low battery voltage device

plenty of low voltage cut out devices available.... redarc is one with a good web site but there are plenty of others.....there are plenty of battery management systems...some over the top ..some basic but functional.......

battery type eg AGM cranking etc not really relevant as far as LV cut out device other than the fact that cranking batteries dont like being discharged....AGM are more tolerant

I don't let my agm's fall below 12V !!!!!

A voltmeter is probably the cheapest way ( and learn how to interpret it under load )

My inverter has a low voltage cut out. Whenever the battery gets too flat the inverter cuts power and beeps.

Other than that get a voltmeter, $20 from auto shop.

Barnesy

Most low voltage cutouts can only handle a max of 10amps. I suspect your motor will use more than that.

thanks for help.i have multimeters etc and do use them but was looking for foolproof device for when sons in law etc use my boat peter

Hi Peter

I agree with others that a voltmeter is essential.

If you need a high current option the use the automatic cut out with a solenoid.

These cut off at 11.2V and reconnect at 12.5V.




Regards

Derek.

We use one a low voltage cutout to control a 70 amp relay. Sort of similar to the bits Derek showed above.

I haven't checked how much power is drawn by the relays.

We have used this setup for a couple of years now to power the fridge, lights, laptop and phone chargers etc.

Actually the price of the Oatley Electronics low-voltage cutout kit has risen to $22.

It can handle eighty amp loads and draws only one twenty-thousandths of an amp when the load is on or off.

Oatley Low-voltage Cutout Kit
.

Peter, I have a low voltage cut out on the main fridge (built in). The fridge controller also has a digital voltmeter built in. I use the volt meter all the time. Have only run the batteries down to cut out once and avoid it like the plague since.
Nothing beats monitoring battery state yourself.

As for the trolling motor, I just use a rule of thumb. I use a 90 AH AGM on a 55 lb thrust Minn Kota (with the battery maximizer technology built in). Based on experience, I get about 2.5 to 3 hours of run time, for about 40 AH of power. I simply base this on the time it takes my 25 Amp charger to recharge the battery after a fishing trip (never much more than 90 mins - generally a lot less). Even being on the water for 6 or 7 hours, we don't use the electric for more than 2.5 to 3 hours. I charge after every use.

At full speed these motors draw close to 50 Amps. So if you wanted a battery monitor it would need to be one of the high current ones.

Norm C