I have decided to add a second battery to my 2013 AWD Express. On a recent trip I killed the battery quite dead. I had a 37qt ARB and a MT17 Engel running and had been fine on the trip because I drove every day. Well then I spent 2 nights in one spot and even with some solar (60w and cloudy conditions) the truck was full dead when I tried to start it the second morning. Dead like 5v if I remember right (Engel set as freezer w/o low cut off, oops). Too dead for the solar to notice it when I hooked it up. I ended up tricking the solar by connecting my largish 40ah LiFePO4 battery pack to the truck battery long enough for the solar to wake up. Once it started charging up I d/c'd the LiFePO4 and let the solar do it's thing for an hour or so. I got it to start with the sluggishness of a weak battery on a frozen Minnesota morning (even though it was a warm Idaho day). So here I am, decided to add a house battery (and a bit more solar). I want to be able to charge both batteries from the alternator or both from the solar (I'll end up with 120-160w). I saw this blue sea piece that seemed to do what I need and offers the option to be able to plug in AC to charge. Might come in handy. I carry jumper cables and don't winch so I don't need to have the built in battery combiner. Any reason not to use this? If I am reading correctly it will isolate the batteries when discharging but combine them when charging from either side. I think it is all I need (+ cables, fuses, ferules etc) . Any issues with the charger being "only" 3 step?
https://www.bluesea.com/products/7605/10A_BatteryLink_Charger_[North_America]
They're available for about 160$. Seems like a great start. Am I missing anything?
Thanks,
-G
Good thinking on using the lithium pack to get things going...
I'm going to go against the grain here a bit from the above posts. This thing looks like a great deal/idea - however, i believe blue sea does not design/mfr their own power elecronics. This is not necessarily a bad thing if they know what they are doing.
This product looks like a copy of another charger - which I'll be darned if I can find at the moment...and their other chargers looks like copies made by dozens of companies...again, not necessarily a bad thing.
Let's give them the benefit of the doubt since Blue Sea is very well regarded. 10A is a bit light and will take it a while to charge your deeply discharged Aux battery.
Most onboard dual bank charger start at $70ish dollars. An 65A blue sea ACR/$60ish is a bit light depending on your alternator...I've seen 85A flowing into my 100Ah Group 31 Sam's Club Deep Cycle AGM (that I also use as my starting battery) from my Jeep's 165A alternator.
If your truck is going to sit for longish periods with some small loads near an AC source, this is a wonderful idea. If however, you are rarely near an AC source, your dual battery system would be much better served by a DC charger for the Aux battery. The main battery /alternator will fully charge the Aux battery multiple times faster than the alternator alone - I've used both sytle systems in vehicle and marine applications for years - there is no comparison.
In the Jeep, I've been running a CTEK MPPT controller / DC charger for quite a while and it fully recharges the 100ah Aux battery in about half to 3/4 of the time as the stock 165A alternator. (Depends on DoD level of the aux battery).
The CTEK will steer the solar charge current as necess5 - charge the main battery then switch over to the Aux battery.
Ii is limited to 20A from solar (or alternator source.) For an additional sum, a 80-120A(?) module can be added, increasing bulk charging current from the alternator.
Another company, Kisae came out with a 30 & 50A DC charger - it has an integrated MPPT controller and DC charger. It cannot charge the main battery from solar however.
ACRs are good for applications like winching, starting, emergency use, etc where low impedance source / high current/lots of instaneous power are necessary - but with the commodity level pricing/advanced feature set of the DC chargers, the shortcomings of an ACR systems come to light in a hurry.
On the one hand, ACRs are less expensive and more simplistic - if your alternator offers 14.2V or above, your AGM will be treated OK (but far from optimally as AGMs really need 14.5-14.7 or more depending on temp).
Note however, I did not say more reliable - while I've never had a DC charger or ACR system crap out (on its own - neglecting external forces), you'll find anecodotal stories for each system.
Bottom line : if you drive daily on your trips, even a short amount - say an hour or two- a DC charger is awesome and may even replace your need for solar (it did on my Jeep : multiple radios, Dometix CFX 63DZ, laptop, cell hotspot, circulating fans for dog/human at night. I no longer deploy my 50- 300W portable solar on 3 day trips if I drive an hour a day...the a >3hr trip tops up the battery nicely).
The DC chargers are more expensive than this combine ACR/AC charger or just an DIY Blue Sea ACR system, but for my use, a DC charger makes much more sense.
