Mastervolt DC-DC Converter

[John61CT]

Good quality brand, correct?

I've got a chance to buy a 12-12v IVO 8772, rated 20A

NOS $60

Must be an OLD model (90's?), can't find details online.

intended use is echo charging a small LiFePo4 bank

anyone familiar?
can output voltage be tweaked?
does it have any charging intelligence?

 

[MitchM]

mastervolt has a US dealer in FL who can answer those questions for you. i'd shy away from master volt. they a re expensive and IMHO have very minimal instructions. My jefferson 45 inverter/charger lasted 35 years, my master volt top of the line did not make it to 10. we have master volt as an OEM on our nauticat 321 and i am not impressed. $378 battery charger went within 10 years.... then when i called for the 'drop in' which i needed to interlink with the amstervolt proprietary MICC display panel 9telling me peukert coefficients etc which i like ) it took another week of q and a to get someone to tell my why the new unit hot wiring was not a drop in for the old, though shown as such on the diagram. the new unit required major re wiring. -- (that was not described in the unhelpful 'install manual , and in particular the function of the 3 a trickle 'slave' feed. )i am a competent marine 12v /120v electrician and it took me a week to get answers from master volt on what should have been a straight drop in install with a d cnet install manual. i had to charge my boat batteries, gerry rigging off shore power with my 3 stage auto charger, for 2 weeks- a week to g et the unit then another week to get answers , waiting for the info i needed. (I cannot imagine a yard charging a paying customer for the hours i spent trying to get a straight answer from master volt to unravel such issues ???) IMHO call Blue Sea and ask them what the cost is of a new unit by any mfgr, to do what you want.

 

[John61CT]

Thanks for the feedback. They certainly look like an excellent product but mostly oriented toward the European market, which I suspect routinely pays top dollar without as much DIY.

No matter how good a product line might be, service and support to me are much more important factors. Maybe it would be different if you spoke Dutch

 

[Mark Maulden]

Why not just buy an echo charger-hook it up-and you're done..probably also a lot smaller pkg and more reliable. Etc etc

 

[Maine Sail]

intended use is echo charging a small LiFePo4

Hope your insurance is paid up..

 

[John61CT]

So cryptic!

My intention is to charge at max 3.40-3.45vpc (13.6-13.8)

Maybe float at 13.3?

I figure the battery2battery charger approach gives more control limiting current. Obviously the lithium bank's also behind a good BMS.

I believe the Sterling units are good, but only see them sold new ($$) so I'm looking for something less expensive to get me started with a small bank for experimentation.

Keep in mind my MC-614 regulated alt is just one source of charge, I don't want to pay for that level of fine control with every source, which is why charging the more persnickety and expensive (experimental) lithium bank from off the main lead bank seems a good design approach, lots less demanding ways to get source juice into lead.

Other choices I'm looking at are

1 direct charge the LiFePO4 off the Alt, then echo charge the lead bank off the lithium one

2 wait (maybe years) to save up for an ideal one-vendor system (Victron?) that manages everything explicitly designed for Lithium. An example unit for this B2B function would be their "Buck-Boost DC-DC Converter"

So are you saying the whole B2B idea is NG wrt Lithium, or just that these Mastervolt units don't offer the required level of control, or that you also don't like the whole brand, or. . . ?

More explicit feedback would be great.

 

[John61CT]

Why not just buy an echo charger-hook it up-and you're done..probably also a lot smaller pkg and more reliable. Etc etc

If you mean a "voltage following" combiner approach that doesn't convert (step up/down voltage), that's no good between a lead bank and the more demanding LiFePO4.

Ideally I would be able to top up one bank from the other even when the Alt isn't running, and that would also require a voltage boost.

Pretty sure a full-fledged "battery-to-battery charger" is what's required for this use case, but if something simpler and/or cheaper would do the trick, I'd like to hear about it.

 

[Mark Maulden]

Shoulda said that up front..I defer to Maine's comment..