Applications
- Bow thruster battery

Table 1. Comparison of Ample Cross Charging Products.
  #EL5xx #ASxx-aaa #SOLxx-aaa #1029
Amperage Rating (Continuous) 5 100 or 200 100 or 200 200
Solid-State x     x
Precision Multi-stage Regulation x      
Temperature Compensated x Note 1    
Primary Bat.V Sensing x x x  
Secondary Bat.V Sensing x x    
May Overcharge Secondary Battery     x x
May Discharge Primary Battery       x
Stand-alone operation x x   x
Low-cost Alternative     x  
Simplest Design and Installation     x x
xx stands for 12 or 24 Volts
aaa stands for 100 or 200 Amps
Note 1: with optional #2018 Temperature sensor