Batteries toast again…

[AH64ID]

I considered this...just depends on how much I drive to keep the LFP full in the summer when running the fridge. I could also hook it up such that I can quick toggle the solar input to LFP vs. starter batt.

Toggling would also require a charge profile change each time.

 

[stillhere]

Toggling would also require a charge profile change each time.

Ah...right...I didn't think about that. the solar charger is bluetooth so that would be easy to do but, I don't want to have to deal with that.

Unless I run 2 dollar chargers and then have the switch take the solar input then distribute based on which way I have it pointed. May sound complicated but it's really simple...but overkill probably.

I just need to see how long I can run the LFP battery with how much I drive. DC to DC is only 20 amps and the LFP is around 300AH.

Other option would be one more solar panel. I have plenty of space on the roof. The 170 watts I am installing already will be on the hood.

 

[Trash Panda]

For their inflated price point, I have yet to see an advantage of those supposedly higher quality X2 batteries.

I despise Walmart, but they definitely get my business for vehicle batteries. The warranty & quality are everything I could ever ask for.

 

[stillhere]

For their inflated price point, I have yet to see an advantage of those supposedly higher quality X2 batteries.

I despise Walmart, but they definitely get my business for vehicle batteries. The warranty & quality are everything I could ever ask for.

Time will tell. I had a yellow top in my last truck and it took a beating and never failed me. I drained it down quite far a number of times and it just trucked along.

We'll see about the x2 battery. My guess is at least a 1/3 of the price is the 4 year warranty.

I've read good things about the Walmart batteries.

Menards has AGM batteries that have the highest reserve capacity that I've seen compared to any of the top brands and they are only around $180.

 

[Trash Panda]

Time will tell. I had a yellow top in my last truck and it took a beating and never failed me. I drained it down quite far a number of times and it just trucked along.

We'll see about the x2 battery. My guess is at least a 1/3 of the price is the 4 year warranty.

I've read good things about the Walmart batteries.

Menards has AGM batteries that have the highest reserve capacity that I've seen compared to any of the top brands and they are only around $180.

You get the exact same warranty with the everstart AGM’s for a fraction of the cost.

I too have been curious about the Menards options, and I might have to try one out on my half ton when the time comes.

 

[stillhere]

You get the exact same warranty with the everstart AGM’s for a fraction of the cost.

I too have been curious about the Menards options, and I might have to try one out on my half ton when the time comes.

I put one of them in my dad's old Expedition...but he only had the vehicle for another couple years so we didn't get to see how long it lasted. That said, it never batted an eye.

I might throw one in my beater SUV when the current battery dies.

 

[pinco]

Do you typical only change them 1 at a time? I've always been told that with a multi battery setup you should change them all at once. So if you replace one when its weak and the other is "good" (maybe 80% is good?) then you install a new battery with the old "good" battery. This tends to weaken the system by the old battery feeding off the new one... and the cycle continues. Any opinions on this? Or, maybe you are changing them in pairs...

I always change in pairs. This time they only had one in stock, I installed it, ran fine but will still get a new one for the drivers side as soon as it arrives

 

[HarryN]

I have a LFP battery, inverter and 12v fridge in the bed that is charged via a DC to DC charger off the starter battery. I'm debating whether the solar setup will go directly to the LFP battery or the starter battery...or if I split the solar and run part to the starter battery and part to the LFP. The latter will be the only way I can keep the starter battery topped off unless I hook it up to a charger when parked but that's just not practical for me.

There are a couple of options:

This is a small trickle charger that works for 12 volt starter / 12 volt auxiliary house batteries. It provides a small trickle charge.

It is temperature compensated so it deals with the need to slightly change the charging algorithm as the starter battery temp changes.

Prevent Dead RV Starter Batteries – House2Start Charger

Prevent dead starter batteries in your RV. House2Start charges your engine battery automatically from the house battery.

house2start.com

_________________

These newer red BTB chargers from Sterling have a built in reverse charge function.

Importantly - it only activates when the house battery voltage is high enough. The intention is to channel excess solar from the house battery to the starter battery.

There is also a manual way to use it in sort of a jump starter method.

Sterling Power USA

battery to battery chargers, battery to battery charging. Charge a 12v battery from a 24v. Charge a 24v from 12v. on the run battery charger, on the water charger, marine DC to DC battery chargers, dc powered charger, mobile power supply, inverters, generators, professional mariner, piggyback...

www.sterling-power-usa.com

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There is a company that makes a dual output solar charge controller that will charge both the house and starter battery - but I cannot remember the name of it.

_____________

The main challenge for a battery in the bed are the Li battery BMS limits. For nearly all of them, the minimum charge temperature ( for the core of the battery ) is ~ 30-35 F, at that point the BMS will block further charging. 'Usually but not always", the minimum discharge temperature is ~ 5 F, bot some trip both off at the same time.

 

[stillhere]

There are a couple of options:

This is a small trickle charger that works for 12 volt starter / 12 volt auxiliary house batteries. It provides a small trickle charge.

It is temperature compensated so it deals with the need to slightly change the charging algorithm as the starter battery temp changes.

Prevent Dead RV Starter Batteries – House2Start Charger

Prevent dead starter batteries in your RV. House2Start charges your engine battery automatically from the house battery.

house2start.com

_________________

These newer red BTB chargers from Sterling have a built in reverse charge function.

Importantly - it only activates when the house battery voltage is high enough. The intention is to channel excess solar from the house battery to the starter battery.

There is also a manual way to use it in sort of a jump starter method.

Sterling Power USA

battery to battery chargers, battery to battery charging. Charge a 12v battery from a 24v. Charge a 24v from 12v. on the run battery charger, on the water charger, marine DC to DC battery chargers, dc powered charger, mobile power supply, inverters, generators, professional mariner, piggyback...

www.sterling-power-usa.com

____________________

There is a company that makes a dual output solar charge controller that will charge both the house and starter battery - but I cannot remember the name of it.

_____________

The main challenge for a battery in the bed are the Li battery BMS limits. For nearly all of them, the minimum charge temperature ( for the core of the battery ) is ~ 30-35 F, at that point the BMS will block further charging. 'Usually but not always", the minimum discharge temperature is ~ 5 F, bot some trip both off at the same time.

Thanks for the suggestion. My LFP has a BMS that limits charge and discharge based on temp conditions, as you noted. It also has a built in heater that controls input charge and activates the heater when certain amperage input is detected. I don't intended to need it much in really cold temps so not overly worried. I think mine will discharge down to -4 C.

The reverse charge thing is very interesting...I will have to look into that further. Thanks for the suggestion.