Batteries in a small van

[jpaddler]

I'm putting together a small system, for a small van.

Won't be able to build a separate battery box for venting, and the batteries will be mounted under the bed, so flooded golf cart batteries are a no go.

Planing on using a ctek ds250 dual charger, with the smartpass, and 200 watts of solar on the roof to feed them.

Unfortunately there are no adjustable parameters using this system, so lithium batteries won't work either. (14.4 charge/13.6 float)

Agm's seem to be the best choice for the application, I've been looking at some of the deep cycle versions on Amazon, and wondering if anyone has had success with the Japanese imports?

Keyko, npp, universal power, and even renogy all seem to be about the same, and offer 100 and 200ah sizes.

I know I'll need at least 200ah, so is it better to have 2 smaller batteries, over a larger one?

Any advice would be appreciated.

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[Gideon33w]

Batteries vent when charging. I assume you will be sleeping while it's dark out. So, no venting concerns.
Keep in mind, many people on here don't have vented boxes despite that being the "right" way.
Enough ventilation to keep a human alive is enough ventilation for a flooded battery in my opinion.

 

[Trebor English]

I have a small van.  It's a 1999 Ford Windstar mini van.  I have a 100 watt solar panel.  I replaced the starter battery with a 75 amp hour deep cycle trolling motor battery.  I got the biggest battery that would fit in the original location.  It is a cheap flooded battery.  Under the hood there is no venting problem and it doesn't take up any space inside.

 

[Reducto]

I'm on my second compact cargo conversion and have had flooded batteries in both. No venting to the outside or anything special, just boxes to cover all the wiring. I am still alive and have never noticed any smells.

 

[jpaddler]

Actually I'm on call, so there will be sleeping during the day

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[jonyjoe303]

myself I would rather have 2 "small" batteries over 1 large one, they are easier to move around. Even a "small" group 34 102 ah agm will weigh in at 70 pounds but 1 person can move it. But group 34's do take up space.

I notice 2 of the brands you mention keyko/universal power have the same bulk charge rate 14.5 - 14.9 volts and they look the same, maybe made by same company? If the ctek maxes out at 14.4 volts it might not be a good charger for them.  
There might be some voltage drop from charger to battery, the ctek might be putting out 14.4 volts but the battery might only read 14 volts. AGM's prefer the higher voltages to get a good charge, sitting at 14 volts thats almost float voltage, they will be chronically undercharge. On my system I had to raise the the bulk voltage on the controller (programmable) to 15 volts to get my agm to read 14.4 volts. 

You mention there are no adjustable parameters on the ctek, that will be a problem if you have serious voltage drop between the controller and battery. The battery itself has to read exactly 14.4 volts or higher to get a proper charge. I don't think a .1 or .2 will make much difference but 1/2 volt might.

 

[Weight]

Why not get batteries from a place you can exchange if warranty is needed. As well as ones made in the USA. My choice would be Duracell from Sam's Club or Batteries Plus Bulbs. I have flooded EGC2 and have no problem with gasses. But they also have agm batteries. Despite some-one-here not liking them, they are a well regarded battery. There are other manufactures, if money is handy.

 

[jpaddler]

I believe the ctek has temperature compensation, and it's 14.4 at 77 degrees.
I downloaded a tech manual for lifeline agm batteries, and that seems to fall in line with their recommendations.

I know it starts out with a 15+ volt charge, to help fight sulfation. That's one of the reasons, it was unsuitable for battleborn lithium.

I'm open to other charging options, but I liked the idea of one that could charge while I was driving back and forth on the regular 200 mile jaunt, and a solar controller when I was parked. Going into the winter months, the solar will be less of a factor

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[frater secessus]

If my math is right that CTEK + Pass combo will be north of $500.  If you gave up on having alt/solar combined in the ctek you could go lithium with something like:

• $300 Morningstar sunsaver mppt + RS-232 or $150 Victron 75/15 + dongle <-- look what I did, John61ct!  
• $60 isolator <-- voltage drop may be your friend in this case.  Or use a non-lossy isolator with a 13.something volt High Voltage Disconnect.

This approach could result in $150-300 for your pocket, or for gas money, or toward that BattleBorn bank.

Just spitballin' here.  Let us know what you decide.

 

[John61CT]

What makes you think you need any DCDC charger?

You need solar, get solar as above.

If you want both batts to get charged from all sources, need an ACR, combiner.

Best to put the Alt and solar directly on the bigger House batt, small-current ACR like Yandina or Echo Charger is fine for the little Starter.

Use jumper cable in a pinch.

 

[jpaddler]

My starter battery should be fine, needed to be able to charge the batteries from solar and driving when possible.

I only have enough roof space for 2, 100 watt panels, and I'm not sure it that will provide for my needs in the middle of winter.

I don't know enough about simple isolators, to know if that will up the voltage, and amps, like the ctek seems to do.

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[John61CT]

No DCDC charger can increase power.

No need to increase volts unless long distance and too-thin wire.

 

[John61CT]

The only true deep cycling AGM I recommend are Odyssey, Lifeline and Northstar.

Call them for a dealer near you.

 

[John61CT]

> simple isolators

usually means diode based, drops voltage

Go combiner as above

 

[John61CT]

If LFP House bank then charge off a Sterling or ProMariner "batt to batt" DCDC charger, fully adjustable setpoints.

 

[jpaddler]

Thanks, I'll look into those

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[musicman]

I'm putting together a small system, for a small van.

Won't be able to build a separate battery box for venting, and the batteries will be mounted under the bed, so flooded golf cart batteries are a no go.

Planing on using a ctek ds250 dual charger, with the smartpass, and 200 watts of solar on the roof to feed them.

Unfortunately there are no adjustable parameters using this system, so lithium batteries won't work either. (14.4 charge/13.6 float)

Agm's seem to be the best choice for the application, I've been looking at some of the deep cycle versions on Amazon, and wondering if anyone has had success with the Japanese imports?

Keyko, npp, universal power, and even renogy all seem to be about the same, and offer 100 and 200ah sizes.

I know I'll need at least 200ah, so is it better to have 2 smaller batteries, over a larger one?

Any advice would be appreciated.

Sent from my Nexus 6P using Tapatalk

 

[musicman]

Depending on your budget for batteries, it seems to follow that you get what you pay for. A lifeline 200 amp/ hr the last I checked runs about 700. You have to figure in shipping. Lifeline is made in the USA and hand assembled, but will last  10 years.

 

[Weight]

Any battery needs to be maintained and properly charged or it will not last one year. Practice on less expensive batteries. East Penn is a large USA manufacturer with an excellent reputation. Their products are readily available.

 

[frater secessus]

> simple isolators

usually means diode based, drops voltage

I've been thinking that maybe diode based isolators could redeem their reputation when used with lithium banks, since:

1. Li don't care much about partial state of charge; and
2. the diode induced voltage drop, if big enough and predictable enough, could keep the Li from exceeding the magic 13.8v point.  

I'd definitely want to test it to death before inflicting it on a $$$ Li bank. 

Caveat for onlookers:  playing with other people's money here;  I have only raggedy lead-acid batts