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Battery management is key to good SLA battery health and a true benefit of using batteries for power audio toys. The bare-boned look of the Dodd Audio battery and Soneil charger kit could be discouraging at sight. However, the 10-page pdf file of 2403SR specifications published on Soneil's website comes as a relief. Here are the highlights:

  • Automatic switch-mode high-efficiency charger that transforms 115/230VAC into 24VDC at about 100,000Hz (1,667 times faster than conventional chargers).
  • Built-in circuit protection guards against short circuit, reversed polarity, over-voltage, over-current and AC surges.
  • Soft start and soft stop protects the battery as well as other circuit connected to the charger.

Despite its compact size, the Soneil charger has the intelligent circuit and microprocessors necessary to handle multi-stage charging cycles. This is how: 

Stage 1: Deep discharge charging pulse mode - the charger starts charging at 0.5V and gives pulse current up to 5V. This has the effect of removing loose sulphation formed during the deep discharge state of the battery. 
Stage 2: Constant current mode (CC) - the charger changes to constant 1.5A current. When the battery voltage reaches up to 28.8V, the charging stage changes from (CC) constant current to CV (constant voltage) mode. 
Stage 3: Constant voltage mode (CV) - the charger holds the battery at 28.8V and the current slowly reduces. When the current reaches 0.5 C (c = battery capacity) that's called the switching point. It's one of the great features of this battery charger. It can adjust the current automatically according to battery capacity. Other chargers without microprocessors are not able to automatically adjust the charge current . 
Stage 4: Standby voltage mode - the charger maintains battery voltage at 27.6V and current slowly reduces to zero (automatic cut-off). Charger can be left connected indefinitely without harming the battery. 
Recharging:  The charger has automatic cut-off and true float features. If the battery voltage drops to 27.6V, the charger changes from any mode to constant current mode and restarts charging. The charging cycle will go from Stage 2 to Stage 4. Two color LEDs indicate charge status - orange for charging, green for charged.


How often is recharge needed? Dodd Audio states that "the Virtue amp can run an average of 4 to 5 hours at high levels without needing a charge." In actual use, I found that with the new battery  fully charged to 28.80+ VDC after playing three 60- to 70-minute CDs at full orchestral levels, the battery still measured 26.80V. After 5 hours it dropped to 26.62V. After 6 hours it sat at 26.35V, still a long way from the minimum 24V required to run the Tripath amp. But I usually recharged it at that point.

How fast does it charge? As soon as I put the battery charger on, the battery went back up to 27.70v in a matter of 10 seconds. In 30 minutes it was as high as 29.25v. This was incredible. I unplugged the charger and let it drain naturally for a few days. I kept monitoring. Unplugged for 4 days = 26.33v, unplugged for 5 days = 26.28v. Then I recharged. This time things got even more incredible. In a matter of 10 seconds the voltage jumped right up to 29.20v. That’s hard to believe. I took the reading a few more times. It was 29.20+V. I checked the specs again: "Automatic switch-mode high-efficient charger transforms 115/230 VAC into 24VDC at about 100,000Hz cycles (1,667 times faster than a conventional charger)." Even so I didn’t know it could be that fast. However, my latest finding is that after 4 to 5 months, the battery 'stabilizes' and will only charge up to around 27.80V.
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