Battery Charge Gauge Recommendations

[scottyb]

An RC guy knows what the healthy limits are for his Lipos. They follow max charge & discharge rates and limit rules... the same basic knowledge is required for the wet cells if you want to get the most out of them, a little research reveals a few basic guidelines when using wet cell packs. Here is the chart I send with every meter to help users get a basic understanding of proper useage.

[Rickochet]

Originally Posted by scottyb

An RC guy knows what the healthy limits are for his Lipos. They follow max charge & discharge rates and limit rules... the same basic knowledge is required for the wet cells if you want to get the most out of them, a little research reveals a few basic guidelines when using wet cell packs. Here is the chart I send with every meter to help users get a basic understanding of proper useage.

Good info, thanks. I was also looking at the mounting/trim plates that you offer with the DVM's. Very nice.

[scottyb]

Originally Posted by Rickochet

Good info, thanks. I was also looking at the mounting/trim plates that you offer with the DVM's. Very nice.

The simple little stainless steel trims offer some leeway in cutting the hole for the meter. The meter itself has only 1/16 lip on it. So it covers the hole and dresses it up a little.

[JohnnieB]

I kicked around the idea of monitoring individual battery voltages the first time I read that thread, but came to my senses.
A dash mounted DVM give you a good overview of what is happening with the pack and then a handheld to get down to the hitty-gritty if something doesn't look right is good enough for me.
On the other hand, SWMBO (She Who Must Be Obeyed) is the antithesis of a technical person, so I'm installing an analog gauge for her.
Of course, I'm calibrating it to read SoC with 38.2V at the top of the green and 37.1 (70%) at the top of the red.

FWIW: Here's my take on the bargraph type Soc meters.

Some of them have a fixed calibration and some reset (recalibrate) when they lose power, while others reset when they sense the battery being charged.

The first type are similar to analog meters. They may be accurate or may be way off, but high, low or right on, they always read the same.

The last two can be accidentally, mistakenly, inadvertently and/or unknowingly be reset to something other than a fully charged battery pack, so I don't trust them at all.

The worst case I've read about here was a EZGO/Curtis three wire meter with the B+ and the switched B+ leads reversed. The display was supposed to be switched off when the key was turned off, but the meter was being switched off also and when the key was turned on, whatever the battery pack voltage happened to be, became 100%. The poor guy was wondering why his cart was sluggish when the meter said the batteries were fully charged. (They were actually at about 50%)

@ AzPete: Have you tried resetting your bargraph meter? or is it truely FUBAB. (A phrase I learned in the AF )

I bought one that I never installed, so I think I'll play with it some and see if I can figure out what makes it tick. Or use it for target practice with my 625JM.

[gpeak]

The only advantage of the individual monitoring, as I see it, is you can identify if a battery is not holding a charge...therefore identifying a bad battery.

[AzPete]

Originally Posted by JohnnieB

@ AzPete: Have you tried resetting your bargraph meter? or is it truely FUBAB. (A phrase I learned in the AF )

:

FUBAR(F'd Up Beyond All Repair/Recognition for those wondering)... If I run the batteries bellow the recommended dead voltage to about 36v, it will drop down one bar.....then it goes suddenly to the bottom at 35.5 volts or so. The two times it moved before I got the digital I was lucky to get the cart the last 100 feet to the charger when it dropped the first bar. I left it in just because......lol

[JohnnieB]

Originally Posted by AzPete

FUBAR(F'd Up Beyond All Repair/Recognition for those wondering)... If I run the batteries bellow the recommended dead voltage to about 36v, it will drop down one bar.....then it goes suddenly to the bottom at 35.5 volts or so. The two times it moved before I got the digital I was lucky to get the cart the last 100 feet to the charger when it dropped the first bar. I left it in just because......lol

FUBAB (Fouled Up Beyond All Believe - for the PC types.)
Whichever ETLA (Extended Three Letter Acronym) you use, if you looked it up in your Funk & Wagnalls, you'd find a picture of your meter next to it.

You could go with an Alpha-Omega theme and plug the hole with a horizontal analog meter. Even if it wasn't accurate, the needle would at least move.