Battery Float Charger(s)

Thank you, I would separate the 2 batteries and use to battery tenders.

"Get it there" battery charger

"Keep it there" battery maintainer.

You are correct about the disconnect. Unless your MAINTAINER is high amperage an inadvertent load that sucks more power then the maintainer can provide will turn the battery into scrap metal.

Lots of ways to parallel batteries but two maintainers keep stuff separated and plug if one maintainer goes **** up you have a second. If batteries are different construction the charging voltage can be unique by setting a switch.

Trickle charge setting is a work of art. Basically be using DELTA T resistance to maintain float voltage. Gotta drawer full of 750 - 800 ma transformers to play with?

This is what I use.


Battery Tender Plus 021-0128, 1.25 Amp Battery Charger is a Smart Charger, it will Fully Charge and Maintain a Battery at Proper Storage Voltage without the Damaging Effects Caused by Trickle Chargers


Temperature compensated to ensure optimum charge voltage according to ambient temperature
Automatically switches from full charge to float charging mode
Charges as fast or faster than 3a charger
Reverse-polarity protection to ensure user safety
Red & Green indicator lights
Battery Tender Plus 12V - 1.25 Amp, Automatically switches from full charge to float charging mode
The Battery Tender Plus is a 1.25-amp battery charger designed to fully charge a battery and maintain it at proper storage voltage without the damaging effects caused by trickle chargers

You are using "float" and "trickle" when you mean "automatic" and "manual" except, just to confuse things, some "automatics" shut off when they think the battery is charged up (usually too early, not charged up yet) and "maintenance" chargers (or "tenders") which stay on at a "Float" voltage.

I hope that makes things clear :)

Meanwhile, just let your rig's converter do its job on your battery bank however it is wired, doing all the batteries at once, and leave the disconnect switch alone. Never touch that stupid thing ever again! Your converter cannot look after your batteries with them disconnected.

Both float and trickle chargers are devices that slowly emit low-voltage charges to your car battery, restoring the battery to a fully charged status over several hours. Subtle differences between the two devices determine which charger is best for you.

Float Chargers

Float chargers are equipped with electronics that allow the device to cycle on and off. This is beneficial if you are going to have the charger connected to the battery for a long period. The device automatically turns off when the battery is fully charged and turns on again when the battery's charge lowers.

Trickle Chargers

Trickle chargers work similarly to float chargers. You connect the trickle charger to the battery terminal and a slow, steady stream of low-voltage electricity recharges the battery. Trickle chargers, however, do not come with the on/off feature of the float charger. Electricity continues to flow to your battery until you remove the trickle charger.

camilllit wrote:
When the battery disconnect switch is turned OFF, does that TOTALLY disconnect batteries from EVERYTHING?

We don't know. You'll have to check that out yourself.

What do you mean, 'float charger'? Batteries in parallel will accept the charge they need.

Just plug in the main cord and leave the batteries on.