Battery Monitors

[HappyMdRSailor]

Originally Posted by Maine Sail

My customers who have live in ignorant bliss get about two years from batteries. Not all are electrically savvy, as some are here. Many of them have even ponied up for AGM's after being told they were the "best" then had a HUGE hole where their wallet used to be and they dies in the same or usually a shorter time frame....

I have not had a single customer install a battery monitor and not be happy. In ever case they have extended battery life often times by double and in some cases 3X. This I can only assume is because of the awareness that simply was not there before, not because Ah counters are pin-point accurate...

Keep in mind that approx 80% of my customers reside on moorings, not at docks. Once the BM's have been installed many opted to go for solar once they realized the alt was never getting them back to 100% SOC....

The absolute accuracy of the BM is not what I find people benefit from, it is the awareness and understanding of how the system is charging and discharging which they can now see....

Still BM's are not perfect and NEED proper calibration and a manual synch as often as possible, when known full, to remain as accurate as possible...

+1
That's the secret right there...

Tip # 2 Place a warning placard adjacent to the BM that any unauthorized sync will result in fairly uncomfortable consequences...

[Ex-Calif]

Originally Posted by skipmac

Hi Ex-C

If you are referring to Sailorboy1's Victron BMV600 (or 602 that will also monitor voltage only on a second bank) it will read amps in or out of the battery so + or - amps.

It will also show total amp hours used and/or total amp hours back to the battery BUT NOTE, the amps going back to the battery are not necessarily the same as how much charge is back into the battery. This can be approximated by proper programming of the battery parameters in the meter and regular synching of the SOC.

I will look at the SOC but consider that just a ball park estimate and use the monitor mainly to watch voltage, instantaneous amps in/out and amp hours used.

Sorry for thread hijack - Yes I have a BMV702 coming but I didn't want it for the SOC part. I ended up getting it because it is the only reasonably priced device I could find that measures positive and negative amps.

What I really wanted was a simple ammeter that measures +/-50amps and records the totals.

Couldn't find anything for a price that didn't rival the BMV.

Thanks everyone.

[AnchorageGuy]

We too have used the Victron on both of our boats for many years. We do extensive cruising, this current cruise is on it's second year, And we typically get 7 years out of our house bank. This means replacing batteries before they are totally useless and leave us in a pinch. So they probably would last longer. The monitor is in constant use to determine the amount of discharge and how much charging we need to do, rather than guess work. With the alarm function, it never gets so low that we might damage them from discharge while sitting at anchor. This is one piece of equipment that has paid for itself many times. Chuck

[sparrowhawk1]

Houston we have a problem. Yep looks like this meter only measures amps one way : ( so looks like I'm going to have to get a switch for it and turn it to amps going in in the morning amps going out at night. Or maybe buy another meter for 30 bucks, hook it up to the same shunt, wires reversed. Edit I probably have to get the exact same meter to use the same shunt. There's one from the same company that the face looks exactly the same, it's wired exactly the same but its 250amps instead of 500. And it cost 30 bucks instead of 50. Does anyone know if I can use the same shunt? Edit2: just remembered it can be calibrated

[sparrowhawk1]

On searching eBay for another meter I found one by the same company( looks exactly like the 1 I have) that measures forward and reverse amperage but it's only rated for 20 amps. . Circuit board is separate from the face so maybe I'll be able to find one that does 500 amps and just by the circuit board

[sailorboy1]

Originally Posted by sparrowhawk1

Circuit board is separate from the face so maybe I'll be able to find one that does 500 amps and just by the circuit board

500 amps, on a boat?

[sparrowhawk1]

Originally Posted by sailorboy1

500 amps, on a boat?

Well reading the inverter threads I need to wire my 1500 watt 3000 peak inverter for at least 300 amps. Some say more, the debate goes on. Besides the 500 amp was only five bucks more than the 250 amp when I bought it but now I wish I bought 2 250 amps

[zboss]

My battery monitor is very mean... but kinda sexy... she sits by my batteries in a tight leather outfit and glasses holding a whip and everytime I walk by she says "bad boy!" and give me a sly smile and a crack of the whip against my bare behind. Over all, she isn't that bad of deal and she is sometimes pleasant to work with.

[roetter]

Originally Posted by sailorboy1

500 amps, on a boat?

Absolutey - but only if you have 100+A coming in from your solar at noon.

Two times Victron 3000 in parallel to power a toaster, coffee maker, washing machine, induction cook top, and the hot water heater. It takes me over six months to have to refill my propane, and Diesel last about 6 months too. We see a marina once a year to do some work on the boat.

[sailorboy1]

So I have admit that my BM allowed me to discover a problem with my alternator/regulator not fully charging my batteries before going into float the other day.

So I guess they have a use after all besides making you a slave of looking at them.

[capt-couillon]

This time around. (All new wiring) I did decide to improve my battery monitoring. A digital guage is so much easier to get an accurate reading than analog. Installed the 35 dollar kit volt/ampmeter Voltmeter Ammeter Kit - Blue Backlight LCD - Electronics-DIY.com cause I'm cheap, and not scared of a soldering iron. Stock is up to 10 amps (I have one of those "minimal" cruisers) but you can install a lower value shunt resistor to up the max (requires recalibrating)

That guage coupled with the fact my solar controller keeps track of total amp/hr in and total amp/hr out is more than adequate for me. A 'dumb" system, but along with a hydrometer to keep us all honest, more than enough info.

Now if the price of LiPo cells would just come down a bit, I mignt really be high tech. My favorite aspect of the LiPos is the fact they don't care if you bring them to 100% when charging. Std LAs get unhappy with constant under charging which can be an issue with only solar, and a 5 amp light coil on the kicker.

Just sayin' ....