DC-DC charger recommendation

[Excalibur5]

I'm trying to figure out the best way to charge my engine start battery along with my LIPO4 House bank. It seems the best way to skin the cat here is to use a DC-DC charger. I would think a trickle charger here would be fine, as it is only topping the battery up after a start cycle.

Problem is, the only DC-DC chargers I'm finding are quite spendy ($200 or more) anyone have a recommendation for a basic unit that will keep the house bank isolated from the start side, but still keep the battery charge maintained?

All of my charge sources are wired to only charge the LIPO4 battery, but I could wire it up to enable me to parallel the LIPO4 and the Start battery if necessary via one of the "1-2-both" switches.

[Reefmagnet]

Look in auto stores for basic dc-dc chargers. As long as you can keep them dry, they will be fine. They can be rated as low as 10A.

[tkeithlu]

Hear go. Another approach is to add an alternator that supplies the starter battery. I use ordinary Delco single wire (internal regulator) alternators on my main engine and genset to charge only the two starter batteries. The two batteries are side by side, so on cold mornings (Shh! We don't admit to those in Florida) a single jumper cable joins the positives for parallel use.

https://www.amazon.com/Tekonsha-2024...448103&sr=8-14

[smac999]

Victron Orion smart. Come in different amp sizes.
A trickle charger is not enough as the engine battery is still running gauges, fuel pump etc I’d want something 15a+


An xantrax echo charger could also work but will undercharge the start battery since the hoyse battery vintage will be lower then what the start wants.

[patja]

Do you have an inverter? You can get a nice 5 amp Victron AC charger with bluetooth monitoring for under $100

[s/v Thea]

I use one of these https://www.renogy.com/12v-dc-to-dc-...ttery-charger/

[SunPoweredYachts]

Have you looked into an ACR (Automatic Charging Relay) which in summary would charge battery 1 until "full" and then overflow to charge battery 2 (by connecting them in parallel). Blue Sea has them and Victron has a Cyrix-Li-ct that works with a LiPO4 house bank and lead acid start battery.

[YANDINA]

Originally Posted by SunPoweredYachts

Have you looked into an ACR (Automatic Charging Relay) which in summary would charge battery 1 until "full" and then overflow to charge battery 2 (by connecting them in parallel). Blue Sea has them and Victron has a Cyrix-Li-ct that works with a LiPO4 house bank and lead acid start battery.

An ACR between lead-acid and Lithium batteries has to be modified to account for the different voltages. Yandina has lithium versions of the Combiners available. 100amp, 200 amp, 600 amp.