Battery monitor recommendations

JimboFunFinder · 02-14-2024, 01:01 PM

What are you guys and gals using to monitor the charging and condition of your batteries? I just invested ~$300 in purchasing two 100 Amp SLA gel 12V batteries and want to do some boondocking. What is good in the $50 to $100 dollar range which will tell me the remaining battery capacity? Bluetooth is not essential.
Thanks!

profdant139 · 02-14-2024, 04:47 PM

I use an old fashioned hand held multi-meter. I check the voltage. 12.7 is full. 12.1 is as low as I go.

There are conversion tables available on the web that indicate state of charge at each voltmeter reading. I have a 110 amp hour battery and never let it get below a 50 percent state of charge.

JimboFunFinder · 02-14-2024, 07:01 PM

ProfDant,
Yeah, that has been my modus operandi for 40+ years as an eng and it has served me well but I notice some of the new gadgets calculate the charging current as well as the discharge by inserting a shunt in series with the batteries. I have seen shunts range from a low of 100A, to 300A, to 1000A and even higher. It seemed that the information might have some value.

Remember me from several years ago? I have been out of commission due to hip replacement surgeries, the COVID lockdown and in 2021 I acquired Myasthenia Gravis. We are just now planning our first short term trip to Hendersen/LV to find how I do with camping after being out of it for 4 1/2 years. Besides I miss the Red Rock park. If I do well we hope to take a road trip back east in the spring.

profdant139 · 02-16-2024, 05:45 PM

I certainly do remember you, Jimbo, and I am sure that lots. of other Club Members do too! Welcome back, and keep on camping!

I also lost a year to medical issues -- I had to have back surgery and was left with "foot drop," partial paralysis of one foot. After a year of physical therapy and custom orthotics, we are back on the road again.

JimboFunFinder · 02-16-2024, 07:10 PM

Congratulations on successfully recovering from a major surgery and the following physical therapy!
Keep on camping! One day I hope our paths cross.

APD · 02-20-2024, 09:05 AM

Jim, Dan Howdy. I haven't been on here in a while myself. Still enjoying our 139 on several trips a year.
Renogy makes a monitor for under $90 on Amazon. Look up a Renogy Model 500A.

dustyone · 02-23-2024, 06:56 PM

I bought a simple LED voltage meter that you could insert into something. They're small and I'm out of it right by my controller where I could see it easy. You can keep an eye on your voltage which will tell you the status of your battery. There are quite a few different voltage charts out there that will help you out.

gator · 02-26-2024, 05:23 AM

I use a Trimetric from Bogart Engineering.

Make sure you have proper charger for the new batteries. If they are lead acid based them ensure you can "condition" them. My trailer is hasn't been plugged in since 2016. The batteries are recharged from solar, whether I'm camping or the trailer is sitting in storage.

If you buy the bogart they also sell a charge controller that marries with the monitor. If you have deep pockets the majority of the campers are migrating to Victron's "prison". Once inside their prison you will be compelled to purchase a ton of products which of course all integrate very well. It is a slick system, but not if your doing it on a shoe string budget. I put my system together back in 2016 for $2500 which included 4 Lifeline batteries and 2 additional 100 watt solar panels, all new wiring the Trimetric monitor and the charge controller.

Good luck.

herdbull · 03-25-2024, 04:04 PM

I purchased one of these. It isn't too bad on the pocket book and is "ok" for what it does. I've had Victrons in the past but didn't want to spend $150 on this go round. If money wasn't a big factor I'd with a Victron BMV-700 or BMV-702.

https://www.amazon.com/LNEX-Portable.../dp/B08V1VZNGH

herdbull · 03-26-2024, 08:28 AM

I posted this yesterday but I'm new here so maybe it needed to be reviewed? Anyhow, I went with a LNEX monitor from Amazon. It's about $70 and does just enough to monitor both AH's and voltage. Comes with a shunt and has a straightforward installation.

In my previous campers I have installed a Victron BMV-700/702. While I prefer the Victron because of it's capabilities the LNEX works just fine. As with any system just keep an eye on the water level's in the batteries.

Eagle · 03-31-2024, 02:26 PM

I installed a 12 volt voltage monitor that reads the battery voltage all the time.
Works for me.

herdbull · 04-01-2024, 10:25 AM

I would definitely invest in a monitor that tracks AH and voltage. While a voltage only display is good something like the one I referenced that tracks AH really helps with charging times/requirements and gives you a feel for if your batteries are truly doing the job you are asking for them.