solar panel

[avanti]

Originally Posted by papab

If I don't have the A/B switch, then I have a feedback loop, from charger output to inverter input. Seems like a bad idea.

Oh, I see. So, you are planning on inverting the DC from your vehicle alternator and using the resulting AC to run a charger as an alternative to a DC-DC charger? Hmm. A few people do that, but most folks seem to consider it inefficient and unnecessary. The counter-argument is that the inefficiency doesn't matter, since there is plenty of power from the vehicle. By my taste, it seems unnecessary, at least if you plan to plug-in occasionally and get a proper charge.

But, even if you want to do this, there is no point in adding an expensive, high-current A/B switch at the battery. Just turn off either the inverter or the charger and you are fine. If you really want a switch, put it between the inverter and the charger, where a simple light switch would suffice.

A combination inverter charger couldn't be used to charge up the battery from the van battery. Everyone I've seen either inverts, or charges from 115V input.

If you are planning on charging through the inverter with power from the van, what it the purpose of the VSR and its associated circuit? Are you trying to support the ability to charge either directly OR through he inverter->charger? Seems like you should just make up your mind. OR, is that just for keeping the van battery charged? If so, you should consider a Trik-L-Start.

Not available for the diesel.

I don't understand. What does diesel have to do with it? Electrical system is the same.

[booster]

If you do the inverter setup, is the intent to be able to use the inverter to also power the coach 110v when on batteries?

[papab]

Originally Posted by booster

Your original idea of the bat to bat charger may be worth revisiting, now that I look at it again.

I say that mainly because of the rather "fluid" recommendations that have come out from lifeline over the last couple of years on charging their batteries. Over a few phone call and email sessions with them I have been told no more that .4C max rate to 1C and the there is always the 5C they list in the spec sheets. Lifeline, and quite a few of the other manufacturers are also starting to like higher charge voltages, especially in short shots to prevent heating and overgassing, to work like mini equallizations. It might pay to give Lifeline a call and talk to them about it. My guess is that they would not have any problem at all with charge profiles that Sterling uses. Personally, I think the idea of doing a higher voltage at the beginning of the absorption cycle is a good idea, as it gets your capacity back faster at a time when all the power is going to recharging, not gassing. Lifeline also shows low float voltages recommended, I think 13.3v, but all float situations are not created equally. Having 13.5 or 13.6 on the batteries for a 5 hour drive every couple of days (and float will only be a little of the time) is a whole lot different that a 3 month storage at that voltage. I think Lifeline would have absolutely no issue with it.

The B to B charger is such a good solution for what you are trying to do, and would be very simple and reliable, another shot at it may be a good idea. The 120 amp one would be just right for you.

Thanks for the info, but the other stuff is ordered, I'm not revisiting it.

[papab]

Originally Posted by avanti

Oh, I see. So, you are planning on inverting the DC from your vehicle alternator and using the resulting AC to run a charger as an alternative to a DC-DC charger? Hmm. A few people do that, but most folks seem to consider it inefficient and unnecessary. The counter-argument is that the inefficiency doesn't matter, since there is plenty of power from the vehicle. By my taste, it seems unnecessary, at least if you plan to plug-in occasionally and get a proper charge.

Inefficient, but necessary. Quicker charge and better charge. I won't be plugging in often enuf.

But, even if you want to do this, there is no point in adding an expensive, high-current A/B switch at the battery. Just turn off either the inverter or the charger and you are fine. If you really want a switch, put it between the inverter and the charger, where a simple light switch would suffice.

With no switch & you wanted to charge from the engine, the output of the charger would be on the vehicle bus, the voltage would be higher than the van system wanted so it would turn down it's output & there wouldn't be any output from the alternator, which is what you're using to charge with.

[quote:i74jxqq7]
A combination inverter charger couldn't be used to charge up the battery from the van battery. Everyone I've seen either inverts, or charges from 115V input.

If you are planning on charging through the inverter with power from the van, what it the purpose of the VSR and its associated circuit? Are you trying to support the ability to charge either directly OR through he inverter->charger? Seems like you should just make up your mind. OR, is that just for keeping the van battery charged? If so, you should consider a Trik-L-Start.

[/quote:i74jxqq7]
The VSR is to prevent draining the start batt. Yes, either. Mostly charging from the van, occasionally when plugged in.

Originally Posted by avanti

Have you looked at the CTEK dual (alternator/solar) DC charger? It seems to be getting some attention.

Not available for the diesel.

Originally Posted by avanti

I don't understand. What does diesel have to do with it? Electrical system is the same.

Sorry I misread, I thought your were talking about the dual alternator setup. The CTEK looks nice for a 20 amps. I want quicker, better. Lifeline says at least 30 amps (.2C), more is better.

[papab]

Yes, but we won't use it much, just use plugs on the inverter.

[briancummings]

You will NEVER fully charge the batteries with only 13.6-13.8 volt input, you need at LEAST 14.4, preferably 14.6