Battery Monitor

[twinboat]

Originally Posted by Duner

It does come with a 100 amp shunt, which may work for you. If you have 500 or 1000 watt inverter.

They do offer a 300 and 500 amp shunt. I have a 500 amp shunt since I have a 2000 watt inverter and 500 amp-hour bank of batteries.

Without a shunt, it is just a voltmeter and it won't measure the % state of charge. That's important because you don't want to go below 50% state of charge, as it is much harder on the battery life. With deep discharge/charge cycle, you may only get 100-200 cycles. If you only discharge to 50% or less, you may get 1000-2000 cycles.

These are the issues you need to consider when sizing the battery bank, the inverter size, and the amount of stuff you want to keep powered up and how long.

Good luck,
Bill

I think you are confusing my 2 posts.

The EBay unit comes with a shunt and it seems that they offer larger capacity ones.

The Belmar unit does not, but will give you % state of charge, as others have said.

[Duner]

Originally Posted by twinboat

I think you are confusing my 2 posts.

The EBay unit comes with a shunt and it seems that they offer larger capacity ones.

The Belmar unit does not, but will give you % state of charge, as others have said.

Ya, your exactly right, I did confuse the two units. The Belmar unit is a totally new concept (to me), and as the Compass Marine review stated, it at first seems like snake oil. Exactly how it works accurately, is beyond me, and is proprietary.

From the Compass Marine review, I did learn a shortcoming of my Victron ah meter. As the batteries age they lose capacity and so the Victron needs to be set to a lower ah setting than the new ah rating of the batteries new. He suggestion maybe 2-3% reduction per year. He also said that most all the batteries he's tested, no new battery actually tested out to the rated capacity in the specs. So my 2 yr old AGM's rated at 500 ah may be closer to 450 ah. I won't really know til I run the 20 ah discharge test.

[PbdBlue]

Originally Posted by pasdad1

This is a very interesting monitor that doesn't require a shunt....it "learns" your battery bank by monitoring trends. The very detailed review is an interesting read.

Attachment 137643

It is an interesting read but the one flaw in his testing is that he discharged the battery at a constant rate. It is significantly easier to forecast the battery condition that way. Keeping track under varying loads is a much more difficult thing to do by measuring voltage alone. I'm not convinced that under typical RV usage it will be as accurate as a conventional system. A side by side comparison along with specific gravity readings from the battery would have been much more meaningful.

[utahrd]

I installed a Vitron BMV-700 in my Creekside and am very happy with it. Pretty easy install. Just remember to connect all the non-battery 12V grounds on the correct side of the shunt.

[bukzin]

Originally Posted by voyaginator

I just install this http://goo.gl/3HKzhe to monitor each memory bank.
Really easy to setup, works surprisingly well, and quite inexpensive.
Good reviews as well.

Wow, thats a lot of good reviews!

Looks like good option for the price