Guest dual charger
- Thread starter BBlalock
- Start date
Barry Rietz
New member
BB, Assuming the Guest "dual" charge system is operating correctly, you might check the age of the house battery. Once sulphated, the battery would continue to draw current and never reach the full charge state.
Sorry, I should have said I recently replaced that battery. Both are 24 Series. I replaced both maybe in May and kept having charge issues with the house. I replaced that one at least 1 time since that. No problem with the start one. As you can tell my Guest is from 2012.
I'm just wondering if I should be able to watch my Yamaha system meter to see if it is cooking the battery. After I have been running a long time shouldn't the charge show maybe 13 instead of 14+?
I'm just wondering if I should be able to watch my Yamaha system meter to see if it is cooking the battery. After I have been running a long time shouldn't the charge show maybe 13 instead of 14+?
Unfortunately the guest chargers are not "smart chargers". A smart charger will sample the batteries' resting state voltage, and only turn on if there is a low battery (Less than 12.6 volts for instance). Ideally one would run the guest type of charger after they are through with the boat, (outboards generally don't keep the charge up to 100%). Then the battery would be turned off.
Ideally a battery charger should come only a few hours a day. One way to affect this is to use a timer on the power input into the boat. (Or buy a smart charger--which are for the most part more expensive.). This may be the best course if you are leaving the boat where it may get water in the cockpit and the battery must be constantly maintained to be sure that the bilge pump is suppled with adequate 12 volt power.
If there are no parasitic drains (such as a radio, voltage charge relay or GPS memory), then the battery should not loose it charge except thru a minimal natural attrition of about 4% of charge a week. For example my battery on the Caracal Cat is turned off between uses, and even after several months, the battery is at a state to start the outboard easily. Generally I'll put a charger on one day a month.
AGM batteries have a lower self discharge rate of 1 to 2% a month, and the LI batteries are even lower than that.
I like to measure the state of charge with a Victron 702 or 712 meter. However when I was experimenting with a cheaper set up to use liFePO4 batteries in a SUV or truck for a cross country trip to power a chest freezer, I found this Battery monitor for about $42/. There cheaper ones out there, but I have not tried them (some require a manual reset and are fine for one experiment, but not for continuous use.)
Also Victron has a "smart Shunt" which is considerably less than the 712 monitor. This relies on a smart phone to read the information of state of charge. amps in and out, and voltage.
These monitors tell you not only the voltage, but the state of charge, amps in and out etc.
Ideally a battery charger should come only a few hours a day. One way to affect this is to use a timer on the power input into the boat. (Or buy a smart charger--which are for the most part more expensive.). This may be the best course if you are leaving the boat where it may get water in the cockpit and the battery must be constantly maintained to be sure that the bilge pump is suppled with adequate 12 volt power.
If there are no parasitic drains (such as a radio, voltage charge relay or GPS memory), then the battery should not loose it charge except thru a minimal natural attrition of about 4% of charge a week. For example my battery on the Caracal Cat is turned off between uses, and even after several months, the battery is at a state to start the outboard easily. Generally I'll put a charger on one day a month.
AGM batteries have a lower self discharge rate of 1 to 2% a month, and the LI batteries are even lower than that.
I like to measure the state of charge with a Victron 702 or 712 meter. However when I was experimenting with a cheaper set up to use liFePO4 batteries in a SUV or truck for a cross country trip to power a chest freezer, I found this Battery monitor for about $42/. There cheaper ones out there, but I have not tried them (some require a manual reset and are fine for one experiment, but not for continuous use.)
Also Victron has a "smart Shunt" which is considerably less than the 712 monitor. This relies on a smart phone to read the information of state of charge. amps in and out, and voltage.
These monitors tell you not only the voltage, but the state of charge, amps in and out etc.
So it appears I can test the Guest by using my smart charger to get the battery up to 100%. Then plug in power to the boat and check to see if the Guest drops the voltage to storage amount. If my meter shows 13+ across the terminals then the Guest is cooking the house battery?
I'm planning to replace that 9 year old unit anyway but want to make sure it is the problem first.
When I bought Finale I was told the Guest would check the start battery first and charge if necessary then move on to the house and charge if necessary and then go into storage mode. It sounds like you guys are saying that isn't correct. Am I right on that? :smiled
I'm planning to replace that 9 year old unit anyway but want to make sure it is the problem first.
When I bought Finale I was told the Guest would check the start battery first and charge if necessary then move on to the house and charge if necessary and then go into storage mode. It sounds like you guys are saying that isn't correct. Am I right on that? :smiled
My guest which is likely a 2007 shows when it is charging and maintaining for both batteries. I believe it does both simultaneously. Yes I think the best way to test is when it goes into the "green" light charged mode is to check to see if its in a maintain or a charge state. Hope you get it figured out.
And I do too, although I have not used the Guest in about 10 years or more. In storage I use a small BatteryMinder (brand) trickle charger for each battery. They do a "desulfating" cycle every so many cycles. I don't think they are smart chargers (probably for sure not) but my last batteries lasted 6 years and were still 90 - 95 percent when I changed them out. (I have been using them on the boat batteries, the Motorcycle and the truck or car for about 10 years. Have not replaced the car battery yet. Only have had the truck for a couple years and it had a new battery when I got it.
I have considered taking the Battery Minders with me to use IF I go into a marina just for topping off, But I do that so seldom, and for such short times that it has not been an issue.
I would like to go to a new, smart charger but everything I have seen needs to go into a non exposed environment --- instead of under the splashwell.
Oh, the batteries are FLA Interstate RV Marine deep cycle.
Harvey
SleepyC :moon
T.R. Bauer
New member
I have killed, and known many more people, that have killed a battery with the best of intentions. Old chargers generally give too many amps to a battery and never really shut off. The batteries eventually get tired of that, run low on water, crystallization occurs in the cells, and then they are goners. I have a charger like that in my motorhome. If that is what you're dealing with, then once month charging is probably enough, that is unless you have a bunch of stuff taking power. In the boat, I just turn the batteries off and walk away because I don't have anything that can't shut off. New multistage stuff is far better tech.
Ok I'm going to allow myself to sound dumb, but here goes. I have been reading and watching videos concerning chargers and multi battery set ups.
Question: Is my Guest charger doing any charging while underway?
I seldom hook up shore power to the boat. I do not store the boat with shore power. I have the Perko 2 position switch and I see what I think is a battery isolator on the bulkhead by the house battery. The house battery is the one that seems to keep having issues. I think I normally run on position 1(house), not the ALL position.
I do not have a generator and in 4 years have spent only 1 night on the hook. We have used shore power for AC maybe 14 nights. I don't run the charger and AC at the same time.
Any ideas or suggestions will be appreciated. Remember, be nice.
:smilep
Question: Is my Guest charger doing any charging while underway?
I seldom hook up shore power to the boat. I do not store the boat with shore power. I have the Perko 2 position switch and I see what I think is a battery isolator on the bulkhead by the house battery. The house battery is the one that seems to keep having issues. I think I normally run on position 1(house), not the ALL position.
I do not have a generator and in 4 years have spent only 1 night on the hook. We have used shore power for AC maybe 14 nights. I don't run the charger and AC at the same time.
Any ideas or suggestions will be appreciated. Remember, be nice.
:smilep
BBlalock":2vhsst96 said:
The battery charger needs AC power to charge the batteries. The motor should be providing DC power to recharge the batteries when underway. However, depending on your engine and how much time you spend at low speed, you may not be getting that much power into the batteries. Newer engines have bigger alternators. On my BF90D there is a big difference in the power available to charge the batteries from the engine between idle and cruising speed (~18mph). Also, the engine can provide lots more amps to the battery than the Quest charger did. A battery charger is convenient when you have AC power, but the engine does a much better job charging the batteries.
I guess the question would be, what issues are you having with the battery? I operate on one (the house) battery most of the time. The second battery is only used (paralleled to the house) when starting the engine after a night on the hook with services on (fans, lights, fridge, etc.). I will often run the engine at 1K rpm for about 20-30 minutes before retiring to give some juice to the house battery when anchored out. Having a battery monitor helps manage the battery.
After 4 years or so, the house battery gets replaced.
If you FLA batteries you should check the water level from time to time. My batteries are in the lazarette so checking the water involves taking the batteries out of the compartment. This is a PITA and means the water level does not get checked as often as it should. The first time I checked them, I was surprised at the low water level.
The engine alternator generally will charge up the batteries to about 80%. That last 10% is with a absorption and float on the 110 V shore power charge.
That said--many outboard owners never put their batteries on a charger. The Guest chargers on the C Dory as made two top off the batteries. If you are using multiple 12 volt items, even with the charger on lets say 5 amps per battery, it may not keep up with "house loads"
The battery switch is dumb--it only connects two batteries or isolates them. If you are running with the engine and battery switch is on house, then you are not charging that house battery. You will only be starting the engine starting battery. The best solution is to use a Automatic voltage Relay AVR or Voltage sensitive relay, VSR. They are the same thing. This is put on the start battery as primary source. Once it is charged to a certain voltage, then the house battery is paralleled and charges also. Not expensive and easy to install. All boats should have them.
If you don't have a VSR you should start on the engine start battery, Then in about 10 minutes put the switch on "All". Switch to #2 when you stop and use the boat,. This makes sure that the start battery is not depleted.
The Honda 90's alternators put out only 17 amps until about 2007, when then went to about 40 amps. The engine's electric needs take part of that charge.
Solution: as above, after 10 minutes switch batteries to "All" all current switches have "make before break" and thus protect the alternator. If you want the best, easiest and safest, put in an VSR.
That said--many outboard owners never put their batteries on a charger. The Guest chargers on the C Dory as made two top off the batteries. If you are using multiple 12 volt items, even with the charger on lets say 5 amps per battery, it may not keep up with "house loads"
The battery switch is dumb--it only connects two batteries or isolates them. If you are running with the engine and battery switch is on house, then you are not charging that house battery. You will only be starting the engine starting battery. The best solution is to use a Automatic voltage Relay AVR or Voltage sensitive relay, VSR. They are the same thing. This is put on the start battery as primary source. Once it is charged to a certain voltage, then the house battery is paralleled and charges also. Not expensive and easy to install. All boats should have them.
If you don't have a VSR you should start on the engine start battery, Then in about 10 minutes put the switch on "All". Switch to #2 when you stop and use the boat,. This makes sure that the start battery is not depleted.
The Honda 90's alternators put out only 17 amps until about 2007, when then went to about 40 amps. The engine's electric needs take part of that charge.
Solution: as above, after 10 minutes switch batteries to "All" all current switches have "make before break" and thus protect the alternator. If you want the best, easiest and safest, put in an VSR.
Another solution is to install a DC/DC charger that prioritizes the starting battery. These will charge the starting battery when the motor is on and only allow current to flow to the house battery when the current exceeds a certain amount, usually only when the engine is on and the starting battery is charged. Adding a solar or AC "trickle" battery maintainer will keep the starting batter charged when sitting for a long time. Since I have large solar panels, I use a dual input (alternator or solar) DC/DC charger that prioritizes charging the starting battery...when the sun shines, it charges the starting battery first, and then the house batteries.thataway":1rotb6hy said:
Thanks for this. The more research I did the more I was thinking the Guest can't be my problem. The house batt when new tested at 100% and then a short time later tests at 80%. And that is after I put it on my smart portable charger. Both batteries are start 24 series. I'm planning to move the house to the port locker and get a marine deep cycle and larger than 24 series.
I pulled the house out and had 3 cells I put water in. 1 was almost down to the top of the plates and the other 2 were just down a bit. Easy to see lower but not too bad.
The start battery is maybe 6 mos older and no issues.
Am I right in saying the vsr controls the charging to the batteries so they get what is needed and not too much?
So is it possible the vsr might be my issue if I'm not using the Guest but very seldom? :smiled
Benton
I pulled the house out and had 3 cells I put water in. 1 was almost down to the top of the plates and the other 2 were just down a bit. Easy to see lower but not too bad.
The start battery is maybe 6 mos older and no issues.
Am I right in saying the vsr controls the charging to the batteries so they get what is needed and not too much?
So is it possible the vsr might be my issue if I'm not using the Guest but very seldom? :smiled
Benton
Which DC to DC charger are you using? I have experience with several (Victron and Sterling). Neither of these will "Priortize" the start battery, any more than a VSR does. (I am using a VSR between start and house--and the DC to DE to a 3rd battery bank--both in the RV and was in Thataway.
I do not have solar, since it would take over 300 watts to meet our demands when at anchor--and I find it cheaper to run the Honda generator, and charge thru a high output (80 amp) charger, if necessary.
No, the VSR is not "smart" other than it connects and disconnects. There is no control of the amount of energy put into each battery.
See the above set of exchanges, ref a DC to DC charger. There may be a DC charger which does this--the DC chargers I have used (Victron and Sterling, do give proper charge to the Li battery bank, but do not have any control to the starting battery. Their circuits are not set up for that.
Adding solar is one option. I used the very small (30 watt) solar panels to maintain the house and start batteries of both boats and vans when stored in Las Vegas or S. Calif. When I would come back after 6 months, all batteries were fully charged.
thataway":3n9mht3l said:
I guess it depends on how your boat is wired. On my boat the battery switch determines which battery is in the circuit (1, 2, both (paralleled), none). I do not have an ACR. I normally operate off the house battery (selected at the battery switch) and can see it charging when running the motor.
It does not make sense to me that the "on-side" battery would not be in the charging circuit.