power converter charger?

[Wellcraft290]

Which amp would you recommend? all about the same price. just wondering if 60 amp would be way too much or would it just charge the batteries faster?
https://www.amazon.com/gp/product/B01ER ... 4JRX&psc=1

plan on having AC, tv, fan, typical stuff. stereo

[John61CT]

Amps and type of regulation depends on the chemistry and Ah capacity.

Describe your bank, and how many hours you have shore power available.

Also your genset if any.

[tony.latham]

plan on having AC, tv, fan, typical stuff. stereo

What do you want this box to do? Charge the battery? Or power the DC stuff?

Why not a Progressive Dynamics box?

T

[John61CT]

Any decent charger / converter (same thing really) will do both just fine.

Setpoint adjustability is sometimes a real plus.

But amps rate the real question

[RJ Howell]

I have a 30a service in my commercial trailer. Runs all the typical stuff. I have a 60a in my workshop..

Seems a bit big to me..

[Wellcraft290]

Will have one 100 ah battery at first then two. Really just normal items being run, but the price is basically the same. Just wondering if too much is a bad thing. I mean if was double the price etc wouldn't consider it but the 60 amp and 30 amp are basically identical in price.

just trying to determine if any downside to too many amps. will use to power the 12v items when hooked to shore power and to charge the battery. seems to have a 4 stage charging system.

[RJ Howell]

Assuming you have distribution box you'll be running this into, then 60a supply is not going to matter. You'll be fusing the appliances in the distribution box. 3 stage/ 4 stage chargers mean little to me as 'can I set' the modes of charge is more important to me. I don't like generic settings..

[Wellcraft290]

well planning on a similar setup to this


https://www.youtube.com/watch?v=HeNZgiKPFnA

[John61CT]

Absolutely no downside to 60A if it only costs a bit more, nor 600A

max amps is legal CYA, except maybe GEL chemistry

AGM 0.4C is the minimum I would do, for longevity.

[Trebor English]

Your battery has a max charge current rating. You want two batteries so double that. When charging the battery at the absorption voltage the current will taper off. However, if the batteries are deeply discharged they can take a lot of amps before going over 14.4 volts when first plugged in. I would not go bigger than 50% more than the max combined battery current rating.

If you have, for example, an Eu1000 generator, 7.5 amps at 120v, 900 watts, continuous, a 60 * 15 = 900 watt charger might have a startup problem and the generator might not be enough at a higher elevation. A 45 amp 675 watt max charger might work better. With a 30 amp plug in, that's not an issue.

[tony.latham]

I'm scratching my head on why you want to convert 110 volts to 12 volts when you have a battery.

I get why it would be a good thing to have a charger cooking away while hooked up to shore power. A smart charger would cost about $60 and you could select FLA or AGM...

Educate me?

Tony

[bdosborn]

The rule of thumb for maximum flooded cell battery life is to charge at a C/8 rate or battery amp-hrs divided by 8. So if your goal is 200Amp-hr battery bank you should pick a 200/8=25 amp charger for maximum battery life. People bump up the charge rate in order to charge faster at the cost of reduced battery life.

AGM batteries can be charged at up to C*4 rate, or 400% of the capacity for the bulk charge cycle for a short period. The battery charger and cables would be huge at that rate, most people limit the charge rate to C/4 or so.

My LiFePO4 battery has a C/3 charge rate, so 54 amps in my case. I use an Iota 45A charger with a LiFePO4 charge controller.

NAWS Link

Bruce

[John61CT]

AGM **needs** a high rate for longevity, much higher than most owners ever provide.

FLA will merrily bubble away, no problem as long as you keep the water up.

Of course it is critical that the right **voltage** is held until endAmps is reached, at which point stop charge, drop to Float.

But, again, there is NO lead battery that will suffer ANY harm from "too high" a current available.

The chemistries are self-limiting, simply will not, cannot accept more amps than they can handle.

Other than GEL, special case.

[John61CT]

My LiFePO4 battery has a C/3 charge rate, so 54 amps in my case.

BMS may impose a limit but the cells themselves can draw multiple C-rate if available.

But allowing that hurts longevity.

0.3-5C is fine in warmish weather, stay lower in the cold.

At very high temps very little loss of cycles right up to 0.8C even higher.

Really discussions of lead and LFP are so different, should be in separate threads, too confusing for newbs, irrelevant to the OP.

[John61CT]

I'm scratching my head on why you want to convert 110 volts to 12 volts when you have a battery.

Called charging. Same as "converters" so called traditionally by the US RV industry.

A good quality unit sized right for a big deep cycling bank can easily cost $400+

Cheap garage style chargers have little place in that context.