Inverter Questions

[pfmathis]

Originally Posted by Scalf77

I am aligned with Eric (86Scotty), my thought is his intent for two inverters was to use so he could charge his house battery while driving. It has also been mentioned in this forum http://www.sportsmobileforum.com/for...tml#post234319 by member Mike Wilson. see his diagram post *149. I believe his description starts at #143. The basic scenario is that you use an inverter off of your alternator/start battery to provide AC to your shore charger. This of course charges your house battery while you drive. In Mikes application it turns his alternator into a 3 stage battery charger.

I would agree that it had multiple levels on inefficiency, We are converting to DC to AC and then AC to DC, you always loose some power in those conversions.


The fact that OP want's to go to Lithium batteries mean that the typical isolator/separator solution won't really work. In that case the best solution is a dedicated second alternator with Balmar regulator on it that supports Lithium, or a DC to DC charger from Sterling Power , or the KISAE DMT-1250 I referenced in my previous post.

On second reason to have two inverters, would if you wanted a large inverter to handle your heavy loads say 2000 to 3000 watts, but wanted a small 400 watt unit to handle small conversions, that become more inefficient with the larger unit.

Those are the two reasons for two inverter off the top of my head.

-greg

Greg - I really appreciate your input. The DC to DC charger looks to be the best option - in my limited knowledge and experience - since I'll be able to not only connect to my current CCP's and charge while driving, but also be able to add solar at a later time without too many additional gyrations. From what I'm also reading, an inverter/charger is probably the best way to go versus singular purpose inverter and charger units (for shore power charging). Additionally, when looking at battery types, I've been thinking of going with a lithium type simply because of the weight/size advantage along with ability for increased number of charging cycles and greater draw down. Am I being naive thinking that these alone are good enough reasons to go with a much higher priced battery?

Finally, one last question (for now), should I decide to place my electrical setup in the rear of the van (inverter/charger, batteries, DC-DC charger, etc), is there a problem running the large cable from the CCP (attached to the driver seat pedastal) to the charger - such as current loss or anything else I should be concerned with?

[Scalf77]

DMT-1250 has a 50 Amp input they recommend 70 Amp fuse, I believe the CCP has 65 amp fuse on it so it is close, you may have to limit DMT-1250 to a 45 amps, they like a 60 amp out put fuse. , so you cable size will depend on those fuses of course you can increase to minimize voltage loss, there is a good calculator here Circuit Wizard - Blue Sea Systems or this is one that I wrote it is spreadsheet form https://drive.google.com/open?id=1v_...2DV0GDVznGwhf0

I would probably stay with a Inverter/Charger to save space and connections.

I will be installing one of the DMT-1250 in my own van in couple of weeks, I will probably do a write up.

=greg

[ConnieKat]

Hi,
I’m in the same boat as I have no propane. What I’d like to know is what the best gadgets are for heating, cooling, cooking etc.? Most of what I’ve seen pulls way too much power. I’m hoping to fit a 3rd battery by
redesigning my gaucho, and still have to install solar
panels. LED lighting everywhere. I have an alcohol stove, hot pot for water, slow cooker, and small steamer. Also a microwave I’ve never used. Same with a borrowed electric heater.
Recommendations on the best needed gadgets would be greatly appreciated!
Thanks,
ConnieKat

[seasmith]

Originally Posted by Scalf77

DMT-1250 has a 50 Amp input they recommend 70 Amp fuse, I believe the CCP has 65 amp fuse on it so it is close, you may have to limit DMT-1250 to a 45 amps, they like a 60 amp out put fuse. , so you cable size will depend on those fuses of course you can increase to minimize voltage loss, there is a good calculator here Circuit Wizard - Blue Sea Systems or this is one that I wrote it is spreadsheet form https://drive.google.com/open?id=1v_...2DV0GDVznGwhf0

I would probably stay with a Inverter/Charger to save space and connections.

I will be installing one of the DMT-1250 in my own van in couple of weeks, I will probably do a write up.

=greg

Greg,
Nice spreadsheet. Is there a rule-of-thumb for fuse rating, relative to Load or Max Current ?

[JohnandMandi]

When properly cared for, AGMs last a long time. We have been on the road for 4 years, about to ship back to the US, and our Deka 4D has only lost about 6% of capacity. We are 100% 12v, including fridge, and carry a small 150w pure sine to charge our laptop, run hair clippers, and handle other random needs for 110v.

We cannot connect to shore power, something we would/will add, having a blue seas ACR and a single 255 watt Kyocera solar panel as our only charge sources. We designed our system for 2 4Ds (400 amps) but only installed one, 200 amps has been plenty since we don’t have a microwave, hot pot, rice cooker or whatever else. Key is to always stay above 70% of capacity, we normally don’t drop below 90% (again, fridge is 12v and runs continuously).

Our house battery is installed under the van on the Ujoint Offroad rear skid plate in the factory location for the spare. It is exposed to the outside temperatures, having been in conditions above 100 degrees and well below freezing at high altitude (over 16,000 feet).

On the Carretera Austral our Blue Seas ACR failed, we have been 100% solar since, still no issues. As stated above, the only change we’d make is to be able to connect to shore power...probably just a portable 3-stage battery charger. We agonized over what and how to build out the electrical, in the end deciding on a basic setup and implementing power management practices. Almost everything we own has a 12v charger, AA and AAAs are rechargeable, and we planned to charge ipads and the laptop while we drove (proved to be unnecessary).

Our suggestion is to really consider the practicality of your system. While saving weight is paramount, leaving out things that might go unused is the single best way to optimize not only the over all weight of the van, but also living in it.

[86Scotty]

Originally Posted by pfmathis

Finally, one last question (for now), should I decide to place my electrical setup in the rear of the van (inverter/charger, batteries, DC-DC charger, etc), is there a problem running the large cable from the CCP (attached to the driver seat pedastal) to the charger - such as current loss or anything else I should be concerned with?

No problem at all, just size your cable accordingly for power loss over the distance. There are lots of charts online for this, just Google it.

I bypassed the CCP on my Transit due to it's limited amperage. About 6" over from the CCP is the battery so I went direcly off of it with a Blue Sea 7610 isolator and 250 amp breaker. No problems at all. The Transit is super easy to work in and around after you remove all of the needless plastic around the driver's seat/battery cover etc. You'll see what I mean. It's like they decided there wasn't enough useless plastic trim in the way and decided to add 5 more pieces after the fact. It's totally convoluted. I removed it all.