Lithium battery dilemma

Albynsw

Well-Known Member
Thanks for the feedback, that gives me more confidence that I will be ok with my current setup.
@Triton14 the difference which is making me nervous is that we traditionally are one night stopover style tourers whereas I am wanting to slow things down a bit and try sit a bit longer. This is a bit of a shakedown trip with the longer term vision of renting our our house and living on the road so just getting a feel with it all and what we want to do.
 

Albynsw

Well-Known Member
Righto you brainiacs that all makes sense except I am in the middle of the installation so can’t do any real world testing. If I need to increase my battery size I will need to relocate the installation position, currently it is going in behind the back seat but if I go bigger I will need to relocate to the canopy which I prefer not to as wanting to keep weight forward as much as I can
This is where I have started the install so it is all pretty tight



8DC57C9A-02E7-4747-82C9-CF7B05F3C7D7.jpeg
 

Lost1?

Well-Known Member
Do they still make bazooka tubes for subs these days? Maybe you could fabricate one with 2 smaller subs or build the sub box vertically? 3 x skinny 54Ah itech world batteries in parallel will give you the battery power you need. Or there are a couple of 60AH batteries around that are no more than 150mm wide or less. Add 200 W of solar hard wired in and you could comfortably run both fridges (or one as a freezer), a tablet or ultra portable laptop and probably a charge a camera for the 3 days you want to remain static. How attached are you to the battery you already own?
 

Albynsw

Well-Known Member
Do they still make bazooka tubes for subs these days? Maybe you could fabricate one with 2 smaller subs or build the sub box vertically? 3 x skinny 54Ah itech world batteries in parallel will give you the battery power you need. Or there are a couple of 60AH batteries around that are no more than 150mm wide or less. Add 200 W of solar hard wired in and you could comfortably run both fridges (or one as a freezer), a tablet or ultra portable laptop and probably a charge a camera for the 3 days you want to remain static. How attached are you to the battery you already own?

A smaller sub box would give me more room to play with. Not particularly attached to the battery apart from it is brand new
 

Krumpy

Member
I’d bet on you having enough battery. especially If you’re careful(not having kids in and out of the fridge all day) 90 ah is a lot of juice with that much solar
 

Albynsw

Well-Known Member
So with the solar i have a 170watt panel permanently mounted on the roof and a 200 watt solar blanket

What is the go with wiring them up, the fixed panel will be permanently connected to my Enerdrive dc-dc charger, can I just piggyback the blanket to the same connection or does it need to go through a separate controller?
I do have a seperate 20amp MPPT controller I could use and run that back to the battery as well
 

Krumpy

Member
So with the solar i have a 170watt panel permanently mounted on the roof and a 200 watt solar blanket

What is the go with wiring them up, the fixed panel will be permanently connected to my Enerdrive dc-dc charger, can I just piggyback the blanket to the same connection or does it need to go through a separate controller?
I do have a seperate 20amp MPPT controller I could use and run that back to the battery as well
Piggy back it. The enerdrive will handle that no worries
 

peterfermtech

Well-Known Member
So with the solar i have a 170watt panel permanently mounted on the roof and a 200 watt solar blanket

What is the go with wiring them up, the fixed panel will be permanently connected to my Enerdrive dc-dc charger, can I just piggyback the blanket to the same connection or does it need to go through a separate controller?
I do have a seperate 20amp MPPT controller I could use and run that back to the battery as well
Unlike with the lead acid your solar will be charging basically full current from start to finish. This means you will probably dump 50 amps + a day back into your battery just from the roof mount.
I get 8 amps from my 140 watt flexible panel mounted on my RTT which keeps my 60 AH Lithium topped up.
 

CTL

Well-Known Member
The Enerdrive will handle the combined panels IF they are the same voltage. If they aren’t the same voltage, the combined solar output will derate to the lowest voltage.
Also the Enerdrive will prioritise to the alternator’s input and ignore the roof top solar whilst the engine is running. If you want to punch in extra amps whilst driving (check your battery’s max recommended input first) then wire the roof top solar to your second MPPT direct to your battery and fit an Anderson plug to the Enerdrive’s solar input to connect your blanket to when parked up.
 

boobook

Well-Known Member
If you put the ppanels in parallel, you need to add blocking diodes. Otherwise panels turn into a load when they are in the shade. Use your second MPPT if you are not comfortable adding the diodes.
 

Albynsw

Well-Known Member
I just looked at the specs. My fixed panel is 21v open circuit and 17.8v working voltage , the blanket is 23.15v open circuit and 19.1v
 

CTL

Well-Known Member
So your blanket will only output at the fixed panel’s specs if connected in parallel.
Very unusual if panels these days don’t have inbuilt diodes to stop feedback from the battery.
 
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