Inverter charger what do you think

[Randy Rutledge]

I recently bought a ProMariner Truepower 2500QS at a pawn shop the unit works like a UPS for shore power auto switching to battery backup when shore power is lost and is a 50AMP charger when connected to shore power that has 7 programmable (switch selectable) charging profiles for different battery . Unfortunately I really liked the way if functioned until it would go into error mode so I returned it for a refund.

My problem; I think I want one for the boat. I know that this could encourage me to eat up a battery bank in a few hours or could be a great convenience if used properly having 120VAC on demand and 50AMPS charging capacity.

My question to the Forum is, is this a good idea or is this a bad idea and your thoughts on why good or bad (1- Bad! $630 cost) also suggested battery capacity you would recommend.

Thanks for your thoughts.

 

[Tom Metzger]

My problem; I think I want one for the boat. I know that this could encourage me to eat up a battery bank in a few hours or could be a great convenience if used properly

A few hours? How about a minutes?

Randy - The first question is what do you want to power with 120VAC and how long will it be on? Keep in mind that this unit will draw up to 250 amps from your battery bank if you intend to use 2500 watts. 30 minutes use would be 125 amp hours. If you have a fridge and you are on the Gulf you will probably need another 100+ ah/day for your normal 12VDC use. For this you would probably want to have 600 ah in your house bank.

It goes without saying that this would take a lot of time & diesel to recharge.

When you figure out how much load you actually have and what your wants/needs are you can probably pick a more modest size and save a lot of money. The inverter, batteries, rewiring, large alternator & regulator, battery monitor. It adds up.

I find that I can get along with a 140 watt plug-in inverter to run my laptop. It would also run my TV if it ran on 120V.

BTW, a very similar thread came up on SBO today. Maine Sail suggests that my battery estimate is low. http://forums.sbo.sailboatowners.com/showthread.php?t=168290

 

[Maine Sail]

One caution I have for any inverter charger is the ability to have the unit NOT auto transfer. Auto transfer is often called standby or search mode and you want a product that allows this to be 100% disabled when plugged into shore power..

There have been many instancess where the boat loses shore power and the inverter auto transfers, not good.. If the water heater (ideally should not be able to be powered from an inverter but entails an entire other thread) or other AC loads were left on the inverter takes the bank to 10.5V. When the power resumes the inverter may not charge the batteries because it now detects low voltage and assumes a fault condition such as a bad battery or internal short... Even if the inverter does not have any loads the search/standby function can draw from .5A to over 2A just sitting there waiting or searching for AC loads. Not all IC's have a good way to disable auto-transfer.

If looking for an IC I would urge caution on units bought on price or the newer "high frequency" products. While the high frequency products get better each year, and some are better than others, they are not up to the abuse a big heavy transformer based inverter/charger can take...

IMHO Magnum, Outback & Victron are about the best and Magnum has outstanding customer support right here in the US. The ProMariner's are built in China and older ones had some issues and they lack custom programability in favor of dip switches... They are a pretty bare bones IC...

If you are not looking for huge loads to drive then often a small pure sine inverter, 400W - 1000W, using it's own dedicated 120V outlet is a preferable solution, and an easier installation. You can then choose a good quality battery charger and when one of them goes you are not out both devices...

 

[Randy Rutledge]

Thanks guys, I know 2500 watts is overkill, I liked the 50 amp charge rate, I didn't like the price, not a sealed unit. You have echoed my concerns about the function of the auto switching and load on battery bank.

Now to look for a solution for 1200 watts and good charging rate with sealed units and hopefully a few bucks trimmed off the cost of my wish list. The Honda EU2000 is still on the list and will suffice when a smaller inverter will not do the job.