geem
Well-Known Member
They all have a set charge voltage. It is only these different set charge voltages that cause some to drop out of charge mode before others.
Using two chargers on one battery bank
- Thread starter tgpt21
- Start date
They all have a set charge voltage. It is only these different set charge voltages that cause some to drop out of charge mode before others.
lw395
Well-Known Member
No, that's not universally true.
Some smart chargers measure what they assume is the resting voltage of the battery in an attempt to determine whether it needs charging at all.
Others may start up in float mode, then if the current exceeds a threshold they will start a bulk cycle.
Many 'smart' chargers always start in bulk charge mode, but in some applications that's not actually smart at all.
geem
Well-Known Member
Ok, so assuming all chargers are in bulk charge mode, it is only the set bulk charge voltage that drops one out before another. I have three different marine battery charger onboard and none start in float mode when you turn them on. Which manufacturer does this? It would be worth knowing so people are aware of the limits of this type of charger. If you are living aboard and using a generator to charge your batteries with multiple chargers then you would want to avoid that type of charger. We only use our battery chargers whilst we make water with a 220v watermaker running on the generator. We want to maximise the battery charging whilst making water as it goes against the grain to run the generator just to charge the batteries. Most of the time solar and wind keep the batteries in reasonable charge but you cant beat a boost with a good high output smart charger periodically.
lw395
Well-Known Member
Anything that calls itself more than a 3 stage charger, it's probably best to RTFM to see if it's suitable to co-charge.
More and more chargers seem to have analysis and voodoo desulfation stages when switched on these days.
More and more chargers seem to have analysis and voodoo desulfation stages when switched on these days.
geem
Well-Known Member
When you said some chargers start in float mode I was expecting you to tell us the name of said charger. I haven't come across any that do this. Most modern digital chargers have three stage charging and a desulphation option.
lw395
Well-Known Member
I don't want to name the other charger as they are a client of my client. It's not a retail or marine unit anyway.
But this kind of thing has also been reported with Xantrex chargers in the past.
Even without a second charger, if you shut down the generator with the battery at say 70% SOC, then quickly switch on the charger, you could have enough volts of surface charge to put the Xantrex into float.
Most charger manufacturers seem pretty coy about what exactly happens in their switch-on/analyse/desulphate phase.
But this kind of thing has also been reported with Xantrex chargers in the past.
Even without a second charger, if you shut down the generator with the battery at say 70% SOC, then quickly switch on the charger, you could have enough volts of surface charge to put the Xantrex into float.
Most charger manufacturers seem pretty coy about what exactly happens in their switch-on/analyse/desulphate phase.
solent clown
RIP
fascinating thread. Having had nothing but trouble with intelligent chargers and being very wary of them it is good to hear otherwise on here. None of ours ever worked on a totally flat battery - in the field on expedition this was a problem, so we went back to older tech. May be a time to revist and have a look at what is available now
