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jeepcamper avatar image
jeepcamper asked

Upgrading my power management system to Victron and have questions

Hi All,

I have been running a 125 aH AGM in my camping rig (for coach battery) for five years and it finally gave up the ghost. This setup was only good for about 36 hours…so I ordered a matching pair of the same battery for a total of 250 aH.

Since I need to build storage for the additional battery, it’s time to upgrade my charging system. I’ve been doing a ton of research on Victron products and think I’m getting close.

Needs:

  • Two VMAX SLR125 125 aH AGM batteries in parallel for a 12v system (both new)
  • Usually use less then 4 amps when boondocking (for a bedroom fan at night and fridge at all times)
  • Will be adding some LED lights for night use
  • Jeep has 160 amp alternator
  • Previously used a National Luna battery box and NOCO Gen2 (10 amp per bank) for shore power and charged straight off the alternator

Battery Specs:

  • Specifications:

    Nominal Voltage 12V

    20Hr Capacity 125Ah

    RC (min) 260

    Energy (kWH) 1.7

    Terminal Posts 8mm

    Dimensions 12.9"w x 6.8"d x 8.5"h/8.7th**

    Weight 75lb

    Charging Current* 8A-35A

    Charging Voltage 14.4V-14.9V

    Float Voltage 13.5V-13.8V

Plan to order:

  • Victron Blue Smart IP22 12/30 for shore power
  • Orion Tr Smart DC-DC 12/12-30 for charging on alternator
  • Victron shunt (TBD)
  • BMV-712 monitor (TBD)
  • Probably a Victron near-battery temp & voltage sensor (temp drops below freezing here in winter)

As you can see, this is a simple system and I’m only trying to add power for additional camp days. Solar charing is off the menu until I purchase a new roof top tent that will accommodate solar panels. For now, alternator and shore power will be the only charging methods.

I’m hoping that knowledgable people here can check my work and suggest any changes if I’m on the wrong track. There are no Victron dealers or installers in my area, and I worked in the car stereo field when young. I can handle the wiring, but it’s bee a while since I’ve tackled something so intricate.

Also, I’d like to make sure that all Victron components will handle a 200 aH LifePo4 bank in the future when these AGMs die again.

Am I correct in choosing a 30a charger for home and a 30a DC-DC for alternator charging?

Many thanks for any help!

AGM Batteryorion dc-dcip22
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3 Answers
kevgermany avatar image
kevgermany answered ·

Looks good. The monitors come with a shunt. There's a temperature sensor for the BMV712. Home charging you have plenty of time, so 30A is good. Might be worth thinking about doubling up on the Orion, will charge at twice the rate and need less driving time to keep the batteries charged.

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jeepcamper avatar image
jeepcamper answered ·

You are a Prince. Thank you!

I wouldn’t mind putting in a 50 - 60 amp DC/DC charger since I have 16mm cables run through the vehicle alread., To my knowledge, Victron doesn’t make one larger than 30 amps (that uses the Bluetooth app). Is this correct?

If I make accomodations for a larger converter (and run new wire if necessary), how many amps can I send to the service batteries without taxing my 160 A alternator? According to the specs, I can charge the pair of batteries at 70 A max. This is the part that I’m having trouble fining info for.


I might need to bulk up the batteries while boondocking and am therefore not opposed to more power!

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jeepcamper avatar image
jeepcamper answered ·

I ordered two Orion TR Smart 12/30 chargers, but have not found a single diagram on connecting them in parallel. I’ve read the manuals available from Victron.

I can hazard a guess. Connect + on TR#1 to most positive on service bank, and connect + on TR#2 to most positive on service bank and connect - on both TRs to the shunt (which is connected to most negative on bank)? The collaboration is handled from within the smart phone app?

It would be wonderful to find a resource that will tell me for sure. I hate to guess with a thousand dollars worth of gear.

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