Quietly maintaining charge (parallell chargers)

[chicagoandy]

I am looking for a quiet solution to maintain my 12V 200ah Office Backup, which is setup as a DIY UPS.

I have a
- 200ah 12V battery
- 2200 watt Inverter
- Victron Smart Shunt
- Automatic Transfer switch.

These keep Router/Internet/laptops/microservers up and running for 24hrs. Great!

The SmartShunt and Inverter are always-on, but the other loads only connect when the power fails.

My question is about maintaining the charge on the battery as the Inverter & Shunt are drawing a few watts.

Currently I am using a 40Amp 12V charger. However, when the fan kicks it is is very noisy.

I need the large charger to recharge after an outage. However, the always-on inverter and also the Victron shunt do slowly drain the voltage. As a result the large noisy fan on the charger kicks on every few hours for 20 seconds, which is annoying.

I am thinking of adding a second, much smaller charger, to keep the battery healthy.

Primary Charger: Li Time 12V 40 amp Charger. Noisy fan.

Secondary Charger: Two options.

1. Victron 12V 7amp charger. Large heatsink, no fan.
2. Battery Tender 12V 3 amp Lifepo4 Battery Charger / Maintainer.

My hope is the Battery maintainer will cover the losses from the inverter/shunt, so that the noisy fan on the primary charger doesn't kickin unless there's a substantial load.

Has anyone done something similar? Any better solutions for quietly maintaining a DIY UPS battery?

 

[OffGridInTheCity]

You can do multiple, small amp chargers (8 x 5a or maybe 6 x 7a) hooked to the battery in parallel and get the noise to 0 but still have 40a overall.