In my old bus I used a cheap solenoid wired through the ignition switch. When the ignition was on/ motor running the crank and the house batteries were connected and charged from the alternator. As soon as the ignition was turned off the batteries were isolated and only the house batteries were drained.
The amount of extra power you get from the fancy setup is minimal and the money better spent on extra battery or better batteries.
One of the beauties of lithium batteries is that they charge faster as there is no absorb and float and you can drain them a lot more with no harm 20% is recommended but lower if needed and you still have full voltage and they never need to be brought back to 100% SOC (full charge) and they are expected to last at 8 - 13 years but as far as we know none have every died yet through use so life expectancy is not fully known.
1/3 the weight and size and you can drain and charge as fast as you like. I pull 60A @ 24v off mine regularly using an aircon and water heater as well as the normal household vacuum cleaner and I run a 240v fridge 212 ltr capacity.
Hope the 120w solar is not too heavy or is it 2 x 60w giving 120w?
For the solar try and get a decent plug installed to connect direct to your batteries so you can just plug in with a decent connection. Dont use a cigerette plug as there is too much resistance. Ither the special plug with return fingers all around or better still a dedicated anson plug. Aslo the wires between the panels and the plug should be a large as possible, most of the ones sold are realy too small but see how it goes and then get thicker cables if you think you are not getting the charge you expect.
Remember with AGM's etc when you go to absorb mode you are only about 80% charged and the last 15-20% takes a long time.
Hope you enjoy your solar and it makes your travels better.
Seems like you have the right mind for travel. Find the spot and stay till YOU want to move and then just to the next great spot.
Regards Brian
jimricho said
01:12 AM May 28, 2012
beiffe wrote:
Remember with AGM's etc when you go to absorb mode you are only about 80% charged and the last 15-20% takes a long time.
From time to time I "top up" my aux battery in the tug (Optima Yellow Top) from a Ctek (mains) charger for this very reason. It's "semi permanently" set up in the vehicle and also serves as power supply for my Bushman fridge when on a powered site.
Jim
dawa said
02:44 PM May 28, 2012
Thank you for your kind words.
yes those panels are heavy little brutes.
they have alligator clips onto the battery at present.
Maybe i need to get that changed?
Dawa
03_troopy said
01:58 AM May 29, 2012
beiffe wrote:
In my old bus I used a cheap solenoid wired through the ignition switch. When the ignition was on/ motor running the crank and the house batteries were connected and charged from the alternator. As soon as the ignition was turned off the batteries were isolated and only the house batteries were drained.
The amount of extra power you get from the fancy setup is minimal and the money better spent on extra battery or better batteries.
The advantage of the not very expensive "fancy setup" though, is that when you go to start the tug, you don't automatically parralell the two batteries and drain the charge from the starting battery to the house battery, just when you need all the power you can get from the starting battery. I guess no system is going to suit everyone, but for the sake of less than $200 for the smart isolator that draws in the vicinity of 15mA to 20mA, It's cheap insurance.
beiffe said
12:22 AM May 30, 2012
The batteries are not connected when you are starting the engine. It is not till you return the key to the RUN position that the solenoid activated.
Regards Brian
03_troopy said
02:23 AM May 30, 2012
That's interesting Brian, when people fit a basic solenoid they usually just wire it so it is energised by the "ignition on" wire, which would normally be live during engine start, therefore connecting both batteries when the key is turned from off to run and while start is selected. Have you fitted it differently somehow? I'm interested to know as It would be a cheaper way of doing it than the smart isolators.
The amount of extra power you get from the fancy setup is minimal and the money better spent on extra battery or better batteries.
One of the beauties of lithium batteries is that they charge faster as there is no absorb and float and you can drain them a lot more with no harm 20% is recommended but lower if needed and you still have full voltage and they never need to be brought back to 100% SOC (full charge) and they are expected to last at 8 - 13 years but as far as we know none have every died yet through use so life expectancy is not fully known.
1/3 the weight and size and you can drain and charge as fast as you like. I pull 60A @ 24v off mine regularly using an aircon and water heater as well as the normal household vacuum cleaner and I run a 240v fridge 212 ltr capacity.
Hope the 120w solar is not too heavy or is it 2 x 60w giving 120w?
For the solar try and get a decent plug installed to connect direct to your batteries so you can just plug in with a decent connection. Dont use a cigerette plug as there is too much resistance. Ither the special plug with return fingers all around or better still a dedicated anson plug. Aslo the wires between the panels and the plug should be a large as possible, most of the ones sold are realy too small but see how it goes and then get thicker cables if you think you are not getting the charge you expect.
Remember with AGM's etc when you go to absorb mode you are only about 80% charged and the last 15-20% takes a long time.
Hope you enjoy your solar and it makes your travels better.
Seems like you have the right mind for travel. Find the spot and stay till YOU want to move and then just to the next great spot.
Regards
Brian
From time to time I "top up" my aux battery in the tug (Optima Yellow Top) from a Ctek (mains) charger for this very reason. It's "semi permanently" set up in the vehicle and also serves as power supply for my Bushman fridge when on a powered site.
Jim
Thank you for your kind words.
yes those panels are heavy little brutes.
they have alligator clips onto the battery at present.
Maybe i need to get that changed?
Dawa
The advantage of the not very expensive "fancy setup" though, is that when you go to start the tug, you don't automatically parralell the two batteries and drain the charge from the starting battery to the house battery, just when you need all the power you can get from the starting battery. I guess no system is going to suit everyone, but for the sake of less than $200 for the smart isolator that draws in the vicinity of 15mA to 20mA, It's cheap insurance.
Regards
Brian