two battery chargers?

[Richard19068]

If I have 2 five amp chargers and hook them both up to a single battery, will they work together as a ten amp charger or still just at five amps? Will this damage anything?

Hey, they say there aren't any stupid questions!

Thanks

 

[Witzend]

What kind of chargers are they?

 

[Don S/V ILLusion]

You can connect two chargers in parallel to produce double the current. Whether or not it's a good idea and whether your specific charger(s) are going to be damaged are both issues which we can't address without more info, e.g., battery bank size, type of charger, avg. demand, etc.

 

[Richard19068]

Thanks for the replys and my apologies for the lack of data.

They would be two Guest Charge Pro 2606A 6 amp 3 stage portable battery chargers.

Three-stage chargers extend the life of your battery
Portable, three-stage electronic chargers feature built-in thermal and overload protection, reverse polarity protection and LED ready indicators. Prewired with a 6 ft. AC cord and 4 ft. DC outputs. Alligator clips can be left connected indefinitely.
User Selectable Functions: None—fully automatic
Status Indicators: State of charge LED indicators
Temperature Compensation: No
Input Wiring: 6' AC power cord
Output Wiring: 4' or 6' leads with ring terminals
Waterproof: Yes
Safety Features: Shockproof, ignition-protected, reverse polarity protected, vibration protected, DC fusing
Case Size/Material: ABS Plastic
Mounting Hardware Included/Required: Requires bolts backed by a flat washer and secured to the mounting surface with a split ring lock washer (not included)
Remote Available: No
Warranty: Lifetime for water damage; two years for manufacturing defects

The battery would be a 90 or 105 amp hour group 27 dual purpose starting/deep cycle from Costco.

The reason for the two chargers would be to hopefully charge faster after weekend draindowns.

Thanks again

 

[Don S/V ILLusion]

You might want to re-think this move. Although the chargers would work okay in parallel, their combined charge rate of 12 amps would take a while to completely recharge a 50% depleted 100 amp battery - recognize these charger will not produce 6 amps each for long before they ramp down.
On the other hand, most battery mfgs recommend a charge rate of 20% of capacity - in your case, a 20 amp charger. You aren't that far below that with both combined so if you have no compelling need for a quick recharge, this would work for you.

 

[sailingdog]

I seriously doubt that hooking up both will have much benefit. The chargers will see the voltage the other creates and step down their charging rate based on the false voltage reading... They may also be damaged by doing this. You'd be much better off selling these two and getting a bigger Iota battery charger. A 15 amp model is only $123...a 30 amp model, which is a bit larger than you really should be using, is only $128.

 

[Stu Jackson]

You can combine stuff all you want, BUT

what the batteries will accept is another story.

Try this: http://c34.org/bbs/index.php/topic,4787.0.html

 

[Richard19068]

Re: You can combine stuff all you want, BUT

Stu, I understand in general about acceptance rates. So let's say my theoretical 100 amp hour battery is down by 60 amps with 40 remaining so it's in an area where the acceptance rate is on the higher end of the scale. (yes, I know drianing it this far is causing damage and lowering life, etc. etc. etc.). The question still in my mind is, will the two six amp chargers work together as a higher amp charger or will I still get just a potential six amps or will, as sailingdog suggests, they cancel each other out and or cause any damage to the battery or chargers?

I appreciate your opinion.

Thanks

 

[Chuckbear]

You can indeed connect two chargers to double your charging output, BUT, you can't do this with all chargers. We have two Iota 45 amp chargers combined and it gives me the same charging capabilities of a 90 amp charger. I can not speak for the Guest chargers and would highly recommend you contact the folks at Guest and pose the question to them giving you charger model. If you already have 2 chargers it might be worth pursuing but if you will need to buy a second it might make better sense economically to just buy a bigger charger. The Iota is, in my opinion, one of the best chargers available and at a fraction of the cost of any marine charger. Chuck

 

[Witzend]

Normally you should not have to do this, if you have depleted the bat. that much on a regular basis you will have bigger problems down the road. It actual might be better if they were not the same charger, here's why. The stage sensing circuits take time (in the ms range) to adjust the current output to meet the target E (voltage). Since the units are the same type this delay could send the units into oscillation. One says E too low, up the I (Current), the other say oops, E ok now, lower the I, and so forth. So they may fight each other. This could put a strain on these circuits. I'm not saying this will definitely happen, it would just be a concern.

 

[Chuckbear]

Normally you should not have to do this, if you have depleted the bat. that much on a regular basis you will have bigger problems down the road. It actual might be better if they were not the same charger, here's why. The stage sensing circuits take time (in the ms range) to adjust the current output to meet the target E (voltage). Since the units are the same type this delay could send the units into oscillation. One says E too low, up the I (Current), the other say oops, E ok now, lower the I, and so forth. So they may fight each other. This could put a strain on these circuits. I'm not saying this will definitely happen, it would just be a concern.

Some chargers will do exactly this while other will not, which is why a discussion with Guest will answer your question. Mixing chargers will most certainly cause problems more so than using the same charger if they are capable of being combined. I think Richards 60% discharge was theoretical. Chuck

 

[Richard19068]

I don't normally discharge past 50%. That was just for discussion.

I sent an e-mail to Guest but have not heard back yet.

Thanks for the replys.

 

[Ron20324]

The stage sensing circuits take time (in the ms range) to adjust the current output to meet the target E (voltage). Since the units are the same type this delay could send the units into oscillation. One says E too low, up the I (Current), the other say oops, E ok now, lower the I, and so forth. So they may fight each other. This could put a strain on these circuits. I'm not saying this will definitely happen, it would just be a concern.

....

....Which is why my owners manual says do not run the engine and the battery charger at the same time. Otherwise, see what Guest says- for the definitive answer.

 

[Richard19068]

Guest said it would damage the battery

Guest finally got back to me with a short reply that said it would damage the battery. No further explanation.

Thanks for the discussion.