Thread: C-Tek Bluetooth battery monitor.

Originally Posted by DI5CO

Maybe something like this one!

https://www.ebay.com.au/itm/142181724151

Looks like you can only have one of these set up on your vehicle - cannot monitor multiple batteries.

Doesn't one of these effectively do the same thing?

12V/24V LED Car Volt Meter Voltmeter Cigarette Lighter Charger W/ Dual USB White | eBay

For the issue of monitoring dual batteries, I have one lower console cigarette lighter plug wired to my 2nd battery, so I could check the voltage of either battery by choosing which cigarette plug I plug it in to.

I find most factory sockets suffer quite significant voltage variation on many vehicles - I doubt the D4 is much better.

Must do that one day - probe the battery and the aux sockets

Originally Posted by cjc_td5

Doesn't one of these effectively do the same thing?

12V/24V LED Car Volt Meter Voltmeter Cigarette Lighter Charger W/ Dual USB White | eBay

For the issue of monitoring dual batteries, I have one lower console cigarette lighter plug wired to my 2nd battery, so I could check the voltage of either battery by choosing which cigarette plug I plug it in to.

That would work - but I have three batteries in the car, and would also like to be able to monitor battery in camper trailer as well.

Other than the C-Tek, which only reports % and not voltage, I have found this one for a similar price (Australian company).

Bluetooth Battery Monitor - Solar 'N' Sat

You can monitor up to five batteries at the same time using this system.

Hi BMKal, if you are interested in that device, shop around because you can get it for a lot less than $95.

Note, the "MAXIMUM" range is 6m but that sounds like in GOOD conditions and at just 6m, you can forget monitoring any battery in a camper trailer or caravan.

I found, through R&D of my own wireless breakaway battery monitors, that you need at least a MINIMUM ( not maximum ) range of 15m and I test mine to a MINIMUM range of 20m, to make sure batteries located at the rear of a van or trailer can be properly monitored from the driver's seat in the tow vehicle.

This is what I use on a daily basis ....



The iiD Tool displays voltage on the dash and I have a cig socket voltmeter.
These are generally within 0.1V of each other which is acceptable for a running figure.
I'm only really looking for a trend with running voltage anyway (two photos not taken at same time).
I'm not 100% certain where the iiD voltage is taken from, ie which ECU.

For a better indication of battery SoC you need the vehicle to be asleep and this is disturbed when you open a door.
So I have installed a switchable voltmeter in this rear panel.


It can be read from the outside, which allows for doors to stay shut, vehicle locked, etc.


The switch allows me to select either aux or cranking, although they read the same whenever the Traxide isolator is open (above 12.0V)

The off position prevents any drain from the voltmeter LED display.
I typicaly only use it when away on trips when you're interested in battery state.

Very simple to install as well.


I have a panel voltmeter on the camper trailer so just use that to keep an eye on its two batteries.

Cheers,
Scott

Originally Posted by drivesafe

Hi BMKal, if you are interested in that device, shop around because you can get it for a lot less than $95.

Note, the "MAXIMUM" range is 6m but that sounds like in GOOD conditions and at just 6m, you can forget monitoring any battery in a camper trailer or caravan.

I found, through R&D of my own wireless breakaway battery monitors, that you need at least a MINIMUM ( not maximum ) range of 15m and I test mine to a MINIMUM range of 20m, to make sure batteries located at the rear of a van or trailer can be properly monitored from the driver's seat in the tow vehicle.

Thanks Tim. Yes, I've seen them for about $55 on eBay. For my purposes, it looks like the best product I've seen. Not often that I have a trailer with a battery to be monitored, but I would probably be more likely to look at the trailer's battery condition when I am out of the vehicle anyway. But at least I can keep an eye on the cranking battery and the two batteries I have connected via your DBS from inside the car.

One question though - when connecting one of these monitors (any brand) to monitor the cranking battery, would you connect to the two terminals on the battery - or would you connect the earth wire to an earth point on the body of the vehicle. Given the warnings I've seen on many occasions about connecting anything directly to the negative terminal of the cranking battery, I'm assuming that the negative wire from a battery monitor should go a negative post on the car body.

Originally Posted by BMKal

One question though - when connecting one of these monitors (any brand) to monitor the cranking battery, would you connect to the two terminals on the battery - or would you connect the earth wire to an earth point on the body of the vehicle. Given the warnings I've seen on many occasions about connecting anything directly to the negative terminal of the cranking battery, I'm assuming that the negative wire from a battery monitor should go a negative post on the car body.

With the very small amount of current these devices draw, it will not effect the BMS if you do connect to the cranking battery negative.

But, most of the time, there is usually an earth close by anyway.

Choice is yours!