Do I Need Seperate Chargers For Different Battery Types??

[Joe Mullee]

I currently have two gell cell battery banks on board (starting and house). I plan on changing out the house bank with wet cells this week.

My question: I don't have the manual for my TrueCharge 10 amp Smart Battery Charger at home (it's on board). I know it can charge up to two banks (maybe 3) at a time. Generally speaking, can a smart charger be hooked up to gells and wet cells simultaneously? If not and I go with wet cells for the new house bank is it advisable to keep the current charger for the gell and get a second seperate charger for the wet cells?

As always thanks for any advice.

Joe Mullee

 

[Don S/V ILLusion]

Re: Do I Need Seperate Chargers For Different Battery Types?

Joe
They require different charge voltages as you know and you charger can't differentiate nor is there an easy solution with an eco-charger. You might also consider selling the existing charger in favor of a new one which can do both (gel and wet cell voltages) just to cut down on the wiring. The other variable is the life left in the gels which only you might guess.

 

[kloudie1]

Re: Do I Need Seperate Chargers For Different Battery Types?

Yup.. Don is correct.. I am pretty sure the Truecharge can do wet or gel but not at the same time.. If I remember correctly, the gel charge voltage is lower than the flooded cells (?) so you can charge both on the gel setting but the wets willl not get to 100%.. If you charge the gels at the wet setting, it will shorten their lives.. So one switch to isolate the gels from the charger could be used to isolate them when you switch the Truecharge to "wet" and top off the wets.. Make a sign on a keychain to remind yourself ..

 

[Joe]

My question: I don't have the manual for my TrueCharge 10 amp Smart Battery Charger at home (it's on board). .................. Generally speaking, can a smart charger be hooked up to gells and wet cells simultaneously?

First, here's a copy of the manual: http://www.xantrex.com/documents/Battery-Chargers/TRUECharge/Truecharge10(445-0071-01-01_rev-3).pdf

I have asimilar unit. The TrueCharge 10amp cannot charge Wet and Gel at the same time.. it's either one or the other. There is a converter switch under a small plate at the bottom of the unit that allows you to switch between gel and wet cell mode.

The least expensive strategy is to purchase a dedicated charger for the starting battery. Here's one for $65 from Defender.

 

[Dan Johnson]

Hey Joe M!

My Guest charger has a 10 amp output for the house battery and a 5 amp output for the starter battery (billed as a 15 amp charger). It can do wet or gel, but not one of each.

I'd go with the other Joe and keep the True Charger for the house bank and get a smaller one like he suggested for the starter battery. Actually, the engine should make up what loss occurs at starting if you run it on the starter battery for a while. The 35 amp standard alternator should top it back up in a short running period. That thought may mean you don't need another charger at all, or, maybe a small solar panel will do.

 

[Joe Mullee]

Will The Altenator Charge Both At The Same Time?

I usually start the engine using only the starting battery. I then turn the battery switch to "ALL" and charge both banks while underway. Will my standard 35 amp altenator charge both the wet house bank and gell starting battery at the same time without any modification?

Joe

 

[Steve Dion]

Re: Do I Need Seperate Chargers For Different Battery Types?

Xantrex XC charger can charge 3 different battery types from one charger at the same time.

I have one of these and it works great. One of the big advantages is that it charges each bank with up to 30 amps (or 50 for the other model). It actually cycles through the different banks and switches the charge formula based on the settings.

The chargers woudl be a Xantrex XC3012 or XC5012.

 

[Don S/V ILLusion]

I usually start the engine using only the starting battery. I then turn the battery switch to "ALL" and charge both banks while underway. Will my standard 35 amp altenator charge both the wet house bank and gell starting battery at the same time without any modification?

Joe

Joe
Not a simple y/n. Realize a 35 amp alt practically never produces it's full rated output, particularly after the batteries get a partial recharge. The alt will cut back significantly thereby cutting the charge rate such that it can take hours to reach a full charge. The larger the bank being fed, the longer it takes.
The other consideration is charge voltage. Gels are fragile when it comes to charger voltage. When everything gets connected together, the charger can't differentiate between batteries and recharges based on what it sees, typically the lowest battery. As you can't set the alt charge voltage to an acceptable level for gels without constantly undercharging the wet cells, you create more problems.

 

[Maine Sail]

I usually start the engine using only the starting battery. I then turn the battery switch to "ALL" and charge both banks while underway. Will my standard 35 amp altenator charge both the wet house bank and gell starting battery at the same time without any modification?

Joe

Joe,

Your standard alternator is a possible reason as to why you're replacing your gels. Most gels should not see more than 14.1V. Anything higher and you can develop bubbles in the jello like electrolyte that are all but impossible to remove. Unless your alt is very old it is likely putting out more than 14.1 volts which can lead to short gel battery life.. Gels when treated well and charge correctly can be some of the longest lasting batteries out there.

You can always charge your wets at 14.1 volts but it will just take longer to get them closer to full and you can often wind up under charging them.

A 35A alt is going to be very, very small for a 390Ah bank..

 

[Snotter]

Re: Do I Need Seperate Chargers For Different Battery Types?

In addition to all of the above, I'd be nervous about putting your 1-2-both-off switch in the 'both' position.

 

[Dan Johnson]

Joe M...

Don and Maine Sail have answered your alternator question. The alternator services wet batteries well. Gels require special care.

Also, using the "both" setting may indeed be the source of the problem as well. I rarely use the "both" setting, except when the engine and weather are both cold. The extra "umph" helps the Yannie to turn over long enough to want to start.

When underway I charge one bank for an hour then the other, starting with the starting battery first as that is where the switch is initially. Both banks are 27 dual purpose deep cycle wet batteries and I seem to get at least four to five seasons out of this arrangement with staggered purchasing years (except for the bad one that wouldn't hold a charge at less than a year old).

When docked, I keep the switch set for the house battery and periodically at night use the charger to "float" the use of any of the cabin lights (halogens), and to keep the house battery up.