New product that enables charging chassis batteries when on shore/gen power

April 24, 2011, 09:40:04 pm

At the recent Buddy Rally, James Triana discussed a gizmo that is being put on the IH-45 (as standard as I remember) and was available through FOT parts. It is a voltage sensitive relay made by a New Zealand marine electronics company.

It is used to charge the chassis batteries when on shore or generator power. It can be thought of as an automatic booster switch in that it is installed in parallel with the booster switch (or the battery isolator) and passes current through to charge the chassis batteries if it sees that the house batteries are being charged. It's all integrated - not mechanical and rather straight forward to install.

Note that the description on the web page says the relay is to charge the house battery when the "start/engine" battery (chassis) is being charged. This is because the device was designed for marine use in that the start battery has priority. So if you install one in your coach you need to REVERSE which battery is attached to the red post - install the coach/house battery to the red post.

See: 125 Amp Voltage Sensitive Relay (VSR)

I know this sounds somewhat similar to the Trik-L-Start of which I have no direct experience - but James commented that the relay is superior in that it works to make a direct connection (it is rated at 125 amps) and is solid state.

So --- no negative from me about the Trik-L-Start - just letting you know about a new product

Re: New product that enables charging chassis batteries when on shore/gen power

Reply #1 – April 24, 2011, 10:06:55 pm

The key here with this product is it avoids the issue of the voltage drop across the diodes of an isolator.
The 125 Amp capacity is great from a charging system. I see its best use in the alternator path. With the Phenix - most of which are all electric coaches - there can be serious power draw from the reefer and front AC (they started offering the front AC via inverter a few years back).

All your need from the house bank to the start bank is a trickle maintainer circuit if you think about it - Its charged until you park, then has a minor draw from the ECU/TCUs (etc). This is where the trick -L- start works so well.

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