How to charge house batteries?

MambaJack · 09-12-2018, 09:30 PM

At the point of installing electric in my conversion, and looking for best practice in charging my house batteries. I plan to use the bus for weekend / maybe a little longer... trips, but would like the ability to stay away a few days in a spot that doesn't have hookups.

My needs are DC ( lights, prob 10 led 3w, water pump, 4 phones, maxair fan ), AC ( apartment refrigerator, led monitor, ps4, laptop charger).

I was looking at 4 to 8 6v gc2 batteries 230ah. and a 2500w Aims combination Inverter/Charger. would like to hook up solar eventually, but not necessarily right away.

Oh, and just installed a 50amp inlet

Any help is much appreciated!
dave

JDOnTheGo · 09-13-2018, 07:50 AM

Howdy Dave,

Most RV's/conversions use a battery charger/converter (like this one from Progressive Dynamics). It will charge batteries (charger) and provide 12VDC power to your house system (converter) from 120VAC shore power or generator. Since your inverter has a charger built in, you already have this functionality. Just be sure it is a smart charger (4 stages) so it cares for your batteries.

Charging from engine driven alternator is not uncommon (take a look at this unit from Sterling).

As you mentioned, solar is a very popular option for charging. Solar works well as a 'topping' charger (bulk charge with generator and then let solar finish the job over the course of the day) or as the primary charging source. All of these options can be combined.

If running a refrigerator from inverter, I'd suggest a pure sine wive version (based on my experience running a Samsung refrigerator/freezer from MSW).

Jameson · 09-13-2018, 08:55 AM

Quote:

Originally Posted by JDOnTheGo

Charging from engine driven alternator is not uncommon (take a look at URL="https://www.amazon.com/gp/product/B071RKX5W2/ref=as_li_qf_asin_il_tl?ie=UTF8&tag=jdficom-20&creative=9325&linkCode=as2&creativeASIN=B071RKX 5W2&linkId=130bafb84469f8129a6f8a7600fd6df4"]this unit from Sterling[/URL]).

Great info! Thanks for sharing. In your research have you found any more economical options for charging off the alternator? This model seems steep.

JDOnTheGo · 09-13-2018, 09:05 AM

Lots of options. If you are looking for short term cheap and don't mind (likely) destroying your batteries over the mid term - connecting house batteries directly to your engine/chassis electrical system is an option (using a battery contactor/relay). Some folks don't mind replacing all their house batteries every year and that's totally ok. If you want to get many years of service from those $$$, using "smart"/multi-stage chargers is important. As is a quality battery monitor to keep track of their state of charge and avoid damaging them to over-discharge.

2kool4skool · 09-13-2018, 09:26 AM

Regarding multi-stage chargers. Do not equalize charge LI or AGMs.

Jameson · 09-13-2018, 09:55 AM

Quote:

Originally Posted by JDOnTheGo

Lots of options. If you are looking for short term cheap and don't mind (likely) destroying your batteries over the mid term - connecting house batteries directly to your engine/chassis electrical system is an option (using a battery contactor/relay). Some folks don't mind replacing all their house batteries every year and that's totally ok. If you want to get many years of service from those $$$, using "smart"/multi-stage chargers is important. As is a quality battery monitor to keep track of their state of charge and avoid damaging them to over-discharge.

Thanks. I have a direct with relay connection now as my initial battery bank and limited use didn't justify the cost of a high end component.
The search continues as my next upgrade will be quality batteries.

MambaJack · 09-13-2018, 11:25 AM

Quote:

Originally Posted by JDOnTheGo

Howdy Dave,

Most RV's/conversions use a battery charger/converter (like this one from Progressive Dynamics). It will charge batteries (charger) and provide 12VDC power to your house system (converter) from 120VAC shore power or generator. Since your inverter has a charger built in, you already have this functionality. Just be sure it is a smart charger (4 stages) so it cares for your batteries.

Charging from engine driven alternator is not uncommon (take a look at this unit from Sterling).

As you mentioned, solar is a very popular option for charging. Solar works well as a 'topping' charger (bulk charge with generator and then let solar finish the job over the course of the day) or as the primary charging source. All of these options can be combined.

If running a refrigerator from inverter, I'd suggest a pure sine wive version (based on my experience running a Samsung refrigerator/freezer from MSW).

Thanks. I like the idea of that pd charger. But got a little confused as to how to wire it. When I'm plugged in. I want to charge the batteries. With possibly 2 50amps coming in. Do I need to separate panels? One from the inverter and one from shore?

MambaJack · 09-13-2018, 11:26 AM

Quote:

Originally Posted by JDOnTheGo

Howdy Dave,

Most RV's/conversions use a battery charger/converter (like this one from Progressive Dynamics). It will charge batteries (charger) and provide 12VDC power to your house system (converter) from 120VAC shore power or generator. Since your inverter has a charger built in, you already have this functionality. Just be sure it is a smart charger (4 stages) so it cares for your batteries.

Charging from engine driven alternator is not uncommon (take a look at this unit from Sterling).

As you mentioned, solar is a very popular option for charging. Solar works well as a 'topping' charger (bulk charge with generator and then let solar finish the job over the course of the day) or as the primary charging source. All of these options can be combined.

If running a refrigerator from inverter, I'd suggest a pure sine wive version (based on my experience running a Samsung refrigerator/freezer from MSW).

I actually don't have an inverter yet. Was just looking to see if the inverter charger was a better option

JDOnTheGo · 09-13-2018, 01:36 PM

Some like a combined inverter/charger, others don't. One requires less wiring/complexity. One allows for greater flexibility (choice of components). One requires complete replacement if only "half" of it fails or you choose to upgrade. No right or wrong, just what you prefer.

You need a transfer switch to flip between shore/generator power and inverter power (going to your 120VAC distribution panel - or one of them if you have 50 amp service (two 120VAC legs)). This can be accomplished with a separate transfer switch OR and an inverter with an internal transfer switch. It either case, shore power is usually the default so the inverter is bypassed when shore power exists.

You may also like: