Just got my battery, now what?

[ArmyRetired]

My (1st) SOK 206Ah battery arrived today. Now what?

I'm a total noob with most things electric and have never dabbled into solar.

My wife and I have a 30 foot RV trailer. The single LA battery is about dead so I decided to replace it. Due to the covid RV surge, it is getting harder to find campground spots without knowing our schedule a year out. That is pushing me to think about boondocking. I'm pretty sure upgrading from the 100Ah LA battery to the 206Ah SOK is a good start.

Step one: need a lithium compatible AC converter. That alone could get us through a long weekend with just DC use from the single SOK. We've got a generator to recharge if necessary, and have used it for our current LA battery. Takes forever.

Step two: but...wouldn't AC power be nice? Now we "need" an inverter. Not planning on running the air conditioners, but normal outlet things would be nice. Not necessarily a hair dryer or microwave, but most other AC appliances. Coffee pot would be nice.

Step three: solar? The ability to be out long enough to fill up waste tanks without plugging in is appealing. This is a future desire.

Watching Will Prowse go through his cool solar videos is inspiring, but I think an all-in-one is probably more my speed. That would cover all three steps above. Now that leads to the next question: 12V or 24V? With only one 12V battery, I'm limited to the first choice. But with the MPP 12V version, AC converter is limited to 20A, and inverter to 800W. The 24V version needs an additional battery, but sounds like it would cover most of my current/future needs.

Additional questions:

1) If I got the 24V MPP all-in-one (and additional 206Ah battery), the AC converter is 60A. Does it have the ability to charge the SOK's at their recommended 50A?

2) How would I use a 24V battery bank to run the 12V RV systems?

3) Would 50A shore power connected to either the 12V or 24V all-in-one be able to run the dual AC's(air)? Any special wiring required? It's hot down here in the south and we like our air conditioners. Remember, electricity isn't my friend.

4) Late add: how do I charge each individual SOK 12V battery so they are at the same state of charge before connecting them in series? If I get the 24V all-in-one it only has a 24V charger.

Unfortunately I don't know what I don't know...

Thanks for any suggestions!

 

[Just John]

When I purchased my generator about 5 or 6 years ago, my research found that RV users with 15,000 BTU air conditioners needed about a 3000-watt generator, and even then some (but not the majority) needed to install soft start capacitors (basically reduces the peak surge current needed). I have a generator that is rated 3400 watts on propane (higher on gasoline) that had no problems running a 10,000 BTU air conditioner, full sized refrigerator, modem, router, television and lights with power to spare. Inverter and generator should be about the same, but if you can afford it get a low frequency reputable brand (low frequency generally means better surge capacity). Going with 12v means LOTS of amps, better to go 24v and get a unit designed to run your 12v loads as an addition (just my opinion). Being able to run even one of your air conditioning units is going to take a lot more battery. Victron and other (much cheaper) 24v all in one units are likely what you want.

 

[ArmyRetired]

I guess I might not be using the right terminology. I want an inverter to run AC (alternating current) circuits, not A/C (air conditioning).

My question on running both, or one, air conditioning units is only when on shore power. How is that wired? I’m assuming not through the all-in-one. I don’t plan on ever running the air conditioning via batteries and inverter.

 

[Hedges]

1) I think SOK is recommending not charging the 100 AH battery in excess of 50A (0.5C). Not a minimum or preferred charge current such as lead-acid has.

2) DC-DC converter. Possibly a setup to keep an AGM battery charged, if you have high current loads (levelers, etc.) that exceed DC-DC spec.

3) Have to read specs for pass-through power (some hybrids have AC input, charge batteries from shore power and pass through to loads like A/C. Others, you would have a manual or automatic bypass.)

4) First, confirm the batteries are allowed to be used in series. Probably, but some brands aren't (can't handle the voltage)
You would fully charge each battery to some voltage well up the upper knee. possibly 4 x 3.65V, or some other voltage slightly below the high-voltage disconnect of SOC's BMS. They would then be top balanced, so used in series they would get full at the same time.

When drained to low-voltage disconnect, one may get there before the other. Perhaps set inverter such that even if one battery is in flat part of curve and only the other goes down the knee, inverter disconnects before BMS. If you had ordered two batteries at once saying it was for 24V use, SOC would probably have provided a pair matched in state of charge and capacity.

50A x 24V isn't all that may watts, about 1kW. Ideally your future hybrid/all-in-one supports more PV, up to whatever you can fit, while regulating charging current to perhaps 50A or less. The extra PV could then help run AC loads.

BMS (hopefully) has low temperature cutout to prevent charging below freezing, maybe an adjustable temperature.
If SOK says 50A (0.5C) is OK, that is at 25 degrees C. The maximum current it should receive is reduced in cold weather. Of course, that would recharge in 2 hours. Maybe you'll have 6 or 8 hours to recharge. So I would consider setting up the system to charge around 12.5A, and select low-temperature cutout at whatever temperature is OK for that charge rate.

 

[carl2591]

one note of caution.. if you do not know electricity it can get expensive to find out how much you do not know. find a friend or do some youtube video to figure it out. many of Wills videos are good for info on the equipment and batteries.. hooking them up, getting the right inverters etc is a bit more complicated..

I run a 2000 watt pure sine wave inverter currently hooked up to 2 6v T-105 220Ah lead batteries (that will be changing soon) hooked up to 460 watts of 12v solar panels going to a 30 amp PWM controller with #4 wire. I also have a 335 watt 24v panel on the camper shell of my truck hooked up to a 20 amp MPPT controller with 45 ft of wire to get panel in sun and is tiltable for max power. for boondocking you can also get a composting toilet to make the time in the wood longer as gray water is easier to deal with and you have one large gray tank vs a black and a gray tank. good luck and be safe.

 

[SOK-MIN]

for reference .

 

[Smokin]

Hook the new Battery to a ic-7300 Icom HF Trancever and an Anon 2KW amp and lite it up

 

[12VoltInstalls]

My question on running both, or one, air conditioning units is only when on shore power. How is that wired? I’m assuming not through the all-in-one. I don’t plan on ever running the air conditioning via batteries and inverter.

Basically a very simple way: see if there is a way to disconnect the on board converter. (You have to disable it to do this successfully while on battery). Once converter is powered off, plug your shorepower cord into an adapter plugged into your inverter. Presto! 120VAC everywhere, just don’t turn on an AC unit…