Dual battery monitors - where are they?

[swashbuckler]

I'm looking for a small form factor dual battery display. Like this (which appears to be off the market), or this (which is volts and amps - I'm looking for volts and volts), or this (which is AMAZINGLY expensive for what it does).



I've seen the styles that National Luna and Sierra Expeditions sell, among others - too big for my application, too expensive for my budget. I can always install two of the EBay monitors, though I'd rather not, or I could put a single monitor on a switch too, but that's still not exactly what I want. Are there any other solutions out there that put two outputs on a single small screen and don't cost an arm and a leg?

 

[DaveNay]

http://www.riorand.com/riorand-smal...-3-5-30v-0-200-two-channel-12-volt-gauge.html

That one isn't great IMHO because it alternates between the two voltages so you have to look at it for a length of time. Depending on your needs, it may work.

 

[MarcoPolo]

Here is the one I have an eye on. Its not dual monitor, but lots of info for monitored battery.
http://www.ebay.com/itm/Programmab-...827?pt=LH_DefaultDomain_0&hash=item2a30eac1c3

 

[Joe917]

You are wasting your money buying a voltmeter to monitor your battery bank, it might look good but it is next to useless. You need an amp hour meter hooked up to a shunt, it is the only reliable way to know what is going on. Unfortunately they cost more. The good news is you only need to monitor your house battery if all your camping loads are hooked up to it.

 

[swashbuckler]

http://www.riorand.com/riorand-smal...-3-5-30v-0-200-two-channel-12-volt-gauge.html

That one isn't great IMHO because it alternates between the two voltages so you have to look at it for a length of time. Depending on your needs, it may work.

That's not horrible, thanks for the link.

You are wasting your money buying a voltmeter to monitor your battery bank, it might look good but it is next to useless. You need an amp hour meter hooked up to a shunt, it is the only reliable way to know what is going on. Unfortunately they cost more. The good news is you only need to monitor your house battery if all your camping loads are hooked up to it.

No camping loads right now - my aux battery is purely a backup in case I drain the primary. The monitor is just there to tell me when I need to cut in the aux to keep it charged.

 

[fredgoodsell]

I found the one you saw on Amazon on Ebay:
http://www.ebay.com/itm/TOPO-Dual-b...864?pt=LH_DefaultDomain_0&hash=item2a38241f68

 

[swashbuckler]

I found the one you saw on Amazon on Ebay:
http://www.ebay.com/itm/TOPO-Dual-b...864?pt=LH_DefaultDomain_0&hash=item2a38241f68

Hey, thanks! That just might be the ticket.

 

[wrcsixeight]

As said, battery voltage cannot be used as a fuel gauge. Only on a rested battery, one that has not seen charging nor discharging current for some time will voltage be accurate st to state of charge, and voltage vs state of charge varies battery to battery and with battery age and condition.

Amp hour counters are a true monitor, but far too many people think the % remaining is accurate, not knowing that the battery has lost some percentage of capacity. The 'amp hour from full' screen is a much better screen to look at, but it also assumes that the battery started at a true 100% charge, and very few discharge cycles are started on a battery that is truly fully charged. The blinking green light lies.

So a voltmeter, is not a Monitor, but one can monitor a voltmeter and be better off than the person without a voltmeter, as long as they know voltage is not accurate as to state of charge, unless on a rested battery.