Charging batteries with a car charger while hooked to solar

[mtnman1000]

I am looking to get a 200-400W solar system with a 30 amp PWM charge controller (bundle) hooked to 2-4 Trojan t-105's and am wondering how I can charge the batteries using a 40 Amp 3 stage charger using my Honda generator without disconnecting the charge controller. The solar bundle manufacturer states I need to unhook the charge controller but I am thinking there must be a way to not have to do that so have come here to ask.

[Sunking]

I am looking to get a 200-400W solar system with a 30 amp PWM charge controller (bundle) hooked to 2-4 Trojan t-105's and am wondering how I can charge the batteries using a 40 Amp 3 stage charger using my Honda generator without disconnecting the charge controller. The solar bundle manufacturer states I need to unhook the charge controller but I am thinking there must be a way to not have to do that so have come here to ask.

First you are making a huge mistake using battery panels and PWM charger, a very expensive mistake.

It takes a 300 watt PWM system to equal a 200 watt MPPT system. With MPPT you can use less expensive Grid Tied Panels. So here is a cost estimate.

200 watt GTI panel = $200
15 amp MPPT Charge Controller = $200
Total $400

300 watt Battery Panels = 500 to $600
15 amp PWM controller = $50
Total $550 to $600

Which would you buy.

As for interfacing the generator, no problem just hook it up.

[inetdog]

The only reasons I can think of to disconnect the CC when using the generator would be:

1. Possibility of uncontrolled voltage spikes from the AC charger damaging the CC.
2. If, when the batteries are charging in bulk mode, the sum of the current from the CC and the current from the charger exceeds the allowed current rating of the batteries.
(C/8 for FLA. C/4 or higher for AGM.)

[mschulz]

The only reasons I can think of to disconnect the CC when using the generator would be:

1. Possibility of uncontrolled voltage spikes from the AC charger damaging the CC.
2. If, when the batteries are charging in bulk mode, the sum of the current from the CC and the current from the charger exceeds the allowed current rating of the batteries.
(C/8 for FLA. C/4 or higher for AGM.)

Couldn't both of these be solved with a disconnect between the charger controller and battery bank? Flip the switch/breaker before switching to Generator.

[inetdog]

Couldn't both of these be solved with a disconnect between the charger controller and battery bank? Flip the switch/breaker before switching to Generator.

Sure. That is one way to "unhook" without having to actually remove wires.
But (and this is important) many CCs require that you connect them to the battery before you connect them to the solar panels in order for the electronics in the CC to start up properly.
So if you do disconnect using any method, you may well have to open the panel circuit first before reconnecting.